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Last updated on September 25, 2017. This conference program is tentative and subject to change
Technical Program for Thursday July 13, 2017
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ThAT1 Invited Session, Roentgen Hall |
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Brain and Physiological Networks: Methods and Applications |
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Chair: Faes, Luca | Univ. of Trento |
Co-Chair: Ding, Lei | Univ. of Oklahoma |
Organizer: Faes, Luca | Univ. of Trento |
Organizer: Ding, Lei | Univ. of Oklahoma |
Organizer: Astolfi, Laura | Univ. of Rome Sapienza |
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08:00-08:15, Paper ThAT1.1 | Add to My Program |
Causal Brain-Heart Information Transfer During Visual Emotional Elicitation in Healthy Subjects: Preliminary Evaluations and Future Perspectives |
Faes, Luca | Univ. of Trento |
Greco, Alberto | Univ. of Pisa |
Lanata', Antonio | Univ. of Pisa |
Barbieri, Riccardo | Pol. Di Milano |
Scilingo, Enzo Pasquale | Univ. of Pisa |
Valenza, Gaetano | Univ. of Pisa |
Keywords: Physiological systems modeling - Multivariate signal processing, Causality, Physiological systems modeling - Signal processing in physiological systems
Abstract: Complex heartbeat dynamics is known to reflect subject’s emotional state, thanks to numerous links to brain cortical and subcortical regions. Likewise, specific brain regions are deeply involved in vagally-mediated emotional processing and regulation. Nevertheless, although the brain-heart interplay has been studied during visual emotion elicitation, directional interactions have not been investigated so far. To fill this gap, in this study we investigate brain-heart dynamics during emotional elicitation in healthy subjects through measures of Granger causality (GC) between the two physiological systems. Data were gathered from 22 healthy volunteers who underwent pleasant/unpleasant affective elicitation using pictures from the International Affective Picture System. Neutral emotional stimuli were elicited as well. High density electroencephalogram (EEG) signals were processed to obtain time-varying maps of cortical activation, whereas the associated instantaneous cardiovascular dynamics was estimated through inhomogeneous point-process models. Concerning the information transfer brain-to-heart, GE highlighted significant valence-dependent lateralization with respect to resting states. Furthermore, as a proof of concept, the study of heart-to-brain dynamics considering EEG oscillations in the γ band (30-45 Hz) highlighted differential information transfer between neutral and positive elicitations directed to the prefrontal cortex.
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08:15-08:30, Paper ThAT1.2 | Add to My Program |
Information Transfer and Information Modification to Identify the Structure of Cardiovascular Networks |
Faes, Luca | Univ. of Trento |
Nollo, Giandomenico | Univ. of Trento |
Krohova, Jana | Comenius Univ. in Bratislava |
Czippelova, Barbora | Department of Physiology, Comenius Univ. Jessenius Faculty |
Turianikova, Zuzana | Department of Physiology, Comenius Univ. Jessenius Faculty |
Javorka, Michal | Comenius Univ. Jessenius Faculty of Medicine |
Keywords: Physiological systems modeling - Multivariate signal processing, Causality, Directionality
Abstract: To fully elucidate the complex physiological mechanisms underlying the short-term autonomic regulation of heart period (H), systolic and diastolic arterial pressure (S, D) and respiratory (R) variability, the joint dynamics of these variables need to be explored using multivariate time series analysis. This study proposes the utilization of information-theoretic measures to measure causal interactions between nodes of the cardiovascular/cardiorespiratory network and to assess the nature (synergistic or redundant) of these directed interactions. Indexes of information transfer and information modification are extracted from the H, S, D and R series measured from healthy subjects in a resting state and during postural stress. Computations are performed in the framework of multivariate linear regression, using bootstrap techniques to assess on a single-subject basis the statistical significance of each measure and of its transitions across conditions. We find patterns of information transfer and modification which are related to specific cardiovascular and cardiorespiratory mechanisms in resting conditions and to their modification induced by the orthostatic stress.
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08:45-09:00, Paper ThAT1.4 | Add to My Program |
Inferring Directed Interactions between Cortical Dipole Activities Using Coupled Delay Differential Equations (I) |
Leistritz, Lutz | Jena Univ. Hospital, Friedrich Schiller Univ. Jena |
Huonker, Ralph | |
Witte, Herbert | Jena Univ. Hospital Friedrich Schiller Univ |
Goetz, Theresa | Inst. of Medical Statistics, Computer Sciences and Documenta |
Keywords: Causality, Connectivity measurements, Directionality
Abstract: Using time courses of three cortical dipole sources, we provide evidence that the framework of general delay differential equations is suited to infer effective connectivity without a priori connectivity assumptions.
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09:00-09:15, Paper ThAT1.5 | Add to My Program |
Signal-Adaptive, Frequency-Selective and Time-Variant Analysis of Interactions between Time Series: Comparison of Linear, Nonlinear, Undirected and Directed Approaches (I) |
Schiecke, Karin | Jena Univ. Hospital. Friedrich Schiller Univ. Jena |
Piper, Diana | Jena Univ. Hospital, Friedrich Schiller Univ. Jena |
Pester, Britta | Jena Univ. Hospital; Friedrich Schiller Univ. Jena |
Benninger, Franz | Epilepsy Monitoring Unit, Department of Child and Adolescent Neu |
Feucht, Martha | Epilepsy Monitoring Unit, Department of Child and Adolescent Neu |
Witte, Herbert | Jena Univ. Hospital Friedrich Schiller Univ |
Leistritz, Lutz | Jena Univ. Hospital, Friedrich Schiller Univ. Jena |
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09:15-09:30, Paper ThAT1.6 | Add to My Program |
Probing Electrophysiological Intrinsic Brain Networks through Modeling and Computation (I) |
Ding, Lei | Univ. of Oklahoma |
Yuan, Han | Univ. of Oklahoma |
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09:15-09:30, Paper ThAT1.7 | Add to My Program |
Functional Connectivity Analysis of Multiplex Muscle Network across Frequencies |
Kerkman, Jennifer N. | Vrije Univ. Amsterdam |
Daffertshofer, Andreas | Vrije Univ. Amsterdam |
Gollo, Leonardo | QIMR Berghofer Medial Res. Inst |
Breakspear, Michael | QIMR Berghofer Medical Res. Inst |
Boonstra, Tjeerd W. | Univ. of New South Wales |
Keywords: Connectivity measurements, Time-frequency and time-scale analysis - Time-frequency analysis, Coupling and synchronization - Coherence in biomedical signal processing
Abstract: Physiological networks reveal information about the interaction between subsystems of the human body. Here we investigated the interaction between the central nervous system and the musculoskeletal system by mapping functional muscle networks. Muscle networks were extracted using coherence analysis of muscle activity assessed using surface electromyography (EMG). Surface EMG was acquired from 36 muscles distributed throughout the body while participants were standing upright and performing a bimanual pointing task. Non-negative matrix factorization revealed functional connectivity in four frequency bands. The spatial arrangement differed considerably across frequencies supporting a multiplex network organisation. Graph-theory analysis of layer-specific network revealed a consistent fat-tail distribution of the edges weights, distinct efficiency values, and core-periphery properties. These frequency bands may be spectral fingerprints of different neural pathways that innervate the spinal motor neurons to control the musculoskeletal system.
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ThAT2 Invited Session, Cho Room |
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Biomedical Applications of Terahertz Imaging and Spectroscopy |
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Chair: MacPherson, Emma | Chinese Univ. of Hong Kong |
Co-Chair: Kim, Seongsin M. | The Univ. of Alabama |
Organizer: MacPherson, Emma | Chinese Univ. of Hong Kong |
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08:00-08:15, Paper ThAT2.1 | Add to My Program |
Terahertz in Vivo Imaging of Human Skin (I) |
MacPherson, Emma | Chinese Univ. of Hong Kong |
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08:15-08:30, Paper ThAT2.2 | Add to My Program |
Label-Free Terahertz Reflection Imaging for Detection of Malignant Brain Tumor (I) |
Ji, Young Bin | Yonsei Univ |
Keywords: Optical molecular imaging, Infra-red imaging, Brain image analysis
Abstract: Terahertz reflection imaging (TRI) is suitable for detection of malignant brain tumor detection. The feasibility of brain tumor detection was demonstrated by experiments with orthotopic mouse tumor models and human specimens.
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08:30-08:45, Paper ThAT2.3 | Add to My Program |
Recent Advances in Terahertz Medical Imaging (I) |
Oh, Seung Jae | Yonsei Univ |
Keywords: Optical imaging, Electrical source imaging
Abstract: We have showed recent advances in terahertz medical imaging research, including the detection of multiple cancers such as stomach cancer and brain tumors, deep penetration techniques for tissue penetration, and the development of new medical devices for otolaryngology.
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08:45-09:00, Paper ThAT2.4 | Add to My Program |
Investigation of THz Bio-Metamaterials for Biosensing and Imaging (I) |
Smiley, Brianna | Univ. of Alabama |
Park, Seung Jo | Univ. of Alabama |
Pal, Sharmistha | Univ. of Alabama |
Maleski, Alexander | Univ. of Alabama |
Gungordu, M. Zeki | Univ. of Alabama |
Mollah, A. Shahab | Univ. of Alabama |
Philip, Elizabath | Univ. of Alabama |
Kung, Patrick | Univ. of Alabama |
Kim, Yonghyun | Univ. of Alabama |
Kim, Seongsin M. | The Univ. of Alabama |
Keywords: Optical imaging
Abstract: Subwavelength patterned THz bio-metamaterials has been fabricated as a platform for direct cell cultures and bio-sensing application in THz frequency. Using THz spectroscopy, the transmission characteristics were compared with various different cells, including normal MSF-10A breast cancer cell, MDA-MB 231 metastatic breast epithelial cells, and rat neural cortex cells. Such bio metamaterials based sensor system is promising for high sensitivity and selective bio sensing and can be extended to imaging in THz frequency.
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09:00-09:15, Paper ThAT2.5 | Add to My Program |
Towards Clinical Cancer Diagnosis Using Terahertz Spectroscopy (I) |
Cheon, Hwayeong | Univ. of Seoul |
Son, Joo-Hiuk | Univ. of Seoul |
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09:15-09:30, Paper ThAT2.6 | Add to My Program |
A Handheld Terahertz Probe for Differentiating Benign and Malignant Breast Tissue Using (I) |
Wallace, Vincent | The Univ. of Western Australia |
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ThAT4 Oral Session, Min Room |
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New Sensing Techniques I |
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Chair: Fang, Qiang | RMIT Univ |
Co-Chair: Scilingo, Enzo Pasquale | Univ. of Pisa |
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08:00-08:15, Paper ThAT4.1 | Add to My Program |
A New Hand Function Assessment Method Using an Infrared Imaging Device |
Fang, Qiang | RMIT Univ |
Gu, Xudong | The 2nd Hospital of Jiaxing |
Keywords: Physiological monitoring - Instrumentation, Wearable antennas and in-body communications
Abstract: Many post-stroke patients suffer various degrees of hand function and fine motor skills impairment. Both passive and active hand rehabilitation training are beneficial in improving strength and dexterity of hands. However, hand rehabilitation programs should be prescribed, based on an accurate assessment of hand function. Here we propose a novel method for hand function assessment that can accurately measure multiple joint angles of a hand simultaneously using a portable infrared imaging device. Different from the traditional assessment methods that are often based on clinicians’ subjective observation and ordinal charts, this method provides an accurate, fast and objective evaluation using infrared imaging sensors. This novel hand function assessment method can be used to replace the currently popularly used traditional method for fine hand function modeling and assessment in rehabilitation medicine and can play an important role in precision post-stroke function analysis.
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08:15-08:30, Paper ThAT4.2 | Add to My Program |
Frequency-Range Optimized Preprocessing Methods for Quantitative Analysis of Glucose in Blood Serum from Broadband Dielectric Spectra |
Wang, Rui | NTT Device Tech. Labs |
Nakamura, Masahito | NTT Corp |
Tanaka, Yujiro | NTT Device Tech. Labs |
Tajima, Takuro | NTT Device Tech. Lab |
Keywords: Physiological monitoring - Modeling and analysis, Bio-electric sensors - Sensing methods, Physiological monitoring - Instrumentation
Abstract: This paper presents the results of combining scatter correction and spectral derivation preprocessing methods with frequency-range optimization to improve the accuracy of blood glucose concentration prediction when using a Partial Least Square Regression model. Using broadband dielectric spectroscopy, absorption spectrums in the frequency range of 500 MHz to 50 GHz were gathered from blood serums. Partial Least Square Regression models were trained using data gathered from samples of varying glucose concentrations and temperatures, and the quality of the predictions were evaluated by performing leave-one-out cross validation. Potential improvements in prediction accuracy were assessed by finding the optimal frequency ranges of dielectric absorption spectrums through iteration, in addition to treatments using common preprocessing methods. The most effective combination of preprocessing method and its corresponding characteristic frequency range was determined from validation using several samples. Finally, among all the preprocessing methods and the frequency ranges explored, performing Savitzky-Golay filtering without derivations lowered the average root mean squared error amongst all the samples from 172 mg/dL without preprocessing, to 143 mg/dL. Additionally, by focusing on a specific frequency range, the root mean squared error dropped to 80.2 mg/dL.
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08:30-08:45, Paper ThAT4.3 | Add to My Program |
Three-Dimensional Electrodes Formation Using Liquid Metal in Micro Channels for 3-Axis Capacitive Force Sensor |
Tatsuho, Nagatomo | Keio Univ |
Miki, Norihisa | Univ |
Keywords: Physical sensors and sensor systems - Mechanical sensors and systems, Mechanical sensors and systems, Physical sensors and sensor systems - New sensing techniques
Abstract: In this study, we propose three-dimensional formation of electrodes made of liquid metal. First, three-dimensional micro channels are formed by stacking PDMS layers. Second, liquid metal, galinstan, is introduced into the channels to form electrodes and wirings. This process is crucial to develop miniaturized 3-axis capacitive force sensor. In our previous work, we proposed a ball-point-pen like capacitive sensor, however, it was difficult to be miniaturized to be mounted onto an endoscope retaining the function. We successfully manufactured 3-axis cylindrical capacitive force sensor, 5 mm in diameter and small enough to be mounted onto an endoscope. We experimentally characterized the sensor. The proposed and demonstrated sensor can be readily applicable for endoscopic palpation.
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08:45-09:00, Paper ThAT4.4 | Add to My Program |
Monitoring Voluntary Blink Magnitude through a Wearable Eye-Tracking System: A Preliminary Study |
Lanata', Antonio | Univ. of Pisa |
Guidi, Andrea | Univ. of Pisa |
Greco, Alberto | Univ. of Pisa |
Valenza, Gaetano | Univ. of Pisa |
Scilingo, Enzo Pasquale | Univ. of Pisa |
Keywords: Physiological monitoring - Instrumentation, Physiological monitoring - Novel methods
Abstract: This study proposes a novel approach to measure the contractile force of eye blink that is generally obtained from the orbicularis oculi activity through Ocular ElectroMyo- Graphy (O-EMG). Here, O-EMG is compared with the eye information acquired through a wearable head-mounted eyetracking system in order to investigate the possibility of using the eye-tracking in place of the O-EMG. Eight subjects were simultaneously monitored through an O-EMG and the eyetracker while they were performing a structured protocol implying a variation in the blink contractile strength. Results showed that eye-tracking features were able to statistically discriminate three kinds of contractile forces similarly to EMG features. The consequent correlation analysis revealed that all the EMG-related features were significantly correlated with the eye-tracking ones with a p-value <106. Moreover, considering the extracted eye-tracking features, i.e. Integrated Gaze Path (IGP) and Eye-closed Duration (ECD), IGP reported a higher Spearman’s correlation values with eye-blink reflex magnitude (EBM) than ECD. These encouraging results suggest that the ocular information extracted from the eye-tracking could be profitably used in non-invasive ecological environments where wearability and comfortability play a crucial role in detecting spontaneous response.
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09:00-09:15, Paper ThAT4.5 | Add to My Program |
Can Accelerometry Data Improve Estimates of Heart Rate Variability from Wrist PPG Sensors? |
Kos, Maciej Rafal | Northeastern Univ |
Li, Xuan | Northeastern Univ |
Khaghani-Far, Iman | Northeastern Univ |
Gordon, Christine | Northeastern Univ |
Pavel, Misha | Northeastern Univ |
Jimison, Holly | Northeastern Univ |
Keywords: Physiological monitoring - Modeling and analysis, Wearable body sensor networks and telemetric systems
Abstract: A key prerequisite for precision medicine is the ability to assess metrics of human behavior objectively, unobtrusively and continuously. This capability serves as a framework for the optimization of tailored, just-in-time precision health interventions. Mobile unobtrusive physiological sensors, an important prerequisite for realizing this vision, show promise in implementing this quality of physiological data collection. However, first we must trust the collected data. In this paper, we present a novel approach to improving heart rate estimates from wrist pulse photoplethysmography (PPG) sensors. We also discuss the impact of sensor movement on the veracity of collected heart rate data.
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09:15-09:30, Paper ThAT4.6 | Add to My Program |
Flexible Sensor Sheet for Real-Time Pressure Monitoring in Artificial Knee Joint During Total Knee Arthroplasty |
Tanabe, Fumika | Osaka Univ |
Yoshimoto, Shusuke | Osaka Univ |
Noda, Yuki | Osaka Univ |
Araki, Teppei | Osaka Univ |
Uemura, Takafumi | Osaka Univ |
Takeuchi, Yoshinori | Osaka Univ |
Imai, Masaharu | Osaka Univ |
Sekitani, Tsuyoshi | Osaka Univ |
Keywords: Physical sensors and sensor systems - Mechanical sensors and systems, Bio-electric sensors - Sensor systems, Implantable sensors
Abstract: As described in this paper, we propose a sheet-type pressure sensor to support assistive technology for artificial knee joint replacement. The proposed pressure sensor consists of two sheets: an electrode sheet with metal wiring and a flexible polymer-based insulating layer on 80 um polyimide film, as well as a pressure-sensitive conductive sheet that can function as a pressure-to-resistance sensor. We developed a 5 cm x 7 cm pressure sensor sheet with 116 sensing points. The multiple sensing sheet is expected to monitor the pressure distribution in an artificial knee joint during total knee arthroplasty to improve patients' quality of life.
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ThAT5 Minisymposium, Lee Room |
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Current Advances in Seismocardiography and Ballistocardiography |
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Chair: Tavakolian, Kouhyar | Assistant Professor |
Co-Chair: Di Rienzo, Marco | Fondazione Don Carlo Gnocchi |
Organizer: Tavakolian, Kouhyar | Assistant Professor |
Organizer: Di Rienzo, Marco | Fondazione Don Carlo Gnocchi |
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08:00-08:15, Paper ThAT5.1 | Add to My Program |
Detecting Indications of Acute Myocardial Infarction Using Smartphone Only Solution (I) |
Koivisto, Tero | Univ. of Turku |
Lahdenoja, Olli | Tech. Res. Center, Univ. of Turku |
Hurnanen, Tero | Tech. Res. Center, Univ. of Turku |
Jafari Tadi, Mojtaba | Univ. of Turku |
Lehtonen, Eero Lennart | Univ. of Turku |
Vasankari, Tuija | Heart Center, Turku Univ. Hospital |
Saraste, Antti | Heart Center, Turku Univ. Hospital |
Kiviniemi, Tuomas | Heart Center, Turku Univ. Hospital |
Airaksinen, Juhani | Heart Center, Turku Univ. Hospital |
Pänkäälä, Mikko | Univ. of Turku |
Keywords: Physiological monitoring - Novel methods
Abstract: In an acute myocardial infarction (AMI) a blood vessel of the heart is fully or partially blocked by e.g. a rupture of an atherosclerotic plaque. If the coronary arteries are fully blocked, the height of the observed ST elevation in electrocardiogram (ECG) is directly related to the severity of permanent damage to the heart muscle. This type of heart attack is also called STEMI (ST-elevation myocardial infarction). A percutaneous coronary intervention (PCI) – an invasive procedure - can be performed to remove the blockage from coronary arteries and it should be performed rapidly after the onset of the symptoms. However, sometimes the person suffering from AMI do not realize to acquire for help soon enough. In order to facilitate the rapid treatment we describe a smartphone-only solution for the early detection of STEMI condition.
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08:15-08:30, Paper ThAT5.2 | Add to My Program |
Wearable Gyrocardiography: Towards Continuous Assessment of Myocardial Contractility and Hemodynamics (I) |
Jafari Tadi, Mojtaba | Univ. of Turku |
Lehtonen, Eero Lennart | Univ. of Turku |
Saraste, Antti | Heart Center, Turku Univ. Hospital |
Pänkäälä, Mikko | Univ. of Turku |
Koivisto, Tero | Univ. of Turku |
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08:30-08:45, Paper ThAT5.3 | Add to My Program |
Seismocardiogram Features and Ultrasound Counterparts (I) |
Di Rienzo, Marco | Fondazione Don Carlo Gnocchi |
Lombardi, Prospero | Fondazione Don Carlo Gnocchi ONLUS |
Racca, Vittorio | Fondazione Don Carlo Gnocchi ONLUS |
Peritore, Angelica | Fondazione Don Carlo Gnocchi ONLUS |
Pezzano, Antonio | Fondazione Don Carlo Gnocchi ONLUS |
Vaini, Emanuele | Pol. Tecnologico, Fondazione Don Carlo Gnocchi |
Keywords: Physiological monitoring - Instrumentation, Portable miniaturized systems, Physical sensors and sensor systems - Mechanical sensors and systems
Abstract: In this pilot study we investigated the correspondence between the fiducial points (FPs) in the seismocardiogram (SCG) commonly associated with the opening and closure of mitral and aortic valves, and the real valve movements as detected by M-mode echo images. The minimal and maximal error was observed for the opening (2.9 ms) and closure (-12.8), respectively, of the mitral valve, with a large inter-subject variability. These figures support the use of the traditional SCG FPs in research, but foster further investigations for their application in clinics.
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08:45-09:00, Paper ThAT5.4 | Add to My Program |
Seismocardiographic Correlations to Age, Gender and BMI (I) |
Sørensen, Kasper | Aalborg Univ |
Jensen, Ask Schou | Aalborg Univ |
Hansen, John | Aalborg Univ |
Søgaard, Peter | Aalborg Univ. Hospital |
Struijk, Johannes | Aalborg Univ |
Schmidt, Samuel Emil | Aalborg Univ |
Keywords: Physiological monitoring - Instrumentation, Mechanical sensors and systems, Integrated wearable and portable systems
Abstract: SCG could present a easy to use tool in diagnostics and continues monitoring of patient with heart conditions. However, no description of normal time and amplitude values for healthy subjects exists. This paper describes the normal cardiac time intervals and amplitudes of the SCG signal in 44 healthy subjects. LVET was significantly different between male and females. IVCT, IVRT and absolute amplitude of AC was significantly (p<0.05) correlated with age. AO amplitude was significantly correlated with BMI
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ThAT6 Oral Session, Zworykin Room |
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Biomaterial Cell Interaction and Bioprinting |
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Chair: Kim, Keekyoung | Univ. of British Columbia Okanagan Campus |
Co-Chair: Wiest, Joachim | Cellasys GmbH |
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08:00-08:15, Paper ThAT6.1 | Add to My Program |
Micro-Patterned Films of Bio-Functionalized Conducting Polymers for Cellular Engineering |
Park, SooHyun | Penn State Univ |
Abidian, Mohammad Reza | Univ. of Houston |
Majd, Sheereen | Univ. of Houston |
Keywords: Biomimetic materials, Biomaterial-cell interactions - Biologics
Abstract: Conducting polymers (CPs) are easy to process and have tunable physical and chemical properties including conductivity, volume, color, and hydrophobicity. Therefore, these organic polymers are attractive in a broad spectrum of bioelectronic applications ranging from implantable electrodes to biosensors and actuators. Patterned films of CPs, especially with various surface chemistries, provide versatile and sophisticated building-blocks for bioelectronics. In this context, we recently introduecd a simple and efficinet technique of hydrogel-mediated electropolymerization to directly pattern films of PPy (polypyrrole) with spatially-addressable chemistries. This technique employs a topographically patterned hydrogel stamp to deliver polymer precursors to the surface of electrode during the PPy electropolymerization. This method enables easy incorporation of different molecules into CP film during the polymerization. Herein, we aim to extend the scope of hydrogel-mediated electropolymerization to pattern other types of CPs and to explore the potential of bio-functionalized CP films for cell adhesion studies. Using this method, patterned films of two distinct CPs, PPy and PEDOT, were generated with a number of dopants. The produced films were characterized for morphology, impedance, and chemical composition. Patterned CP films were bio-functionalized by incorporation of a lamimin peptide into these films. Lastly, the resultant substartes were tested for cell adhesion where laminin-doped CP showed a higher level of cell adhesion compared to PSS (polystyrene sulfonate)-doped CP films. These results together demonstrate the potential application of patterned films of bio-functionalized CPs for cellular engineering.
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08:15-08:30, Paper ThAT6.2 | Add to My Program |
Visible Light-Based Stereolithography Bioprinting of Cell-Adhesive Gelatin Hydrogels |
Wang, Zongjie | Univ. of British Columbia |
Tian, Zhenlin | Univ. of British Columbia |
Jin, Xian | Univ. of British Columbia |
Holzman, Jonathan | Univ. of British Columbia |
Menard, Frederic | Univ. of British Columbia |
Kim, Keekyoung | Univ. of British Columbia Okanagan Campus |
Keywords: Scaffolds in tissue engineering - Biofabrication, Scaffolds in tissue engineering - Patterned 3D, Scaffolds in tissue engineering - Rapid prototyping
Abstract: Stereolithography-based bioprinting offers advantages in resolution and rapid printing time, and thus has received major attention in recent years. However, traditional stereolithography-based bioprinting utilizes an ultraviolet light which may cause mutagenesis and carcinogenesis of cells. In this paper, we present a new visible light crosslinkable bioink that is based on cell-adhesive gelatin. The bioink consists of Eosin Y (EY) based photoinitiator and gelatin methacrylate (GelMA) pre-polymer solution. We examined the feasibility of using visible light from a commercial beam projector to pattern the EY-GelMA bioink. We measured the absorbance of bioink to characterize its sensitivity to visible light and performed bioprinting to test its ability to promote cell adhesion. It is found that the EY-GelMA bioink has an absorption peak at roughly 522 nm, and that it can be successfully crosslinked by visible light from the commercial projector. We performed the bioprinting experiments and visualized the cell morphology using nuclei/F-actin staining. Experimental results show that most of the cells attached to the EY-GelMA bioink after five days’ culturing. Ultimately, the EY-GelMA bioink can support both visible light crosslinking and cell adhesion, offering great potential in bioprinting and tissue engineering.
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08:30-08:45, Paper ThAT6.3 | Add to My Program |
Manual Centrifuge System: Bearing-Based Hand Spinner Made with 3-D Printer |
Yoo, Sunyoung | Seoul National Univ |
Lee, Seung Jae | Seoul National Univ |
Seo, Jong Mo | Seoul National Univ. School of Engineering |
Keywords: Microfluidic applications, Microfluidic techniques, methods and systems, Biomaterials - Chemical and electrochemical sensors
Abstract: Compact disk (CD) Microfluidic platforms are being studied for medical applications such as blood tests. However, its size is bulky and electricity is needed to realize centrifuge force. In this paper, bearing-based hand spinner is designed using three-dimensional printer. This spinner does not need electricity and keeps rotating direction during spinning unlike paperfuge. The properties of spinner vary depending on bearing type which is positioned at the center. The type of weighting area also affects RPM changes over time. When separation experiment is implemented, separating mixture into red ink and oil is achieved properly with ceramic ball bearing.
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08:45-09:00, Paper ThAT6.4 | Add to My Program |
Directed Cell Migration in Co-Cultures by Topographic Curvature for Heterogeneous Tissue Engineering |
Okutani, Chihiro | Univ. of Tokyo |
Wagatsuma, Akira | Univ. of Tokyo |
Mabuchi, Kunihiko | The Univ. of Tokyo |
Hoshino, Takayuki | Univ. of Tokyo |
Keywords: BioMEMS/NEMS - Tissue engineering and biomaterials, Micro- and nano-technology, Translational issues in tissue engineering and biomaterials
Abstract: Placing cells in the proper position is important for tissue engineering. Previous works addressed this subject in the way of controlling cell migration by micro- or nano-patterning the substrates. However, the problem of changing spatial cell density freely under co-culture conditions is remaining. To solve this problem, in this work, we report that C2C12 spatial cell density changes by the patterning geometric boundary of the topographical structures. In 48 h after seeding cells, at the liner boundary (ridge-groove) structures, C2C12 Groove/Ridge ratio was under 0.70 both under monoculture conditions and under co-culture conditions. In contrast, at the combining the liner boundary and the round boundary (ridge-groove + hole) structures, the ratio was over 0.89 under both culture conditions. This our finding will provide a new device which enables to manipulate spatial cell density under co-culture conditions for heterogeneous tissue engineering.
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09:00-09:15, Paper ThAT6.5 | Add to My Program |
Development of Biomimetic System for Scale up of Cell Spheroids - Building Blocks for Cell Transplantation |
Baba, Kazutomo | Univ. of Tsukuba |
Sankai, Yoshiyuki | Univ. of Tsukuba |
Keywords: Scaffolds in tissue engineering - Biofabrication, Scaffolds in tissue engineering - Multiscale, Scaffolds in tissue engineering - Self-assembled
Abstract: Artificial assembly of mature tissues in vitro is challenging from many viewpoints. Therefore, production of intermediate building blocks – cell spheroids expected to be a viable alternative. The purpose of this research is to develop a biomimetic system for scale up grow/maintenance of spheroids in vitro, and to confirm basic performance of the device. The system consists of a 3D culture unit and a medium perfusion unit. The 3D culture unit is dedicated for spheroid culture without using scaffolds, eliminating concerns about biocompatibility of artificial materials. our culture vessel allows easy disassembly and tissue extraction, as well as the resulting tissue can be formed into an any desirable shape. The spheroids are cultured in a sealed environment and their life are sustained by hollow fiber perfusion fluidics. We confirmed by visual and by microscopic examination that no contamination did occur before and after spheroid inoculation. Moreover, we confirmed growth and fusion between cells when C2C12 spheroids were cultured in this system.
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09:15-09:30, Paper ThAT6.6 | Add to My Program |
Enabling 3D Hepatocyte Spheroids for Microphysiometry |
Eggert, Sebastian | Cellasys GmbH |
Alexander, Frank | Cellasys GmbH |
Wiest, Joachim | Cellasys GmbH |
Keywords: Nano-bio technology design, Microfluidic techniques, methods and systems, Translational issues in tissue engineering and biomaterials - Bioreactors
Abstract: Advances in the areas of tissue engineering and microfabrication techniques have enabled promising in vitro platforms, known as Organs-on-Chips, with the aim of mimicking complex in vivo conditions for more accurate toxicology studies. To analyze the physiological change induced by chemicals or toxic substances continuously, sensors can be used in order to measure the intracellular and extracellular environment of single cells, cell constructs, or tissue, and therefore the integration of monitoring techniques into 3D tissue culture platforms provides an essential step for the next generation Organ-on-Chip platforms. However, current in vitro platforms are not capable of combining the culture of 3D models with monitoring techniques. To address this, a novel spheroid encapsulation is designed for fluidic contact between 3D models in microwells and Intelligent Mobile Lab for In Vitro Diagnostics (IMOLA-IVD) BioChip sensors while preventing spheroid fusion. In this work, spheroid culturing protocols were developed for optimized spheroid growth and an evaluation of spheroid integrity on different porous layers was performed in order to provide a defined spheroid encapsulation on BioChip sensors.
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ThAT7 Oral Session, Herrick Room |
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Joint Mechanics |
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Chair: Lee, Taeyong | Ewha Womans Univ |
Co-Chair: Lee, Hyunglae | Arizona State Univ |
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08:00-08:15, Paper ThAT7.1 | Add to My Program |
Gender Difference of Ankle Stability in the Sagittal and Frontal Planes |
Lee, Hyunglae | Arizona State Univ |
Hanzlick, Harrison | Arizona State Univ |
Keywords: New technologies and methodologies in biomechanics, Joint biomechanics, Biomechanics and robotics in physical exercise
Abstract: This paper offers quantification of ankle stability in relation to simulated haptic environments of varying stiffness. This study analyzes the stability trends of male and female subjects independently over a wide range of simulated environments after subjects were exposed to vigorous position perturbation. Ankle stability was quantified for both degrees-of-freedom of the ankle in the sagittal and frontal planes. Subjects’ stability consistently decreased when exposed to environments of negative simulated stiffness. In the frontal plane, male and female subjects exhibited nearly identical stability levels. In the sagittal plane, however, male subjects demonstrated marginally more stability than female subjects in environments with negative stiffness. Results of this study are beneficial to understanding situations in which the ankle is likely to lose stability, potentially resulting in injury.
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08:15-08:30, Paper ThAT7.2 | Add to My Program |
Effects of Counteracting External Valgus Moment on Lateral Tibial Cartilage Contact Conditions and Tibial Rotation |
Shriram, Duraisamy | Singapore Univ. of Tech. and Design |
Parween, Rizuwana | Singapore Univ. of Tech. and Design |
Lee, Yee Han Dave | Changi General Hospital Singapore |
Karupppasamy, Subburaj | Singapore Univ. of Tech. and Design (SUTD) |
Keywords: Joint biomechanics, Applied tissue and organ models and motion analysis, New technologies and methodologies in biomechanics
Abstract: Knee osteoarthritis that prevalently occurs at the medial compartment is a progressive chronic disorder affecting the articular cartilage of the knee joint, and lead to loss of joint functionality. Valgus braces have been used as a treatment procedure to unload the medial compartment for patients with medial osteoarthritis. Valgus braces through the application of counteracting external valgus moment shift the load from medial compartment towards the lateral compartment. Previous biomechanical studies focused only on the changes in varus moments before and after wearing the brace. The objective of this study was to investigate the influence of opposing external valgus moment applied by knee braces on the lateral tibial cartilage contact conditions using a 3D finite element model of the knee joint. Finite element simulations were performed on the knee joint model without and with the application of opposing valgus moment to mimic the unbraced and braced conditions. Lateral tibial cartilage contact pressures and contact area, and tibial rotation (varus-valgus and internal-external) were estimated for the complete walking gait cycle. The opposing valgus moment increased the maximum contact pressure and contact area on the lateral tibial cartilage compared to the normal gait moment. A peak contact pressure of 8.2 MPa and maximum cartilage loaded area of 28% (loaded cartilage nodes) on the lateral cartilage with the application of external valgus moment were induced at 50% of the gait cycle. The results show that the use of opposing valgus moment may significantly increase the maximum contact pressures and contact area on the lateral tibial cartilage and increases the risk of articular cartilage damage on the lateral compartment.
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08:30-08:45, Paper ThAT7.3 | Add to My Program |
Assessment of 3D Morphological Characteristics of the Shoulder Bones Using Statistical Shape Modeling: An Application to Handedness |
Inyang, Adijat Omowumi | Univ. of Cape Town |
Fouefack, Jean-Rassaire | Univ. of Cape Twon |
Sivarasu, Sudesh | Univ. of Cape Town |
Roche, Stephen | Univ. of Cape Twon |
Borotikar, Bhushan | Imt-Atlantique |
Burdin, Valerie | IMT Atlantique/Inst. Mines Telecom - INSERM U1101 |
Mutsvangwa, Tinashe Ernest Muzvidzwa | Univ. of Cape Town |
Keywords: Joint biomechanics
Abstract: In this study we have described the use of statistical shape modeling (SSM) technique in evaluating the morphological variation of shoulder bones from a South African population. The anatomical landmark selections were carried out, followed by the registration of the meshes which were validated before establishing the dense correspondence. The SSMs were built and average shape comparison from each side for each bone were made in order to evaluate handedness. In general, there was no error found around the gleno-humeral region which may suggest that the usage of contralateral healthy shoulder could serve as an informed decision making tool for surgery and prosthesis design.
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08:45-09:00, Paper ThAT7.4 | Add to My Program |
The Use of Shear Thickening Polymer As a Hip Protecter |
Lee, Taeyong | Ewha Womans Univ |
Hwang, Dong-Gyu | Ewha Womans Univ |
Ogihara, Naomichi | Keio Univ |
Ito, Kohta | Keio Univ |
Keywords: Joint biomechanics
Abstract: External hip protectors are used by the elderly in preventing hip fracture due to sideway falls. There are some commercial hip protectors which has both energy absorbing and energy shunting properties. In this study, a novel hip protector using shear thickening polymer (STP) is studied. The purpose of this work is to determine the optimal thickness of STP needed for maximum force attenuation. A mechanical test rig to simulate a person falling with sufficient impact energy to fracture the greater trochanter if unprotected was used together with biofidelic femur model which simulates the layer of flesh with skin. 8mm of STP together with 5mm foam gives the best force attenuation. When comparing the overall thickness with commercial hip protectors, STP hip protectors tested have much less thickness. Reduced thickness increases the compliance and comfort of STP hip protectors.
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09:00-09:15, Paper ThAT7.5 | Add to My Program |
Risk Estimation for Intervertebral Disc Pressure through Musculoskeletal Joint Reaction Force Simulation |
Imamura, Yumeko | The National Inst. of Advanced Industrial Science and Tech |
Ayusawa, Ko | National Inst. of Advanced Industrial Science and Tech |
Yoshida, Eiichi | National Inst. of Advanced Industrial Science and Tech |
Keywords: Optimization in musculoskeletal biomechanics, Modeling and simulation in musculoskeletal biomechanics, Dynamics in musculoskeletal biomechanics
Abstract: This research proposes a novel method that evaluates joint reaction forces by motion analysis using a musculoskeletal model. While general muscle tension estimations minimize the sum of the muscle tensions, the proposed method utilizes the joint reaction forces themselves in the objective function of the optimization problem in addition to conventional method. This method can estimate a pattern of the muscle tensions that maximizes or minimizes a specific joint force. As a typical outcome, the proposed method allows evaluating intervertebral disc compressive force caused by co-contraction of muscles while avoiding risk underestimation. We analyzed the actual lifting motion as an example and confirmed that the method can estimate the muscle tension distribution under different tension conditions.
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09:15-09:30, Paper ThAT7.6 | Add to My Program |
Subject-Specific Shoulder Muscle Attachment Region Prediction Using Statistical Shape Models: A Validity Study |
Salhi, Asma | IMT Atlantique |
Burdin, Valerie | IMT Atlantique/Inst. Mines Telecom - INSERM U1101 |
Mutsvangwa, Tinashe Ernest Muzvidzwa | Univ. of Cape Town |
Sivarasu, Sudesh | Univ. of Cape Town |
Brochard, Sylvain | CHRU Brest |
Borotikar, Bhushan | Imt-Atlantique |
Keywords: Modeling and simulation in musculoskeletal biomechanics
Abstract: Subject-specific musculoskeletal models can predict accurate joint and muscle biomechanics thereby helping clinicians and surgeons. Current modeling strategies do not incorporate accurate subject-specific muscle parameters. This study reports a statistical shape model (SSM) based method to predict subject-specific muscle attachment regions on shoulder bones and illustrates the concurrent validity of the predictions. Augmented SSMs of scapula and humerus bones were built using bone meshes and five muscle attachment (origin/insertion) regions which play important role in the shoulder motion and function. Muscle attachments included Subscapularis, Supraspinatus, Infraspinatus, Teres Major and Teres Minor on both the bones. The regions were represented by subset of vertices on the bone meshes and were tracked using vertex identifiers. Subject-specific muscle attachment regions were predicted using external set of bones not used in building the SSMs. Validity of predictions was determined by visual inspection and also by using four similarity measures between predicted and manually segmented regions. Excellent concurrent validity was found indicating the higher accuracy of predictions. This method can be effectively employed in modeling pipelines or in automatic segmentation of medical images. Further validations are warranted on all the muscles of the shoulder complex.
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ThAT8 Oral Session, Schwan Room |
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Brain-Computer Interface I |
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Chair: Kiral-Kornek, Filiz Isabell | Univ. of Melbourne |
Co-Chair: Holmes, David | Mayo Clinic |
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08:00-08:15, Paper ThAT8.1 | Add to My Program |
Neural Decoding of Attentional Selection in Multi-Speaker Environments without Access to Separated Sources |
O'Sullivan, James | Columbia Univ |
Chen, Zhuo | Columbia Univ |
Herrero, Jose | Feinstein Inst. for Medical Res |
Sheth, Sameer | Columbia Univ. Medical Center |
McKhann, Guy | Columbia Univ. Medical Center |
Mehta, Ashesh | Feinstein Inst. for Medical Res |
Mesgarani, Nima | Columbia Univ |
Keywords: Brain-computer/machine interface, Sensory neuroprostheses - Auditory, Neural signal processing
Abstract: People who suffer from hearing impairments can find it difficult to follow a conversation in a multi-speaker environment. Modern hearing aids can suppress background noise; however, there is little that can be done to help a user attend to a single conversation without knowing which speaker is being attended to. Cognitively controlled hearing aids that use auditory attention decoding (AAD) methods are the next step in offering help. A number of challenges exist, including the lack of access to the clean sound sources in the environment with which to compare with the neural signals. We propose a novel framework that combines single-channel speech separation algorithms with AAD. We present an end-to-end system that 1) receives a single audio channel containing a mixture of speakers that is heard by a listener along with the listener’s neural signals, 2) automatically separates the individual speakers in the mixture, 3) determines the attended speaker, and 4) amplifies the attended speaker’s voice to assist the listener. Using invasive electrophysiology recordings, our system is able to decode the attention of a subject and detect switches in attention using only the mixed audio. We also identified the regions of the auditory cortex that contribute to AAD. Our quality assessment of the modified audio demonstrates a significant improvement in both subjective and objective speech quality measures. Our novel framework for AAD bridges the gap between the most recent advancements in speech processing technologies and speech prosthesis research and moves us closer to the development of cognitively controlled hearing aids.
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08:15-08:30, Paper ThAT8.2 | Add to My Program |
TrueNorth-Enabled Real-Time Classification of EEG Data for Brain-Computer Interfacing |
Kiral-Kornek, Filiz Isabell | Univ. of Melbourne |
Mendis, Dulini | Univ. of Melbourne |
Nurse, Ewan | Univ. of Melbourne |
Mashford, Benjamin Scott | IBM Res. Australia |
Freestone, Dean Robert | The Univ. of Melbourne |
Grayden, David B. | The Univ. of Melbourne |
Harrer, Stefan | IBM Res |
Keywords: Brain-computer/machine interface, Neural interfaces - Implantable systems, Neural signals - Nonlinear analysis
Abstract: Brain-computer interfaces are commonly proposed to assist individuals with locked-in syndrome to interact with the world around them. In this paper, we present a pipeline to move from recorded brain signals to real-time classification on a low-power platform, such as IBM’s neuromorphic TrueNorth chip. Our results on a EEG-based hand squeeze task show that using a convolutional neural network and a time preserving signal representation strategy provides a good balance between high accuracy and feasibility in a real-time application. This pathway can be adapted to the management of a variety of conditions, including spinal cord injury, epilepsy and Parkinson’s disease.
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08:30-08:45, Paper ThAT8.3 | Add to My Program |
An Eighty-Target High-Speed Chinese BCI Speller |
Han, Chengcheng | Xi’an Jiaotong Univ |
Xu, Guanghua | Xi'an Jiaotong Univ |
Xie, Jun | Xi'an Jiaotong Univ |
Li, Min | School of Mechanical Engineering, Xi’an Jiaotong Univ |
Zhang, Sicong | Xi’an Jiaotong Univ |
Luo, Ailing | Xi’an Jiaotong Univ |
Keywords: Brain-computer/machine interface, Brain functional imaging - Evoked potentials, Human performance - Activities of daily living
Abstract: A high-speed Chinese BCI speller was designed and implemented in this paper. A visual stimulation method called the motion checkerboard stimulation was used to elicit SSMVEP. With a 10×8 high-density matrix interface, phonetic symbols or characters were presented for selection, and only two selections per character were required. According to experiment, the ITR of the eighty-target motion checkerboard paradigm achieved 99.1 bits/min, the average accuracy of sinogram spelling system scored above 94.1% and the speed was up to one sinogram per 12 s. These results suggest that the proposed Chinese speller can input vast number of characters with higher speed and less operations, providing a high practicability communication method for people with motor disabilities.
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08:45-09:00, Paper ThAT8.4 | Add to My Program |
Cortical Oscillatory Dynamics of Tactile Selective Sensation - for a Novel Type of Somatosensory Brain-Computer Interface |
Yao, Lin | Univ. Medical Center Goettingen, Georg-August-Univ |
Chen, Mei Lin | Univ. of Waterloo |
Sheng, Xinjun | Shanghai Jiao Tong Univ |
Mrachacz-Kersting, Natalie | Aalborg Univ |
Zhu, Xiangyang | Shanghai Jiao Tong Univ |
Farina, Dario | Bernstein Center for Computational Neuroscience, Univ |
Jiang, Ning | Univ. of Waterloo |
Keywords: Brain-computer/machine interface, Neurorehabilitation
Abstract: In this study, cortical oscillatory dynamics with respect to tactile selective sensation tasks were investigated. Subjects were required to perform three tactile attention tasks, prompted by cues presented in random order and while both wrists were simultaneously stimulated: 1) selective sensation of the left hand (SS-L), 2) selective sensation of the right hand (SS-R), 3) bilateral selective sensation (SS-B). Even-related (de)synchronization (ERD/ERS) analysis revealed a clear contralateral activation of somatosensory cortex during the SS-L and SS-R tasks, and a bilateral activation during SS-B tasks. Additionally, we found a clear ERS in occipital region of the brain during all the SS tasks. Diverse activation pattern among SS-L, SS-R and SS-B offers novel brain signals for somatosensory Brain-computer Interfaces.
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09:00-09:15, Paper ThAT8.5 | Add to My Program |
Dynamic Tracking of Non-Stationarity in Human ECoG Activity |
Yang, Yuxiao | Univ. of Southern California |
Chang, Edward | UCSF |
Shanechi, Maryam | Univ. of Southern California |
Keywords: Brain-computer/machine interface, Brain physiology and modeling - Neural dynamics and computation, Neural stimulation
Abstract: Modeling brain network dynamics is essential in understanding neural mechanisms and developing neurotech nologies such as closed-loop stimulation therapies for a wide range of neurological disorders. Brain network activity could have non-stationary and time-variant dynamics, especially when the subject’s brain is monitored for a long period, e.g., using the electrocorticogram (ECoG). This non-stationarity makes the modeling of dynamics challenging. In our prior work, we developed a framework to identify time-invariant linear state-space models (SSMs) to describe both stationary spontaneous neural population dynamics and input-output (IO) neural dynamics in response to electrical stimulation. Here, we develop an adaptive identification algorithm that estimates time-variant SSMs to track possible non-stationarity in brain network dynamics. We apply the adaptive algorithm to track high-density human ECoG dynamics in three subjects over a long time-period. We find that the adaptive identification algorithm can estimate time-variant SSMs that significantly outperform time-invariant SSMs in all subjects. Our results demonstrate that non-stationary dynamics exist in high-dimensional human ECoG signals over long time-periods, and that the proposed adaptive SSM identification algorithm can successfully track these non-stationarities. These results have important implications for more accurate estimation of neural biomarkers for different brain states and for adaptive closed-loop stimulation therapy across a wide range of neurological disorders.
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09:15-09:30, Paper ThAT8.6 | Add to My Program |
Movement-Related Brain Oscillations Vary with Lesion Location in Severely Paralyzed Chronic Stroke Patients |
Ray, Andreas Markus | Tuebingen Univ |
López-Larraz, Eduardo | Univ. of Tübingen |
da Cruz Figueiredo, Thiago | Univ. of Tübingen |
Birbaumer, Niels | Eberhard-Karls-Univ |
Ramos-Murguialday, Ander | Eberhard Karls Univ. of Tubingen/TECNALIA |
Keywords: Brain-computer/machine interface, Motor learning, neural control, and neuromuscular systems, Neurological disorders - Stroke
Abstract: In the past few years, innovative upper-limb rehabilitation methods have been proposed for chronic stroke patients. These methods aim at functional motor rehabilitation using Brain-machine interfaces to constitute an alternate pathway from the brain to the muscles. Even in patients with absence of residual finger movements, recovery could be achieved. The extent to which these interventions are affected by individual lesion topology is yet to be understood. In this study EEG was measured in 30 chronic stroke patients during movement attempts of the paretic arm. We show that the magnitude of the event-related desynchronization was smaller in patients presenting lesions with involvement of the motor cortex. This could have important implications on the design of new rehabilitation schemes for these patients, which might benefit from carefully tailored interventions.
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ThAT9 Minisymposium, Plonsey Room |
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Challenges in the Restoration of Vision through Retinal Neurostimulation |
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Chair: Weiland, James | Univ. of Michigan |
Co-Chair: Suaning, Gregg | The Univ. of Sydney |
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08:00-08:15, Paper ThAT9.1 | Add to My Program |
Cortical Responses Driven by Epi-Retinal Stimulation in Rodent (I) |
Xie, Hui | City Univ. of Hong Kong |
Wang, Yi | City Univ. of Hong Kong |
CHAN, Leanne LH | City Univ. of Hong Kong |
Keywords: Sensory neuroprostheses - Visual, Neural stimulation, Neural interfaces - Tissue-electrode interface
Abstract: Neuronal excitation threshold is known to be influenced by the distance from the stimulating electrodes to the target cell. Closer proximity with the target require less electrical energy for stimulation. Is it possible to obtain the optimal proximity to stimulate the target cell with the minimum electrical energy? This study stimulated the retinal ganglion cells with various stimulating distances and measured the cortical electrically evoked potentials (EEPs). Results showed that EEPs increased with impedance, an indirect measurement of electrode-retina distance, reached a response maximum and decreased when impedance further increased.
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08:15-08:30, Paper ThAT9.2 | Add to My Program |
Challenges in Suprachoroidal Retinal Neuroprosthesis (I) |
Suaning, Gregg | The Univ. of Sydney |
Keywords: Neural interfaces - Implantable systems, Sensory neuroprostheses - Visual, Neural stimulation
Abstract: Profoundly blind people are capturing their first glimpses of what the future holds through first-generation retinal neuroprosthesis technologies now in clinical use. Several other of these ‘bionic eyes’ are at various stages of clinical development, including a device by the author with a stimulating electrode array that is surgically placed within the suprachoroidal space – that is, the interface between the choroid and the sclera. While the placement of a device at this site offers a number of unique advantages, the increased distance to the target neurons also presents a number of challenges that must be overcome in order to realize a clinically-beneficial device. Here, the advantages and challenges of the suprachoroidal approach are compared, and a case is made for its pursuit as a clinical therapy in the treatment of degenerative disorders of the retina.
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08:30-08:45, Paper ThAT9.3 | Add to My Program |
Experimental Animal Model for the Evaluation of the Artificial Retina (I) |
Seo, Jong Mo | Seoul National Univ. School of Engineering |
Chung, Hum | Seoul National Univ. School of Medicine |
Cho, Bum Joo | Seoul National Univ. School of Medicine |
Keywords: Sensory neuroprostheses - Visual
Abstract: The feasibility of the retinal stimulation to restore vision can be evaluated in the animal model as a pre-clinical experiment. Rabbit is a good animal model not only for the electrophysiological but also surgical experiment, but there is no hereditary retinal degeneration model in wild type rabbit. Genetically modified retinal degeneration model was introduced but not commonly used because of the difficulty in breeding. Medically induced retinal degeneration models with systemic injection of sodium iodate deteriorate the outer retina including photoreceptor and plexiform layers and only mimicking end-stage retinal degeneration. By using intravitreal sodium iodine injection, monocular photoreceptor degeneration can be achieved and can mimic various stages of the retinal degeneration. In this model, dose-dependent retinal degeneration and related histological and physiological changes will be introduced.
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08:45-09:00, Paper ThAT9.4 | Add to My Program |
Development of a Second-Generation Device for Suprachoroidal-Transretinal Stimulation (I) |
Kanda, Hiroyuki | Osaka Univ |
Kamei, Motohiro | Osaka Univ |
Sakaguchi, Hirokazu | Osaka Univ |
Endo, Takao | Osaka Univ |
Hirota, Masakazu | Osaka Univ |
Morimoto, Takeshi | Osaka Univ |
Nishida, Kentaro | Osaka Univ |
Kishima, Haruhiko | Osaka Univ |
Miyoshi, Tomomitsu | Osaka Univ |
Terasawa, Yasuo | NIDEK Co |
Oosawa, Kouji | Nidek Co., Ltd |
Ozawa, Motoki | Nidek Co., Ltd |
Fujikado, Takashi | Osaka Univ |
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09:00-09:15, Paper ThAT9.5 | Add to My Program |
Strategies to Improve Visual Function for Retinal Prosthesis Patients (I) |
Weiland, James | Univ. of Michigan |
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ThAT10 Oral Session, Schmitt Room |
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General and Theoretical Informatics - Predictive Analytics I |
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Chair: Hwang, Dosik | Yonsei Univ |
Co-Chair: Ho, Joyce C. | Emory Univ |
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08:00-08:15, Paper ThAT10.1 | Add to My Program |
Prediction of Adenocarcinoma Development Using Game Theory |
ATHREYA, ARJUN | Univ. of Illinois at Urbana-Champaign |
Armstrong, Don | Univ. of Illinois at Urbana Champaign |
Gundling, William | Department of Molecular and Integrative Physiology, Univ. O |
Wildman, Derek | Univ. of Illinois |
Kalbarczyk, Zbigniew | Univ. of Illinois at Urbana-Champaign |
Iyer, Ravishankar | Univ. of Illinois at Urbana-Champaign |
Keywords: General and theoretical informatics - Predictive analytics, Health Informatics - Disease profiling and personalized treatment, Bioinformatics - Gene expression pattern recognition
Abstract: Recent research shows that gene expression changes appear to correlate well with the progression of many types of cancers. Using changes in gene expression as a basis, this paper proposes a data-driven 2-player game-theoretic model to predict the risk of adenocarcinoma based on Nash equilibrium. A key innovation in this work is the pay-off function which is a weighted composite of the expression of a cohort of tumor-suppressor genes (as one player) and an analogous cohort of oncogenes (as the other player). Another novelty of the model is its ability to predict the risk that a healthy sample will develop adenocarcinoma, if its associated gene expression is comparable to that of early-stage tumor samples. The model is validated using two of the largest publicly available adenocarcinoma datasets. The results show that i) the model is able to distinguish between healthy and cancerous samples with an accuracy of 93%, and ii) 95% of the healthy samples said to be at risk had gene expressions comparable to those of samples with stage I or stage II tumors, thereby predicting the imminent onset of adenocarcinoma.
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08:15-08:30, Paper ThAT10.2 | Add to My Program |
Learning from Different Perspectives: Robust Cardiac Arrest Prediction Via Temporal Transfer Learning |
Ho, Joyce C. | Emory Univ |
Park, Yubin | The Univ. of Texas at Austin |
Keywords: General and theoretical informatics - Predictive analytics, Health Informatics - Disease profiling and personalized treatment, General and theoretical informatics - Data mining
Abstract: Predicting and preventing cardiac arrest is one of the biggest challenges of contemporary cardiology, as a patient’s survival depends on the effectiveness of the emergency response teams. While "black-box” models have shown to have better predictive accuracies for cardiac risk stratification, early warning scoring systems are more prominent in the hospital setting due to their ease of implementation and interpretability. We propose a temporal transfer learning approach to utilize information from adjacent time points to yield an early cardiac arrest prediction model that is robust in predictive accuracies as well as maintains the interpretability of the model coefficients. Our model estimates the logistic regression coefficients simultaneously for various time points to share knowledge from different observation windows. This framework can overcome small sample size issues, and result in robust estimation of the model coefficients. We find that our model consistently outperforms a logistic regression model fit only on vital sign data from a single time slice for 763 intensive care unit patients. Moreover, we find that the estimated coefficients from our model captures temporal trends in the data.
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08:30-08:45, Paper ThAT10.3 | Add to My Program |
Predictive Modeling for Corrective Maintenance of Imaging Devices from Machine Logs |
Balasheb Patil, Ravindra | Philips Res. India |
Patil, Meru | Philips India Limited |
Ravi, Vidya | Philips |
Naik, Sarif Kumar | Philips Electronics India Ltd |
Keywords: General and theoretical informatics - Predictive analytics, General and theoretical informatics - Artificial Intelligence, General and theoretical informatics - Algorithms
Abstract: In the cost sensitive healthcare industry, an unplanned downtime of diagnostic and therapy imaging devices can be a burden on the financials of both the hospitals as well as the original equipment manufacturers (OEMs). In the current era of connectivity, it is easier to get these devices connected to a standard monitoring station. Once the system is connected, OEMs can monitor the health of these devices remotely and take corrective actions by providing preventive maintenance thereby avoiding major unplanned downtime. In this article, we present an overall methodology of predicting failure of these devices well before customer experiences it. We use data-driven approach based on machine learning to predict failures in turn resulting in reduced machine downtime, improved customer satisfaction and cost savings for the OEMs. One of the use-case of predicting component failure of PHILIPS iXR system is explained in this article.
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08:45-09:00, Paper ThAT10.4 | Add to My Program |
Data-Driven Strategies for Robust Forecast of Continuous Glucose Monitoring Time-Series |
Fiorini, Samuele | Univ. of Genoa |
Martini, Chiara | Univ. of Genoa |
Malpassi, Davide | Univ. of Genoa |
Cordera, Renzo | Univ. of Genoa |
Maggi, Davide | Univ. of Genoa |
Verri, Alessandro | Univ. of Genoa |
Barla, Annalisa | Univ. of Genoa |
Keywords: Health Informatics - Disease profiling and personalized treatment, General and theoretical informatics - Machine learning, General and theoretical informatics - Predictive analytics
Abstract: Over the past decade, continuous glucose monitoring (CGM) has proven to be a very resourceful tool for diabetes management. To date, CGM devices are employed for both retrospective and online applications. Their use allows to better describe the patients' pathology as well as to achieve a better control of patients' level of glycemia. The analysis of CGM sensor data makes possible to observe a wide range of metrics, such as the glycemic variability during the day or the amount of time spent below or above certain glycemic thresholds. However, due to the high variability of the glycemic signals among sensors and individuals, CGM data analysis is a non-trivial task. Standard signal filtering solutions fall short when an appropriate model personalization is not applied. State-of-the-art data-driven strategies for online CGM forecasting rely upon the use of recursive filters. Each time a new sample is collected, such models need to adjust their parameters in order to predict the next glycemic level. In this paper we aim at demonstrating that the problem of online CGM forecasting can be successfully tackled by personalized machine learning models, that do not need to recursively update their parameters.
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09:00-09:15, Paper ThAT10.5 | Add to My Program |
Prediction of Temperature Induced Office Worker’s Performance During Typing Task Using EEG |
Nayak, Tapsya | Univ. of Texas at San Antonio |
Zhang, Tinghe | Univ. of Texas, San Antonio |
Mao, Zijing | Univ. of Texas at San Antonio |
Xu, Xiaojing | Univ. of Tennessee, Knoxville |
Pack, Daniel | Univ. of Tennessee |
Dong, Bing | Univ. of Texas, San Antonio |
Huang, Yufei | Univ. of Texas at San Antonio |
Keywords: General and theoretical informatics - Predictive analytics, Health Informatics - Human factors (ergonomics) in health information systems
Abstract: Understanding how indoor environment affect office worker’s performance and developing methods to predict human performance in changing indoor environment have become highly important research topic bearing significant economic and sociological impact. While past research groups have attempted to find predictors for performance they do not provide satisfactory predictions. We conduct in this paper a study to predict human performance by developing a regression model using neurophysiological signals collected from electroencephalogram (EEG), during simulated office-work tasks under different indoor room temperatures (22 and 30 Celsius). We found that using brain power spectral densities (PSD) from EEG as predictors provides the higher R^2 than predictors using skin temperature or heart rate by approximately over 3 folds. Finally, we showed that the predictor using EEG is more robust than regression models using skin temperature and heart rate. Our work show the potential of using brain signals to accurately predict human office work performance.
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09:15-09:30, Paper ThAT10.6 | Add to My Program |
Consensus Motifs As Adaptive and Efficient Predictors for Acute Hypotensive Episodes |
Pathinarupothi, Rahul Krishnan | Amrita Vishwa Vidyapeetham |
Rangan, Ekanath | Amrita Vishwa Vidyapeetham |
Keywords: General and theoretical informatics - Predictive analytics
Abstract: Acute hypotensive episodes (AHE) are characterized by continuously low blood pressure for prolonged time, and could be potentially fatal. We present a novel AHE detection system, by first quantizing the blood pressure data into clinically accepted severity ranges and then identifying most frequently occurring blood pressure pattern among thesewhich we call consensus motifs. We apply machine learning techniques (support vector machine) on these consensus motifs. The results show that the use of consensus motifs instead of raw time series data extends the predictability by 45 minutes beyond the 2 hours that is possible using only the raw data, yielding a significant improvement without compromising the clinical accuracy. The system has been implemented as part of a new framework called RASPRO (Rapid Summarization for Effective Prognosis) that we have developed for Wireless Remote Health Monitoring.
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ThAT11 Oral Session, Greatbatch Room |
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Blood Pressure Monitoring |
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Chair: Mukkamala, Ramakrishna | Michigan State Univ |
Co-Chair: Sugimachi, Masaru | Natl Cardio Center Res. Inst |
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08:00-08:15, Paper ThAT11.1 | Add to My Program |
Model-Based Estimation of Radial Artery Blood Pressure from Recordings of the Nexfin Monitor |
Imaduddin, Syed | Massachusetts Inst. of Tech |
Heldt, Thomas | Massachusetts Inst. of Tech |
Keywords: Vascular mechanics and hemodynamics - Vascular Hemodynamics, Pulmonary and critical care - Bioengineering applications in Intensive care, Cardiovascular and respiratory system modeling - Vascular mechanics and hemodynamics
Abstract: We propose a model-based reconstruction technique to estimate radial artery blood pressure from measurements obtained by the Nexfin noninvasive blood pressure monitor. The Nexfin monitor provides brachial artery pressure estimates by transforming a pressure measured at the finger. The estimated brachial pressure differs significantly from the radial artery pressure commonly measured in intensive care applications. Our reconstruction method is based on a transmission line model of the arterial network and transforms brachial to radial pressure estimates. Applying the method to 22 records from six patients reduced mean pulse pressure differences between reconstructed and measured radial artery pressures from -17.9 (s.d. 12.1) mmHg to 1.8 (12.0) mmHg. Mean systolic and diastolic pressure differences changed from -18.7 (10.5) and -0.7 (6.2) to -0.8 (10.5) and -2.6 (6.9) mmHg, respectively. Our method can be applied to more general problems of estimating pressure waveforms downstream from an upstream measurement location.
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08:15-08:30, Paper ThAT11.2 | Add to My Program |
A Simple Method for Reconstruction of Continuous Brachial Artery Pressure from Continuous Digital Artery Pressure in Humans |
Zhang, Pandeng | Chinese Acad. of Sciences |
qiu, quanli | SIAT |
Luo, ying | Shenzhen Sun Yat-Sen Cardiovascular Hospital |
zhou, yanxia | Shenzhen Municipal Second People’s Hospital, Guangdong Pro |
Liu, Jia | Chinese Acad. of Sciences |
Keywords: Cardiovascular and respiratory signal processing - Cardiovascular signal processing, Cardiovascular and respiratory system modeling - Cardiovascular control models, Cardiovascular and respiratory signal processing - Pulse transit time
Abstract: This paper presents a practical approach to reconstruct brachial artery pressure (BAP) distally from digital artery pressure (DAP). We hypothesize that continuous BAP can simply be approximated by sum of two halves of the continuous DAP shifted by the time delay. In order to test it, we enrolled 30 healthy volunteers for two experiments. We firstly showed that the pressure wave in the digital artery can be considered twice as much as the forward/backward wave in the finger. A simplified individualized transfer function was then derived so as to estimate BAP from DAP. Finally, by comparing with a reference BAP, we found that the proposed method can correct the DAP. The errors of the proposed method in estimating systolic and diastolic pressures are 2.82±3.58 and -2.32±4.06 mmHg, respectively. These results agree with the standard of Association for the Advancement of Medical Instrumentation (AAMI). Our method is therefore promising in estimating continuous proximal blood pressure from peripheral blood pressure in practice.
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08:30-08:45, Paper ThAT11.3 | Add to My Program |
Measurement of Carotid Blood Pressure and Local Pulse Wave Velocity Changes During Cuff Induced Hyperemia |
PM, Nabeel | Indian Inst. of Tech. Madras |
Karthik, Srinivasa | HTIC IIT Madras |
Joseph, Jayaraj | HTIC, Indian Inst. of Tech. Madras |
Sivaprakasam, Mohanasankar | Indian Inst. of Tech. Madras |
Keywords: Vascular mechanics and hemodynamics - Pulse wave velocity, Cardiovascular and respiratory signal processing - Pulse transit time, Cardiovascular and respiratory signal processing - Heart Rate and Blood Pressure Variability
Abstract: We present a prototype design of dual element photoplethysmograph (PPG) probe along with associated measurement system for carotid local pulse wave velocity (PWV) evaluation in a non-invasive and continuous manner. The PPG probe consists of two identical sensing modules placed 23 mm apart. Simultaneously measured blood pulse waveforms from these arterial sites were processed and the pulse transit time delay was resolved using the developed application-specific software. The ability of developed PPG probe and associated measurement system to detect acute changes in carotid local PWV due to blood pressure (BP) variations was experimentally validated by an in-vivo study. Intra-subject carotid BP elevation was achieved by an upper arm cuff based occlusion, which offered a controlled way of local PWV escalation. The elevated carotid BP values were also recorded by a calibrated pressure tonometer prior to the study, and was used as a reference. A significant increment (1.0 – 2.6 m/s) in local PWV was observed and was proportional to the BP increment induced by the occlusive reactive hyperemia. Study results demonstrated the feasibility of real-time signal acquisition and reliable local PWV evaluation under normal and elevated BP conditions using the developed measurement system.
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08:45-09:00, Paper ThAT11.4 | Add to My Program |
Analysis of a GMR-Based Plethysmograph Transducer and Its Utility for Real-Time Blood Pressure Measurement |
Chugh, Vinit Kumar | IIT Kharagpur |
kalyan, kubera | IIT Kharagpur |
Chandrika Sreekantan, Anoop | Indian Inst. of Space Science and Tech. Trivandrum |
Patra, Amit | Indian Inst. of Tech. Kharagpur |
Negi, Shubham | IIT Kharagpur |
Keywords: Cardiovascular and respiratory signal processing - Pulse transit time, Vascular mechanics and hemodynamics - Pulse wave velocity, Cardiovascular and respiratory signal processing - Cardiovascular signal processing
Abstract: The paper presents study and analysis of a Giant Magneto Resistance (GMR)-based magneto plethysmograph and illustrates its efficacy as a tool for real-time cuff-less measurement of Blood Pressure (BP). The proposed scheme employs two GMR sensors and associated biasing and signal conditioning in its architecture. The delay between output of the GMR sensors is used to estimate the BP. The methodology, circuits and signal processing stages used are described in the paper. A prototype of the GMR-sensing solution is developed and tested. Initially, tests are carried out to determine the quality and characteristics of the plethysmographs produced by developed sensor unit, in different conditions such as various body positions, bias current etc. Good quality bio-signals were obtained during the above tests. Then, the experiments were conducted on 29 volunteers to find the feasibility of developed scheme as a BP monitor. The results obtained show that the performance of developed BP monitor is within acceptable limits.
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09:00-09:15, Paper ThAT11.5 | Add to My Program |
Regression Analysis and Transfer Function in Estimating the Parameters of Central Pulse Waves from Brachial Pulse Wave |
Chai, Rui | Northeastern Univ |
LI, Siman | Northeastern Univ |
Xu, Lisheng | Northeastern Univ |
Yao, Yang | Northeastern Univ |
Hao, Liling | Northeastern Univ |
Keywords: Cardiovascular and respiratory signal processing - Cardiovascular signal processing
Abstract: This study mainly analyzed the parameters such as ascending branch slope (A_slope), dicrotic notch height (Hn), diastolic area (Ad) and systolic area (As) diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), subendocardial viability ratio (SEVR), waveform parameter (k), stroke volume (SV), cardiac output (CO) and peripheral resistance (RS) of central pulse wave invasively and non-invasively measured. These parameters extracted from the central pulse wave invasively measured were compared with the parameters measured from the brachial pulse waves by a regression model and a transfer function model. The accuracy of the parameters which were estimated by the regression model and the transfer function model was compared too. Our findings showed that in addition to the k value, the above parameters of the central pulse wave and the brachial pulse wave invasively measured had positive correlation. Both the regression model parameters including A_slope, DBP, SEVR and the transfer function model parameters had good consistency with the parameters invasively measured, and they had the same effect of consistency. The regression equations of the three parameters were expressed by Y'=a+bx. The SBP, PP, SV, CO of central pulse wave could be calculated through the regression model, but their accuracies were worse than that of transfer function model.
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09:15-09:30, Paper ThAT11.6 | Add to My Program |
Novel Blood Pressure Estimation Method Using Single Photoplethysmography Feature |
Chen, Yang | Harbin Inst. of Tech. Shenzhen Graduate School |
Cheng, Shuo | Harbin Inst. of Tech |
Wang, Tong | Harbin Inst. of Tech. Shenzhen Grauate School |
Ma, Heather Ting | Harbin Inst. of Tech. Shenzhen Graduate School |
Keywords: Cardiovascular and respiratory signal processing - Pulse transit time, Cardiovascular and respiratory system modeling - Cardiovascular Disease
Abstract: Continuous blood pressure (BP) monitoring has a significant meaning to the prevention and early diagnosis of cardiovascular disease. However, existing continuous BP monitoring approaches, especially cuff-less BP monitoring approaches, are all contraptions which complex and huge computation required. For example, for the most sophisticated cuff-less BP monitoring method using pulse transit time (PTT), the simultaneous record of photoplethysmography (PPG) signal and electrocardiography (ECG) are required, and various measurement of characteristic points are needed. These issues hindered widely application of cuff less BP measurement in the wearable devices. In this study, a novel BP estimation method using single PPG signal feature was proposed and its performance in BP estimation was also tested. The results showed that the new approach proposed in this study has a mean error -0.91±3.84 mmHg for SBP estimation and -0.36±3.36 mmHg for DBP estimation respectively. This approach performed better than the traditional PTT based BP estimation, which mean error for SBP estimation was -0.31±4.78 mmHg, and for DBP estimation was -0.18±4.32 mmHg. Further investigation revealed that this new BP estimation approach only required measurement of one characteristic point, reducing much computation when implementing. These results demonstrated that this new approach might be more suitable implemented in the wearable BP monitoring devices.
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ThAT12 Invited Session, Geddes Room |
Add to My Program |
Modeling of Modern Devices and Technologies with Computational Human
Phantoms - I |
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Chair: Hyde, Damon | Boston Children's Hospital and Harvard Medical School |
Co-Chair: Horner, Marc | ANSYS, Inc |
Organizer: Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Organizer: Horner, Marc | ANSYS, Inc |
Organizer: Noetscher, Gregory | Worcester Pol. Inst |
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08:00-08:15, Paper ThAT12.1 | Add to My Program |
Computational Modeling for Regulatory Science at the FDA (I) |
Iacono, Maria Ida | Food and Drug Administration |
Rajan, Sunder | Food and Drug Administration |
Kainz, Wolfgang | Food and Drug Administration |
Lochner, Donna R. | Food and Drug Administration (FDA) |
Angelone, Leonardo M. | US Food and Drug Administration, Center for Devices and Radiolog |
Keywords: Neural stimulation (including deep brain stimulation)
Abstract: This abstract describes some examples of regulatory-oriented research conducted by the Food and Drug Administration (FDA). FDA recognizes the great potential of computational modeling and simulation as an efficient and effective method for the evaluation of safety and the effectiveness of medical devices, including computational modeling of active and passive implants to determine if unsafe levels of heating arise during patient and implant’s exposure to magnetic resonance imaging (MRI) systems and modeling of neurostimulation. Future regulatory applications of computational modeling include use of models in virtual clinical trials, in which device testing can be simulated against population of virtual patients.
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08:15-08:30, Paper ThAT12.2 | Add to My Program |
Application of Realistic Human Head Models for Evaluating Induced Electric Fields: A Discussion on Feasible Model Creation, Influential Model Assumptions, and Necessary Degree of Complexity (I) |
Wenger, Cornelia | Novocure GmbH |
Miranda, Pedro Cavaleiro | Faculdade De Ciências, Univ. De Lisboa |
Keywords: Clinical engineering, Ambulatory Therapeutic Devices - Personalized therapeutic devices and emergency response systems, Neural stimulation (including deep brain stimulation)
Abstract: During the last decades, several brain stimulation techniques were developed which are employed for different medical and research applications. These techniques make use of the interaction between electric fields (EF) and living tissue, specifically within the brain. Since it is troublesome to measure the induced EF in vivo, realistic human head models have been created and used to study its distribution. The creation of suitable head models is currently based on segmentation algorithms that mask out tissue maps from anatomical MRIs. This task is non-trivial, time-consuming and is further complicated by the presence of pathologies. Furthermore, the simulated EF is influenced by assumed model physics and the choice of appropriate dielectric properties of tissues. Thus, one of the main objectives for investigational studies should be to develop a pipeline for fast and robust model creation of individuals including the application-specific device. Ideally, these models have a minimum degree of complexity while yielding accurate results. Possible workflows and mentioned influential aspects will be discussed with the example of Tumor Treating Fields (TTFields) which are low intensity alternating electric fields in the 100-500 kHz frequency range that are used as anti-mitotic cancer treatment.
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08:30-08:45, Paper ThAT12.3 | Add to My Program |
Neurotrauma Evaluation in a 3D Electro-Mechanical Model of a Nerve Bundle (I) |
Cinelli, Ilaria | NUI of Galway |
Destrade, Michel | CNRS / Univ. Pierre Et Marie Curie |
Duffy, Maeve | NUI Galway |
McHugh, Peter | NUI of Galway |
Keywords: Neural stimulation (including deep brain stimulation)
Abstract: Alteration of neuron structure can induce abnormalities in signal propagation, as seen in trauma. We propose a unique framework for 3D finite element modelling of a nerve bundle in Abaqus CAE 6.13-3, combining a real-time fully coupled electro-mechanical, modulated threshold for spiking activation and independent alteration of the electrical properties for each 3-layer fibre. The significance of this study is the difference in distribution of residual stresses and strains at the membrane for different sizes and types of fibres.
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08:45-09:00, Paper ThAT12.4 | Add to My Program |
Subject Specific Bioelectric Head Modeling: Effects of Numerical Method Choice and Clinical Considerations (I) |
Hyde, Damon | Boston Children's Hospital and Harvard Medical School |
Dannhauer, Moritz | Univ. of Utah |
Brooks, Dana | Northeastern Univ |
Warfield, Simon K. | Harvard Medical School |
Keywords: Diagnostic devices - Physiological monitoring, Neural stimulation (including deep brain stimulation)
Abstract: Electroencephalography (EEG) source localization (ESL) and transcranial current stimulation (TCS) rely on accurate bioelectric models, individualized to each subject. Improvements in MRI sequences and image processing have enabled construction of these models at millimeter or better accuracy, with an ever increasing number of tissue compartments. However, refinements to model accuracy often necessitate additional MR imaging, while producing ever decreasing improvements to model quality. In a clinical environment, this tradeoff between increased cost of care and improved diagnostic capability must be weighed. Here, we present results suggesting that selection of a particular numerical technique and software implementation, an often neglected aspect of numerical modeling, can induce errors on the same scale as recent advancements in patient specific modeling. In the context of clinical individualized head models, these errors can help in establishing a basis for evaluating the tradeoffs that must be made in constructing standard imaging protocols for the construction of individualized head models.
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09:00-09:15, Paper ThAT12.5 | Add to My Program |
Evaluating Electric Field Distribution in the Heads of Patients Treated with Tumor Treating Fields Using Realistic Human Models Created with a Deformable Template (I) |
Urman, Noa | Novocure |
Hershkovich, Hadas Sara | Novocure Ltd., Haifa, Israel |
Weinberg, Uri | Novocure |
Wenger, Cornelia | Novocure GmbH |
kirson, Eilon David | Novocure |
Bomzon, Ze'ev | Novocure |
Keywords: Clinical engineering, Ambulatory Therapeutic Devices - Personalized therapeutic devices and emergency response systems
Abstract: A method for rapidly creating realistic head models of Glioblastoma patients for computational studies on the distribution of Tumor Treating Fields within the head is described. The method utilizes a model of a healthy individual as a template which is non-rigidly deformed to approximate the patient's anatomy. The tumor is segmented manually and planted into the deformed template to create the patient model. The method does not require accurate segmentation of patient MRIs, and is therefore rapid and robust.
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09:15-09:30, Paper ThAT12.6 | Add to My Program |
Modeling Fibrous Tissues Via Boundary Element Method Using a Thin-Wire Approximation. Test Results (I) |
Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Pascual-Leone, Alvaro | Harvard Medical School |
Nummenmaa, Aapo | Massachussetts General Hospital |
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ThAT13 Oral Session, Dunn Room |
Add to My Program |
Implantable Sensors I |
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Chair: Seo, Min-Woong | Shizuoka Univ |
Co-Chair: Song, Dong | Univ. of Southern California |
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08:00-08:15, Paper ThAT13.1 | Add to My Program |
Chronic Multi-Region Recordings from the Rat Hippocampus in Vivo with a Flexible Parylene-Based Multi-Electrode Array |
Xu, Huijing | Univ. of Southern California |
Meng, Ellis | Univ. of Southern California |
Berger, Theodore | Univ. of Southern California |
Song, Dong | Univ. of Southern California |
Keywords: Implantable sensors - Biocompatibility, Implantable prosthetic devices
Abstract: Neural activities of free-moving animals provide valuable insights into behavior, memory formation and cognitive function of the hippocampus. Unitary activities simultaneously recorded from multiple sub-regions of the hippocampus enable detailed study of hippocampal neural circuits, but require high fidelity recordings with high temporal and spatial resolution. In this work, we explored the possibility of using Parylene-C as the structural material for a penetrating, multi-electrode array designed to record from multiple sub-region of the rat hippocampus. A 64-channel Parylene-based flexible electrode array was designed and fabricated. The layout of the electrode array was arranged to conform to the shape of cell body layers of the rat hippocampus. An insertion technique of temporarily reduce the effective length of the probe with polyethylene glycol (PEG) was developed and tested in vivo. The multi-electrode array was implanted into a rat hippocampus for chronic experimentation and unitary activities were collected both during the implantation and after recovery while the animal ran freely in an open field. Unitary activities with an average signal to noise ratios (SNR) of 3 to 4 were recorded with the Parylene probe over the period of one month after implantation.
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08:15-08:30, Paper ThAT13.2 | Add to My Program |
Development and Characterization of a Fully Flexible Stimulation System Based on Embedded Liquid Metal Channels |
DAVID, Romain | Keio Univ |
Miki, Norihisa | Univ |
Keywords: Implantable systems
Abstract: Neuronal stimulation systems design is highly impacted by the overall resolution and adaptability of the device to the targeted application and area to stimulate. In this study, we propose a novel design for neural micro-stimulation electrode presenting high resolution and adaptability to any targeted area via a high flexibility. We introduce the use of liquid metal micro-channels encapsulated into a polymer volume, achieving micro-stimulation pads at the tip of the channels. It presents a high degree of patternability to match different possible applications, as well as flexibility and interesting mechanic properties to make it insertable and adaptable in soft tissues. The design, fabrication process, and study of the electrical and mechanical behavior and stability of the device are discussed. Conductive U-shaped micro-channels down to a total diameter of 110 μm could be produced.
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08:30-08:45, Paper ThAT13.3 | Add to My Program |
Using Impedance to Track Fracture Healing Rates in Mice in Vivo: A Pilot Study |
Lin, Monica | UC Berkeley / UC San Francisco |
Hu, Diane | Univ. of California - San Francisco |
Yang, Frank | Univ. of California - San Francisco |
Herfat, Safa | Univ. of California, San Francisco |
Bahney, Chelsea | Univ. of California, San Francisco |
Marmor, Meir | Univ. of California, San Francisco |
Maharbiz, Michel | Univ. of California, Berkeley |
Keywords: Implantable sensors, Physiological monitoring - Instrumentation, Implantable technologies
Abstract: Fracture injuries are highly prevalent worldwide, with treatment of problematic fractures causing a significant burden on the U.S. healthcare system. Physicians typically monitor fracture healing by conducting physical examinations and taking radiographic images. However, nonunions currently take over 6 months to be diagnosed because these techniques are not sensitive enough to adequately assess fracture union. In this study, we display the utility of impedance spectroscopy to track different healing rates in a pilot study of an in vivo mouse tibia fracture model. We have developed small (56 µm) sensors and implanted them in an externally-stabilized fracture for twice-weekly measurement. We found that impedance magnitude increases steadily over time in healing mice but stalls in non-healing mice, and phase angle displays frequency-dependent behavior that also reflects the extent of healing at the fracture site. Our results demonstrate that impedance can track differences in healing rates early on, highlighting the potential of this technique as a method for early detection of fracture nonunion.
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08:45-09:00, Paper ThAT13.4 | Add to My Program |
Effect of Temperature Variation on Remote Pressure Readout in Wirelessly Powered Intracranial Pressure Monitoring System |
Khan, Muhammad Waqas Ahmad | Tampere Univ. of Tech |
Rizwan, Muhammad | Tampere Univ. of Tech. Finland |
Sydänheimo, Lauri | Tampere Univ. of Tech |
Ratmat-Samii, Yahya | Univ. of California, Los Angeles |
Ukkonen, Leena | Tampere Univ. of Tech |
Bjorninen, Toni | Tampere Univ. of Tech |
Keywords: Implantable sensors, Physiological monitoring - Modeling and analysis, Physiological monitoring - Instrumentation
Abstract: An implantable pressure monitoring system is a compelling approach to home monitoring of intracranial pressure in the long term. In our approach, an on-body unit powers a cranially concealed system where a piezoresistive element senses the pressure. A data transmission unit built in the same platform emits a signal at a pressure dependent frequency through a miniature far field antenna. In this work, we focus on assessing the impact of variable temperature on the pressure readout at an off-body unit through in-vitro experiments.
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09:00-09:15, Paper ThAT13.5 | Add to My Program |
Implantable Bladder Volume Sensor Based on Resistor Ladder Network Composed of Conductive Hydrogel Composite |
Kim, Mi Kyung | Korea Advanced Inst. of Science and Tech. (KAIST) |
Kim, Hyojung | Korea Advanced Inst. of Science and Tech |
Jung, Yeon Su | KAIST |
AlAdem, Kenana | Khalifa Univ |
BAWAZIR, SARAH | Khalifa Univ |
Stefanini, Cesare | Scuola Superiore Sant'Anna |
Lee, Hyunjoo Jenny | Korea Advanced Inst. of Science and Tech. (KAIST) |
Keywords: Implantable sensors, Physiological monitoring - Novel methods, Physical sensors and sensor systems - New sensing techniques
Abstract: An accurate bladder volume monitoring system is a critical component in diagnosis and treatment of urological disorders. Here, we report an implantable bladder volume sensor with a multi-level resistor ladder which estimates the bladder volume through discrete resistance values. Discretization allows the sensor output to be resilient to the long-term drift, hysteresis, and degradation of the sensor materials. Our sensor is composed of biocompatible polypyrrole/agarose hydrogel composite. Because Young’s modulus of this composite is comparable to that of the bladder wall, the effect of mechanical loading of the sensor on the bladder movement is minimized which allows more accurate volume monitoring. We also demonstrate the patterning and molding capability of this material by fabrication various structures. Lastly, we successfully demonstrate the functionality of the multi-level resistor ladder sensor as a bladder volume sensor by attaching the sensor on the pig’s bladder and observing the impedance change of the sensor.
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09:15-09:30, Paper ThAT13.6 | Add to My Program |
Integrating Coupled Magnetoelastic Sensors Onto a Flexible Hernia Mesh for High Dynamic Range Strain Measurements |
Liao, Amy | UC Berkeley |
Harris, Hobart | UCSF |
Maharbiz, Michel | Univ. of California, Berkeley |
Keywords: Implantable sensors, Physical sensors and sensor systems - Mechanical sensors and systems, Physical sensors and sensor systems - Magnetic sensors and systems
Abstract: Despite better performance over primary repairs, tension-free ventral hernia repairs with mesh still suffer from a high recurrence rate. High stress gradients in the mesh are thought to contribute to hernia recurrence. We propose a postoperative monitoring system based on a coupled pair of magnetoelastic strain sensors to enable patients and physicians to non-invasively measure and track the strain distribution across the hernia mesh. Our design combines an encased resonator with a spring-loaded transducer to achieve high signal amplitude with a wide dynamic range. We also demonstrate a fabrication protocol to integrate the resonant strain sensors with a commercial polypropylene mesh. The packaged sensor is capable of detecting up to 37.5 millistrain, an order of magnitude greater than previously demonstrated.
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ThAT14 Oral Session, Schaldach Room |
Add to My Program |
Machine Learning in Imaging I |
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Chair: Ye, Jong Chul | Korea Advanced Inst. of Science & Tech |
Co-Chair: Haider, Clifton | Mayo Clinic |
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08:00-08:15, Paper ThAT14.1 | Add to My Program |
Abnormality Detection of Mammograms by Discriminative Dictionary Learning on DSIFT Descriptors |
Tavakoli, Nasrin | Isfahan Univ. of Tech |
Karimi, Maryam | Isfahan Univ. of Tech |
Nejati, Mansour | Isfahan Univ. of Tech |
Karimi, Nader | Isfahan Univ. of Tech |
Soroushmehr, S.M.Reza | Univ. of Michigan, Ann Arbor |
Samavi, Shadrokh | McMaster Univ |
Najarian, Kayvan | Univ. of Michigan - Ann Arbor |
Keywords: Image segmentation
Abstract: Detection and classification of breast lesions using mammographic images are one of the most difficult studies in medical image processing. A number of learning and non-learning methods have been proposed for detecting and classifying these lesions. However, the accuracy of the detection/classification still needs improvement. In this paper we propose a powerful classification method based on sparse learning to diagnose breast cancer in mammograms. For this purpose, a supervised discriminative dictionary learning approach is applied on dense scale invariant feature transform (DSIFT) features. A linear classifier is also simultaneously learned with the dictionary which can effectively classify the sparse representations. Our experimental results show the superior performance of our method compared to existing approaches.
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08:15-08:30, Paper ThAT14.2 | Add to My Program |
Exudate Detection for Diabetic Retinopathy with Convolutional Neural Networks |
Yu, Shuang | Commonwealth Scientific and Industrial Res. Organization |
Xiao, Di | Commonwealth Scientific and Industrial Res. Organization |
Kanagasingam, Yogi | The Australian Ehealth Res. Centre, Perth, CSIRO |
Keywords: Retinal imaging, Image feature extraction, Image segmentation
Abstract: Exudate detection is an essential task for computer-aid diagnosis of diabetic retinopathy (DR), so as to monitor the progress of DR. In this paper, deep convolutional neural network (CNN) is adopted to achieve pixel-wise exudate identification. The CNN model is first trained with expert labeled exudates image patches and then saved as off-line classifier. In order to achieve pixel-level accuracy meanwhile reduce computational time, potential exudate candidate points are first extracted with morphological ultimate opening algorithm. Then the local region (64 64) surrounding the candidate points are forwarded to the trained CNN model for classification / identification. A pixel-wise accuracy of 91.92%, sensitivity of 88.85% and specificity of 96% is achieved with the proposed CNN architecture on the test database.
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08:30-08:45, Paper ThAT14.3 | Add to My Program |
CEUS-Based Classification of Liver Tumors with Deep Canonical Correlation Analysis and Multi-Kernel Learning |
Lehang, Guo | Shanghai Tenth People’s Hospital |
Dan, Wang | Shanghai Tenth People’s Hospital |
Huixiong, Xu | Shanghai Tenth People’s Hospital |
Yiyi, Qian | Shanghai Univ |
Chaofeng, Wang | Shanghai Univ |
Zheng, Xiao | Shanghai Univ |
Zhang, Qi | Shanghai Univ |
Shi, Jun | Shanghai Univ |
Keywords: Image feature extraction, Image classification
Abstract: The contrast-enhanced ultrasound (CEUS) has been a widely accepted imaging modality for diagnosis of liver cancers. In clinical practice, several typical images selected from enhancement patterns of the arterial, portal venous and late phases can provide reliable information basis for diagnosis. In this work, we propose to develop a CEUS-based computer-aided diagnosis (CAD) for liver cancers with only three typical CEUS images selected from three phases, which simulates the clinical diagnosis mode of radiologists. In the proposed CAD, the deep canonical correlation analysis (DCCA) is first performed on three CEUS pairs between arterial and portal venous phases, arterial and late phases, respectively, due to the effectiveness of multi-view fusion of DCCA. The generated six-view features are then fed to a multiple kernel learning (MKL) classifier to further promote the predictive diagnosis result. The experimental results indicate that the proposed DCCA-MKL algorithm achieves best performance for discriminating benign liver tumors from malignant liver cancers.
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08:45-09:00, Paper ThAT14.4 | Add to My Program |
A Multi-View Deep Convolutional Neural Networks for Lung Nodule Segmentation |
Wang, Shuo | Chinese Acad. of Sciences |
Mu, Zhou | Stanford Univ |
Gevaert, Olivier | The Stanford Center for Biomedical Informatics Res. Stanfor |
Tang, Zhenchao | Shandong Univ. Weihai |
Dong, Di | Chinese Acad. of Sciences |
Liu, Zhenyu | Inst. of Automation, Chinese Acad. of Sciences |
Tian, Jie | Chinese Acad. of Sciences |
Keywords: X-ray CT imaging, X-ray imaging applications
Abstract: We present a multi-view convolutional neural networks (MV-CNN) for lung nodule segmentation. The MV-CNN specialized in capturing a diverse set of nodule-sensitive features from axial, coronal and sagittal views in CT images simultaneously. The proposed network architecture consists of three CNN branches, where each branch includes seven stacked layers and takes multi-scale nodule patches as input. The three CNN branches are then integrated with a fully connected layer to predict whether the patch center voxel belongs to the nodule. The proposed method has been evaluated on 893 nodules from the public LIDC-IDRI dataset, where ground-truth annotations and CT imaging data were provided. We showed that MV-CNN demonstrated encouraging performance for segmenting various type of nodules including juxta-pleural, cavitary, and non-solid nodules, achieving an average dice similarity coefficient (DSC) of 77.67% and average surface distance (ASD) of 0.24, outperforming conventional image segmentation approaches.
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09:00-09:15, Paper ThAT14.5 | Add to My Program |
Surgical-Tools Detection Based on Convolutional Neural Network in Laparoscopic Robot-Assisted Surgery |
Choi, Bareum | Asan Inst. for Life Sciences, Asan Medical Center |
Jo, Kyungmin | Asan Inst. for Life Sciences, Asan Medical Center |
Choi, Songe | Asan Inst. for Life Sciences, Asan Medical Center |
Choi, Jaesoon | Asan Inst. for Life Sciences, Asan Medical Center |
Keywords: Image classification
Abstract: Laparoscopic surgery, a type of minimally invasive surgery, is used in a variety of clinical surgeries because it has a faster recovery rate and causes less pain. However, in general, the robotic system used in laparoscopic surgery can cause damage to the surgical instruments, organs, or tissues during surgery due to a narrow field of view and operating space, and insufficient tactile feedback. This study proposes real-time models for the detection of surgical instruments during laparoscopic surgery by using a CNN(Convolutional Neural Network). A dataset included information of the 7 surgical tools is used for learning CNN. To track surgical instruments in real time, unified architecture of YOLO apply to the models. So as to evaluate performance of the suggested models, degree of recall and precision is calculated and compared. Finally, we achieve 72.26% mean average precision over our dataset.
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09:15-09:30, Paper ThAT14.6 | Add to My Program |
Deep Learning-Based Diabetic Retinopathy Assessment on Embedded System |
Ardiyanto, Igi | Univ. Gadjah Mada |
Adi Nugroho, Hanung | Univ. Gadjah Mada |
Buana, Ratna Lestari Budiani | Univ. Gadjah Mada |
Keywords: Retinal imaging, Image classification, Functional image analysis
Abstract: Diabetic Retinopathy (DR) is a disease which affect the vision ability. The observation by an ophthalmologist usually conducted by analyzing the retinal images of the patient which are marked by some DR features. However some misdiagnosis are usually found due to human error. Here, a deep learning-based low-cost embedded system is established to assist the doctor for grading the severity of the DR from the retinal images. A compact deep learning algorithm named Deep-DR-Net which fits on a small embedded board is afterwards proposed for such purposes. In the heart of Deep-DR-Net, a cascaded encoder-classifier network is arranged using residual style for ensuring the small model size. The usage of different types of convolutional layers subsequently guarantees the features richness of the network for differentiating the grade of the DR. Experimental results show the capability of the proposed system for detecting the existence as well as grading the severity of the DR symptomps.
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ThAT15 Minisymposium, Webster Room |
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Bioengineering Advances in the Diagnosis and Treatment of Sleep Apnea I |
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Chair: Khoo, Michael | Univ. of Southern California |
Co-Chair: Penzel, Thomas | Charite Univ. Berlin |
Organizer: Khoo, Michael | Univ. of Southern California |
Organizer: Penzel, Thomas | Charite Univ. Berlin |
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08:00-08:15, Paper ThAT15.1 | Add to My Program |
Development of Methods for Sleep Disordered Breathing to Identify Phenotypes |
Penzel, Thomas | Charite Univ. Berlin |
Schoebel, Christoph | Charite Univ. Berlin |
Glos, Martin | Charite-Univ. Berlin |
Schwarz, Lisa | Charite - Univ. Berlin |
Prochnow, Lisa | Charite - Univ. Berlin |
Fietze, Ingo | Charite-Univ. Berlin |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Cardiovascular & Metabolic consequences of sleep disorders, Cardiovascular and respiratory system modeling - Sleep-cardiorespiratory Interactions
Abstract: Sleep disordered breathing a very common disorder with prevalence rates of up to 49% in large epidemiological studies on subjects older than 40 years. A recent study showed that applying CPAP treatment to patients with sleep disordered breathing recruited by their number of apnea and hypopnea events alone, does improve sleepiness but does not improve overall cardiovascular mortality. Based on older large studies however it is knownthat sleep disordered breathing is a cardiovascular risk and that treatment lowers mortality and morbidity. These results appear to be contradictory. However, they might be explained if patient population investigated are carefully reviewed further, and if sleep apnea severity metrics are reconsidered. According to this, it appears that studies speak of different populations. Whereas epidemiological studies use sampled subjects willing to participate, earlier studies used patients contacting a sleep center with complaints and symptoms. In this paper two studies are presented with an assessment of anatomical metrics for upper airway morphology in order to derive parameters for better prediction. Different phenotypes can explain why some people benefit from treatment and others do not benefit equally. Therefore more than just counting apnea and hypopnea events is needed in order to identify patients at risk and patients who have a lower risk when treated. This will require large data set evaluations with hard outcome data.
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08:15-08:30, Paper ThAT15.2 | Add to My Program |
ECG Detection and Risk-Stratification of Sleep Apnea by the Analysis of Cyclic Variation of Heart Rate (I) |
Hayano, Junichiro | Nagoya City Univ |
Watanabe, Eiichi | Fujita Health Univ |
Yoshida, Yutaka | Nagoya City Univ. Graduate School of Medical Sciences |
Yuda, Emi | Nagoya City Univ. Graduate School of Medical Sciences |
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08:30-08:45, Paper ThAT15.3 | Add to My Program |
Analyses of Breathing Pattern During Wakefulness As a Tool for Identifying OSA Phenotype and for Predicting the Success of Treatment (I) |
Yamauchi, Motoo | Nara Medical Univ |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Sleep apnea therapy, Cardiovascular and respiratory signal processing - Time-frequency, time-scale analysis of respiratory variability
Abstract: Continuous positive airway pressure (CPAP) has been widely recognized as a standard therapy for Obstructive sleep apnea (OSA) having favorable effects on consequences of OSA as well as mortality. However, one of the current issues in clinical practice is poor CPAP adherence. Considering that OSA phenotypes consist of physiological factors, individuality of respiratory control system may affect treatment success. Thus, we have hypothesized that assessment of breathing irregularity during wakefulness could identify OSA phenotype and predict CPAP adherence since breathing pattern might be a window to look at the respiratory control system. We found that irregular breathing during wakefulness in the diagnostic polysomnography (PSG) related to the one specific OSA phenotype which was mixed apnea-dominant OSAS, and also predicted poor CPAP adherence and acceptance. Our findings suggest that just looking at breathing pattern in the diagnostic PSG is a simple tool to be able to predict OSA phenotype and success of CPAP treatment.
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08:45-09:00, Paper ThAT15.4 | Add to My Program |
Dynamic Upper Airway MRI During Sleep Onset: An Experimental Study (I) |
Kim, Yoon-Chul | Samsung Medical Center, Sungkyunkwan Univ. School of Medici |
Khoo, Michael | Univ. of Southern California |
Nayak, Krishna | Univ. of Southern California |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Periodic breathing & central apnea, Sleep - Snoring
Abstract: We introduce a novel MRI-based acquisition technology that has made it successful to obtain the airway dynamics and physiological signals simultaneously during sleep onset. The MRI technology exploits a state-of-the-art k-space trajectory design and compressed sensing reconstruction. It enables the assessment of airway collapse location and airway volume dynamics during sleep disordered breathing.
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ThAT17 Oral Session, Einthoven Hall |
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Signal Processing - Wearable Devices |
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Chair: Shi, Bertram E | Hong Kong Univ. of Science and Tech |
Co-Chair: Barbieri, Riccardo | Pol. Di Milano |
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08:00-08:15, Paper ThAT17.1 | Add to My Program |
Remote Gaze Tracking System for 3D Environments |
LIU, Congcong | Hong Kong Univ. of Science and Tech |
HERRUP, Karl | Hong Kong Univ. of Science and Tech |
Shi, Bertram E | Hong Kong Univ. of Science and Tech |
Keywords: Physiological systems modeling - Signal processing in physiological systems, Data mining and processing in biosignals
Abstract: Eye tracking systems are typically divided into two categories: remote and mobile. Remote systems, where the eye tracker is located near the object being viewed by the subject have the advantage of being less intrusive, but are typically used for tracking gaze points on fixed two dimensional (2D) computer screens. Mobile systems such as eye tracking glasses, where the eye tracker are attached to the subject, are more intrusive, but are better suited for cases where subjects are viewing objects in the three dimensional (3D) environment. The subject’s gaze points are indicated as 2D points on images from a scene camera also attached to the subject. In this paper, we describe how remote gaze tracking systems developed for 2D computer screens can be used to track gaze points in a 3D environment. The system is non-intrusive. It compensates for small head movements by the user, so that the head need not be stabilized by a chin rest or bite bar. The system maps the 3D gaze points of the user onto 2D images also located remotely from the subject. Our measurement results from this system indicate that it is able to estimate gaze points in the scene camera to within one degree over a wide range of head positions.
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08:15-08:30, Paper ThAT17.2 | Add to My Program |
Estimation of Blood Pressure from Non-Invasive Data |
Shukla, Satya Narayan | Univ. of Massachusetts Amherst |
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08:30-08:45, Paper ThAT17.3 | Add to My Program |
Assessment of Instantaneous Cardiovascular Dynamics from Video Plethysmography |
Valenza, Gaetano | Univ. of Pisa |
Iozzia, Luca | Pol. of Milan |
Cerina, Luca | Pol. of Milan |
Mainardi, Luca | Pol. Di Milano |
Barbieri, Riccardo | Pol. Di Milano |
Keywords: Nonlinear dynamic analysis - Volterra-Wiener models in physiological systems, Signal pattern classification, Physiological systems modeling - Signal processing in physiological systems
Abstract: Although there is growing interest in estimating cardiovascular information using contactless video plethysmog- raphy (VP), an in-depth validation of time-varying, nonlinear dynamics of the related pulse rate variability is still missing. In this study we estimate the heartbeat through VP and standard ECG, and employ inhomogeneous point-process nonlinear models to assess instantaneous heart rate variability measures defined in the time, frequency, and bispectral domains. Exper- imental data were gathered from 60 young healthy subjects (age: 24±3 years) undergoing postural changes (rest-to-stand maneuver). Video recordings are processed using our recently proposed method based on zero-phase component analysis. Results show that, at a group level, there is an overall agreement between linear and nonlinear indices computed from ECG and VP during resting state conditions. However, significant differences are found, especially in the bispectral do- main, when considering data gathered while standing. Although significant differences exist between cardiovascular estimates from VP and ECG, results can be considered very promising as instantaneous sympatho-vagal changes were correctly identified. More research is indeed needed to improve on the precise estimation of nonlinear sympatho-vagal interactions.
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08:45-09:00, Paper ThAT17.4 | Add to My Program |
Towards VO2 Monitoring: Validation of a Heart Rate Based Algorithm |
Manzoni, Cecilia | EPFL |
Carrard, Apolline | VO2Sport |
Fontana, Elisa | VO2Sport |
Lemay, Mathieu | CSEM |
Bertschi, Mattia | CSEM |
Delgado-Gonzalo, Ricard | CSEM |
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09:00-09:15, Paper ThAT17.5 | Add to My Program |
A Portable Platform to Collect and Review Behavioral Data Simultaneously with Neurophysiological Signals |
Jiang, Tianxiao | Univ. of Houston |
Siddiqui, Hasan | Univ. of Houston |
Ray, Shruti | Univ. of Houston |
Ince, Nuri Firat | Univ. of Houston |
Ozturk, Musa | Univ. of Houston |
Asman, Priscella | Univ. of Houston |
Keywords: Time-frequency and time-scale analysis - Empirical mode decomposition in biosignal analysis
Abstract: This paper presents a portable platform to collect and review behavioral data simultaneously with neurophysiological signals. The whole system is comprised of four parts: a sensor data acquisition interface, a socket server for real-time data streaming, a Simulink system for real-time processing and an offline data review and analysis toolbox. A low-cost microcontroller is used to acquire data from external sensors such as accelerometer and hand dynamometer. The microcontroller transfers the data either directly through USB or wirelessly through a bluetooth module to a data server written in C++ for MS Windows OS. The data server also interfaces with the digital glove and captures HD video from webcam. The acquired sensor data are streamed under User Datagram Protocol (UDP) to other applications such as Simulink/Matlab for real-time analysis and recording. Neurophysiological signals such as electroencephalography (EEG), electrocorticography (ECoG) and local field potential (LFP) recordings can be collected simultaneously in Simulink and fused with behavioral data. In addition, we developed a customized Matlab Graphical User Interface (GUI) software to review, annotate and analyze the data offline. The software provides a fast, user-friendly data visualization environment with synchronized video playback feature. The software is also capable of reviewing long-term neural recordings. Other featured functions such as fast preprocessing with multithreaded filters, annotation, montage selection, power-spectral density (PSD) estimate, time-frequency map and spatial spectral map are also implemented.
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09:15-09:30, Paper ThAT17.6 | Add to My Program |
A Simple, Remote, Video Based Breathing Monitor |
Regev, Nir | Ben-Gurion Univ. of the Negev |
Wulich, Dov | Ben-Gurion Univ. of the Negev |
Keywords: Physiological systems modeling - Signal processing in physiological systems, Nonlinear dynamic analysis - Biomedical signals, Nonlinear dynamic analysis - Nonlinear filtering
Abstract: Breathing monitors have become the all-important cornerstone of a wide variety of commercial and personal safety applications, ranging from elderly care to baby monitoring. Many such monitors exist in the market, some, with vital signs monitoring capabilities, but none remote. This paper presents a simple, yet efficient, real time method of extracting the subject's breathing sinus rhythm. Points of interest are detected on the subject's body, and the corresponding optical flow is estimated and tracked using the well known Lucas-Kanade algorithm on a frame by frame basis. A generalized likelihood ratio test is then utilized on each of the many interest points to detect which is moving in harmonic fashion. Finally, a spectral estimation algorithm based on Pisarenko harmonic decomposition tracks the harmonic frequency in real time, and a fusion maximum likelihood algorithm optimally estimates the breathing rate using all points considered. The results show a maximal error of 1 BPM between the true breathing rate and the algorithm's calculated rate, based on experiments on two babies and three adults.
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ThAT18 Oral Session, Montgomery Hall |
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Principal and Independent Component Analysis I |
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Chair: Chai, Rifai | Univ. of Tech. Sydney |
Co-Chair: Minhas, Atul Singh | Univ. of Liverpool |
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08:00-08:15, Paper ThAT18.1 | Add to My Program |
On the Use of Higher-Order Tensors to Model Muscle Synergies |
Ebied, Ahmed | Univ. of Edinburgh |
Spyrou, Loukianos | Univ. of Edinburgh |
Kinney-Lang, Eli | Univ. of Edinburgh |
Escudero, Javier | Univ. of Edinburgh |
Keywords: Principal and independent component analysis - Blind source separation, Signal pattern classification, Time-frequency and time-scale analysis - Wavelets
Abstract: The muscle synergy concept provides the best framework to understand motor control and it has been recently utilised in many applications such as prosthesis control. The current muscle synergy model relies on decomposing multi-channel surface Electromyography (EMG) signals into a synergy matrix (spatial mode) and its weighting function (temporal mode). This is done using several matrix factorisation techniques, with Non-negative matrix factorisation (NMF) being the most prominent method. Here, we introduce a 4 th-order tensor muscle synergy model that extends the current state of the art by taking spectral information and repetitions (movements) into account. This adds more depth to the model and provides more synergistic information. In particular, we illustrate a proof-of-concept study where the Tucker3 tensor decomposition model was applied to a subset of wrist movements from the Ninapro database. The results showed the potential of Tucker3 tensor factorisation in finding patterns of muscle synergies with information about the movements and highlights the differences between the current and proposed model.
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08:15-08:30, Paper ThAT18.2 | Add to My Program |
Exploring Optimal Myoelectric Feature Indices for Forearm Control Strategy Using Robust Principal Component Analysis |
Kanoga, Suguru | National Inst. of Advanced Industrial Science and Tech |
Murai, Akihiko | National Inst. of Advanced Industrial Science and Tech |
Tada, Mitsunori | National Inst. of Advanced Industrial Science and Tech |
Keywords: Principal component analysis, Data mining and processing - Pattern recognition, Signal pattern classification
Abstract: Forearm movements realize various functions needed in daily life. For reproduction of the motion sequences, active myoelectric devices have been developed. Usually, feature indices are extracted from observed signals in control strategy; however, the optimal combination of indices is still unclear. This paper introduces sparsity-inducing penalty term in principal component analysis (PCA) to explore optimal myoelectric feature indices. An electromyographic database including seven forearm movements from 30 subjects was used for performance comparison. Linear classifier with sparse features showed best performance (7.86±3.82% error rate) that was significantly better than linear classifier with all features because of recovering low rank matrix in original data. Furthermore, the sparse features had a large contribution of underlying data structure with less number of principal components than PCA. Root-mean-square, time-domain features, autoregressive coefficients, and Histogram purported to be important in projected feature space; therefore, the feature indices are important to myoelectric strategies.
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08:30-08:45, Paper ThAT18.3 | Add to My Program |
Coupling Scatter Correction with Bandpass Filtering for Pre-Processing in the Quantitative Analysis of Glucose from Near-Infrared Spectra |
Alrezj, Osamah | Sheffield Univ |
Patchava, Krishna Chaitanya | The Univ. of Sheffield |
Benaissa, Mohammed | The Univ. of Sheffield |
Alshebeili, Saleh | KSU |
Keywords: Principal component analysis
Abstract: This paper proposes a novel pre-processing method based on combining bandpass filtering with scatter correction techniques Multiplicative Scatter Correction (MSC) and Standard Normal Variate (SNV) to enhance the prediction capability of the linear regression models Partial Least Squares Regression (PLSR) and Principal Component Regression (PCR) in near infrared (NIR) spectroscopy. The method is implemented into a calibration model, evaluated and then validated for the prediction of the glucose concentration from NIR spectra of an aqueous mixture of human serum albumin and glucose in a solution of distilled water and phosphate buffer. The results obtained demonstrate improved prediction performance for both PCR and PLSR. Compared to the efficient feature weighting pre-processing (RRelief), the proposed method is shown to yield better prediction reducing the Root Mean Square Error Prediction RMSEP.
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08:45-09:00, Paper ThAT18.4 | Add to My Program |
Modified Thresholding Technique of MMSPCA for Extracting Respiratory Activity from Short Length PPG Signal |
Motin, Mohammod Abdul | PhD Student, Univ. of Melbourne |
Karmakar, Chandan | Deakin Univ |
Palaniswami, Marimuthu | The Univ. of Melbourne |
Keywords: Principal component analysis, Physiological systems modeling - Signal processing in physiological systems
Abstract: In this paper, we propose an automatic threshold selection of modified multi scale principal component analysis (MMSPCA) for reliable extraction of respiratory activity (RA) from short length photoplethysmographic (PPG) signals. MMSPCA was applied to the PPG signal with a varying data length, from 30 seconds to 60 seconds, to extract the respiratory activity. To examine the performance, we used 100 epochs of simultaneously recorded PPG and respiratory signals extracted from the MIMIC database (Physionet ATM data bank). The respiratory signal used as the ground truth and several performance measurement metrics such as magnitude squared coherence (MSC), correlation coefficients (CC), and normalized root mean square error (NRMSE) were used to compare the performance of MMSPCA based PPG derived RA. At the data length of 30 seconds, MSC, CC and NRMSE for proposed thresholding were 0.65, 0.62 and -0.82 dB respectively where as they were 0.68, 0.47 and 0.25 dB respectively for existing thresholding. These results illustrated that the proposed threshold selection performs better than existing threshold selection for short length data.
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09:00-09:15, Paper ThAT18.5 | Add to My Program |
Channels Selection Using Independent Component Analysis and Scalp Map Projection for EEG-Based Driver Fatigue Classification |
Chai, Rifai | Univ. of Tech. Sydney |
Naik, Ganesh R | Univ. of Tech. Sydney |
Ling, Steve | Univ. of Tech. Sydney |
Tran, Yvonne | Univ. of Tech. Sydney |
Craig, Ashley | The Univ. of Sydney |
Nguyen, Hung T. | Univ. of Tech. Sydney |
Keywords: Independent component analysis, Signal pattern classification, Physiological systems modeling - Signal processing in physiological systems
Abstract: This paper presents a classification of driver fatigue with electroencephalography (EEG) channels selection analysis. The system employs independent component analysis (ICA) with scalp map back projection to select the dominant of EEG channels. After channel selection, the features of the selected EEG channels were extracted based on power spectral density (PSD), and then classified using a Bayesian neural network. The results of the ICA decomposition with the backprojected scalp map and a threshold showed that the EEG channels can be reduced from 32 channels into 16 dominants channels involved in fatigue assessment as chosen channels, which included AF3, F3, FC1, FC5, T7, CP5, P3, O1, P4, P8, CP6, T8, FC2, F8, AF4, FP2. The result of fatigue vs. alert classification of the selected 16 channels yielded a sensitivity of 76.8%, specificity of 74.3% and an accuracy of 75.5%. Also, the classification results of the selected 16 channels are comparable to those using the original 32 channels. So, the selected 16 channels is preferable for ergonomics improvement of EEG-based fatigue classification system.
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09:15-09:30, Paper ThAT18.6 | Add to My Program |
Motion Artifact Reduction in PPG Signals Based on Periodic Component Factorization |
Lo, Po Wen | The Chinese Univ. of Hong Kong |
Li, Charles X.-T. | The Chinese Univ. of Hong Kong |
Wang, Jiankun | The Chinese Univ. of Hong Kong |
Meng, Max Q.-H. | The Chinese Univ. of Hong Kong |
Keywords: Principal and independent component analysis - Blind source separation, Independent component analysis, Principal component analysis
Abstract: Continuous blood pressure measurement based on pulse transit time (PTT) is a deeply research topic over recent decades. Advanced algorithms have been proposed by scholars to give satisfactory estimation in stationary position. Nevertheless, pulse transit time (PTT) is shown to be strongly affected by hand movement and the estimation of blood pressure is no longer accurate under strenuous exercise. Because of this, a novel algorithm called Periodic Component Factorization (PCF), which is an extension of Independent Component Analysis (ICA), for better removal of motion artifact (MA) from photoplethysmography (PPG) signals is proposed in this paper. Compared to FastICA algorithm based on nongaussianity such as kurtosis and skewness, PCF is able to extract dependent source components from noisy signals when the PPG signal shows quasi-periodicity or periodicity. This newly proposed algorithm undoubtedly shows its practicality and effectiveness in removing motion artifact of PPG signals.
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ThBT1 Minisymposium, Roentgen Hall |
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Neural Hyperscanning: Toward Multiple-Brain Models of Cognitive Functions |
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Chair: Astolfi, Laura | Univ. of Rome Sapienza |
Co-Chair: Ding, Mingzhou | Univ. of Florida |
Organizer: Astolfi, Laura | Univ. of Rome Sapienza |
Organizer: Ding, Mingzhou | Univ. of Florida |
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10:50-11:05, Paper ThBT1.1 | Add to My Program |
Quantifying Brain-To-Brain Synchrony with Total Interdependence (I) |
Wan, Lu | Univ. of Florida |
Ding, Mingzhou | Univ. of Florida |
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11:20-11:35, Paper ThBT1.3 | Add to My Program |
Linear & Nonlinear Hyperlink Analysis Based on Subspace Decomposition and MIC for Two-Person Neuroscience Study (I) |
Zhang, zong | Beijing Normal Univ. Key Lab. of Cognitive Neuroscie |
Zhao, Yang | Beijing Normal Univ. Key Lab. of Cognitive Neuroscie |
Dai, Ruina | Key Lab. of Cognitive Neuroscience and Learning, Beijing No |
Duan, Lian | Key Lab. of Cognitive Neuroscience and Learning, Beijing No |
Li, Zheng | Beijing Normal Univ |
Zhu, Chaozhe | Key Lab. of Cognitive Neuroscience and Learning, Beijing No |
Long, Zhiying | Beijing Normal Univ |
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11:50-12:05, Paper ThBT1.5 | Add to My Program |
Hyperscanning: A New Approach to the Study of the Physiological Basis of Human Social Interaction (I) |
Astolfi, Laura | Univ. of Rome Sapienza |
Keywords: Connectivity measurements, Causality, Directionality
Abstract: Hyperscanning, or multiple-subject recording, enables the simultaneous collection of brain activity in different subjects during a social exchange. The group of interacting subjects is thus modeled as a complex system, in which the internal structure of each subject’s brain activation is studied together with the relation arising between the different parts of the system, i.e. the different subjects’ brains. Such multiple-subject modeling has opened a new avenue in social cognitive neuroscience, with an impact both on physiological as well as on pathological conditions, but at the same time it has raised methodological and modeling challenges which are among the most interesting opportunities in neuroscience methods development. In this paper, the theoretical framework justifying the need for simultaneous recording and multivariate modeling of multiple subjects data will be discussed, together with some examples of multi-subject models related to collaboration, joint action and empathic pro-social behavior, obtained by high density EEG and source reconstruction techniques.
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ThBT2 Minisymposium, Cho Room |
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Radiation Induced Acoustic Imaging |
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Chair: Min, Jung-Joon | Chonnam National Univ. Medical School |
Co-Chair: Lee, Changho | Chonnam National Univ. Medical School |
Organizer: Min, Jung-Joon | Chonnam National Univ. Medical School |
Organizer: Lee, Changho | Chonnam National Univ. Medical School |
Organizer: Kim, Chulhong | Pohang Univ. of Science and Tech |
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10:50-11:05, Paper ThBT2.1 | Add to My Program |
Theranostic with Radiation-Induced Ultrasound Emission (TRUE) (I) |
Xiang, Liangzhong | Univ. of Oklahoma |
Keywords: X-ray CT imaging, Ultrasound imaging - Breast, Optical imaging and microscopy - Microscopy
Abstract: To break through the photoacoustic imaging depth limit, we use an x-ray excitation source as opposed to visible light, therefore developing a novel imaging modality, called x-ray acoustic tomography (XACT). To break through the photoacoustic imaging resolution limit (~220 nm), we are developing a super-resolution photoacoustic tomography to push the imaging resolution down to 20 nanometers. We expect these new imaging techniques to find widespread applications in both fundamental and applied sciences including biomedical research.
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11:05-11:20, Paper ThBT2.2 | Add to My Program |
Targeted Molecular Theranostics Using Engineered Microbes (I) |
Min, Jung-Joon | Chonnam National Univ. Medical School |
Keywords: PET and SPECT imaging, Multimodal molecular imaging
Abstract: We report a method of cancer theranostics using an attenuated Salmonella typhimurium strain engineered to produce cancer therapeutics as well as generate imaging signals. in tumor tissues. Engineered bacteria effectively suppress tumor growth and metastasis in mouse models and prolong survival. The engineered bacteria can be imaged by optical imaging, positron emission tomography and optoacoustic tomography.
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11:20-11:35, Paper ThBT2.3 | Add to My Program |
Photoacoustic Imaging with Biodegradable Agents (I) |
Lee, Changho | Chonnam National Univ. Medical School |
Kim, Chulhong | Pohang Univ. of Science and Tech |
Keywords: Optical imaging, Optical molecular imaging
Abstract: Multifunctional nanomaterials are widely used for molecular biomedical imaging, therapy, and drug delivery applications. In particular, photoactive nanomaterials have worked as contrast and therapeutic agents based on their heat generation ability after laser irradiation. Various formulations including metals, carbon, and organic nanoparticles are used as multifunctional preparations, but there are problems of photostability and biodegradability. In this study, we showed in vivo noninvasive photoacoustic imaging of lymph nodes & bladder and photothermal therapy in skin cancer tumor using N-doped carbon dots capable of biodegradation.
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ThBT3 Oral Session, Park Room |
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X-Ray and CT Imaging I |
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Chair: Kim, Hyung Joong | Kyung Hee Univ |
Co-Chair: Moratal, David | Univ. Pol. De València |
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10:50-11:05, Paper ThBT3.1 | Add to My Program |
Interactive Patient-Specific 3D Approximation of Scapula Bone Shape from 2D X-Ray Images Using Landmark-Constrained Statistical Shape Model Fitting |
Mutsvangwa, Tinashe Ernest Muzvidzwa | Univ. of Cape Town |
Wasswa, William | Mbarara Univ. of Tech |
Burdin, Valérie | Inst. Telecom/Telecom Bretagne - INSERM U650 |
Borotikar, Bhushan | Imt-Atlantique |
Douglas, Tania S | Univ. of Cape Town |
Keywords: X-ray CT imaging, Deformable image registration
Abstract: We report on an interactive tool for patient-specific 3D approximation of scapula bone shape from 2D X-ray images using landmark-constrained statistical shape model fitting. The 3D point localization of points on the 2D X-ray images was done through X-ray stereophotogrammetry. The inferior angle, acromion and the coracoid process were identified as reliable landmarks from the two different perspectives, anteroposterior (AP) and oblique lateral views in a landmark selection study of the 3D point localization. Approximation of a 3D scapula surface through fitting the scapula SSM to the 3D reconstructed coordinates of the selected landmarks was performed. The 3D point localization yielded average (X, Y, Z) coordinate reconstruction errors of (X=0.14, Y=0.07, Z=0.04) mm. The landmark-constrained fitting algorithm yielded an average error between the mean posterior model landmarks and the corresponding target landmarks of 0.49 mm using the three landmarks and later 0.19 mm with sixteen landmarks. Average surface to surface error between CT ground truth model and approximated model from within the dataset improved from 3.20 mm to 2.46 mm from using three landmarks to using sixteen landmarks, respectively. Average surface to surface error between CT ground truth model and approximated model from outside the dataset improved from 4.28 mm to 3.20 mm from using three landmarks to using sixteen landmarks, respectively. This showed that the SSM can be used to approximate a patient-specific 3D model from 2D images, with better predictions if the model is constrained using more landmarks.
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11:05-11:20, Paper ThBT3.2 | Add to My Program |
Arytenoid Cartilage Feature Point Detection Using Laryngeal 3D CT Images in Parkinson's Disease |
Desai, Nandakishor | Univ. of Melbourne |
Rao, Aravinda | The Univ. of Melbourne |
Palaniswami, Paari | Monash Univ |
Thyagarajan, Dominic | Monash Medical Centre |
Palaniswami, Marimuthu | The Univ. of Melbourne |
Keywords: X-ray CT imaging, Image segmentation, Image feature extraction
Abstract: Parkinson's disease is a neurodegenerative disorder that results in progressive degeneration of nerve cells. It is generally associated with the deficiency of dopamine, a neurotransmitter involved in motor control of humans and thus affects the motor system. This results in abnormal vocal fold movements in majority of the Parkinson's patients. Analysis of vocal fold abnormalities may provide useful information to assess the progress of Parkinson's disease. This is accomplished by measuring the distance between the arytenoid cartilages during phonation. In order to automate this process of identifying arytenoid cartilages from CT images, in this work, a rule-based approach is proposed to detect the arytenoid cartilage feature points on either side of the airway. The proposed technique detects feature points by localizing the anterior commissure and analyzing airway boundary pixels to select the optimal feature point based on detected pixels. The proposed approach achieved 83.33% accuracy in estimating clinically-relevant feature points, making the approach suitable for automated feature point detection. To the best of our knowledge, this is the first such approach to detect arytenoid cartilage feature points using laryngeal 3D CT images.
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11:20-11:35, Paper ThBT3.3 | Add to My Program |
Multiple Mucociliary Transit Marker Tracking in Synchrotron X-Ray Images Using the Global Nearest Neighbor Method |
JUNG, HYE-WON | UNISA |
Lee, Ivan | The Univ. of South Australia |
Lee, Sang-Heon | The Univ. of South Australia |
Parsons, David | Women's and Children's Hospital |
Donnelley, Martin | Univ. of Adelaide, Women's and Children's Hospital |
Keywords: X-ray imaging applications, Multivariate image analysis, Image visualization
Abstract: Recent research has enabled in-vivo examination of mucociliary transit in live airways by analysing the movement patterns of micron-sized markers in high resolution synchrotron X-ray images. However, high levels of false positives and false negatives severely impact the performance of many automated tracking algorithms. This paper proposes an improved approach to track valid mucociliary transit markers using a modified gating region and cost matrix. The proposed method offers a more effective way to associate markers with the correct trackers. Improved visualization methods are also introduced to assist the interpretation of the tracking results. The tracking method has achieved a tracking accuracy of 81.7% track purity and 71.3% track effectiveness.
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11:35-11:50, Paper ThBT3.4 | Add to My Program |
A One-Dimensional Fluid Simulation Method of the Narrow Vessel for the Real-Time Angiography Simulation |
Lee, Jongbeom | KAIST (Korea Advanced Inst. of Science and Tech |
Kim, Myeongjin | KAIST (Korea Advanced Inst. of Science and Tech |
Lee, Doo Yong | KAIST |
Keywords: X-ray - Interventional radiology
Abstract: This paper proposes a one-dimensional fluid simulation method for the real-time simulation of the contrast medium in the narrow blood vessel. The narrow vessel is modeled with the branches organized in the hierarchy. The density of the contrast medium on each branch is computed using the one-dimensional fluid model. The density at the end of branch is conveyed to the starting point of the following branch. A position of the density computation is determined to continuously convey the simulation results from the large vessel to the narrow vessel. The average computation time with the proposed method is 16.18 ms that is less than 21.25 ms of the particle-based method.
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11:50-12:05, Paper ThBT3.5 | Add to My Program |
The Use of Subject-Specific Finite Element Analysis of L1-L4 Vertebra to Screening Osteoporosis in Postmenopausal Women |
Alacreu, Elena | Center for Biomaterials and Tissue Engineering, Univ. Pol |
Arana, Estanislao | Radiology Department, Fundación Inst. Valenciano De Oncologí |
Moratal, David | Univ. Pol. De València |
Keywords: X-ray CT imaging, X-ray imaging applications
Abstract: The aim of this work is to study Computed Tomography (CT)-based Finite Element (FE) modelling of lumbar vertebra to classify osteoporotic patients using dualenergy x-ray absorptiometry (DXA) as reference. Cohort comprised 15 postmenopausal female patients with CT-DXA pairs. Sixty subject-specific CT-based FE models were constructed of L1 to L4 vertebrae. Load-displacement in each node of the models was analyzed. Mean kurtosis values of displacement distributions between osteoporosis and healthy groups at L1 level showed a statistically significant difference (p<0.005). The CT-based FE model of L1 vertebra with patient specific material properties can be used to identify osteoporosis patients.
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12:05-12:20, Paper ThBT3.6 | Add to My Program |
Environment Effects at Phantom-Based X-Ray Pose Measurements |
Thuerauf, Sabine | Fortiss GmbH An-Inst. Tech. Univ. München Mailing |
Koerner, Mario | Siemens Healthcare GmbH |
Vogt, Florian | Siemens Healthcare GmbH |
Hornung, Oliver | Siemens Healthcare GmbH |
nasseri, M. Ali | Tech. Univ. Muenchen |
Knoll, Alois | Tech. Univ. Munich |
Keywords: X-ray imaging applications, Multimodal image fusion, Image enhancement
Abstract: Image-based pose measurements relative to phantoms are used for various applications. Some examples are: tracking, registration or calibration. If highly precise measurements are needed, even changes of environment factors influence the measurements. This work evaluates how humidity and room temperature affect an image based pose measurements using a phantom. The pose measurement is used for the specific use case of an absolute accurate calibration of a C-arm X-ray system. However, the results are transferable to other applications, too. We describe the effects on different measurement parameters and experimentally evaluate the imprecisions caused by water absorption and thermal expansion of the phantom. The real world results show, that it is needed to monitor the environment effects if measurement precisions in the sub-millimeter scale are necessary.
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ThBT4 Oral Session, Min Room |
Add to My Program |
New Sensing Techniques II |
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Chair: Yoshimoto, Shusuke | Osaka Univ |
Co-Chair: OH, TONG IN | Kyunghee Univ |
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10:50-11:05, Paper ThBT4.1 | Add to My Program |
Development of an Intraluminal Intestinal Photoplethysmography Sensor |
Patel, Zaibaa | City, Univ. of London |
Thaha, Mohamed | The Royal London Hospital, Bart’s Health NHS Trust |
Kyriacou, Panayiotis | City Univ. London |
Keywords: Physiological monitoring - Novel methods, Integrated sensor systems, Physiological monitoring - Instrumentation
Abstract: Intestinal ischemia is a serious medical condition and can lead to life threatening sepsis. Currently, there are no reliable techniques available for directly monitoring intestinal viability for prolonged periods of time, and intraoperatively the majority of the surgeons still rely on subjective methods, such as visual inspection to assess viability of intestine. The development of an intraluminal optical sensor for monitoring intestinal viability is being proposed. The sensor will continuously monitor changes in blood volume and oxygen saturation. The developed reflectance photoplethysmography/pulse oximetry sensor comprises of two emitters (red and infrared) and a photodiode. A photoplethysmography processing and data acquisition system was also utilized. The prototype sensor was evaluated in a pilot study in the buccal mucosa of 12 healthy volunteers, given the locations similarity to the intestinal mucosa and its easy accessibility. Good quality photoplethysmography signals with high signal-to-noise ratio were acquired from the buccal mucosa in all the volunteers. Preliminary blood oxygen saturation values from the intraluminal sensor were in broad agreement with the standard finger pulse oximeter probes.
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11:05-11:20, Paper ThBT4.2 | Add to My Program |
Instrumentation, Electrode Choice and Challenges in Human Skin Memristor Measurement |
Pabst, Oliver | Univ. of Oslo |
Tronstad, Christian | Oslo Univ. Hospital |
Martinsen, Ørjan G | Univ. of Oslo |
Keywords: Physiological monitoring - Novel methods, Physiological monitoring - Instrumentation, Bio-electric sensors - Sensing methods
Abstract: Recording of the passive electrical properties of human skin is a well-established method in clinical applications and research. By applying a small constant voltage or current to the skin, its conductance can be determined without changing it. If a strong electrical signal is applied, the conductance can change. In fact, such nonlinear effects in skin can be observed and it has been shown that the skin acts like a memristor. These nonlinear properties of human skin are not studied systematically yet and hence represent a new field of research. This paper presents a measurement system that is suitable for doing human skin memristor measurements including hardware, electrode choice and aspects that have to be considered.
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11:20-11:35, Paper ThBT4.3 | Add to My Program |
Flexible Organic TFT Bio-Signal Amplifier Using Reliable Chip Component Assembly Process with Conductive Adhesive |
Yoshimoto, Shusuke | Osaka Univ |
Uemura, Takafumi | Osaka Univ |
Akiyama, Mihoko | Osaka Univ |
Ihara, Yoshihiro | Res. & Development Div. SHINKO ELECTRIC INDUSTRIES CO., |
Otake, Satoshi | Res. & Development Div. SHINKO ELECTRIC INDUSTRIES CO., |
Fujii, Tomoharu | Res. & Development Div. SHINKO ELECTRIC INDUSTRIES CO., |
Araki, Teppei | Osaka Univ |
Sekitani, Tsuyoshi | Osaka Univ |
Keywords: Wearable wireless sensors, motes and systems, Integrated sensor systems, Wearable sensor systems - User centered design and applications
Abstract: This paper presents a flexible organic thin-film transistor (OTFT) amplifier for bio-signal monitoring and presents the chip component assembly process. Using a conductive adhesive and a chip mounter, the chip components are mounted on a flexible film substrate, which has OTFT circuits. This study first investigates the assembly technique reliability for chip components on the flexible substrate. This study also specifically examines heart pulse wave monitoring conducted using the proposed flexible amplifier circuit and a flexible piezoelectric film. We connected the amplifier to a bluetooth device for a wearable device demonstration.
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11:35-11:50, Paper ThBT4.4 | Add to My Program |
Continuous Systolic and Diastolic Blood Pressure Estimation Utilizing Long Short-Term Memory Network |
Lo, Po Wen | The Chinese Univ. of Hong Kong |
Li, Charles X.-T. | The Chinese Univ. of Hong Kong |
Wang, Jiankun | The Chinese Univ. of Hong Kong |
Cheng, Jiyu | The Chinese Univ. of HongKong |
Meng, Max Q.-H. | The Chinese Univ. of Hong Kong |
Keywords: Physiological monitoring - Novel methods, Physiological monitoring - Modeling and analysis
Abstract: A novel blood pressure estimation method based on long short-term memory neural network, one of the recurrent neural networks being commonly used nowadays, is proposed in this paper for better chronic diseases monitoring. Along with the neural network, a newly proposed ambulatory blood pressure (ABP) processing technique called Two-stage Zero-order Holding (TZH) algorithm has also been presented in the paper. The proposed methodology has the advantages over traditional blood pressure estimation algorithms which are based on Pulse Transit time (PTT). The paper addresses the effectiveness of the algorithm by computing the Root-Mean-Squared Errors (RMSE) between the BP estimated and the ground truth. Our algorithm shows precise systolic blood pressure and diastolic blood pressure estimation with the average RMSE values in 2.751 mmHg and 1.604 mmHg respectively across the sample used. Experimental results suggest that BP estimation based on LSTM has great potential to be embedded into monitoring system for better accuracy and generalization.
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11:50-12:05, Paper ThBT4.5 | Add to My Program |
An in Vivo MEMS Sensor System for Percutaneous Measurement of Urinary Bladder |
Clausen, Ingelin | SINTEF Digital, Norway |
W Tvedt, Lars Geir | SINTEF ICT, Norway |
Hellandsvik, Are | SINTEF Digital |
Rognlien, Dag Kristian | SINTEF Digital |
Glott, Thomas | Sunnaas Rehabilitation Hospital |
Keywords: Physiological monitoring - Novel methods, Implantable sensors, Integrated wearable and portable systems
Abstract: An in vivo sensor system for direct measurement of pressure in the human urinary bladder is developed. The core component in the system is a small-sized and highly sensitive piezoresistive MEMS pressure sensor element integrated in a sensor catheter. The sensor catheter is wired to an external module for biasing, sampling, conversion and storage of sensor measurements. Our solution provides a target sensor placed directly into the urinary bladder and a reference sensor placed outside the bladder wall through a suprapubic and minimally invasive technique. Physiological recordings through natural filling and emptying cycles of the bladder are achievable. The case report from the first 17-hours investigation in a patient is presented in this paper. It reveals that the procedure was successful and no complications occurred. The patient expressed good experience during the participation. A functionality test shows that the percutaneous pressure sensor system responds immediately to external pressure stimuli.
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12:05-12:20, Paper ThBT4.6 | Add to My Program |
Performance Assessment of Dry Electrodes for Wearable Long Term Cardiac Rhythm Monitoring: Skin-Electrode Impedance Spectroscopy |
Bosnjak, Antonio | Univ. De Carabobo |
Kennedy, Alan | Intelesens |
Linares, Pedro | Univ. of Carabobo |
Borges, Maira | Univ. De Carabobo |
McLaughlin, James | Univ. of Ulster |
Escalona, Omar Jacinto | Univ. of Ulster |
Keywords: Physiological monitoring - Instrumentation, Bio-electric sensors - Sensor systems, Wearable body-compliant, flexible and printed electronics
Abstract: The use of wearable dry sensors for recording long term ECG signals is a requirement for certain studies of heart rhythm. Knowledge of the skin-electrode electrical performance of dry electrodes is necessary when seeking to improve various processing stages for signal quality enhancement. In this paper, methods for the assessment of dry skin-electrode impedance (Z SE) and its modelling are presented. Measurements were carried out on selected electrode materials such as silver, stainless steel, AgCl (dry) and polyurethane. These had Z SE values between 500 kΩ and 1 MΩ within the main ECG frequency range (1 Hz – 100 Hz); in contrast to plain iron material which had a significantly higher impedance. However, in spite of the high Z SE values, open bandwidth ECG traces were of acceptable quality and stability; with dry AgCl material offering the best ECG trace performance.
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ThBT5 Minisymposium, Lee Room |
Add to My Program |
Emerging Technologies for Cuffless Unobtrusive Blood Pressure Monitoring:
Celebration of 200th Birth Anniversary of Carl Ludwig |
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Chair: Carey, Carole C. | Former U.S. Food and Drug Administration |
Co-Chair: Ding, Xiao-Rong | The Chinese Univ. of Hong Kong |
Organizer: Carey, Carole C. | Former U.S. Food and Drug Administration |
Organizer: Ding, Xiao-Rong | The Chinese Univ. of Hong Kong |
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10:50-11:05, Paper ThBT5.1 | Add to My Program |
Measurement and Analysis of Daily Blood Pressure Over a Two-Year Period (I) |
Chen, Wenxi | Univ. of Aizu |
Tamura, Toshiyo | Waseda Univ |
Keywords: Physiological monitoring - Modeling and analysis, Physiological monitoring - Novel methods
Abstract: We describe an exemplary approach for daily measurement of blood pressure and outcome analysis showing monthly health condition change. Daily blood pressure data were collected from an eighties-aged lady at home in a two-year period. Analysis of systolic blood pressure (SBP) was performed on monthly base by the dynamic time warping algorithm. Results indicate an aberrant change in the monthly biorhythmicity can be found in July, 2001, corresponding to the subject’s health condition change. It implies that proper analysis of daily SBP measured over a long-term period may help reveal functional significance on health condition and provide effective evidence for long-term healthcare.
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11:05-11:20, Paper ThBT5.2 | Add to My Program |
Method for Wearable Central Blood Pressure Monitoring and Its Multi-Signal Conditioning Approach (I) |
Fierro, Germán | Univ. De La Republica |
Silveira, Fernando | Univ. De La Republica |
Armentano, Ricardo Luis | Republic Univ |
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11:20-11:35, Paper ThBT5.3 | Add to My Program |
A Novel Deep Learning Based Approach for Continuous Blood Pressure Estimation (I) |
Miao, Fen | Shenzhen Inst. of Advanced Tech. Chinese Acad. of S |
Liu, Xueliang | Hefei Univ. of Tech |
Li, Ye | Shenzhen Inst. of Advanced Tech. Chinese Acad. of S |
Keywords: Physiological monitoring - Novel methods, Bio-electric sensors - Sensing methods, Physiological monitoring - Modeling and analysis
Abstract: Continuous blood pressure (BP) estimation using machine learning techniques has attracted increasing attention recently. In this study, a novel deep learning based approach is proposed to estimate BP with electrocardiogram (ECG) and photoplethysmographic (PPG) signals. Experimental results based on 73 subjects showed that the proposed approach had an excellent accuracy in BP estimation with a correlation coefficient of 0.88 and a mean error of -0.16 ± 6.72 mmHg for systolic BP, and 0.89 and −0.46± 4.37 mmHg for diastolic BP. Therefore, the proposed approach provided a potential novel insight for the continuous BP estimation.
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11:35-11:50, Paper ThBT5.4 | Add to My Program |
Flexible Electronics for Cuffless Blood Pressure Measurements (I) |
Zhao, Ni | The Chinese Univ. of Hong Kong |
Keywords: New sensing techniques, Optical and photonic sensors and systems, Mechanical sensors and systems
Abstract: With the growing aging population and prevalence of cardiovascular diseases, there is an increasing demand for developing personal healthcare systems that can frequently collect physiological parameters of patients during their daily life, thus allowing early disease detection and timely response of health treatments. Wearable medical electronics have been proposed owing to their capability of continuously monitoring the physiological conditions of individuals outside hospitals. In this talk I will discuss both the existing prototypes of wearable medical systems and the emerging nanotechnologies that enable a new generation of intelligent healthcare devices. The topics will span from fundamental knowledge to technical challenge and market potential.
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11:50-12:05, Paper ThBT5.5 | Add to My Program |
Unobtrusive Sensing of Intra-Aneurysm Sac Pressure in Patients after Endovascular Aneurysm Repair (I) |
Poon, Carmen C. Y. | The Chinese Univ. of Hong Kong |
Zheng, Yali | The Chinese Univ. of Hong Kong |
Lau, James Y. W. | The Chinese Univ. of Hong Kong |
Keywords: Mechanical sensors and systems, Physiological monitoring - Instrumentation, Implantable technologies
Abstract: Unobtrusive sensing technologies for blood pressure (BP) range from wearable devices to implantable devices. In this paper, treatment to abdominal aortic aneurysm by an endovascular approach will be reviewed. The benefits and clinical implications of unobtrusive sensing of intra-aneurysm sac pressure will be discussed. By embedding pressure sensors into endovascular stent grafts, remote monitoring of sac pressure can be performed to potentially detect endoleaks at an early stage.
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12:05-12:20, Paper ThBT5.6 | Add to My Program |
A Systematic Classification of Cuffless Blood Pressure Monitoring Techniques: The Three-Layer Framework (I) |
Sola, Josep | CSEM - Centre Suisse D'electronique Et Microtechnique |
Proença, Martin | Swiss Center for Electronics and Microtechnology (CSEM) |
Braun, Fabian | Csem Sa |
Delgado-Gonzalo, Ricard | CSEM |
Ferrario, Damien | CSEM |
Renevey, Philippe | CSEM |
Verjus, Christophe | CSEM |
Lemay, Mathieu | CSEM |
Chételat, Olivier | CSEM |
Bertschi, Mattia | CSEM |
Krauss, Jens | CSEM |
Keywords: Physiological monitoring - Novel methods, New sensing techniques, Physiological monitoring - Instrumentation
Abstract: The terminology of cuffless Blood Pressure (BP) measuring techniques currently lacks an appropriate consensus, leading to repeated misunderstandings among researchers, clinicians and investors. Numerous techniques designed to measure BP in a continuous and cuffless manner have been disclosed in the past. However, most developments focus either on the sensors or the algorithms, but do not provide a full solution to the cuffless BP monitoring problem. This paper suggests a unified framework to systematically classify and describe BP monitoring techniques. Called the three-layer framework, it assumes that in order to perform a cuffless BP measurement the following layers are required: Layer #1 - Sensing: the first step towards the estimation of a BP value consists in collecting a set of physiologically-relevant signals from the patient’s body. Typical explored sensing technologies are electrocardiography, phonocardiography, impedance plethysmography, photoplethysmography, radio-frequency sensing, and tonometry. Layer #2 – Processing: the second step consists in extracting physiological information from the measured set of raw signals. Different families of algorithms have been suggested, ranging from physiology-based models (e.g., pulse wave velocity algorithms, and pulse wave analysis algorithms) to numerical cardiovascular models. In all cases, this algorithmic layer will translate the time series (of raw data expressed in mV from an analog-to-digital converter) into a feature, or set of features, that relates to the underlying BP. Layer #3 - Calibration: the final step concerns the translation of the calculated feature(s) (expressed in arbitrary units) into a BP value (in mmHg). Numerous calibration strategies have been implemented in the past, including population-wise calibrations, and patient-dependent calibrations (based either on one-shot or intermittent measurements with a reference, on hydrostatic pressure changes, or on numerical models).
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ThBT6 Oral Session, Zworykin Room |
Add to My Program |
Biomaterials and Patterning I |
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Chair: Choi, Samjin | Kyung Hee Univ |
Co-Chair: Maharbiz, Michel | Univ. of California, Berkeley |
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10:50-11:05, Paper ThBT6.1 | Add to My Program |
Protein Patterning Using Germanium As a Sacrificial Layer |
Lu, Bochao | Univ. of California Berkeley |
Maharbiz, Michel | Univ. of California, Berkeley |
Keywords: Micro- and nano-technology, Microfluidic techniques, methods and systems, Nano-bio technology design
Abstract: With the rise of microfluidic diagnostics, there is a need for more efficient methods of patterning surface-attached moieties, including proteins like antibodies, onto microchannel surfaces. This arises because almost all of the solvents and processes used for surface-attachment chemistries (or their payloads) are incompatible with sacrificial layers usually photoresist during microfabrication, rendering it difficult to easily pattern active chemistry onto a surface in manufacture scale. We present a simple method, based on thin film germanium dissolution, which is compatible with both modern nanolithographic techniques and surface chemistries. Simply, because germanium thin films dissolve readily, controllably and rapidly in water (but not organic solvents), these films can be used to mask and protect areas of the substrate during the attachment of surface chemistries. We demonstrate the process and results using microscale patterns. The resolution and alignment of this method depends on the photolithography tool used; nanoscale patterning is not difficult to achieve. In addition, we show that with non-conformal germanium deposition (e.g. e-beam evaporation), the conjugation of surface chemistry on vertical side walls can be manipulated by controlling the thickness of the deposited germanium layer, opening another dimension for microfluidic devices and cell manipulation research.
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11:05-11:20, Paper ThBT6.2 | Add to My Program |
Conducting Polymer Microcontainers for Biomedical Applications |
Antensteiner, Martin | Univ. of Houston |
Khorrami, Milad | Univ. of Houston |
Fallahianbijan, Fatemeh | Penn State Univ |
Borhan, Ali | The Pennsylvania State Univ |
Abidian, Mohammad Reza | Univ. of Houston |
Keywords: Micro- and nano-technology, Biomaterial-cell interactions - Stimuli-sensitive biomaterials, Scaffolds in tissue engineering
Abstract: Advancement in the development of metallic-based implantable micro-scale bioelectronics has been limited by low signal to noise ratios and low charge injection at electrode-tissue interfaces. Further, implantable electrodes lose their long-term functionality because of unfavorable reactive tissue responses. Thus, substantial incentive exists to produce bioelectronics capable of delivering therapeutic compounds while improving electrical performance. Here, we have produced hollow poly(pyrrole) microcontainers (MCs) using poly(lactic-co-glycolic) acid (PLGA) as degradable templates. We demonstrate that the effective surface area of the electrode increases significantly as deposition charge density is increased, resulting in a 91% decrease in impedance and an 85% increase in charge storage capacity versus uncoated gold electrodes. We also developed an equivalent circuit model to quantify the effect of conducting polymer film growth on impedance. These MC-modified electrodes offer the potential to improve the electrical properties of implantable bioelectronics, as well as provide potential controlled release avenues for drug delivery applications.
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11:20-11:35, Paper ThBT6.3 | Add to My Program |
Mechanical Properties of Triply Periodic Minimal Surface Structures Mimicking the Microstructure of Woodpecker’s Cranial Bone |
Ni, Yikun | Beihang Univ |
Wang, Lizhen | Beihang Univ |
Fan, Yubo | Beihang Univ |
Keywords: Scaffolds in tissue engineering - Multiscale, Biomimetic materials - Multi-scale, Biomimetic materials
Abstract: A new triply periodic minimal surface (TPMS) structure mimicking the microstructure of Great Spotted Woodpecker’s cranial bone was designed, fabricated and tested in this study. It was found that the designed structures acquired better mechanical performance compared to the unit structures applied in heterogeneous porous scaffolds. The wall thickness mimicking the woodpecker’s spongy bone and the TPMS surface structure were two contributors to the good mechanical performance of new designed bionic structures.
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11:35-11:50, Paper ThBT6.4 | Add to My Program |
Self-Spreading Method for Forming Lipid Bilayer on a Patterned Agarose Gel: Toward Precise Lipid Bilayer Patterning |
Shimba, Kenta | Tokyo Inst. of Tech |
Shoji, Kazuma | Tokyo Inst. of Tech |
Miyamoto, Yoshitaka | Nagoya Univ |
Yagi, Tohru | Tokyo Inst. of Tech |
Keywords: Micro- and nano-technology, Biomimetic materials, Biomaterials - Chemical and electrochemical sensors
Abstract: Forming artificial cell membranes is a suitable strategy for studying drug responses of membrane proteins. In order to form lipid bilayer with both mechanical stability and membrane protein functions, hydrogel supported bilayer has attracted attentions. Combinational use of self-extraction method for lipid bilayer formation and agarose gel patterning should realize hydrogel-supported bilayer with any shape and large area. In this study, we aimed to form a lipid bilayer on a patterned agarose gel and to characterize the membrane. First, lipid mixture was attached on an agarose gel, and lipid layers spread on the gel surface. With fluorescent observation, it is suggested that thin lipid layer was formed on the agarose gel, and their distance-dependent changes in spreading velocity was consistent with that in lipid bilayer. Next, the lipid layer was characterized with fluorescence recovery after photo breaching experiment. As a result, it is indicated that lipid molecules in the lipid layer on the agarose showed lateral diffusion, a typical characteristic of lipid bilayer. Taken together, we confirmed that lipid bilayer can be formed on the patterned agarose gel with self-spreading method. The hydrogel-supported bilayer will be a suitable tool for drug discovery.
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11:50-12:05, Paper ThBT6.5 | Add to My Program |
Tunable Nanostructured Conducting Polymers for Neural Interface Applications |
Abidian, Mohammad Reza | Univ. of Houston |
Antensteiner, Martin | Univ. of Houston |
Keywords: Micro- and nano-sensors, Biomaterial-cell interactions - Functional biomaterials, Scaffolds in tissue engineering - Biofabrication
Abstract: Advancement in the development of traditional metallic-based implantable electrodes for neural interfacing has reached a plateau in recent years in terms of their ability to provide safe, long-term, and high resolution stimulation and/or recording. The reduction of electrode size enables higher selectivity through increased electrodes per implant device; however, it also results lower sensitivity at electrode-tissue interfaces. This limitation can be addressed through the utilization of conducting polymer (CP) coatings, which increase the effective surface area. In this work, we investigate the surface roughness of two common conducting polymers; poly(pyrrole) (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) in the form of films deposited using both potentiostatic (PSTAT) and galvanostatic (GSTAT) methods. We found that the surface roughness of both CP films can be increased by over 90% through control of both deposition time and applied electrical deposition (current for GSTAT and voltage for PSTAT). The impedance of PPy-modified electrodes was found to decrease by up to 88%. This study shows that the surface roughness of CPs can be modulated to control electrical properties of neural electrodes and may improve the cellular response of neurons.
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12:05-12:20, Paper ThBT6.6 | Add to My Program |
Simple and Fast Polydimethylsiloxane (PDMS) Patterning Using a Cutting Plotter and Vinyl Adhesives to Achieve Etching Results |
Kim, Hyun | Seoul National Univ |
Yoo, Sunyoung | Seoul National Univ |
Kim, Ji sung | Seoul National Univ |
Wang, Zihuan | Seoul National Univ |
Lee, Woon-Hee | Seoul National Univ |
Koo, Kyoin | Univ. of Ulsan |
Seo, Jong Mo | Seoul National Univ. School of Engineering |
Cho, Dong Il | Seoul National Univ |
Keywords: Micro- and nano-technology, Microfluidic techniques, methods and systems, Microfluidic applications
Abstract: Inhibition of polydimethylsiloxane (PDMS) polymerization could be observed when spin-coated over vinyl substrates. The degree of polymerization, partially curing or fully curing, depended on the PDMS thickness coated over the vinyl substrate. This characteristic was exploited to achieve simple and fast PDMS patterning method using a vinyl adhesive layer patterned through a cutting plotter. The proposed patterning method showed results resembling PDMS etching. Therefore, patterning PDMS over PDMS, glass, silicon, and gold substrates were tested to compare the results with conventional etching methods. Vinyl stencils with widths ranging from 200μm to 1500μm were used for the procedure. To evaluate the accuracy of the cutting plotter, stencil designed on the AutoCAD software and the actual stencil widths were compared. Furthermore, this method’s accuracy was also evaluated by comparing the widths of the actual stencils and etched PDMS results.
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ThBT7 Oral Session, Herrick Room |
Add to My Program |
Motion Analysis |
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Chair: Thomas, Louise | Simon Fraser Univ |
Co-Chair: Hesse, Nikolas | Fraunhofer Inst. of Optronics, System Tech. and Image Exploitation IOSB |
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10:50-11:05, Paper ThBT7.1 | Add to My Program |
Human Locomotion Analysis: Identifying a Dynamic Mapping between Upper and Lower Limb Joints Using the Koopman Operator |
Boudali, A. Mounir | The Univ. of Sydney |
Sinclair, Peter James | The Univ. of Sydney |
Smith, Richard | The Univ. of Sydney |
Manchester, Ian | Umeå Univ |
Keywords: Mechanics of locomotion and balance, New technologies and methodologies in biomechanics, Joint biomechanics
Abstract: Human locomotion is a complex process that shows some inherent synergies and coordination, also called inter-joint coordination, between the upper and lower limbs. In this paper, we investigate the use of Koopman operator to identify a dynamic mapping between an upper limb and its contra-lateral lower limb in the human locomotion. We perform a human locomotion analysis in the sagittal plane and restrict the study to the forward motion; more specifically, a straight walking task at a constant speed. We use canes as walking aids to provide additional information about the terrain and enforce a frequency locking between the upper and lower body. This mapping will provide a model of the human locomotion.
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11:05-11:20, Paper ThBT7.2 | Add to My Program |
Fusing Motion-Capture and Inertial Measurements for Improved Joint State Recovery: An Application for Sit-To-Stand Actions |
Matthew, Robert, Peter | UC Berkeley |
Seko, Sarah | UC Berkeley |
Bajcsy, Ruzena | UC Berkeley, CITRIS |
Keywords: Joint biomechanics, Dynamics in musculoskeletal biomechanics, New technologies and methodologies in human movement analysis
Abstract: The estimate of joint angles, velocities, and accelerations is a key component of biomechanical modelling. The literature presents a variety of sensing modalities and algorithms to recover the full joint state, with tuning parameters varying between different applications, actions, and limbs. Comparisons between these methods are frequently limited to angles only, without comparison between the joint velocities and accelerations. This paper introduces an algorithm to fuse motion-capture and inertial measurements to recover the full state during a sit-to-stand task. This algorithm is then compared to three other methods: Kalman filtering on motion-capture or inertial measurements alone and the standard angular recovery/differentiation method. It is shown that the fusion of both optical and inertial measurements reduce the ripple and offset artefacts which become pronounced in high acceleration human motions.
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11:20-11:35, Paper ThBT7.3 | Add to My Program |
Quantifying the Effects of On-The-Fly Changes of Seating Configuration on the Stability of a Manual Wheelchair |
Thomas, Louise | Simon Fraser Univ |
Borisoff, Jaimie F. | British Columbia Inst. of Tech |
Sparrey, Carolyn | Simon Fraser Univ |
Keywords: Robot-aided mobility - Wheelchairs, canes, crutches, and mobility tools, Biomechanics and robotics - Clinical evaluation in rehabilitation and orthopedics, Prosthetics - Modeling and simulation in biomechanics
Abstract: In general, manual wheelchairs are designed with a fixed frame, which is not optimal for every situation. Adjustable on the fly seating allow users to spontaneously adapt their wheelchair configuration to suit different tasks. These changes move the center of gravity (CoG) of the system, altering the wheelchair stability and maneuverability. To assess these changes, a computer simulation of a manual wheelchair was created with adjustable seat, backrest, rear axle position and user position, and validated with experimental testing. The stability of the wheelchair was most affected by the position of the rear axle, but adjustments to the backrest and seat angles also result in stability improvements that could be used when wheeling in the community. These findings describe the most influential parameters for wheelchair stability and maneuverability, as well as provide quantitative guidelines for the use of manual wheelchairs with on the fly adjustable seats.
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11:35-11:50, Paper ThBT7.4 | Add to My Program |
Simulation of Oxygen Uptake and Leg Joint Reaction Force During Ergometer Exercise under Altered Gravity |
Tagawa, Yoshihiko | Kurume Univ |
Yamamoto, Naosuke | Kurume Univ |
Omoto, Masayuki | Kurume Univ |
Matsuse, Hiroo | Kurume Univ. Hospital |
Shiba, Naoto | Kurume Univ. Hospital |
Keywords: Dynamics in musculoskeletal biomechanics, Modeling and simulation in musculoskeletal biomechanics, Optimization in musculoskeletal biomechanics
Abstract: Ergometers are safe devices for patients and elderly individuals, as the exercise intensity can be controlled. Moreover, ergometer exercises, which remove the load from body weight on the leg joint, would better reflect training conditions in locations where the force of gravity is lower than that on Earth, such as the International Space Station or on the surface of Mars. The purpose of this study was not only to validate an ergometer exercise model for measuring oxygen uptake and knee joint reaction force by comparison with experimental results, but also to consider a strategy for electrically stimulating leg joint muscles to modulate them under altered gravity.
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11:50-12:05, Paper ThBT7.5 | Add to My Program |
Analysis of Gait Pattern During Stair Walk for Improvement of Gait Training Robot |
Park, Sang-Eun | Biomedical Engineering Res. Center, Asan Medical Center |
Ho, Ye Ji | The Biomedical Engineering Res. Center, Asan Medical Center |
Moon, Youngjin | Asan Medical Center |
Choi, Jaesoon | Asan Inst. for Life Sciences, Asan Medical Center |
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12:05-12:20, Paper ThBT7.6 | Add to My Program |
Body Pose Estimation in Depth Images for Infant Motion Analysis |
Hesse, Nikolas | Fraunhofer Inst. of Optronics, System Tech. and Image |
Schröder, A. Sebastian | Department of Paediatric Neurology and Developmental Medicine, D |
Müller-Felber, Wolfgang | Department of Paediatric Neurology and Developmental Medicine, D |
Bodensteiner, Christoph | Fraunhofer Inst. of Optronics, System Tech. and Image |
Arens, Michael | Fraunhofer Inst. of Optronics, System Tech. and Image |
Hofmann, Ulrich G. | Univ. of Freiburg |
Keywords: Rehabilitation robotics and biomechanics - Devices and methods for assessment and therapy in infancy
Abstract: Motion analysis of infants is used for early detection of movement disorders like cerebral palsy. For the development of automated methods, capturing the infant's pose accurately is crucial. Our system for predicting 3D joint positions is based on a recently introduced pixelwise body part classifier using random ferns, to which we propose multiple enhancements. We apply a feature selection step before training random ferns to avoid the inclusion of redundant features. We introduce a kinematic chain reweighting scheme to identify and to correct misclassified pixels, and we achieve rotation invariance by performing PCA on the input depth image. The proposed methods improve pose estimation accuracy by a large margin on multiple recordings of infants. We demonstrate the suitability of the approach for motion analysis by comparing predicted knee angles to ground truth angles.
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ThBT8 Oral Session, Schwan Room |
Add to My Program |
Brain-Computer Interface II |
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Chair: Guan, Cuntai | Nanyang Tech. Univ |
Co-Chair: Pei, Weihua | Inst. of Semiconductors, CAS |
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10:50-11:05, Paper ThBT8.1 | Add to My Program |
Electrocortical Amplitude Modulations of Human Level-Ground, Slope, and Stair Walking |
Luu, Trieu Phat | Univ. of Houston |
Brantley, Justin | Univ. of Houston |
Zhu, Fangshi | Univ. of Houston |
Contreras-Vidal, José | Univ. of Houston |
Keywords: Brain-computer/machine interface, Motor neuroprostheses - Prostheses, Brain functional imaging - EEG
Abstract: This study investigates if the electrocortical amplitude modulations relative to the mean gait cycle are different across walking conditions (i.e., level-ground (LW), ramp ascent (RA), and stair ascent (SA)). Non-invasive electroencephalography (EEG) signals were recorded and a systematic EEG processing method was implemented to reduce artifacts. Source localization using independent component analysis and k-means clustering revealed the involvement of four clusters in the brain (Left and Right Occipital Lobe, Posterior Parietal Cortex (PPC), and Sensorimotor Area) during the walking tasks. We found that electrocortical amplitude modulations varied across different walking conditions. Specifically, our results showed that the modulations in the PPC shifted to higher frequency bands when the subjects walked in RA and SA conditions. Moreover, we found low γ modulations in the sensorimotor area in LW walking and the modulations in this cluster shifted to lower frequency bands in RA and SA walking. These results are a promising step toward the development of a non-invasive Neural-machine Interface (NMI) for locomotion mode recognition.
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11:05-11:20, Paper ThBT8.2 | Add to My Program |
EEG-Guided Robotic Mirror Therapy System for Lower LimbRehabilitation |
Marghi, Yeganeh M. | Northeastern Univ |
Farjadian, Amir Bahador | Northeastern Univ |
Yen, Sheng-che | Northeastern Univ |
Erdogmus, Deniz | Northeastern Univ |
Keywords: Brain-computer/machine interface, Neurorehabilitation, Neurological disorders - Stroke
Abstract: Lower extremity function recovery is one of the most important goals in stroke rehabilitation. Many paradigms and technologies have been introduced for the lower limb rehabilitation over the past decades, but their outcomes indicate a need to develop a complementary approach. One attempt to accomplish a better functional recovery is to combine bottomup and top-down approaches by means of brain-computer interfaces (BCIs). In this study, a BCI-controlled robotic mirror therapy system is proposed for lower limb recovery following stroke. An experimental paradigm including four states is introduced to combine robotic training (bottom-up) and mirror therapy (top-down) approaches. A BCI system is presented to classify the electroencephalography (EEG) evidence. In addition, a probabilistic model is presented to assist patients in transition across the experiment states based on their intent. To demonstrate the feasibility of the system, both offline and online analyses are performed for five healthy subjects. The experiment results show a promising performance for the system, with average accuracy of 94% in offline and 75% in online sessions.
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11:20-11:35, Paper ThBT8.3 | Add to My Program |
Boosting Performance in Brain-Machine Interface by Classifier-Level Fusion Based on Accumulative Training Models from Multi-Day Data |
Yang, Huijuan | Inst. for Infocomm Res. Agency Forscience, Tech. An |
Libedinsky, Camilo | A*STAR |
Guan, Cuntai | Nanyang Tech. Univ |
Ang, Kai Keng | Inst. for Infocomm Res |
So, Rosa | Inst. for Infocomm Res |
Keywords: Brain-computer/machine interface, Neural signal processing
Abstract: The nonstationarity of neural signal is still an unresolved issue despite the rapid progress made in brain-machine interface (BMI). This paper investigates how to utilize the rich information and dynamics in multi-day data to address the variability in day-to-day signal quality and neural tuning properties. For this purpose, we propose a classifier-level fusion technique to build a robust decoding model by jointly considering the classifier outputs from multiple base-training models using multi-day data collected prior to test day. The data set used in this study consisted of recordings of 8 days from a non-human primate (NHP) during control of a mobile robot using a joystick. Offline analysis demonstrates the superior performance of the proposed method which results in 4.4% and 13.10% improvements in decoding (significant by one-way ANOVA and post hoc t-test) compared with the two baseline methods: 1) concatenating data from multiple days based on common effective channels, and 2) averaging accuracies across all base-training models. These results further validate the effectiveness of proposed method without re-calibration of the model.
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11:35-11:50, Paper ThBT8.4 | Add to My Program |
Stop State Classification in Intracortial Brain-Machine-Interface |
Koh, Tze Hui | Inst. for Infocomm Res |
Libedinsky, Camilo | A*STAR |
Guan, Cuntai | Nanyang Tech. Univ |
Ang, Kai Keng | Inst. for Infocomm Res |
So, Rosa | Inst. for Infocomm Res |
Keywords: Brain-computer/machine interface, Neural interfaces - Implantable systems, Neural signals - Coding
Abstract: Invasive brain-machine-interface (BMI) has the prospect to empower tetraplegic patients with independent mobility through the use of brain-controlled wheelchairs. For the practical and long-term use of such control systems, the system has to distinguish between stop and movement states and has to be robust to overcome non-stationarity in the brain signals. In this work, we investigates the non-stationarity of the stop state on neural data collected from a macaque trained to control a robotic platform to stop and move in left, right, forward directions We then propose a hybrid approach that employs both random forest and linear discriminant analysis (LDA). Using this approach, we performed offline decoding on 8 days of data collected over the course of three months during joystick control of the robotic platform. We compared the results of using the proposed approach with the use of LDA alone to perform direct classifications of stop, left, right and forward. The results showed an average performance increment of 22.7% using the proposed hybrid approach. The results yielded significant improvements during sessions where LDA showed a heavy bias towards the stop state. This suggests that the proposed hybrid approach addresses the non-stationarity in the stop state and subsequently facilitates a more accurate decoding of the movement states.
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11:50-12:05, Paper ThBT8.5 | Add to My Program |
A Frequency Recognition Method Based on Multitaper Spectral Analysis and SNR Estimation for SSVEP-Based Brain–computer Interface |
Yang, Chen | Tsinghua Univ |
Xu, Han | Tsinghua Univ |
Wang, Yijun | Inst. of Semiconductors, Chinese Acad. of Sciences |
Gao, Xiaorong | Tsinghua Univ |
Keywords: Brain-computer/machine interface
Abstract: Over the past several years, steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) have attracted wide attention in the field of BCIs research due to high information transfer rate, little user training, and applicability to the majority. In conventional recognition methods for training-free SSVEP-based BCIs, the energy difference between the frequencies of electroencephalogram (EEG) background noise is usually ignored, therefore, there is a significant variance among the recognition accuracy of different stimulus frequencies. In order to improve the performance of training-free SSVEP-based BCIs system and balance the accuracy of recognition between different stimulus frequencies, a recognition method based on multitaper spectral analysis and signal-to-noise ratio estimation (MTSA-SNR) is proposed in this paper. A 40-class SSVEP public benchmark SSVEP dataset recorded from 35 subjects was used to evaluate the performance of the proposed method. Under the condition of 2.25s data length, the accuracy of the three methods were 81.1% (MTSA-SNR), 74.5% (canonical correlation analysis, CCA) and 73.4% (multivariate synchronization index, MSI), and the corresponding ITRs were 101 bits/min (MTSA-SNR), 89 bits/min (CCA), 87 bits/min (MSI). In the low frequency range (8-9.8Hz), the average recognition accuracy of the three methods is 82.9% (MTSA-SNR), 82.0% (CCA), 83.3% (MSI). The average accuracy of the three methods was 78.6% (MTSA-SNR), 64.9% (CCA) and 61.8% (MSI) in the high frequency range (14-15.8Hz). According to the results, the proposed method can effectively improve the performance of training-free SSVEP-based BCI system, and balance the recognition accuracy between different stimulation frequencies.
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12:05-12:20, Paper ThBT8.6 | Add to My Program |
Learning to Control an SSVEP-Based BCI Speller in Naïve Subjects |
Zhihua Tang, Zhihua | Hebei Univ. of Tech |
Wang, Yijun | Inst. of Semiconductors, Chinese Acad. of Sciences |
Dong, Guoya | Hebei Univ. of Tech |
Pei, Weihua | Inst. of Semiconductors, CAS |
Chen, hongda | Inst. of Semiconductors, CAS |
Keywords: Brain-computer/machine interface
Abstract: High-speed steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) has been demonstrated in several recent studies. This study aimed to investigate some issues regarding feasibility of learning to control an SSVEP-based BCI speller in naïve subjects. An experiment with new BCI users was designed to answer the following questions: (1) How many people can use the SSVEP-BCI speller? (2) How much time is required to train the user? (3) Does continuous system use lead to user fatigue and deteriorated BCI performance? The experiment consisted of three tasks including a 40-class BCI spelling task, a psychomotor vigilance test (PVT) task, and a test of sleepiness scale. Subjects’ reaction time (RT) in the PVT task and the fatigue rank in the sleepiness scale test were used as objective and subjective parameters to evaluate subjects’ alertness level. Among 11 naïve subjects, 10 of them fulfilled the 9-block experiment. Four of them showed clear learning effects (i.e., an increasing trend of classification accuracy and information transfer rate (ITR)) over time. The remaining subjects showed stable BCI performance during the whole experiment. The results of RT and fatigue rank showed a gradually increasing trend, which is not significant across blocks. In summary, the results of this study suggest that controlling an SSVEP-based BCI speller is in general feasible to learn by naïve subjects after a short training procedure, showing no clear performance deterioration related to fatigue.
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ThBT9 Oral Session, Plonsey Room |
Add to My Program |
Neural Stimulation I |
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Chair: Jun, Sung Chan | Gwangju Inst. of Science and Tech |
Co-Chair: zhang, Cheng | Chinese Acad. of Sciences, Beijing, |
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10:50-11:05, Paper ThBT9.1 | Add to My Program |
A 64-Channels Neural Interface for Biopotentials Recording and PNS Stimulation |
Bisoni, Lorenzo | Univ. Di Cagliari |
Carboni, Caterina | Univ. Di Cagliari |
Puddu, Roberto | Univ. Di Cagliari |
Barabino, Gianluca | Univ. of Cagliari |
Pani, Danilo | Univ. of Cagliari |
Raffo, Luigi | Univ. of Cagliari |
Mueller, Matthias | Univ. of Freiburg |
Stieglitz, Thomas | Univ. of Freiburg |
del Valle, Jaume | Univ. Autonoma De Barcelona |
de la Oliva, Natàlia | Univ. Autònoma De Barcelona |
Delgado-Martínez, Ignacio | National Univ. of Singapore |
Navarro, Xavier | Univ. Autònoma De Barcelona |
Barbaro, Massimo | Univ. of Cagliari |
Keywords: Neural stimulation, Neural interfaces - Body interfaces, Neural interfaces - Bioelectric sensors
Abstract: A biomedical interface that combines into a single and compact device the recording of biopotentials and the electrical stimulation of neural fibres is presented. It is intended for enabling the control over a robotic hand and for restoring the sensory feedback in amputees by directly interfacing the peripheral nervous system (PNS) in closed-loop. A modular system consisting in one or more independent 16-channels bidirectional units was conceived. Each module is based on three 0.35um bulk-CMOS integrated circuits (ICs): a recording unit, a High-Voltage (HV) stimulator and a HV booster. A tunable bandwidth (10Hz-8kHz) allows the recording IC to acquire both electroneurographyc (ENG) and electromiographyc (EMG) signals with a programmable gain up to 43.5dB. The signals are then converted into a digital domain by means of a Sigma-Delta converter. Due to the typical high impedance at the electrode-tissue interface, a programmable HV booster that increases the stimulation voltage up to 19V was designed. It is directly controlled by the stimulation module that generates current-based pulses with a programmable amplitude and pulse-width. The whole system was validated by means of in-vivo experiments in rats.
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11:05-11:20, Paper ThBT9.2 | Add to My Program |
Auditory Responses to Short-Wavelength Infrared Neural Stimulation of the Rat Cochlear Nucleus |
Jiang, Bin | Chongqing Univ |
Xia, Nan | Chongqing Univ |
Hou, Wensheng | Bioengineering Inst. of Chongqing Univ |
Keywords: Neural stimulation, Neurorehabilitation, Neural signal processing
Abstract: Pulsed Infrared laser is well-known for its high spatial resolution and contact-free stimulation mode. In order to improve the current auditory brainstem implants (ABI), short-wavelength infrared light with wavelength of 980 nm was applied to stimulate rats cochlear nucleus. Single neural activity from the contralateral inferior colliculus was recorded during laser stimulation. Animal experimental results showed that 980 nm laser could not directly activate neurons in cochlear nucleus and a photo-acoustic response was observed during stimulation, however, 980 nm laser produces an inhibitory effect on neural responses to sounds; After we added carbon nanoparticles onto the surface of animal cochlear nucleus, 980 nm laser could directly stimulate neurons and no interference between adjacent recording channels was observed. These findings indicated that with the enhancement of carbon nanoparticles, short-wavelength infrared neural stimulation (SW-INS) might be an effective method to overcome the defects of current ABIs. With this method, a new type of optical ABI with transcutaneous stimulating method is quite promising
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11:20-11:35, Paper ThBT9.3 | Add to My Program |
A Computational Study on Effect of a Transcranial Channel As a Skull/Brain Interface in the Conventional Rectangular Patch-Type Transcranial Direct Current Stimulation |
Seo, Hyeon | Gwangju Inst. of Science and Tech |
KIM, Hyoung-Ihl | Gwangju Inst. of Science and Tech |
Jun, Sung Chan | Gwangju Inst. of Science and Tech |
Keywords: Neural stimulation, Neural interfaces - Tissue-electrode interface, Brain physiology and modeling
Abstract: A conceptual model of a transcranial channel was recently proposed for conveying external currents of the skull to the brain; the effects of the transcranial channel combined with high-definition transcranial direct current stimulation (HD-tDCS) was investigated, resulting in discovery of increased stimulus intensity and focality. In this work, rather than HD-tDCS using smaller disc-type electrodes, we proposed the use of the transcranial channel with conventional tDCS using larger patch electrodes. We used multi-scale computational models that couple an anatomically realistic head model with multi-compartmental models of cortical neurons. We then predicted the excitability in the hand knob (target area) based on stimulus-induced electric fields and steady-state membrane polarizations. Conventional tDCS without the transcranial channel resulted in diffuse distributions of electric fields that covered the frontal cortex, while the spatial focality and intensity of the excitability increased significantly at the target area in the presence of the transcranial channel. Thus, it is expected that conventional tDCS with the transcranial channel allows a better targeting neuromodulation with higher intensity and may be promising for applying prolonged and stabilized tDCS.
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11:35-11:50, Paper ThBT9.4 | Add to My Program |
Assessing Rtms Effects in MdDS: Cross-Modal Comparison between Resting State EEG and Fmri Connectivity |
Chen, Yafen | Univ. of Oklahoma |
Li, Chuang | Univ. of Oklahoma |
Shou, Guofa | Univ. of Oklahoma |
Urbano, Diamond | Laureate Inst. for Brain Res |
Cha, Yoon-Hee | Laureate Inst. of Brain Res |
Ding, Lei | Univ. of Oklahoma |
Yuan, Han | Univ. of Oklahoma |
Keywords: Neural stimulation, Brain functional imaging, Brain functional imaging - Source localization
Abstract: Repetitive transcranial magnetic stimulation (rTMS) has been increasingly explored for many neurological and neuropsychiatric conditions. However, the response rate is variable depending on baseline conditions. Optimizing rTMS protocols to improve treatment effects and response rates will depend on reliably assessing brain state conditions. In this regard, neural activity guided optimization has shown potential in several neuroimaging studies. In this paper, we present our ongoing work on optimizing rTMS treatment of a balance disorder called Mal de Debarquement Syndrome (MdDS), a motion perception disorder caused by entrainment to background motion. Our previous work has revealed that a neuroimaging marker of resting state functional connectivity may help predict therapeutic effect. Motivated by our previous pilot study with fMRI, the present study aims to extend the investigation to EEG data that were simultaneously acquired with fMRI, with the aim of transferring the fMRI imaging marker to a more accessible neural recording technology. Our current findings demonstrate that integrating EEG with fMRI measures of neural synchrony and functional connectivity may hold promise in optimizing rTMS protocols.
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11:50-12:05, Paper ThBT9.5 | Add to My Program |
Closed-Loop Low-Frequency DBS Restores Thalamocortical Relay Fidelity in a Computational Model of the Motor Loop |
Huang, Han | Johns Hopkins Univ |
Santaniello, Sabato | Univ. of Connecticut |
Keywords: Neural stimulation, Brain physiology and modeling - Neuron modeling and simulation, Neurological disorders
Abstract: Closed-loop modulation of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD) is investigated to automatically adjust the stimulation to the patients' conditions, optimize the clinical outcomes, and reduce the energy requirements. This study proposes a closed-loop control system for real-time adaptation of the STN-DBS amplitude based on the neural activity in the motor thalamus. Population-averaged post-stimulus time histograms are used to measure the average effects of STN-DBS on the thalamocortical neurons and a L2-norm minimization problem is solved to design the control algorithm, while the frequency of stimulation is kept constant. Applied on a large-scale, biophysically-based, anatomically-compliant model of the cortico-basal ganglia-thalamo-cortical motor loop under PD conditions, our adaptive DBS significantly (P-value P<0.05) improved the relay fidelity of the thalamocortical neurons and restored the average power of the thalamocortical spike trains in the band [3, 100] Hz, two indicators of restored thalamocortical activity. Furthermore, adaptive-DBS significantly decreased the energy requirements when compared with non-adaptive-DBS at the same frequency. Finally, 30- and 60-Hz-adaptive-DBS determined the maximal restoration of thalamocortical activity and outperformed high-frequency, non-adaptive-DBS. Overall, results suggest that a feedback-controlled, low-frequency DBS pattern may result in significant restoration of the thalamocortical encoding while lowering the energy requirements.
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12:05-12:20, Paper ThBT9.6 | Add to My Program |
Electric Field Stimulation Protects Injured Spinal Cord from Secondary Inflammatory Response in Rats |
Huo, Xiaolin | Chinese Acad. of Sciences |
Zhang, Guanghao | Inst. of Electrical Engineering, Chinese Acad. of Sciences |
Wu, Changzhe | Chinese Acad. of Sciences |
zhang, Cheng | Chinese Acad. of Sciences, Beijing, |
Keywords: Neural interfaces - Regeneration, Neural stimulation, Neurorehabilitation
Abstract: Objectives: To investigate acute beneficial effects of electrical field stimulation (EFS) on secondary inflammatory response in spinal cord injury (SCI) rats. Methods: Sprague-Dawley (SD) rats were divided into three groups,sham group rats received laminectomy only, control group rats were subjected to SCI only, and EFS group rats received EFS immediately after the injury. During the 30-min-stimulation, the injury potential modulated to 0 ± 0.5 mV by EFS. At 12h, 24h and 48h after the surgery, the rats in each group were sacrificed. Immunofluorescence staining for macrophage marker (ED-1), the tautomerase activity of macrophage inhibitory factor (MIF) assay and real-time PCR analysis for interleukin-1β (IL-1β) and matrix metalloproteinase-9 (MMP-9) were performed. Results: Compared to the rats in control group, the rats treated with EFS presented less ED-1 positive cells 12h (P < 0.05), 24h (P < 0.01) and 48h (P < 0.05) after the surgery and showed a lower MIF tautomerase activity 12h (P < 0.01), 24h (P < 0.01) and 48h (P < 0.01) after the surgery. Moreover, EFS significantly decreased the mRNA levels of IL-β (P < 0.05) and MMP-9 at 48h (P < 0.01) after the injury. Conclusions: EFS could attenuate secondary inflammatory response of injured spinal cord shortly after SCI, and EFS treatment could be a candidate for SCI therapy.
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ThBT10 Minisymposium, Schmitt Room |
Add to My Program |
Authentication Using Biological Signals |
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Chair: Park, Kwang S. | Seoul National Univ |
Co-Chair: KIM, JASON | Korea Internet & Security Agency |
Organizer: Park, Kwang S. | Seoul National Univ |
Organizer: KIM, JASON | Korea Internet & Security Agency |
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10:50-11:05, Paper ThBT10.1 | Add to My Program |
Merging Bio-Signals with Traditional Biometrics: Taking the Best of Both Worlds (I) |
Sanchez-Reillo, Raul | Carlos III Univ. of Madrid, Univ. Group for Identifica |
Miranda-Escalada, Antonio | Carlos III Univ. of Madrid, Univ. Group for Identifica |
Fernandez-Lopez, Pablo | Carlos III Univ. of Madrid, Univ. Group for Identifica |
Sanchez-Casanova, Jorge | Carlos III Univ. of Madrid, Univ. Group for Identifica |
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11:05-11:20, Paper ThBT10.2 | Add to My Program |
Development of Multi-Modal Bio-Signal Authentication Platform (I) |
KIM, JASON | Korea Internet & Security Agency |
Lee, Saewoom | KISA (Korea Internet & Security Agency) |
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11:20-11:35, Paper ThBT10.3 | Add to My Program |
Implementing Biology-To-Machine (B2M) Protocol for a Telebiometric Biosignal Authentication Application (I) |
Caras, John | Disney-Visa |
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11:35-11:50, Paper ThBT10.4 | Add to My Program |
Human Identification Using Non-Invasive Biological Signals (I) |
Kim, Jeehoon | Seoul National Univ |
Park, Kwang S. | Seoul National Univ |
Keywords: General and theoretical informatics - Security and authentication, General and theoretical informatics - Pattern recognition, General and theoretical informatics - Supervised learning method
Abstract: Physical properties based biometric systems have a crucial problems of falsification. Non-invasive biological signals like electrocardiogram, photoplethysmogram can be additionally applied to personal authentication system requiring high level of security because of its robustness to attacks. In this study, we examined the possibility of non-invasive biological signals of uniqueness and evaluate the authentication accuracy with different physical conditions. Various kinds of non-invasive biological signals (ECG, EEG, PPG, and BCG) were analyzed for human identification using optimized classifiers. The performance of various methodologies is suggested under different conditions and the highest authentication accuracy was 90.3% for ECG of 102 subjects.
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ThBT11 Minisymposium, Greatbatch Room |
Add to My Program |
Recent Advances on Cuff-Less Blood Pressure Measurement Technology I |
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Chair: Hahn, Jin-Oh | Univ. of Maryland |
Co-Chair: Inan, Omer | Georgia Inst. of Tech |
Organizer: Hahn, Jin-Oh | Univ. of Maryland |
Organizer: Inan, Omer | Georgia Inst. of Tech |
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10:50-11:05, Paper ThBT11.1 | Add to My Program |
A Simultaneous Multisite Assessment of the Pulse Transit Time (I) |
Di Rienzo, Marco | Fondazione Don Carlo Gnocchi |
Lombardi, Prospero | Fondazione Don Carlo Gnocchi ONLUS |
Vaini, Emanuele | Pol. Tecnologico, Fondazione Don Carlo Gnocchi |
Keywords: Vascular mechanics and hemodynamics - Pulse wave velocity, Cardiovascular and respiratory signal processing - Pulse transit time, Cardiovascular regulation - Blood pressure variability
Abstract: A new multisensor architecture has been developed for the assessment of cardiovascular variables. The system includes a number of miniaturized nodes -each measuring the seismocardiogram (SCG) and the photoplethysmogram (PPG)- and a hub module which collects data from the nodes, and detects ECG plus a supplementary SCG. In this study we explored the ability of this device to provide a simultaneous multisite estimation of the beat-to-beat Pulse Transit Time (PTT) from sternal SCG and PPGs sensors positioned on the finger tip, ear lobe and forehead in four healthy volunteers. The three PTTs could be estimated in more than 90% of the recorded heart beats. The obtained results encourage further developments of the system focused on the clinical application of this multisite technology.
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11:05-11:20, Paper ThBT11.2 | Add to My Program |
A Patch-Type Multi-Parameter Blood Pressure Monitoring Device: Performance of Surrogate Markers in Two Different Conditions (I) |
Lee, Joonnyong | Seoul National Univ |
Park, Jonghyun | Seoul National Univ. Graduate School |
Yang, Seungman | Seoul National Univ |
Sohn, Jangjay | Seoul National Univ |
Yoo, Byeongwook | Interdisciplinary Program of Bioengineering, Seoul National Univ |
Lee, Saram | Seoul National Univ. Hospital |
Kim, Hee Chan | Seoul National Univ |
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11:20-11:35, Paper ThBT11.3 | Add to My Program |
Non-Invasive and Cuffless Device Based on Pulse Transit Time for Blood Pressure Monitoring (I) |
Sethi, Tavpritesh | Indraprastha Inst. of Information Tech. Delhi |
Prakash, Suriya | CSIR-CEERI |
Gupta, Surendra | CSIR-CEERI |
Subramanian, Meera | CSIR-CEERI |
Morey, Gautam | Sofomo Embedded Solutions Pvt. Ltd |
Dash, Debasis | CSIR-IGIB |
Agrawal, Anurag | CSIR-IGIB |
Pesala, Bala | CSIR-CEERI |
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11:35-11:50, Paper ThBT11.4 | Add to My Program |
Pressure Dependence of Arterial Pulse Wave Velocity: Influence on Calibration of Cuff-Less BP Monitoring Based on Arterial Pulse Transit Time (I) |
Avolio, Alberto P | Macquarie Univ |
Butlin, Mark | Macquarie Univ |
Shirbani, Fatemeh | Macquarie Univ. Faculty of Medicine and Health Sciences |
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11:50-12:05, Paper ThBT11.5 | Add to My Program |
Unobtrusive Blood Pressure Monitoring Via Pulse Transit Time (I) |
Kim, Chang-Sei | Univ. of Maryland |
Ober, Stephanie | Univ. of Maryland Coll. Park |
Carek, Andrew | Georgia Inst. of Tech |
Ashouri, Hazar | Georgia Inst. of Tech |
Inan, Omer | Georgia Inst. of Tech |
Mukkamala, Ramakrishna | Michigan State Univ |
Hahn, Jin-Oh | Univ. of Maryland |
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12:05-12:20, Paper ThBT11.6 | Add to My Program |
Toward Ubiquitous Blood Pressure Monitoring Via Pulse Transit Time: Maximum Calibration Period and Acceptable Accuracy (I) |
Mukkamala, Ramakrishna | Michigan State Univ |
Hahn, Jin-Oh | Univ. of Maryland |
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ThBT12 Invited Session, Geddes Room |
Add to My Program |
Modeling of Modern Devices and Technologies with Computational Human
Phantoms - II |
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Chair: Nagaoka, Tomoaki | National Inst. Info & Comm Tech |
Co-Chair: Horner, Marc | ANSYS, Inc |
Organizer: Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Organizer: Horner, Marc | ANSYS, Inc |
Organizer: Noetscher, Gregory | Worcester Pol. Inst |
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10:50-11:05, Paper ThBT12.1 | Add to My Program |
Estimates of Peak Electric Fields Induced by Transcranial Magnetic Stimulation in a Pregnant Patient Using an FEM Full-Body Model (I) |
Yanamadala, Janakinadh | Worcester Pol. Inst |
Noetscher, Gregory | Worcester Pol. Inst |
Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Pascual-Leone, Alvaro | Harvard Medical School |
Keywords: Neural stimulation (including deep brain stimulation)
Abstract: Transcranial magnetic stimulation (TMS) for treatment of depression during pregnancy is an appealing alternative to fetus-threatening drugs. However, no studies to date have been performed that evaluate the safety of TMS for a pregnant mother patient and her fetus. A full-body FEM model of a pregnant woman has been developed specifically for the present study. This model allows accurate computations of induced electric field in every tissue given different locations of a shape-eight coil, a biphasic pulse, common TMS pulse durations, and using different values of the TMS intensity measured in SMT (Standard Motor Threshold) units. Our simulation results estimate the maximum peak values of the electric field in the fetal area for every fetal tissue separately and for the TMS intensity of one SMT unit.
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11:05-11:20, Paper ThBT12.2 | Add to My Program |
Posture Transformation for Voxel-Based Anatomical Human Models (I) |
Nagaoka, Tomoaki | National Inst. Info & Comm Tech |
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11:20-11:35, Paper ThBT12.3 | Add to My Program |
RF MRI Coil Detuning for Anatomically Realistic Respiratory Cycle Modeled with the Finite Element Method (I) |
Tran, Anh Le | Worcester Pol. Inst |
Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Keywords: Diagnostic devices - Physiological monitoring, Clinical laboratory, assay and pathology technologies
Abstract: Respiratory motion is an important problem in Magnetic Resonance Imaging (MRI), contributing to image blurring during data acquisition and coil detuning. Using the concept of an ideal (perfectly matched and tuned at all available ports) RF transmit coil and the VHP-Female v4.0 dynamic CAD model, we numerically model and estimate the detuning of a full-body RF coil during the respiratory cycle.
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11:35-11:50, Paper ThBT12.4 | Add to My Program |
The Visible Human Project Male CAD Based Computational Phantom and Its Use in Electromagnetic Simulations (I) |
Noetscher, Gregory | Worcester Pol. Inst |
Htet, Aung Thu | Worcester Pol. Inst |
Maino, Nicholas | Worcester Pol. Inst |
Lacroix, Patrick | Wpi |
Keywords: Image-guided devices - RF and microwave ablation
Abstract: Use of numerical simulation tools to provide qualitative estimates on electromagnetic safety, characterize antenna performance for WBAN applications and facilitate ground breaking research on diagnostic and therapeutic bioelectrical solutions has steadily grown over the past twenty years. However, the accuracy and applicability of such tools are directly proportional to the fidelity of the model used during the simulation. This paper describes the construction of a new CAD based male computational phantom, the Visible Human Project (VHP)-Male model, suitable for use in major commercial electromagnetics simulation packages
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ThBT13 Oral Session, Dunn Room |
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Implantable Technologies and Systems |
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Chair: Holmes, David | Mayo Clinic |
Co-Chair: Tang, Sai Chun | Harvard Medical School, Brigham and Women’s Hospital |
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10:50-11:05, Paper ThBT13.1 | Add to My Program |
A Study on Setting of the Fatigue Limit of Temporary Dental Implants |
KIM, Mi Hye | Ministry Od Food and Drug Safety |
EUNJEONG, CHO | Ministry Od Food and Drug Safety |
JIWON, LEE | Ministry of Food and Drug Safety |
EUNKYO, KIM | Medical Devices Res. Div |
SIHYUNG, YOO | Ministry of Food and Drug Safety |
Park, Chang Won | National Inst. of Food and Drug Safety Evaluation, Ministry |
Keywords: Health technology management and assessment
Abstract: A temporary dental implant is a medical device which is temporarily used to support a prosthesis such as an artificial tooth used for restoring patient's masticatory function during implant treatment. It is implanted in the oral cavity to substitute for the role of tooth. Due to the aging and westernization of current Korean society, the number of tooth extraction and implantation procedures is increasing, leading to an increase in the use and development of temporary dental implants. Because an implant performs a masticatory function in place of a tooth, a dynamic load is repeatedly put on the implant. Thus, the fatigue of implants is reported to be the most common causes of the fracture thereof. According to the investigation and analysis of the current domestic and international standards, the standard for fatigue of implant fixtures is not separately specified. Although a test method for measuring the fatigue is suggested in an ISO standard, it is a standard for permanent dental implants. Most of the test standards for Korean manufacturers and importers apply 250 N or more based on the guidance for the safety and performance evaluation of dental implants. Therefore, this study is intended to figure out the fatigue standard which can be applied to temporary dental implants when measuring the fatigue according to the test method suggested in the permanent dental implant standard. The results determined that suitable fatigue standards of temporary dental implants should be provided by each manufacturer rather than applying 250 N. This study will be useful for the establishment of the fatigue standards and fatigue test methods of the manufacturers and importers of temporary dental implants.
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11:05-11:20, Paper ThBT13.2 | Add to My Program |
A Wirelessly Powered Implantable Radiofrequency Nerve Lesioning System for the Treatment of Chronic Pain |
Tang, Sai Chun | Harvard Medical School, Brigham and Women’s Hospital |
McDannold, Nathan | Brigham & Women's Hospital |
Vaninetti, Michael | Univ. of California San Diego, VA San Diego Healthcare Syst |
Keywords: Ablation
Abstract: This paper presents a cost-effective, wireless, implantable radiofrequency lesioning (RFL) device. The implantable device, which is powered by magnetic coupling and does not require an embedded battery, is composed of an energy-receiving coil, a resonant capacitor circuit, and a pair of bipolar RFL electrodes. We use the resonant capacitor circuit to maximize the received power and set the voltage across the electrodes to the desired value. An energy-transmitting coil with a diameter of 40-cm, which is designed to wrap around a patient’s body, is used to generate a uniform magnetic field in a large volume so precise coil alignment is not necessary. Our recently developed coil segmentation technique is utilized to significantly reduce the excitation voltage for the transmitting coil to a safe level. We evaluated the system using ex-vivo chicken muscle tissue. With a transmitting coil excitation of 1.2 Arms for 73 s, the implant can lesion the muscle tissue by achieving a temperature of 55 °C. When the excitation time was increased to 500 s, the tissue temperature increased to 63.6 °C. We have performed FEA simulation to evaluate the human body SAR and found that the SAR level is lower than the safety limit of 2 W/kg suggested by international guidelines.
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11:20-11:35, Paper ThBT13.3 | Add to My Program |
An IC-Based Controllable Stimulator for Respiratory Muscle Stimulation Investigations |
Castelli, Jonathan | Univ. of Bordeaux |
Kolbl, Florian | Univ. of Bordeaux |
Siu, Ricardo | Florida International Univ |
N'Kaoua, Gilles | Cnrs, Ims Umr 5218 |
Bornat, Yannick | IMS Lab |
Mangalore, Ashwin | Univ. of Bordeaux, IMS, CNRS UMR 5218 |
Hillen, Brian | Florida International Univ |
Abbas, James | Arizona State Univ |
Renaud, Sylvie | Univ. of Bordeaux1, IMS, Enseirb |
Jung, Ranu | Florida International Univ |
Lewis, Noëlle | Univ. of Bordeaux 1, IPB, IMS, CNRS UMR 5218 |
Keywords: Muscle stimulation, Ventilators
Abstract: Functional Electrical Stimulation can be used to restore motor functions loss consecutive to spinal cord injury, such as respiratory deficiency due to paralysis of ventilatory muscles. This paper presents a fully configurable IC-centered stimulator designed to investigate muscle stimulation paradigms. It provides 8 current stimulation channels with high-voltage compliance and real-time operation capabilities, to enable a wide range of FES applications. The stimulator can be used in a standalone mode, or within a closed-loop setup. Primary in vivo results show successful drive of respiratory muscles stimulation using a computer-based dedicated controller.
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11:35-11:50, Paper ThBT13.4 | Add to My Program |
An Intracardiac Electrogram Model to Bridge Virtual Hearts and Implantable Cardiac Devices |
Ai, Weiwei | Univ. of Auckland |
Patel, Nitish | Univ. of Auckland |
Roop, Parthasarathi | Univ. of Auckland |
Malik, Avinash | Univ. of Auckland |
Allen, Nathan | Univ. of Auckland |
Trew, Mark L. | Univ. of Auckland |
Keywords: Heart and circulatory support devices, Health technology - Verification and validation
Abstract: Virtual heart models have been proposed to enhance the safety of implantable cardiac devices through closed loop validation. To communicate with a virtual heart, devices have been driven by cardiac signals at specific sites. As a result, only the action potentials of these sites are sensed. However, the real device implanted in the heart will sense a complex combination of near and far-field extracellular potential signals. Therefore many device functions, such as blanking periods and refractory periods, are designed to handle these unexpected signals. To represent these signals, we develop an intracardiac electrogram (IEGM) model as an interface between the virtual heart and the device. The model can capture not only the local excitation but also far-field signals and pacing afterpotentials. Moreover, the sensing controller can specify unipolar or bipolar electrogram (EGM) sensing configurations and introduce various oversensing and undersensing modes. The simulation results show that the model is able to reproduce clinically observed sensing problems, which significantly extends the capabilities of the virtual heart model in the context of device validation.
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11:50-12:05, Paper ThBT13.5 | Add to My Program |
A Wireless Optical Power System for Medical Implants Using Low Power Near-IR Laser |
Saha, Anindo | American International Univ |
Iqbal, Shabab | American International Univ |
Karmaker, Mithun | American International Univ |
Zinnat, Syeda Fairose | American International Univ |
Ali, M. Tanseer | American International Univ |
Keywords: Heart and circulatory support devices
Abstract: An alternative method of transcutaneous wireless optical energy supply to an artificial cardiac pacemaker has been conceived, thereby negating the possibility of electromagnetic interference. In this research, a comparative analysis is made between two distinct arrays of photovoltaic cells, consisting of two different geometries. Being powered by a 5 mW 750 nm laser, that has a different spot size for each topology; both models are tested by their ability to charge a 150 mAh rechargeable LiPo battery, while being embedded underneath a layer of skin tissue. This system in turn, regulates the power supplied to a low power medical implant (< 10 mW), in the place of conventional batteries. For a charging period of 60 minutes, results indicate that a pacemaker utilizing this system can sustain operation for nearly 85 hours, without any noticeable side-effects or changes in temperature.
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ThBT14 Oral Session, Schaldach Room |
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Machine Learning in Imaging II |
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Chair: Unser, Michael | EPFL |
Co-Chair: Seo, Jin Keun | Yonsei Univ |
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10:50-11:05, Paper ThBT14.1 | Add to My Program |
Deep Scattering Convolution Network Based Features for Ultrasonic Fatty Liver Tissue Characterization |
Ramkrishna, Bharath | Indian Inst. of Tech. Hyderabad |
P, Rajalakshmi | Indian Inst. of Tech. Hyderabad |
Keywords: Image classification, Image feature extraction, Multiscale image analysis
Abstract: Accumulation of excess fat in the liver tissue is the leading cause for dysfunction of liver, which can lead to the diseases from fibrosis to end stage cirrhosis. Hence, early detection of fatty liver becomes crucial in avoiding the liver from permanent failure. Depending on the concentration of fat in the tissue, the liver is classified as Normal, Grade 1, Grade 2 and Grade 3 respectively. The texture of liver tissue in ultrasound image is so specific to the concentration of fat, hence classifying the fatty liver is formulated as a texture discrimination problem. In this paper, we present an automated algorithm for grading the tissue of a fatty liver based on the features obtained from the invariant scattering convolution network (ISCN). ISCN, which involves cascade of modulus complex wavelet transforms and averaging operations results in scattering coefficients (SC), these coefficients give stable invariant representations and also maps the texture of fatty liver image to a discriminative manifold giving good features for classification. SC are of high dimension and hence a compact representation feature is obtained by summing all the SC coefficients. Summed SC features along with cubic SVM classifier gave an accuracy of 96.6% in automatically categorizing the fatty content present in the tissue of a liver.
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11:05-11:20, Paper ThBT14.2 | Add to My Program |
NucleiNet: A Convolutional Encoder-Decoder Network for Bio-Image Desnoising |
Liu, Zi-chuan | Nanyang Tech. Univ |
Hu, Yi-fei | Nanyang Tech. Univ |
Xu, Hang | Nanyang Tech. Univ |
Nasser, Lamees | Bioinformatics Inst. (BII), A*STAR |
Boudier, Thomas | A-STAR |
Coquent, Philippe | Nanyang Tech. Univ |
Yu, Hao | Nanyang Tech. Univ |
Keywords: Image segmentation, Image classification, Image visualization
Abstract: Scalable image data analysis is widely demanded in biomedical diagnosis by leveraging rapidly developed optical technology and advanced machine learning algorithm. However, bio-image obtained for single molecular or cell requires denoising with better resolution in diagnosis. This paper introduces a high-throughput and accurate bio-image denoising method for different kinds of three-dimensional microscopy cell images. Using a convolutional encoder-decoder network, one can provide a scalable bio-image platform, called NucleiNet, to automatically segment, classify and track cell nuclei. Using a benchmark of 2480 nuclei images, the experiment results show that we can achieve 0.99 F-score and 0.99 pixel-wise accuracy, which means that over 97% of nuclei can be successfully detected with no merging nuclei found.
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11:20-11:35, Paper ThBT14.3 | Add to My Program |
Automated Discrimination of Dementia Spectrum Disorders Using Extreme Learning Machine and Structural T1 MRI Features |
Kim, Jongin | Gwangju Inst. of Science and Tech |
Lee, Boreom | Gwangju Inst. of Science and Tech. (GIST) |
Keywords: Image classification, Magnetic resonance imaging - MR neuroimaging, Brain image analysis
Abstract: The classification of neuroimaging data for the diagnosis of Alzheimer’s Disease (AD) is one of the main research goals of the neuroscience and clinical fields. In this study, we performed extreme learning machine (ELM) classifier to discriminate the AD, mild cognitive impairment (MCI) from normal control (NC). We compared the performance of ELM with that of a linear kernel support vector machine (SVM) for 718 structural MRI images from Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. The data consisted of normal control, MCI converter (MCI-C), MCI non-converter (MCI-NC), and AD. We employed SVM-based recursive feature elimination (RFE-SVM) algorithm to find the optimal subset of features. In this study, we found that the RFE-SVM feature selection approach in combination with ELM shows the superior classification accuracy to that of linear kernel SVM for structural T1 MRI data.
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11:35-11:50, Paper ThBT14.4 | Add to My Program |
Exploring Transfer Learning for Gastrointestinal Bleeding Detection on Small-Size Imbalanced Endoscopy Images |
Li, Xiuli | IBM Res. – China |
zhang, hao | ANKON Tech. Co., LTD - China |
Zhang, Xiaolu | IBM Res. – China |
liu, hao | ANKON Tech. Co., LTD - China |
xie, Guotong | IBM Res. – China |
Keywords: Image classification, Image feature extraction
Abstract: The success of Convolutional Neural Network (CNN) is attributed to their ability to learn rich midlevel image representations as opposed to hand-crafted low-level features used in many natural image classification methods. Learning CNN, however, amounts to estimating millions of parameters and requires a very large number of annotated image samples. In this paper, we explored transfer learning for gastrointestinal bleeding detection on small-size imbalanced endoscopy images, and showed how image representations learned with CNN on large-scale annotated datasets can be efficiently transferred to other tasks with limited amount of training data. We first transferred pre-trained Inception V3 model trained on the ImageNet dataset to compute mid-level image representation, and then fine-tuned the trained model with labeled endoscopy images, and resumed training from already learned weights. Additionally, we introduce both data augmentation and image resampling to increase the size of the training database and the positive sample rate to perform the Transfer Learning. Our results showed that our transfer learning method produces the best performance on AUC (the area under the receiver operating curve), Precision, Recall and Accuracy as compared to both the hand-crafted feature based method and training CNN model from-scratch method.
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11:50-12:05, Paper ThBT14.5 | Add to My Program |
Brain Tumor Segmentation Using Cascaded Deep Convolutional Neural Network |
Hussain, Saddam | Univ. of Engineering and Tech. Taxila |
Anwar, Syed | Univ. of Engineering and Tech |
Majid, Muhammad | Univ. of Engineering and Tech. Taxila |
Keywords: Image segmentation, Brain image analysis, Magnetic resonance imaging - MR neuroimaging
Abstract: Gliomas are the most common and threatening brain tumors with little to no survival rate. Accurate detection of such tumors is crucial for survival of the subject. Naturally, tumors have irregular shape and can be spatially located anywhere in the brain, which makes it a challenging task to segment them accurately enough for clinical use. In this paper, an automated segmentation algorithm for brain tumor using deep convolutional neural networks (DCNN) is proposed. Deep networks tend to have a lot of parameters thus over-fitting is almost always an issue especially when data are sparse. Max-out and drop-out layers are used to reduce the chances of over-fitting since data are scant. Patch based training method is used for the model where two types of patches sized 37×37 and 19×19 with same center pixel are selected. The proposed algorithm includes preprocessing in which images are normalized and bias field corrected, and post processing where small false positives are removed using morphological operators. BRATS 2013 dataset is used for evaluation of the proposed method, where it outperforms state-of-the-art methods with similar settings in key performance indicators.
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12:05-12:20, Paper ThBT14.6 | Add to My Program |
Surgical Tool Detection in Cataract Surgery Videos through Multi-Image Fusion Inside a Convolutional Neural Network |
ALHAJJ, Hassan | Inserm |
Lamard, Mathieu | Univ. De Bretagne Occidentale |
Charrière, Katia | LaTIM - INSERM UMR 1101, Brest, F-29200 France |
Cochener, Béatrice | CHU Morvan |
Quellec, Gwenole | Inserm |
Keywords: Image classification, Optical imaging and microscopy - Microscopy
Abstract: The automatic detection of surgical tools in surgery videos is a promising solution for surgical workflow analysis. It paves the way to various applications, including surgical workflow optimization, surgical skill evaluation and real-time warning generation. A solution based on convolutional neural networks (CNNs) is proposed in this paper. Unlike existing solutions, the proposed CNN does not analyze images independently: it analyzes sequences of consecutive images. Features extracted from each image by the CNN are fused inside the network using the optical flow. For improved performance, this multi-image fusion strategy is also applied while training the CNN. The proposed framework was evaluated in a dataset of 30 cataract surgery videos (6 hours of videos). Ten tool categories were defined by surgeons. The proposed system was able to detect each of these categories with a high area under the ROC curve (0.953 <= Az <= 0.987). The proposed detector, based on multi-image fusion, was significantly more sensitive and specific than a similar system analyzing images independently (p = 2.98 x 10 -6 and p = 2.07 x 10 -3, respectively).
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ThBT15 Minisymposium, Webster Room |
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Bioengineering Advances in the Diagnosis and Treatment of Sleep Apnea II |
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Chair: Khoo, Michael | Univ. of Southern California |
Co-Chair: Penzel, Thomas | Charite Univ. Berlin |
Organizer: Khoo, Michael | Univ. of Southern California |
Organizer: Penzel, Thomas | Charite Univ. Berlin |
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10:50-11:05, Paper ThBT15.1 | Add to My Program |
Screening Patients for Risk of Sleep Apnea Using Facial Photographs |
de Chazal, Philip | Univ. of Sydney |
Tabatabaei Balaei, Asghar | Univ. of Sydney |
Nosrati, Hadis | The Univ. of Sydney |
Keywords: Sleep - Obstructive sleep apnea
Abstract: We investigated using frontal and profile facial photographic images for screening patients for risk of sleep apnea. A 180 image pairs were used from patients who were diagnosed using an attended overnight polysomnogram test into controls (AHI<10/h) and sleep apnea (AHI≥10/h). A series of 35 landmarks and 71 features motivated by craniofacial structure pertinent to upper airway physiology were identified on the photographs. After reducing the dimension of the feature set using recursive feature selection, the features were processed by a Support Vector Machine (SVM). Classification was performed using linear kernel SVM. The accuracy and area under Receiver Operating Curve (ROC) improved when the number of features reduced from 71 to eight top-ranked features. Further improvement was achieved by adding clinical measurements to the selected features resulting in the accuracy of 80% and the area under ROC of 0.83.
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11:05-11:20, Paper ThBT15.2 | Add to My Program |
Improving Diagnosis of OSA by Interpretation of Breath Sounds in Mhealth (I) |
Jané, Raimon | Inst. De Bioenginyeria De Catalunya (IBEC) |
Castillo, Yolanda | Inst. for Bioengineering of Catalonia (IBEC) |
Cámara, Miguel Ángel | Inst. for Bioengineering of Catalonia |
Blanco-Almazán, Dolores | Inst. for Bioengineering of Catalonia |
Estrada, Luis | Inst. De Bioenginyeria De Catalunya |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Snoring, Sleep - Periodic breathing & central apnea
Abstract: In this work, we characterize and compare the responses of mHealth-based microphones and commercial contact microphones, to evaluate their potential as sensors for OSA diagnosis. This proof-of-concept study suggests that acoustic analysis of snoring, through smartphones, can be a feasible alternative to screen and monitor OSA patients at home.
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11:20-11:35, Paper ThBT15.3 | Add to My Program |
Directional Coupling in Cardiorespiratory System According the Activation of Autonomic Nervous System Depending on Sleep Stages (I) |
Yoon, Heenam | Seoul National Univ |
Lee, Yujin | Seoul National Univ. Hospital |
Jeong, Do-Un | Seoul National Univ. Hospital |
Park, Kwang S. | Seoul National Univ |
Keywords: Cardiovascular and respiratory system modeling - Sleep-cardiorespiratory Interactions, Sleep - Obstructive sleep apnea, Cardiovascular and respiratory signal processing - Non-linear cardiovascular or cardiorespiratory relations
Abstract: In this study, we investigated cardiorespiratory interaction during sleep. Directionality analysis was applied to quantify characteristics of cardiorespiratory coupling. As results, bidirectional interaction in cardiorespiratory system gradually increased from wake to deep sleep in healthy subjects. Previous researches revealed that network connectivity in human physiological systems is decreased in deep sleep. Thus, each of cardiorespiratory system lies on self-sustained state out of external factors, finally two periodic systems are bidirectionally coupled as a natural process. Therefore, bidirectional interaction can contribute to reduce energy consumption which in one of main roles of sleep. Although similar pattern appeared in patients with obstructive sleep apnea (OSA), the coupling strength from respiratory system to cardiac system was higher than those in healthy subjects, and also was associated with OSA severity. Considering the bidirectional coupling as an energy restorative process, these findings may be linked with the fact that OSA patients suffer from daytime sleepiness.
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11:35-11:50, Paper ThBT15.4 | Add to My Program |
Quantitative Monitoring of Sleep Apnea and Hypopnea Using Portable Electrical Impedance Tomography (EIT) (I) |
Woo, Eung Je | Kyung Hee Univ |
OH, TONG IN | Kyunghee Univ |
Wi, Hun | KyungHee Univ |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Periodic breathing & central apnea, Sleep - Sleep apnea therapy
Abstract: Polysomnography has been widely used for evaluation of obstructive sleep apnea (OSA) patients in hospitals. However, there exist clinical needs for simpler means that can be used during natural sleep at home. Most existing devices intended to be used at home measure signals during sleep and extract diagnostic information of OSA from the acquired signals. Unlike these indirect methods, we propose a novel direct method to measure lung ventilation during natural sleep at home using a portable electrical impedance tomography (EIT) device. The first prototype consists of a chest belt with 16 active electrodes and a small battery-operated device including all electronics for EIT, SpO2, and snoring sound. This paper presents its design and preliminary experimental results of OSA detection. Future design will include ECG and body position sensors in addition to those demonstrated in this paper.
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ThBT17 Oral Session, Einthoven Hall |
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Signal Processing - Fetal and Neonatal Physiology |
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Chair: Khandoker, Ahsan Habib | Khalifa Univ. of Science, Tech. and Res |
Co-Chair: Lavanga, Mario | KU Leuven |
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10:50-11:05, Paper ThBT17.1 | Add to My Program |
Automatic Quiet Sleep Detection Based on Multifractality in Preterm Neonates: Effects of Maturation |
Lavanga, Mario | KU Leuven |
De Wel, Ofelie | KU Leuven |
Caicedo Dorado, Alexander | Katholieke Univ. Leuven |
Heremans, Elisabeth | KU Leuven |
Jansen, Katrien | Department of Pediatrics, Univ. Hospital Gasthuisberg, Leuve |
Dereymaeker, Anneleen | Department of Development and Regeneration, Univ. of Leuven |
Naulaers, Gunnar | Univ. Hospitals Leuven |
Van Huffel, Sabine | Katholieke Univ. Leuven |
Keywords: Time-frequency and time-scale analysis - Wavelets, Nonlinear dynamic analysis - Biomedical signals, Signal pattern classification
Abstract: This study investigates the multifractal formalism framework for quiet sleep detection in preterm babies. EEG recordings from 25 healthy preterm infants were used in order to evaluate the performance of multifractal measures for the detection of quiet sleep. Results indicate that multifractal analysis based on wavelet leaders is able to identify quiet sleep epochs, but the classifier performances seem to be highly affected by the infant's age. In particular, from the developed classifiers, the lowest area under the curve (AUC) has been obtained for EEG recordings at very young age (<= 31 weeks post-menstrual age), and the maximum at full-term age (>= 37 weeks postmenstrual age). The improvement in performances can be due to a change in the multifractality properties of neonatal EEG during the maturation of the infant, which makes the EEG sleep stages more distinguishable.
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11:05-11:20, Paper ThBT17.2 | Add to My Program |
Mutual Information for Intrapartum Fetal Heart Rate Analysis |
Granero Belinchon Carlos, Granero | Univ. Lyon, Ens De Lyon, Univ. Claude Bernard, CNRS, Lab. D |
Roux, Stéphane | ENS Lyon, CNRS |
Garnier, Nicolas B. | Univ. Lyon, ENS De Lyon, Univ. Claude Bernard, CNRS |
Abry, Patrice | ENS Lyon, CNRS |
Doret, Muriel | Hospices Civils De Lyon Univ. Lyon I |
Keywords: Physiological systems modeling - Signal processing in physiological systems, Nonlinear dynamic analysis - Biomedical signals, Data mining and processing in biosignals
Abstract: The analysis of the temporal dynamics in intra- partum fetal heart rate (FHR), aiming at early detection of fetal acidosis, constitutes an intricate signal processing task, that continuously receives significant research efforts. Entropy and entropy rates, envisaged as measures of complexity, often computed via popular implementations referred to as Ap- proximate Entropy (ApEn) or Sample Entropy (SampEn), have regularly been reported as significant features for intrapartum FHR analysis. The present contribution aims to show how mutual information enhances characterization of FHR temporal dynamics and improves fetal acidosis detection performance. To that end, mutual information is first connected to ApEn and SampEn both conceptually and with respect to estimation procedure. Second, mutual information, ApEn and SampEn are computed on a large (≃ 1000 subjects) and documented database of FHR data, collected in a French academic hospital. Reported results show that the use of mutual information permits to significantly outperform ApEn and SampEn for acidosis detection, during any stage of labor.
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11:20-11:35, Paper ThBT17.3 | Add to My Program |
Portable Neonatal EEG Monitoring and Sonification on an Android Device |
Poveda Pena, Jonatan | Univ. Pol. De Catalunya |
O'Sullivan, Mark | Univ. Coll. Cork |
Popovici, Emanuel | Univ. Coll. Cork |
Temko, Andriy | Univ. Coll. Cork |
Keywords: Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: Clinical evaluation of electroencephalogram (EEG) is important for understanding and monitoring the electrical activity present in the brain. In collusion with engineering advances, the movement towards portable, rapid and low-cost EEG monitoring is growing. This will allow a greater availability of monitoring technologies for assessing brain function and health in disadvantaged communities. This paper presents an alternative method for interpreting neonatal brain health in real-time via the sonification of EEG on a smartphone. The paper discusses the implementation of the real-time EEG sonification using a phase vocoder and shows how the method is achievable using low-cost smartphone technologies with energy efficient algorithms.
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11:35-11:50, Paper ThBT17.4 | Add to My Program |
A Semi-Markov Chain Approach to Modeling Respiratory Patterns Prior to Extubation in Preterm Infants |
Onu, Charles Chijioke | McGill Univ |
Kanbar, Lara | McGill Univ |
Shalish, Wissam | McGill Univ |
Brown, Karen | McGill Univ |
Sant'Anna, Guilherme Mendes | McGill Univ |
Kearney, Robert Edward | McGill Univ |
Precup, Doina | McGill Univ |
Keywords: Signal pattern classification - Markov models, Physiological systems modeling - Signal processing in physiological systems, Data mining and processing in biosignals
Abstract: After birth, extremely preterm infants often require specialized respiratory management in the form of invasive mechanical ventilation (IMV). Protracted IMV is associated with detrimental outcomes and morbidities. Premature extubation, on the other hand, would necessitate reintubation which is risky, technically challenging and could further lead to lung injury or disease. We present an approach to modeling respiratory patterns of infants who succeeded extubation and those who required reintubation which relies on Markov models. We compare the use of traditional Markov chains to semi-Markov models which emphasize cross-pattern transitions and timing information, and to multi-chain Markov models which can concisely represent non-stationarity in respiratory behavior over time. The models we developed expose specific, unique similarities as well as vital differences between the two populations.
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11:50-12:05, Paper ThBT17.5 | Add to My Program |
Influence of ECG Sampling Rate in Fetal Heart Rate Variability Analysis |
De Jonckheere, Julien | CHRU De Lille |
Jeanne, Mathieu | CHRU De Lille |
Logier, Regis | CHRU De Lille |
Keywords: Time-frequency and time-scale analysis - Wavelets, Time-frequency and time-scale analysis - Nonstationary processing, Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: Fetal hypoxia results in a fetal blood acidosis (pH<7.10). In such a situation, the fetus develops several adaptation mechanisms regulated by the autonomic nervous system. Many studies demonstrated significant changes in heart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).
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ThBT18 Oral Session, Montgomery Hall |
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Neural Networks and Support Vector Machines I |
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Chair: Huang, Yufei | Univ. of Texas at San Antonio |
Co-Chair: Hwang, Han-Jeong | Kumoh National Inst. of Tech |
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10:50-11:05, Paper ThBT18.1 | Add to My Program |
Convolutional Neural Networks for Event-Related Potential Detection: Impact of the Architecture |
Cecotti, Hubert | Univ. of Ulster |
Keywords: Signal pattern classification, Neural networks and support vector machines in biosignal processing and classification, Data mining and processing - Pattern recognition
Abstract: The detection of brain responses at the single-trial level in the electroencephalogram (EEG) such as event-related potentials (ERPs) is a difficult problem that requires different processing steps to extract relevant discriminant features. While most of the signal and classification techniques for the detection of brain responses are based on linear algebra, different pattern recognition techniques such as convolutional neural network (CNN), as a type of deep learning technique, have shown some interest as they are able to process the signal after limited pre-processing. In this study, we propose to investigate the performance of CNNs in relation of their architecture, and also in relation to how they are evaluated: a single system for each subject, or a system for all the subjects. More particularly, we want to address the change of performance that can be observed between specifying a neural network to a subject, or by considering a neural network for a group of subjects, taking advantage of a larger number of trials from different subjects. The results support the conclusion that a convolutional neural network trained on different subjects can lead to an AUC above 0.9 by using an appropriate architecture using spatial filtering and shift invariant layers.
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11:05-11:20, Paper ThBT18.2 | Add to My Program |
Design of Deep Convolutional Networks for Prediction of Image Rapid Serial Visual Presentation Events |
Mao, Zijing | UTSA |
Yao, Wan Xiang | UTSA |
Huang, Yufei | Univ. of Texas at San Antonio |
Keywords: Neural networks and support vector machines in biosignal processing and classification, Signal pattern classification, Data mining and processing - Pattern recognition
Abstract: We report in this paper an investigation of convolutional neural network (CNN) models for target prediction in time-locked image rapid serial visual presentation (RSVP) experiment. We investigated CNN models with 11 different designs of convolution filters in capturing spatial and temporal correlations in EEG data. We showed that for both within-subject and cross-subject predictions, the CNN models outperform the state-of-the-art algorithms: Bayesian linear discriminant analysis (BLDA) and xDAWN spatial filtering and achieved >6% improvement. Among the 11 different CNN models, the global spatial filter and our proposed region of interest (ROI) achieved best performance. We also implemented the deconvolution network to show how we can visualize from activated hidden units for target/nontarget events learned by the ROI-CNN. Our study suggests that deep learning is a powerful tool for RSVP target prediction and the proposed model is applicable for general EEG-based classifications in brain computer interaction research. The code of this project is available at https://github.com/ZijingMao/ROICNN.
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11:20-11:35, Paper ThBT18.3 | Add to My Program |
A Novel Approach for Automatic Detection of Atrial Fibrillation Based on Inter Beat Intervals and Support Vector Machine |
Andersen, Rasmus Sten | Tech. Univ. of Denmark |
Poulsen, Erik S. | Cortrium ApS |
Puthusserypady, Sadasivan | Tech. Univ. of Denmark |
Keywords: Signal pattern classification, Time-frequency and time-scale analysis - Wavelets, Nonlinear dynamic analysis - Biomedical signals
Abstract: Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with a major economic burden for the society. Automatic detection of AF in long term recordings can efficiently assist in early diagnosis and management of comorbidities associated with AF. This study presents a novel approach for AF detection based on Inter Beat Intervals (IBI) extracted from long term electrocardiogram (ECG) recordings. Five time-domain features are extracted from the IBIs and a Support Vector Machine (SVM) is used for classification. The results are compared to a state of the art algorithm based on raw ECG. Both algorithms are evaluated on the MIT-BIH Atrial Fibrillation database resulting in equally high classification performance (Sensitivity ≥ 95%). The proposed approach requires detection of R-peaks in the ECG signal but allows for significantly reduced computation time without loss of performance.
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11:35-11:50, Paper ThBT18.4 | Add to My Program |
Informative Sensor Selection and Learning for Prediction of Lower Limb Kinematics Using Generative Stochastic Neural Networks |
Chong, Eunsuk | Korea Inst. of Science and Tech |
Choi, Taejin | Korea Inst. of Science and Tech |
Kim, Hyungmin | Korea Inst. of Science and Tech |
Kim, Seung-Jong | Korea Inst. of Science and Tech |
Hwang, Yoha | Korea Inst. of Science and Tech |
Lee, Jong Min | Korea Inst. of Science and Tech |
Keywords: Neural networks and support vector machines in biosignal processing and classification, Signal pattern classification - Genetic algorithms, Physiological systems modeling - Signals and systems
Abstract: We propose a novel approach of selecting useful input sensors as well as learning a mathematical model for predicting lower limb joint kinematics. We applied a feature selection method based on the mutual information called the variational information maximization, which has been reported as the state-of-the-art work among information based feature selection methods. The main difficulty in applying the method is estimating reliable probability density of input and output data, especially when the data are high dimensional and realvalued. We addressed this problem by applying a generative stochastic neural network called the restricted Boltzmann machine, through which we could perform sampling based probability estimation. The mutual informations between inputs and outputs are evaluated in each backward sensor elimination step, and the least informative sensor is removed with its network connections. The entire network is fine-tuned by maximizing conditional likelihood in each step. Experimental results are shown for 4 healthy subjects walking with various speeds, recording 64 sensor measurements including electromyogram, acceleration, and foot-pressure sensors attached on both lower limbs for predicting hip and knee joint angles. For test set of walking with arbitrary speed, our results show that our suggested method can select informative sensors while maintaining a good prediction accuracy.
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11:50-12:05, Paper ThBT18.5 | Add to My Program |
Using Non-Iterative Methods and Random Weight Networks to Classify Upper-Limb Movements through Semg Signals |
Cene, Vinicius H. | UFRGS |
Favieiro, Gabriela Winkler | Federal Univ. of Rio Grande Do Sul (UFRGS) |
Balbinot, Alexandre | Federal Univ. of Rio Grande Do Sul (UFRGS) |
Keywords: Signal pattern classification, Neural networks and support vector machines in biosignal processing and classification, Principal component analysis
Abstract: This paper presents the use of two non-iterative methods to perform the classification of 17 different upper-limb movements through sEMG signal processing. The two methods were compared with a SVM classifier using three different databases involving amputee subjects. The non-iterative methods presented equivalent or superior classification accuracy than SVM method. Thereafter a stage of PCA pre-processing method was used in order to promote a better class separation prior the non-iterative classifiers. The best accuracy result without PCA was achieved by the Regularized Extreme Learning Machines algorithm (88,4% for non-amputee subjects and 79,4% for the amputee). The PCA method used boosted the accuracy of the two non-iterative methods which the mean accuracy was 94% for the non-amputee subjects and 85% for the amputee subjects.
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ThCT2 Invited Session, Cho Room |
Add to My Program |
Photoacoustic and Multimodal Imaging |
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Chair: Zhou, Qifa | Univ. of Southern California |
Co-Chair: Chen, Zhongping | Univ. of California, Irvine |
Organizer: zhou, Qifa | Univ. of Southern California |
Organizer: Chen, Zhongping | Univ. of California, Irvine |
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14:20-14:35, Paper ThCT2.1 | Add to My Program |
Multi-Functional Ultrasonic Micro-Elastography Imaging System (I) |
zhou, Qifa | Univ. of Southern California |
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14:35-14:50, Paper ThCT2.2 | Add to My Program |
Wide-Field High-Speed Photoacoustic Imaging of Brains (I) |
YAO, JUNJIE | DUKE Univ. |
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14:50-15:05, Paper ThCT2.3 | Add to My Program |
Optical Coherence Photoacoustic Microscopy (OC-PAM) (I) |
Jiao, Shuliang | Florida International Univ. |
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15:05-15:20, Paper ThCT2.4 | Add to My Program |
Integrated Tri-Modality System for Intravascular Imaging (I) |
Chen, Zhongping | Univ. of California, Irvine |
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15:20-15:35, Paper ThCT2.5 | Add to My Program |
Flow Measurement in Small Animal Glioma Using Plane Wave Ultrasound (I) |
Qiu, Weibao | Shenzhen Inst. of Advanced Tech. Chinese Acad. of S |
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ThCT3 Minisymposium, Park Room |
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Tissue Electromagnetic Property Mapping Using Magnetic Resonance Imaging
(MRI) |
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Chair: Lee, Joonsung | Inst. for Basic Science |
Co-Chair: Lee, Seung-Kyun | Sungkyunkwan Univ |
Organizer: Lee, Joonsung | Inst. for Basic Science |
Organizer: Lee, Seung-Kyun | Sungkyunkwan Univ |
Organizer: Wang, Yi | Cornell Univ |
Organizer: Lee, Jongho | Seoul National Univ |
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14:20-14:35, Paper ThCT3.1 | Add to My Program |
Electric Properties Tomography for MRI - an Introduction (I) |
Katscher, Ulrich | Philips Res. Europe - Hamburg |
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14:35-14:50, Paper ThCT3.2 | Add to My Program |
TE=0 Phase Estimation in Multi-Echo Gradient Echo for Simultaneous Conductivity and Susceptibility Imaging (I) |
Kim, Dong-Hyun | Yonsei Univ |
Keywords: Magnetic resonance imaging - Pulse sequence
Abstract: Simultaneous quantitative imaging of conductivity and susceptibility can provide unique opportunity to investigate both normal and abnormal tissue. Here, a method to probe both properties is introduced. During the reconstruction process, an estimation procedure is needed to accurately determine the quantitative values. An estimation based on Kalman filter approach is used to enhance the estimation. Using Kalman filter based approach, simultaneous electromagnetic property maps were successfully acquired.
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ThCT5 Invited Session, Lee Room |
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Wearable Devices for Cardiovascular Monitoring |
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Chair: Chon, Ki | Univ. of Connecticut |
Co-Chair: Kim, Insoo | Univ. of Connecticut Health Center |
Organizer: Chon, Ki | Univ. of Connecticut |
Organizer: Kim, Insoo | Univ. of Connecticut Health Center |
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14:20-14:35, Paper ThCT5.1 | Add to My Program |
Graphene-Based Implantable Electrocardiogram Flexible Monitoring Device (I) |
Ma, Zhenqiang | Univ. of Wisconsin-Madison |
Bong, Jihye | Univ. of Wisconsin, Madison |
Lee, Juhwan | Univ. of Wisconsin, Madison |
Jung, Yei Hwan | Univ. of Wisconsin, Madison |
Ryu, Jae Ha | Univ. of Wisconsin, Madison |
Attia, Itzhak Z. | Mayo Clinic |
Ladewig, Dorothy | Mayo Clinic |
Friedman, Paul | Mayo Clinic |
Keywords: Implantable sensors - Biocompatibility, Wearable body-compliant, flexible and printed electronics, Bio-electric sensors - Sensor systems
Abstract: Conventional electrophysiological measurement monitors typically involve rigid, bulky and large recording systems that do not conform to curvilinear surfaces of biological tissues. Moreover, the opaque metallic conductors comprising the system limit simultaneous imaging and recording capabilities beneficial for clinical applications. Here, we demonstrate a flexible electrocardiogram (ECG) device using transparent and biocompatible graphene and Parylene C, which permits successful recording of ECG signals under implanted condition, while imaging the underlying tissues.
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14:35-14:50, Paper ThCT5.2 | Add to My Program |
Development of a Low-Cost Wearable Device for Intermittent and Continuous Monitoring of Paroxysmal Atrial Fibrillation (I) |
Chon, Ki | Univ. of Connecticut |
Keywords: Wearable sensor systems - User centered design and applications, Physiological monitoring - Novel methods, Integrated sensor systems
Abstract: There has been an emergence of novel wearable devices for cardiovascular monitoring over the past several years. While event and Holter monitors can be considered some of the first wearable devices for arrhythmia detection, with the advent of smartwatches, smartphones, smart-patches and accelerometer-based wearables such as Fitbit, long-term and cost-effective arrhythmia monitoring is now potentially realizable. Paroxysmal atrial fibrillation detection is of particular interest as it requires long-term monitoring. This talk will detail the latest development of various cost-effective and long-term monitoring devices for arrhythmia detection including atrial fibrillation. In particular, the latest developments on smartwatches, a novel patch and armband devices for arrhythmia detection will be discussed.
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14:50-15:05, Paper ThCT5.3 | Add to My Program |
Wearable Device for Cardiac Rehabilitation (I) |
Lee, Hooseok | Wonkwang Univ. School of Medicine |
Chung, Heewon | Wonkwang Univ. School of Medicine |
Ko, Hoon | Wonkwang Univ. School of Medicine |
Lee, Jinseok | Wonkwang Univ. School of Medicine |
Keywords: Wearable sensor systems - User centered design and applications, Wearable body sensor networks and telemetric systems, Bio-electric sensors - Sensor systems
Abstract: We introduce a wearable device for cardiac rehabilitation (CR) exercise. As an efficient guide for the exercise, we developed a watch-type wearable device and its smartphone application. The wearable sensor measures heart rate (HR) and compares the rate with target heart rate zone (THZ) in real-time. With the measured HR status, the sensor adjusts the exercise intensity to shift the patient’s HR to the THZ. After the exercise, the measured HRs are sent to the smartphone application via Bluetooth. The application provides the THZ retention rate as an objective evaluation indicator.
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15:05-15:20, Paper ThCT5.4 | Add to My Program |
A Pulse Arrival Time Based Index As Surrogates of Ankle Brachial Index for the Assessment of Peripheral Arterial Disease (I) |
Poon, Carmen C. Y. | The Chinese Univ. of Hong Kong |
Yan, Bryan P. | Prince of Wales Hospital, the Chinese Univ. of Hong Kong |
Lau, James Y. W. | The Chinese Univ. of Hong Kong |
Zheng, Yali | The Chinese Univ. of Hong Kong |
Keywords: Physiological monitoring – Instrumentation, Physiological monitoring - Modeling and analysis, Physical sensors and sensor systems - Optical and photonic Sensors and systems
Abstract: Ankle-Brachial Pressure Index (ABI), the ratio of ankle blood pressure to arm pressure, has been used to assess the severity of peripheral arterial disease (PAD) and to predict major cardiovascular events. This study proposes an index which can be readily obtained from electrocardiogram and photoplethysmogram by wearable sensors, and studies its correlation with ABI. Specifically, the ratio of pulse arrival time (PAT) measured from the fingertips to PAT measured from the toes of both sides (PATratio) was calculated. The results of this study showed that the coefficient of determination (R2 ) between PATratio and ABI is 0.57 when measured in sitting posture when measured on 14 subjects. Compared with ABI, the advantages of PATratio are 1) it can be measured at ease with wearable sensors that are available at a relatively low cost; 2) the PAT-derived indices can be measured more conveniently in a sitting posture; and 3) it can potentially provide longer term, continuous monitoring of the vascular function.
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15:20-15:35, Paper ThCT5.5 | Add to My Program |
Exploration and Validation of Alternate Sensing Methods for Wearable Continuous Pulse Transit Time Measurement Using Optical and Bioimpedance Modalities |
Ibrahim, Bassem | |
Nathan, Viswam | Texas A&M Univ |
Jafari, Roozbeh | Texas A&M Univ |
Keywords: Bio-electric sensors - Sensing methods, Physiological monitoring - Novel methods, Integrated sensor systems
Abstract: In this work we explore the viability of a multi-modal sensing device that can be integrated in a wearable form factor for daily, non-invasive ambulatory blood pressure (BP) monitoring. A common approach in previous research has been to rely on measuring the pulse transit time (PTT), which has been shown to be correlated with the BP. In this work, we look into the feasibility of measuring PTT using sensors separated by a small distance on one arm so that any eventual realization of the system is convenient to wear and use over long periods of time. Moreover, we investigate the combined use of two different modalities for cardiovascular measurement: the optical photoplethysmogram (PPG) as well as the bio-potential based impedance (Bio-Z) measurement. These two modalities have been previously only studied on their own or in conjunction with the electrocardiogram (ECG) for the purpose of estimating PTT. We measure the PTT from the wrist to the finger using Bio-Z and PPG sensors, and compare it to the conventional PTT measured from the ECG to PPG at the finger, in order to prove that it can be an effective replacement for existing PTT measurement strategies. Moreover, successful measurement of PTT with two different modalities of sensors at close proximity will allow designs with multiple heterogeneous sensors on a more versatile wearable sensing platform that is optimized for power and is more robust to environmental or skin contact changes. This will enable the next generation of smart watches that capture PTT and BP. Experiments were conducted in vivo with simultaneous ECG, Bio-Z and PPG sensors, and results indicate that the PTT calculated from the Bio-Z and PPG sensors placed at a close distance correlates well with the more established PTT measurement using the ECG in conjunction with PPG, with correlation coefficient as high as 0.92.
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ThCT6 Oral Session, Zworykin Room |
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Tissue Engineering |
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Chair: Kim, Kyung Sook | Kyung Hee Univ |
Co-Chair: Lee, EunAh | Kyung Hee Univ |
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14:20-14:35, Paper ThCT6.1 | Add to My Program |
Experimental Research on Oxygen Enrichment in Bioreactors Based on Oxygen Carriers |
Wu, Changzhe | Chinese Acad. of Sciences |
zhang, Cheng | Chinese Acad. of Sciences, Beijing, |
Zhang, Guanghao | Inst. of Electrical Engineering, Chinese Acad. of Sciences |
Huo, Xiaolin | Chinese Acad. of Sciences |
Keywords: Translational issues in tissue engineering and biomaterials - Bioreactors
Abstract: Dissolved oxygen (DO) concentration plays an important role in the growth and function of cells cultured in bioreactors, especially in dense cultures where cells are often severely oxygen-deprived.To overcome the insufficient oxygen supply in high-density cultured cells, perfluorocarbon oxygen carriers were introduced to enhance the oxygen supply in bioreactors, providing sufficient oxygen for cells cultured in vitro. Methods: 1) The perfluorocarbon oxygen carrier emulsion is prepared. 2) The verification platform for the oxygenation experiment was constructed as follows: an oxygen supply system consisting of an oxygen source, a membrane oxygenator, and a gas valve; a circulation system consisting of a culture circulation pump and a thermostat; and a detection system consisting of a dissolved oxygen sensor, a pH sensor and a temperature sensor. 3) The trends of dissolved oxygen concentration in the bioreactor under different oxygen carrier concentrations, different medium flow rates and different oxygen source pressures were measured. Results: When the oxygen carrier concentration and the medium flow rate were constant, the oxygen source pressure had little effect on oxygenation rate. When the oxygen source pressure and the oxygen carrier concentration were constant, the oxygenation rate increased with increasing flow rate of the medium. When the medium flow rate and the oxygen source pressure were constant, the dissolved oxygen saturation concentration increased exponentially and the oxygenation rate increased significantly with the increase of the oxygen carrier concentration.The introduction of perfluorocarbon oxygen carriers significantly improves the oxygenation efficiency of bioreactors, and effectively promotes the practical application of high density cultures in vitro and in the bioartificial liver.
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14:35-14:50, Paper ThCT6.2 | Add to My Program |
In Vitro Cell Culture Study of the Conditions of Inhibition Effect of Tumors under Alternating Electric Field |
Huang, Chun-Hao | Chang Gung Univ |
Lei, Kin Fong | Chang Gung Univ |
Keywords: Microfluidic applications, BioMEMS/NEMS - Tissue engineering and biomaterials, Electric fields - Tissue regeneration
Abstract: In vitro cell culture device was developed for the investigation of inhibition effect of cell colonies using alternating electric field. Cancer cells were cultured in 3D hydrogel and cell colonies, or called tumor spheroids, were gradually formed in the culture device. During the culture course, alternating electric field was applied and the applied conditions were investigated to optimize the inhibition effect of cell colonies. Results showed that electric field at frequency of 130 kHz and 0.5 Vpp was the minimal effective conditions of the inhibition of cell colonies. The device was demonstrated to provide a practical tool for the investigation of the efficacy and the therapeutic conditions of inhibiting tumors.
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14:50-15:05, Paper ThCT6.3 | Add to My Program |
Evaluation of Histological and Biomechanical Properties on Engineered Meniscus Tissues Using Sonication Decellularization |
Mardhiyah, Ainaaul | International Islamic Univ. Malaysia |
Sha'ban, Munirah | International Islamic Univ. Malaysia |
Azhim, Azran | International Islamic Univ. Malaysia |
Keywords: Scaffolds in tissue engineering, Biomaterial-cell interactions - Functional biomaterials, Biomimetic materials
Abstract: Sonication decellularization treatment requires proper evaluations on its ability to decellularize meniscus tissue efficiently. This study was done to evaluate the histological and biomechanical properties within meniscus scaffolds. Van Gieson staining was done to evaluate the efficiency of cell removal in meniscus tissues. The consequences of treatment on viscoelastic properties are vital for scaffolds quality and were properly investigated. Picrosirius red and Safranin-O/Fast green staining was carried out to detect extracellular matrix materials (ECM). Sonication decellularization treatment has the ability to demonstrated complete nuclei removal compare to control samples as well as maintaining viscoelastic properties, namely stiffness, compression and residual force. Thus, sonication decellularization treatment had successfully produced and prepared a meniscus bioscaffold candidate in which its biomechanical strength is sustained through protection of ECM properties.
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15:05-15:20, Paper ThCT6.4 | Add to My Program |
Improve Blood Compatibility of Bioresorbable Magnesium Stents Coated with Functionalized Anti-CD34 Antibody and Heparin-Collagen Multiplayers |
Kan, Chung-Dann | National Cheng Kung Univ. Hospital, Department Ofsurgery, Ta |
LAI, YI-PING | National Cheng Kung Univ |
Keywords: Scaffolds in tissue engineering, Scaffolds in tissue engineering - Self-assembled
Abstract: Instentrestenosis and late stent thrombosis continue to be the greatest limitations of drug-eluting stents. In this study, an anti-CD34 antibody functionalized multilayer of hepa-rin/collagen type I is developed by layer-by-layer assemble to enhance biocompatibility and recruit endothelial progenitor cells. The SEM results demonstrate that (Hep/Col)5-coated samples have a rougher surface compared to (Hep/Col)2-coated samples and untreated samples. The EDX and FTIR results both confirmed the presence of heparin and collagen onto the modified samples. The immunofluorescence staining outcomes demonstrated that anti-CD34 antibody has success-fully immobilized onto modified Mg discs.
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15:20-15:35, Paper ThCT6.5 | Add to My Program |
Evaluation of Recellularization on Decellularized Aorta Scaffolds Engineered by Ultrasonication Treatment |
Fitriatul, Nurul | International Islamic Univ. Malaysia |
Sha'ban, Munirah | International Islamic Univ. Malaysia |
Azhim, Azran | International Islamic Univ. Malaysia |
Keywords: Scaffolds in tissue engineering, Biomaterial-cell interactions - Engineered vascular tissue, Biomaterial-cell interactions - Functional biomaterials
Abstract: Aortic scaffolds prepared using sonication decellularization treatment has provided a successful medium for repopulation with vascular smooth muscle cells (VSMCs). The objective of this study is to explore the potential of tissue decellularization using ultrasonication treatment and its recellularization before implantation of the cell-seeded scaffolds into host. Aorta tissue samples are decellularized in 2% SDS with sonication for 10 hours and compared with the native tissues. The 4',6-diamidino-2-phenylindole (DAPI) staining was used to evaluate the decellularization and Hematoxylin-Eosin (H-E) staining was used to compare the VSMCs infiltrations onto the decellularized tissues at day-0 and day-6 after cell-seeding. The results histologically showed complete DNA removal from scaffolds after decellularization and subsequent recellularization resulted in successful VSMCs infiltration. Accordingly, the decellularized tissues treated with 2% SDS in sonication demonstrated successful VSMCs repopulation afterward and is speculated to have less toxicity and able to be effectively implanted into host.
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15:35-15:50, Paper ThCT6.6 | Add to My Program |
A Three-Dimensional Cell Culture Device for Simulation of Hepatic Hypertension |
Kuo, Po-Ling | National Taiwan Univ |
Phung, Hao-Dinh | National Taiwan Univ |
Keywords: Microfluidic applications, Cellular force transduction - Mechanical stimuli and mechanotransduction, Cellular force transduction - Cell-matrix mechanical interactions
Abstract: Hepatic stellate cells (HSCs) play a crucial role in the development of liver fibrosis which is characterized by massive tissue scarring, elevated hepatic sinusoidal pressure, and portal hypertension. However, while a multitude of chemical factors have been investigated in the pathogenesis of liver fibrosis, physical factors such as elevated hydrostatic pressure and shear stress caused by blood flow in sinusoids remain unclear. In this study, we developed a three-dimensional (3D) cell culture microfluidic platform that mimics the physical environments of hepatic sinusoids to investigate the effects of elevated hydrostatic pressure on HSCs phenotypes.
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ThCT8 Oral Session, Schwan Room |
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Brain-Computer Interface III |
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Chair: Jahangiri, Amir | Univ. of Essex |
Co-Chair: Lee, Boreom | Gwangju Inst. of Science and Tech. (GIST) |
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14:20-14:35, Paper ThCT8.1 | Add to My Program |
Phase-Based SSVEPs for Real-Time Control of a Motorised Bed |
Gauci, Norbert | Univ. of Malta |
Falzon, Owen | Univ. of Malta |
Camilleri, Tracey | Univ. of Malta |
Camilleri, Kenneth Patrick | Univ. of Malta |
Keywords: Brain-computer/machine interface, Neural signal processing, Brain functional imaging - EEG
Abstract: Brain-computer interface (BCI) systems have emerged as an augmentative technology that can provide a promising solution for individuals with motor dysfunctions and for the elderly who are experiencing muscle weakness. Steady-state visually evoked potentials (SSVEPs) are widely adopted in BCI systems due to their high speed and accuracy when compared to other BCI paradigms. In this paper, we apply combined magnitude and phase features for class discrimination in a real-time SSVEP-based BCI platform. In the proposed real-time system users gain control of a motorised bed system with seven motion commands and an idle state. Experimental results amongst eight participants demonstrate that the proposed real-time BCI system can successfully discriminate between different SSVEP signals achieving high information transfer rates (ITR) of 82.73 bits/min. The attractive features of the proposed system include noninvasive recording, simple electrode configuration, excellent BCI response and minimal training requirements.
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14:35-14:50, Paper ThCT8.2 | Add to My Program |
Hierarchical Decoding of Grasping Commands from EEG |
Omedes, Jason | Univ. of Zaragoza |
Schwarz, Andreas | Graz, Univ. of Tech |
Montesano, Luis | Univ. De Zaragoza |
Müller-Putz, Gernot | Graz Univ. of Tech |
Keywords: Brain-computer/machine interface, Motor learning, neural control, and neuromuscular systems, Neurorehabilitation
Abstract: Brain-Computer Interfaces may present an intuitive way for motor impaired end users to operate assistive devices of daily life. Recent studies showed that complex kinematics like grasping can be successfully decoded from low frequency electroencephalogram. In this work we present a hierarchical method to asynchronously discriminate two different grasps often used in daily life actions (palmar, pincer) from a combined set of motor execution and motor intention. We compared sensorimotor rhythms based features and time features from the low frequency spectrum for best discrimination results. Our results show not only the principle feasibility of the proposed method with detection of asynchronous motor intention at rates of 80% accuracy and subsequent grasping discrimination over 60%, but also that low frequency time domain features provide a more consistent detection pattern. Although the basis of this results is still an off-line analysis we are confident that these results can be transferred to on-line use.
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14:50-15:05, Paper ThCT8.3 | Add to My Program |
Detection of Self-Paced Movement Intention from Pre-Movement Electroencephalogram Signals with Hilbert Transform |
Zeng, Hong | Southeast Univ |
Wu, Changcheng | Southeast Univ |
Song, Aiguo | Southeast Univ |
Xu, Baoguo | Southeast Univ |
Li, Huijun | Southeast Univ |
Pengcheng, Wen | AVIC Aeronautics Computing Tech. Res. Inst |
Liu, Jia | Nanjing Univ. of Information Sciences & Tech |
Keywords: Brain-computer/machine interface, Neural signal processing, Brain functional imaging - EEG
Abstract: The movement related cortical potential (MRCP) is a well-known neural signature of human's self-paced movement intention, which can be exploited by future neuroprosthesis. Most existing studies have explored the amplitude representation for the movement intention. In this paper we investigate the Hilbert transformed MRCP, which implicitly includes phase information complementarily to amplitude information, for the detection of self-paced upper-limb movement intention. On the datasets in which 5 healthy subjects executed a self-initiated upper limb center-out reaching task in three sessions, we have evaluated the detection model with Hilbert transformed MRCP as features and the state-of-art one with the original MRCP as features. Results show that the Hilbert transformed MRCP based detector is more accurate than the original MRCP based one.
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15:05-15:20, Paper ThCT8.4 | Add to My Program |
The Contribution of Different Frequency Bands in Class Separability of Covert Speech Tasks for BCIs |
Jahangiri, Amir | Univ. of Essex |
Sepulveda, Francisco | Univ. of Essex |
Keywords: Brain-computer/machine interface, Time-frequency and time-scale analysis - Time-frequency analysis, Neural signal processing
Abstract: Abstract— Several recent studies demonstrate the possibility of using user initiated covert speech mental tasks in brain computer interfaces with varying degrees of success, but details of the best frequency features had not been investigated. In this work, ten volunteers in the age range of 22-70 years participated in the experiment. Eight of them were neurologically healthy, one user was dyslexic, and another was autistic. The four words “back”, “forward”, “left”, and “right” were shortened into “BA”, “FO”, “LE”, and “RY”, which are phonetically dissimilar and cognitively relevant directional commands. Participants were asked to covertly speak each as soon as the letters appeared on a screen. Volunteers completed five recording runs. During each run the four words were presented in random succession to avoid sequence bias. The recorded EEG data from the ten users were analysed to discover the best features within a Gabor Transform of the signals, i.e., those yielding the highest word-pair classification accuracy for this specific type of linguistic mental activity. Using this BCI, suitable class separability of covert speech tasks is confirmed for all, including disabled users, with consistently high classification accuracy from 75% to 88% in all cases. Like motor imagery tasks, Alpha and Beta band activity were found to contain 12% and 31% of the most important features respectively. Gamma band activity, which indicates high mental functions, contains 57% of the most important features in this study.
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15:20-15:35, Paper ThCT8.5 | Add to My Program |
EEG Classification for Motor Imagery BCI Using Phase-Only Features Extracted by Independent Component Analysis |
Qureshi, Muhammad Naveed Iqbal | Gwangju Inst. of Science and Tech. Gwangju |
Cho, Dongrae | Gwangju Inst. of Science and Tech |
Lee, Boreom | Gwangju Inst. of Science and Tech. (GIST) |
Keywords: Brain functional imaging - EEG, Brain-computer/machine interface, Brain functional imaging - Classification
Abstract: The accurate classification of the electroencephalography (EEG) signals is the most important task towards the development of a reliable motor imagery brain-computer interface (MI-BCI) system. In this study, we utilized a publically available BCI Competition-IV 2008 dataset IIa. This study address to the binary classification problem of the motor imagery EEG data by using a sigmoid activation function-based extreme learning machines (ELM). We proposed a novel method of extracting the features from the EEG signals by first applying the independent component analysis (ICA) on the time series data and transforming the ICA time series data into Fourier domain and then extract the phase information from the Fourier spectrum. This phase information was further used to calculate the maximized cross-correlation connectivity matrix. The upper diagonal of this matrix was then vectorized and it serves as the basic feature for the ELM classification framework. By using the phase-only features we achieved 97.80% (p < 0.0022) nested cross-validated classification accuracy. In addition, this process is relatively computationally inexpensive. Thus, it can be an excellent candidate for the motor imagery BCI applications.
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15:35-15:50, Paper ThCT8.6 | Add to My Program |
Speeding up SVM Training in Brain-Computer Interfaces |
Lee, David | The Catholic Univ. of Korea |
Lee, Hee-Jae | The Catholice Univ. of Korea |
Park, Sang-Hoon | The Catholic Univ. of Korea |
Jung, Woo-Hyuk | The Catholic Univ. of Korea |
KIM JAEHO, JAEHO | The Catholic Univ. of Korea, Dep.Digital Media |
Lee, Sang-Goog | The Catholic of Univ. of Korea |
Keywords: Brain-computer/machine interface, Neural signal processing
Abstract: Traditional Support Vector Machine (SVM) is widely used classification method for brain-computer interface (BCI). However, SVM has a high computational complexity. In this paper, Gaussian Mixture Model (GMM)-based training data reduction is proposed to reduce high computational complexity. The proposed method is configured as follows: First, wavelet-based combined feature vectors are applied for motor imagery electroencephalography (EEG) identification and principal component analysis (PCA) are used to reduce the dimension of feature vectors. Thereafter, the GMM is implemented to reduce training data sizes. Finally, a nonlinear SVM classifier is used to classify the reduced training data. The performance of the proposed method was evaluated using three different motor imagery datasets in terms of accuracy and training time. The results from the study indicate that the proposed method achieves high accuracy with faster computational time in motor imagery EEG classification.
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ThCT9 Oral Session, Plonsey Room |
Add to My Program |
Neural Stimulation II |
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Chair: McKeown, Martin | Univ. of British Columbia |
Co-Chair: Im, Chang-Hwan | Hanyang Univ |
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14:20-14:35, Paper ThCT9.1 | Add to My Program |
Predicting the Stimulation Effectiveness Using Pre-Stimulation Neural States Via Optogenetic Activation of the Medial Septum Glutamatergic Neurons Modulating the Hippocampal Neural Activity |
Park, Sang-Eon | Georgia Inst. of Tech |
Laxpati, Nealen | Emory Univ. School of Medicine, Georgia Inst. of Tech |
connolly, Mark | Emory Univ |
Mahmoudi, Babak | Emory Univ |
Gross, Robert | Emory Univ |
Keywords: Neural stimulation - Deep brain, Neural signal processing, Neurological disorders - Epilepsy
Abstract: In this study, we explored the role of pre-stimulation neural states on the effectiveness of optogenetic stimulation. Optogenetic stimulation was applied to the medial septum glutamatergic neurons to modulate the hippocampal neural activity in a rat tetanus toxin seizure model. The hippocampal local field potential was recorded using a multi electrode array in an awake and behaving rat. Optical stimulation with a 465nm light source was applied at 35Hz in a 20 seconds off / 20 seconds on pattern with simultaneous recording from the hippocampus. Both the baseline and the stimulation period recordings were divided into 2 second segments and used for the further analysis. In the first experiment, a support vector machine (SVM) model classified the neural states by using spectral features between 0 and 50Hz. 447 out of 545 segments (82.02%) were correctly labeled as ‘Baseline’ while only 326 out of 544 (59.93%) segments from the stimulation period were correctly labeled as ‘Stimulation.’ As the ratio of mislabels is significantly higher for the stimulation period (chi-squared, p<0.01), we concluded that the stimulation was not always effective. In the second experiment, an SVM model predicted the stimulation effectiveness using the spectral features of the pre-stimulation segments. The classification result shows that 63.7% of the pre-stimulation segments correctly predicted the stimulation effectiveness. These findings suggest that the prediction of the stimulation effectiveness may improve the stimulation efficacy by implementing a state-based stimulation protocol.
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14:35-14:50, Paper ThCT9.2 | Add to My Program |
Galvanic Vestibular Stimulation (GVS) Effects on Impaired Interhemispheric Connectivity in Parkinson’s Disease |
Lee, Soojin | The Univ. of British Columbia |
Kim, Diana | The Univ. of British Columbia |
McKeown, Martin | Univ. of British Columbia |
Keywords: Neural stimulation, Neurological disorders - Diagnostic and evaluation techniques, Brain functional imaging - EEG
Abstract: Disrupted interhemispheric connectivity (IHC) is being increasingly recognized as a robust feature of a number of neurological diseases, including Parkinson’s Disease (PD). We investigated whether or not Galvanic Vestibular Stimulation (GVS) – a proposed treatment for PD – affected IHC in 11 PD subjects (off medication). In order to avoid the confound of stimulation artifact disrupting the EEG, we investigated the immediate (52-s) period after stimulation (72-s) with noisy 1/f-type GVS stimuli. Partial Least Squares (PLS) regression was used to determine the subject- specific linear combination of EEG electrodes that maximized covariance between hemispheres and then computed coherence between the dominant PLS components. PD subjects had increased IHC below ~10 Hz and decreased >13 Hz IHC compared to 11 healthy, age-matched controls. After GVS in PD subjects, a significant increase in IHC was detected, especially above 30 Hz. We suggest that GVS may partially exert its beneficial effects in PD by “normalizing” impaired IHC.
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14:50-15:05, Paper ThCT9.3 | Add to My Program |
Network-Mediated Responses of ON Ganglion Cells to Electric Stimulation Become Less Consistent across Trials During Retinal Degeneration |
Lee, Jae-Ik | Henry Ford Health System |
Fried, Shelley | Massachusetts General Hospital / Harvard Medical School |
Im, Maesoon | Henry Ford Health System |
Keywords: Neural stimulation, Neural signal processing
Abstract: Microelectronic retinal prostheses are being developed to restore sight in individuals blinded by outer retinal degenerative diseases such as retinitis pigmentosa and age-related macular degeneration. Unfortunately, the quality of vision restored by these devices is still limited. To improve the quality of elicited vision, our group studies the responses of retinal neurons to electric stimulation. Our previous work showed that responses mediated through the retinal network are reproducible with high temporal precision, even for spikes that occur >100 ms after stimulus onset. Because they arise through the network, it is important to understand whether such reliability changes in the degenerate retina. Here, we examined response variability at several different stages of degeneration: postnatal day 14 (P14), P18, P31 and P60 in a well-established mouse model of degeneration (rd10). Spiking responses of ON alpha RGCs were recorded multiple times to an identical electric stimulus. We found that the trial-to-trial variability increased over the course of retinal degeneration. This finding may help to explain the reported variability in the quality of elicited vision across subjects using these devices.
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15:05-15:20, Paper ThCT9.4 | Add to My Program |
An Artifact-Suppressed Stimulator for Simultaneous Neural Recording and Stimulation Systems |
Liu, Xu | Beijing Univ. of Tech |
Yao, Lei | Inst. of Microelectronics, Singapore |
Li, Peng | Inst. of Microelectronics |
liu, lei | Nanyang Tech. Univ. Singapore |
zou, xiaodan | Inst. of Microelectronics, Singapore |
Je, Minkyu | Inst. of Microelectronics |
Xu, Yong Ping | National Univ. of Singapore |
Keywords: Neural stimulation, Motor neuroprostheses - Neuromuscular stimulation
Abstract: This paper proposes an artifact-suppressed stimulator with a referenced and tuned push-pull stimulation (RTPPS) scheme where a tri-polar electrode is employed. The stimulation pulses delivered to two working electrodes are complementary and thus one counteracts with the other to suppress the artifact at the recording site. The prototype stimulator chip is implemented in 0.18-µm CMOS process technology. In-vivo experiments are carried out with the chip to demonstrate the proposed artifact-suppression technique in a simultaneous neural recording and stimulation system. The results show that the stimulation artifact can be greatly reduced. The amplitude of the measured stimulation artifact is therefore constrained in a negligible level (10%-20%) compared to recorded neural spikes.
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15:20-15:35, Paper ThCT9.5 | Add to My Program |
A Machine Learning Approach to Characterizing the Effect of Asynchronous Distributed Electrical Stimulation on Hippocampal Neural Dynamics in Vivo |
connolly, Mark | Emory Univ |
Park, Sang-Eon | Georgia Inst. of Tech |
Gross, Robert | Emory Univ |
Mahmoudi, Babak | Emory Univ |
Keywords: Neurological disorders - Epilepsy, Neural signal processing, Brain physiology and modeling
Abstract: Asynchronous distributed microelectrode theta stimulation (ADMETS) of the hippocampus has been shown to reduce seizure frequency in the tetanus toxin rat model of mesial temporal lobe epilepsy suggesting a hypothesis that ADMETS induces a seizure resistant state. Here we present a machine learning approach to characterize the nature of neural state changes induced by distributed stimulation. We applied the stimulation to two animals under sham and ADMETS conditions and used a combination of machine learning techniques on intra-hippocampal recordings of Local Field Potentials (LFPs) to characterize the difference in the neural state between sham and ADMETS. By iteratively fitting a logistic regression with data from the inter-stimulation interval under sham and ADMETS condition we found that the classification performance improves for both animals until 90s post stimulation before leveling out at AUC of 0.64 ± 0.2 and 0.67 ± 0.02 when all inter-stimulation data is included. The models for each animal were re-fit using elastic net regularization to force many of the model coefficients to 0, identifying those that do not optimally contribute to the classifier performance. We found that there is significant variation in the non-zero coefficients between animals (p < 0.01), suggesting that the ADMETS induced state is represented differently between subject. These findings lay the foundation for using machine learning to robustly and quantitatively characterize neural state.
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15:35-15:50, Paper ThCT9.6 | Add to My Program |
Effects of Transcranial Direct Current Stimulation on Steady-State Visual Evoked Potentials |
Liu, Bingchuan | Tsinghua Univ |
Chen, Xiaogang | Inst. of Biomedical Engineering, Chinese Acad. of Medical |
Yang, Chen | Tsinghua Univ |
Wu, Jian | Tsinghua Univ |
Gao, Xiaorong | Tsinghua Univ |
Keywords: Neural stimulation, Brain functional imaging - Evoked potentials, Brain functional imaging - EEG
Abstract: Recently, transcranial direct current stimulation (tDCS) has attracted increasing attention in the field of neuromodulation because of its capacity to modulate cortex excitability noninvasively. Previous findings have demonstrated its effectiveness in visual studies. However, few studies have referred to steady-state visual evoked potential (SSVEP), a promising visual evoked potential that has been widely used in brain-computer interfaces. The present work investigated the effects of tDCS on SSVEPs. Sham and 1 mA real tDCS (anodal and cathodal) in a PO7-PO8 montage were administered for 15 min in 12 healthy subjects. Compared with sham conditions, both anodal and cathodal tDCS significantly decreased 7-Hz SSVEP power. Also, anodal tDCS increased 10-Hz SSVEP power. Our study demonstrated that tDCS over occipital areas altered brain activity evoked by visual stimuli.
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ThCT10 Oral Session, Schmitt Room |
Add to My Program |
General and Theoretical Informatics - Algorithms I |
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Chair: Kim, Il Kon | Kyungpook National Univ |
Co-Chair: Clifton, David | Univ. of Oxford |
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14:20-14:35, Paper ThCT10.1 | Add to My Program |
A Novel Blood Pressure Estimation Method Combing Pulse Wave Transit Time Model and Neural Network Model |
Xu, Jun | Shanghai Univ |
jiang, jiehui | Shanghai Univ |
zhou, hucheng | Shanghai Univ |
Yan, Zhuangzhi | Shanghai Univ |
Keywords: General and theoretical informatics - Artificial Intelligence, General and theoretical informatics - Pattern recognition
Abstract: Blood Pressure (BP) measurement can assist doctors to assess patients’ cardiovascular status and diagnose heart diseases. Pulse Wave Transit Time (PWTT) model is one frequently used BP estimation method to monitor BP continuously in clinics. However, individual variations may influence the measurement accuracy of PWTT model.Focusing on above promble, this paper proposes a novel BP estimation method combining a classical PWTT model and a neural network model. The novel method is composed of five steps: signal pre-processing, feature extraction, initial PWTT model selection, model correction by neural network model, and final PWTT model identification. A validation experiment based on 10 patients from Multiparameter Intelligent Monitoring in Intensive Care (MIMIC) database showed that the BP estimation results by our method had a minimum mean of error readout value 5 mmHg with a standard deviation of error readout value ±8mmHg. As a result, both the diastolic blood pressure and systolic blood pressure estimation by our method can meet clinical requirements.
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14:35-14:50, Paper ThCT10.2 | Add to My Program |
Assessment of Stress Wave Induced by Diode Laser |
Oh, Han-Byeol | Konkuk Univ |
Kim, Ji-Sun | Konkuk Univ |
Baek, Jin-Young | Konkuk Univ |
Jun, Jae-Hoon | Konkuk Univ |
Keywords: General and theoretical informatics - Algorithms
Abstract: Laser has widely been used in the various fields, by implementing the specular parameters of a laser appeared when the laser irradiates on a certain medium. According to the report, when low-intensity laser irradiates a medium for a long time, there is photothemal effect. On the other hand when the medium is irradiated high-intensity laser for a short time, photomechanical effect occurs. The goal of this study is to detect the stress waves without damaging the medium by using a laser. Thus, the various laser parameter(e.g., peak power) were applied to measure the induced stress on collagen samples. The pulsed laser energy can be converted into mechanical stress in collagen by thermo-elastic effect which results in physical displacement of the sample. The results imply that the degree of stress can be controlled is the various laser parameters.
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14:50-15:05, Paper ThCT10.3 | Add to My Program |
Elastic Modulus Estimation Based on Local Displacement Observation of Elastic Body |
Morita, Mitsuki | Kyoto Univ |
Nakao, Megumi | Kyoto Univ |
Matsuda, Tetsuya | Kyoto Univ |
Keywords: General and theoretical informatics - Algorithms, General and theoretical informatics - Pattern recognition
Abstract: A method is proposed that provides estimates of the spatial variation of elastic moduli using local displacements of the elastic body. A central issue of elastography imaging has been the limited area of measurement. With the proposed method, stiffness parameter estimations are considered as minimization problems using finite-element models. The sparseness of the gradient of tissue elasticity is also exploited to improve estimation accuracy. Simulation experiments show that based on a 5% area of observation of a simple plate model with non-uniform elasticity the spatial variation of Young's modulus is reconstructed to within 5% accuracy. This result suggests that the proposed framework significantly extends the area of estimation overcoming the limitations of conventional elastography techniques.
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15:05-15:20, Paper ThCT10.4 | Add to My Program |
The Classification for “Equilibrium Triad” Sensory Loss Based on Semg Signals of Calf Muscles |
Yu, Hairong | Univ. of Tech. Sydney |
Guo, Kairui | Univ. of Tech. Sydney |
Luo, Jie | Sun Yat-Sen Univ |
CAO, KAI | Univ. of Tech. Sydney |
Nguyen, Hung T. | Univ. of Tech. Sydney |
Su, Steven Weidong | Univ. of Tech. Sydney |
Keywords: Health Informatics - Behavioral health informatics, General and theoretical informatics - Pattern recognition
Abstract: Surface Electromyography (sEMG) has been commonly applied for analysing the electrical activities of skeletal muscles. The sensory system of maintaining posture balance includes vision, proprioception and vestibular senses. In this work, an attempt is made to classify whether the body is missing one of the sense during balance control by using sEMG signals. A trial of combination with different features and muscles is also developed. The results demonstrate that the classification accuracy between vision loss and the normal condition is higher than the one between vestibular sense loss and normal condition. When using different features and muscles, the impact on classification results is also different. The outcomes of this study could aid the development of sEMG based classification for the function of sensory systems during human balance movement.
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15:20-15:35, Paper ThCT10.5 | Add to My Program |
Likelihood-Based Artefact Detection in Continuously-Acquired Patient Vital Signs |
Colopy, Glen Wright | Univ. of Oxford |
Zhu, Tingting | Univ. of Oxford |
Clifton, Lei | Univ. of Oxford |
Roberts, Stephen | Univ. of Oxford |
Clifton, David | Univ. of Oxford |
Keywords: General and theoretical informatics - Artificial Intelligence, General and theoretical informatics - Data intelligence, Health Informatics - Clinical information systems
Abstract: Robust continuous monitoring of patient vital signs (VS) is limited by artefactual data yielding measurements that are not representative of the patient's physiology. These artefacts are typified by several distinct "archetypes". We present several of these archetypal artefacts for heart rate (HR) monitoring, and propose a light weight, real-time algorithm to remove the majority of these artefacts. Most artefacts are not identifiable by their values in absolute terms, but instead by their values relative to other measurements nearby in time. We model temporally-proximate measurements as independent and identically distributed (i.i.d.) samples from a Gamma distribution. Measurements with low likelihood with respect to the distribution are candidates for artefact removal. This light-weight algorithm is important for real-time deployment on wearable sensors, which are becoming increasingly common in hospital and home care. The clinical applicability of artefact-removal is demonstrated in its ability to enhance patient deterioration detection. A Kalman filter-based patient monitoring algorithm is shown to improve early warning of deterioration when the proposed artefact-removal algorithm is used. We demonstrate this real-time system with patient data from a clinical trial that we have undertaken.
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15:35-15:50, Paper ThCT10.6 | Add to My Program |
Accuracy of a Wavelet-Based Fall Detection Approach Using an Accelerometer and a Barometric Pressure Sensor |
Ejupi, Andreas | Simon Fraser Univ. (SFU) |
Galang, Chantel | Simon Fraser Univ |
Aziz, Omar | Simon Fraser Univ |
Park, Edward J. | Simon Fraser Univ |
Robinovitch, Stephen | Simon Fraser Univ |
Keywords: Health Informatics - Mobile and wearable technologies for elderly, Health Informatics - Patient tracking, Sensor Informatics - Wearable systems and sensors
Abstract: Goal: Falls are a major source of morbidity in older adults, and 50% of older adults who fall cannot rise independently after falling. Wearable sensor-based fall detection devices may assist in preventing long lies after falls. The goal of this study was to determine the accuracy of a novel wavelet-based approach to automatically detect falls based on accelerometer and barometric pressure sensor data. Methods: Participants (n=15) mimicked a range of falls, near falls, and activities of daily living (ADLs) while wearing accelerometer and barometric pressure sensors on the lower back, chest, wrists and thighs. The wavelet transform using pattern adapted wavelets was applied to detect falls from the sensor data. Results: In total, 525 trials (194 falls, 105 near-falls and 226 ADLs) were included in our analysis. When we applied the wavelet-based method on only accelerometer data, classification accuracies ranged from 82% to 96%, with the chest sensor providing the highest accuracy. Accuracy improved by 3.4% on average (p=0.041; SD=3.0%) when we also included the barometric pressure sensor data. The highest classification accuracies (of 98%) were achieved when we combined wavelet-based features and traditional statistical features in a multiphase fall detection model using machine learning. Conclusion: We show that the wavelet-based approach accurately distinguishes falls from near-falls and ADLs, and that it can be applied on wearable sensor data generated from various body locations. Additionally, we show that the accuracy of a wavelet-based fall detection system can be further improved by combining accelerometer and barometric pressure sensor data, and by incorporating wavelet and statistical features in a machine learning classification algorithm.
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ThCT11 Minisymposium, Greatbatch Room |
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Recent Advances on Cuff-Less Blood Pressure Measurement Technology II |
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Chair: Mukkamala, Ramakrishna | Michigan State Univ |
Co-Chair: Mestha, Lalit, K. | GE Global Res |
Organizer: Mukkamala, Ramakrishna | Michigan State Univ |
Organizer: Mestha, Lalit, K. | GE Global Res |
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14:20-14:35, Paper ThCT11.1 | Add to My Program |
Non-Invasive Beat-To-Beat Pulse Pressure Measurement and Pulse Wave Analysis at a Spot Check (I) |
Seo, Joohyun | Massachusetts Inst. of Tech |
Sodini, Charles | Massachusetts Inst. of Tech |
Lee, Hae-Seung | Massachusetts Inst. of Tech |
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14:35-14:50, Paper ThCT11.2 | Add to My Program |
Cuffless Blood Pressure Monitoring at the Chest: Single-Channel Reflective PPG Sensors Are Inaccurate (I) |
Sola, Josep | CSEM - Centre Suisse D'electronique Et Microtechnique |
Vybornova, Anna | EPFL |
Braun, Fabian | Csem Sa |
Proença, Martin | Swiss Center for Electronics and Microtechnology (CSEM) |
Delgado-Gonzalo, Ricard | CSEM |
Ferrario, Damien | CSEM |
Verjus, Christophe | CSEM |
Bertschi, Mattia | CSEM |
Pierrel, Nicolas | CHUV |
Degiorgis, Yan | CHUV |
Schoettker, Patrick | CHUV – Centre Hospitalier Univ. Vaudois |
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14:50-15:05, Paper ThCT11.3 | Add to My Program |
Cuffless Blood Pressure Measurement Using Ultrasound and Dual Photoplethysmograph Transducer (I) |
PM, Nabeel | Indian Inst. of Tech. Madras |
Karthik, Srinivasa | HTIC IIT Madras |
Joseph, Jayaraj | HTIC, Indian Inst. of Tech. Madras |
Chenniappan, M | Ramakrishna Medical Centre |
Sivaprakasam, Mohanasankar | Indian Inst. of Tech. Madras |
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15:05-15:20, Paper ThCT11.4 | Add to My Program |
Wearable Continuous BP Monitoring Solution Using PPG Signal (I) |
Singh, Wazir | INDRAPRASTHA Inst. OF INFORMATION Tech. DELHI |
Jain, Monika | Indraprastha Inst. of Information Tech. Delhi |
Singh Chadha, Jaidev | Delhi Tech. Univ. Delhi |
Deb, Sujay | Indraprastha Inst. of Information Tech. Delhi |
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15:20-15:35, Paper ThCT11.5 | Add to My Program |
Arterial Blood Pressure Estimation Using Ultrasound: Clinical Results on Healthy Volunteers and a Medicated Hypertensive Volunteer |
Zakrzewski, Aaron M. | Massachusetts Inst. of Tech |
Anthony, Brian W. | Massachusetts Inst. of Tech |
Keywords: Vascular mechanics and hemodynamics - Arterial pressure in cardiovascular disease, Vascular mechanics and hemodynamics - Vascular mechanics, Cardiovascular and respiratory system modeling - Vascular mechanics and hemodynamics
Abstract: This study presents a non-occlusive and non-invasive ultrasound-based technique to measure blood pressure. Most popular clinically-used arterial blood pressure measurement techniques suffer from important weaknesses including being inaccurate, invasive, or occlusive. In the proposed technique, an ultrasound probe is placed on the patient's carotid artery and the contact force between the probe and the tissue is slowly increased while ultrasound images and contact force data are recorded. From this data, the artery is segmented and the segmentation data is sent into an optimization procedure; after post-processing, blood pressure is displayed to the user. This technique was applied to 24 healthy single-visit volunteers, one multi-visit healthy volunteer, and one multi-visit medicated hypertensive volunteer. Compared to the oscillometric cuff, the accuracy and precision of the algorithm-reported systolic pressure is -2.4 +/- 10.2 mmHg, and for diastolic pressure is -0.3 +/- 8.2 mmHg. This method has the potential to occupy a clinical middle-ground between the arterial catheter and the oscillometric cuff.
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ThCT12 Invited Session, Geddes Room |
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Modeling of Modern Devices and Technologies with Computational Human
Phantoms - III |
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Chair: Wenger, Cornelia | Novocure GmbH |
Co-Chair: Horner, Marc | ANSYS, Inc |
Organizer: Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Organizer: Horner, Marc | ANSYS, Inc |
Organizer: Noetscher, Gregory | Worcester Pol. Inst |
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14:20-14:35, Paper ThCT12.1 | Add to My Program |
Impact of Computational Human Model on the Calculation of RF-Induced Voltages for Medical Devices in MRI (I) |
Brown, James | MSEI |
Qiang, Rui | 1976 |
Stadnik, Paul | Micro Systems Engineering, Inc |
Stotts, Larry | Biotronik |
Von Arx, Jeffrey | Micro Systems Engineering, Inc |
Keywords: Health technology - Verification and validation, Image-guided devices - MRI-compatible instrumentation and device management
Abstract: Patients with active implantable medical devices (AIMDs) are generally denied access to magnetic resonance imaging (MRI), despite that imaging modality’s preferred status for soft tissue imaging. During MRI, the RF fields will induce voltages at the various conductors external to the device enclosure. These voltages can cause device malfunction, or can be rectified by active elements within the AIMD and cause unintended stimulation of tissue. AIMD manufacturers evaluate conditional safety of devices in MRI by conservatively calculating these voltages using computational human models (CHMs). This work explores the impact of variations in the CHM on the calculation of RF-induced voltages for cardiovascular implantable electronic devices.
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14:35-14:50, Paper ThCT12.2 | Add to My Program |
Transmit Coil Design for Wireless Power Transfer for Medical Implants |
Lemdiasov, Rosti | Cambridge Consultants |
Venkatasubramanian, Arun | Cambridge Consultants |
Keywords: Clinical engineering
Abstract: Abstract—A new design approach for the design of transmit coils for Wireless Power Transfer (WPT) is presented. The theoretical formulation involves a figure of merit that has to be maximized to solve for the surface current. Numerical predictions and comparisons with practical measurements for the coil parameters (inductance. resistance) underscore the success of this approach in terms of achieving strong coupling with a receive coil while maintaining low resistance
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14:50-15:05, Paper ThCT12.3 | Add to My Program |
Determining the Dielectric Properties of Human Skin in the Frequency Range of 0.1 to 1 MHZ, and Implications to the Modelling of Tumor Treating Fields (I) |
Hershkovich, Hadas Sara | Novocure Ltd., Haifa, Israel |
Urman, Noa | Novocure |
Naveh, Ariel | Novocure Ltd |
Yesharim, Ofir | Novocure Ltd |
Wassermann, Yoram | Novocure Ltd., Haifa, Israel |
kirson, Eilon David | Novocure |
Bomzon, Ze'ev | Novocure |
Keywords: Clinical engineering, Ambulatory Therapeutic Devices - Personalized therapeutic devices and emergency response systems
Abstract: Tumor Treating Fields (TTFields) are low intensity alternating electric fields in the 100-500 KHz frequency range known to have an anti-mitotic effect on cancerous cells. TTFields are delivered to the patient through two pairs of transducer arrays placed on the patient's skin. Therefore, accurate measurement of the electric properties of skin is important for understanding the distribution of TTFields within the body. To address this issue, we measured impedance of skin folds around the waists of human volunteers in the frequency range of 100 kHz -1 MHz utilizing an experimental setup that mimics the conditions through which TTFields are delivered. Our results show that the skin can be described using a simplified three layer model including epidermis, dermis and sub-cutaneous adipose tissue (SAT), for which we derive electric properties. Assigning these properties to the skin and SAT when simulating TTFields delivery to realistic computational phantoms, results in models with a total resistance that is in good agreement with the total resistance measured in patients receiving TTFields treatment.
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15:05-15:20, Paper ThCT12.4 | Add to My Program |
A Method for Initial Testing CAD Virtual Human Models (I) |
Louie, Sara | Ansys, Inc |
Horner, Marc | ANSYS, Inc |
Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Noetscher, Gregory | Worcester Pol. Inst |
Keywords: Diagnostic devices - Physiological monitoring, Clinical engineering
Abstract: We propose a simple yet generic algorithm for testing a CAD virtual human model. It is based on the determination of Specific Absorption Rate or SAR in an RF MRI coil and comparison with the well-established literature data. The proposed method generates meaningful results for the tested CAD models including VHP-Female v. 3.0 CAD model.
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15:20-15:35, Paper ThCT12.5 | Add to My Program |
A Comparison of Two Anatomical Body Models Derived from the Female Visible Human Project Data |
Massey, Jackson White | Univ. of Texas at Austin |
Prokop, Alexander | Computer Simulation Tech |
Yilmaz, Ali | Univ. of Texas at Austin |
Keywords: Organ modeling
Abstract: Two electromagnetic human body models independently developed from the same image dataset—the voxel-based AustinWoman and surface-based VHP-female models—are compared. In addition to contrasting volumes and cross-section images of their tissues, the power absorbed by the two models under plane-wave excitation are also compared. Four different numerical methods are used to compute the absorbed power and to evaluate computational errors.
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15:35-15:50, Paper ThCT12.6 | Add to My Program |
Model of a Perfectly Matched RF MRI Coil for SAR Computations with Virtual Human Models (I) |
Makarov, Sergey | Electrical and Computer Engineering, Worcester Pol |
Bogdanov, Gene | Worcester Pol. Inst |
Tankaria, Harshal | Worcester Pol. Inst |
Noetscher, Gregory | Worcester Pol. Inst |
Louie, Sara | Ansys, Inc |
Nummenmaa, Aapo | Massachussetts General Hospital |
Keywords: Clinical laboratory, assay and pathology technologies, Clinical engineering
Abstract: Current regulatory procedures require determination of the Specific Absorption Rate or SAR in an RF MRI coil. SAR values are typically derived from simulations performed with virtual humans. The entire problem is not well defined since RF coil designs and numbers of driving ports vary widely. We propose a novel electrical concept of an ideal (perfectly matched and tuned at all available ports) RF transmit coil, which essentially bypasses the coil matching procedure and does not require the circuit co-simulator. The proposed method generates meaningful results for unloaded and loaded (64 and 128 MHz, at several landmarks) full-body birdcage coils.
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ThCT13 Oral Session, Dunn Room |
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Tissue Stimulation Technologies |
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Chair: Panescu, Dorin | Advanced Cardiac Therapeutics |
Co-Chair: Cheng, Leo | The Univ. of Auckland |
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14:20-14:35, Paper ThCT13.1 | Add to My Program |
Measurement of Perception Thresholds for Electrical Noise Stimuli |
Karpul, David | Univ. of Western Sydney, Univ. of Cape Town |
McIntyre, Sarah | Western Sydney Univ |
van Schaik, André | The Univ. of Sydney |
Breen, Paul | Univ. of Western Sydney |
Keywords: Neural stimulation (including deep brain stimulation)
Abstract: In previous research, the application of sub-threshold electrical nerve stimulation (SENS) to peripheral nerves has been shown to improve tactile sensitivity. SENS has applications in the symptomatic treatment of a wide array of conditions that result in the loss of peripheral nerve function. These include diabetes, stroke, and age related peripheral neuropathy. The technology is dependent on careful control of the amplitude of the intervention stimulation relative to the user’s perception threshold. However, little is known about the factors that influence the perception threshold and whether it can be treated as a constant. Here we present a study where we applied a two alternate forced choice paradigm to determine electrical perception threshold. We investigated participant, noise frequency characteristics, electrode location, electrode type, and electrode impedance characteristics as explanatory factors for the variability seen in the threshold outcome. We find that the electrical perception threshold is dependent on the frequency characteristics of the signal applied, but varies widely without correlation to the remaining variables. It was also highly variable when re-tested under identical conditions. Our results cast doubt on the ability to treat the electrical threshold as a single value that holds constant for a particular participant and electrode placement. This finding has significant implications in SENS applications.
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14:35-14:50, Paper ThCT13.2 | Add to My Program |
New Conducted Electrical Weapons: Finite Element Modeling of Safety Margins |
Panescu, Dorin | Advanced Cardiac Therapeutics |
Kroll, Mark William | Univ. of Minnesota |
Brave, Michael | LAAW International, LLC, Scottsdale, AZ |
Keywords: Cardiovascular assessment and diagnostic technologies, Muscle stimulation, Neural stimulation (including deep brain stimulation)
Abstract: Introduction—We have previously published on the ventricular fibrillation (VF) risk with TASER® X26 conducted electrical weapon (CEW). Our risk model accounted for realistic body mass index distributions, modeled the effects of partial or oblique dart penetration, and used epidemiological CEW statistics. As new CEWs have become available to law enforcement, their cardiac safety profile was not quantified. Therefore, we applied our VF probability model to evaluate their cardiac risk. Methods and Results—An eXperimental Rotating-Field (XRF) waveform CEW and the X2 CEW are new 2-shot electrical weapon models designed to target a precise amount of delivered charge per pulse, 64 µC and 62 µC, respectively. They can deploy 1 or 2 probe pairs, delivered by 2 separate cartridges. New Smart Probes (SP), which carry 11.5 mm long CEW darts, can be used with XRF and X2 CEWs. Finite element modeling (FEM) was used to approximate the current and charge densities produced by XRF and X2 CEWs in tissues located in the vicinity of darts, including accounting for the effects of fat, anisotropic skeletal muscles, sternum, ribs, and lungs. Using our previous cardiac risk probabilistic model, the new XRF and X2 CEWs operated with 11.5 mm SPs, had an estimated overall theoretical VF risk of less than 1 in 1 300 000 and 1 in 1 490 000 cases, respectively. We also found that the XRF and X2 CEWs had increased cardiac safety margins with respect to those previously reported for the X26 CEWs when all three CEW models were operated with 9 mm CEW darts. Lastly, the cardiac risk of these new CEWs (< 0.76 ppm) was found to be much lower than reported levels of CEW non-cardiac fatal injuries (e.g. falls and burns, > 7.2 ppm). Conclusions—While not risk-free, the new TASER XRF and X2 CEWs offer increased cardiac safety margins and extremely low cardiac risk profiles. Keywords: Cardiac Risk, CEW, Fibrillation, Finite Element Model, TASER.
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14:50-15:05, Paper ThCT13.3 | Add to My Program |
System Design and Experimental Research of Lower Esophageal Sphincter Stimulator for Treatment of Gastroesophageal Reflux Disease |
Sun, Xinchen | Southeast Univ |
Tao, Wanjun | Southeast Univ |
Zhu, Chuanqing | Sourtheast Univ |
Zhao, Lili | The First Affiliated Hospital of Nanjing Medical Univ |
Wang, Min | Nanjing Medical Univ |
Lü, Xiaoying | Southeast Univ |
Wang, Zhigong | Southeast Univ |
Fan, Zhining | The First Affiliated Hospital of Nanjing Medical Univ |
Keywords: Muscle stimulation, Neural stimulation (including deep brain stimulation), Ambulatory diagnostic and therapeutic devices - TENS
Abstract: Electrical stimulation therapy (EST) of lower esophageal sphincters (LES) is a new technique for the treatment of gastroesophageal reflux disease (GERD). In this paper, an implantable LES stimulator with wireless power transmission is proposed for the treatment of GERD. The LES stimulator is composed of an implantable pulse generator (IPG), an external controller, and a wireless power transmission module. The IPG, whose area is 31×21 mm2, is designed to generate voltage-regulated constant-current stimulation pulses. The external controller allows for wireless programming of the IPG via a Bluetooth Low Energy (BLE) module. The wireless power transmission module provides power for the IPG. According to the measurement of output stimulus waveforms, the proposed LES stimulator is capable of delivering electrical stimulations with a current ranging between 0 and 8 mA. To evaluate the safety and efficacy of the proposed LES stimulator, experiments were performed on 12 male New Zealand white rabbits. Esophageal manometry was performed before and after the procedure and the LES pressure (LESP) has been recorded. The mean LESP is increased significantly in the stimulation group than the sham group (stimulation group: 9.25±1.24 mmHg vs 13.99 ±1.28 mmHg, p<0.05; sham group: 9.00±1.22 mmHg vs 9.23±1.27 mmHg, p=0.267). The results show that the electrical stimulation delivered by the LES stimulator can safely and effectively increase resting LES pressure in acute animal models, suggesting that the implantable LES stimulator is a perspective approach for treating GERD in clinics.
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15:05-15:20, Paper ThCT13.4 | Add to My Program |
Design and Application of a Novel Gastric Pacemaker |
Alighaleh, Saeed | Auckland Bioengineering Inst. Univ. of Auckland |
Angeli, Timothy Robert | Auckland Bioengineering Inst. Univ. of Auckland |
Sathar, Shameer | Univ. of Auckland |
O'Grady, Gregory | Univ. of Auckland |
Cheng, Leo K | The Univ. of Auckland |
Paskaranandavadivel, Niranchan | The Univ. Ofauckland |
Keywords: Muscle stimulation, Diagnostic devices - Physiological monitoring
Abstract: Omnipresent bioelectrical events known as slow waves are responsible for coordinating motility in the gastrointestinal tract. Functional motility diseases, such as gastroparesis, are associated with slow wave dysrhythmias. Electrical stimulation is a potential therapy to correct abnormal slow wave patterns. We present the design and application of a new gastric pacemaker. Real-time changes to the stimulation parameters such as period, amplitude and pulse width were delivered using a graphical user interface, which communicated with the microcontroller to deliver the stimulus. The new pacemaker allows the voltage, delivered current and resistance between pacing electrodes to be continuously monitored. The pacing device was applied experimentally and was able to modulate and entrain gastric slow wave activity. After initiation of pacing, the direction of slow wave propagation was altered. Furthermore, the mean velocity and amplitude of slow wave activity increased from 4.7±1.5 to 5.4±1.3 mm/s, and 1.1±1.1 to 1.7±0.9 mV, respectively. A simplified bidomain electrical model was used to simulate the recorded stimulus artifact. The model illustrated a new approach to evaluate if the stimulus has been delivered to the gastric tissue. The new pacing device and model will be used to investigate the mechanism that allow pacing to entrain slow wave activity.
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15:20-15:35, Paper ThCT13.5 | Add to My Program |
New Conducted Electrical Weapons: Electrical Safety Relative to Relevant Standards |
Panescu, Dorin | Advanced Cardiac Therapeutics |
Nerheim, Max | TASER International |
Kroll, Mark William | Univ. of Minnesota |
Brave, Michael | LAAW International, LLC, Scottsdale, AZ |
Keywords: Cardiovascular assessment and diagnostic technologies, Muscle stimulation, Neural stimulation (including deep brain stimulation)
Abstract: Introduction: We have previously published about TASER® conducted electrical weapons (CEW) compliance with international standards. CEWs deliver electrical pulses that can inhibit a person’s neuromuscular control or temporarily incapacitate. An eXperimental Rotating-Field (XRF) waveform CEW and the X2 CEW are new 2-shot electrical weapon models designed to target a precise amount of delivered charge per pulse. They both can deploy 1 or 2 dart pairs, delivered by 2 separate cartridges. Additionally, the XRF controls delivery of incapacitating pulses over 4 field vectors, in a rotating sequence. As in our previous study, we were motivated by the need to understand the cardiac safety profile of these new CEWs. The goal of this paper is to analyze the nominal electrical outputs of TASER XRF and X2 CEWs in reference to provisions of all relevant international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance. Methods: The outputs of several TASER XRF and X2 CEWs were measured under normal operating conditions. The measurements were compared against manufacturer specifications. CEWs electrical output parameters were reviewed against relevant safety requirements of UL 69, IEC 60335-2-76 Ed 2.1, IEC 60479-1, IEC 60479-2, AS/NZS 60479.1, AS/NZS 60479.2, IEC 60601-1 and BS EN 60601-1. Results and Conclusion: Our study confirmed that the nominal electrical outputs of TASER XRF and X2 CEWs lie within safety bounds specified by relevant standards. KeywordsCardiac, CEW, Fibrillation, Safety, Standards, TASER.
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15:35-15:50, Paper ThCT13.6 | Add to My Program |
New Conducted Electrical Weapons: Thoracic Cage Shielding Effect |
Panescu, Dorin | Advanced Cardiac Therapeutics |
Kroll, Mark William | Univ. of Minnesota |
Brave, Michael | LAAW International, LLC, Scottsdale, AZ |
Keywords: Cardiovascular assessment and diagnostic technologies, Muscle stimulation, Neural stimulation (including deep brain stimulation)
Abstract: Introduction: The TASER® conducted electrical weapon (CEW) delivers electrical pulses that can temporarily incapacitate subjects. For existing CEW models, we have previously presented the distribution of currents in tissues posterior to the sternum and their likelihood of triggering cardiac arrhythmias. New models, the eXperimental Rotating-Field (XRF) waveform CEW (in development) and the X2 CEW (released) have not been investigated. Both the XRF and X2 CEWs target a precise amount of delivered charge per pulse, 64 µC and 62 µC, respectively. The goal of this study was to numerically model the thoracic cage attenuation of currents and electric fields delivered by the new CEWs and to find whether the heart is shielded from the induction of any dangerous arrhythmias. Methods and Results: Finite element modeling (FEM) was used to approximate the current density and electric field strength in tissues around the thoracic cage. FEM boundary conditions were set to correspond to output waveforms of the new CEWs, the XRF and the X2. We analyzed a CEW dart deployment scenario that had both darts located over the anterior aspect of the sternum. We found that the sternum and thoracic cage provided significant attenuation of currents and electrical fields. Conclusion: The sternum and the thoracic cage significantly attenuated currents and electric fields delivered by XRF and X2 CEWs. These tissues ‘shielded’ the heart against potentially dangerous cardiac arrhythmias. The shorter durations and reduced amount of charged delivered by the XRF and the X2 CEWs resulted in increased cardiac safety margins. Keywords: CEW, Fibrillation, Finite Element Model, TASER, Thoracic Cage.
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ThCT14 Invited Session, Schaldach Room |
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Deep Learning in Biomedical Image Analysis |
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Chair: Jeong, Won-Ki | Ulsan National Inst. of Science and Tech. (UNIST) |
Co-Chair: Ye, Jong Chul | Korea Advanced Inst. of Science & Tech |
Organizer: Jeong, Won-Ki | Ulsan National Inst. of Science and Tech. (UNIST) |
Organizer: Ye, Jong Chul | Korea Advanced Inst. of Science & Tech |
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14:20-14:35, Paper ThCT14.1 | Add to My Program |
Detection of Lung Nodules on Thoracic MDCT Images Based on Temporal Subtraction Technique (I) |
Lu, Huimin | Kyushu Inst. of Tech |
Tachibana, Rie | Oshima National Coll. of Maritime Tech |
Tan, Joo Kooi | Kyushu Inst. of Tech |
Kim, Hyoungseop | Kyushu Inst. of Tech |
Hirano, Yasushi | Yamaguchi Univ |
Kido, Shoji | Graduate School of Science and Tech. for Innovation, Yamagu |
Keywords: Image segmentation, Image classification, Image feature extraction
Abstract: The temporal subtraction (TS) technique removes normal structures and enhanced interval changes such as new lesions and changes in existing abnormalities from a medical image. However, many artifacts remaining on the temporal subtraction image can be detected as false positives. This paper presents a novel automatic segmentation using the Watershed method and multi scale gradient vector flow (MSGVF) snakes and a detection method using the extracted features and classifiers for lung small-sized lung nodules (20mm or less) from the temporal subtraction image. Using the proposed method, we conduct an experiment on 30 thoracic multiple-detector computed tomography cases including 31 small-sized lung nodules. The experimental results indicate the efficiency of our segmentation method.
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14:35-14:50, Paper ThCT14.2 | Add to My Program |
Correlation Analysis of Functional MR Images with Education Level (I) |
Kim, Sung-Woo | Korea Univ |
Seong, Joon-Kyung | Korea Univ |
Keywords: Brain image analysis, Functional image analysis, Magnetic resonance imaging - MR neuroimaging
Abstract: Cognitive reserve is the brain’s ability to cope with brain damage or pathology in cognitive processing. To test cognitive reserve hypothesis, we used functional efficiency networks from resting-state functional magnetic resonance imaging. The experimental results show the relationship between education year as estimated cognitive reserve measures and functional efficiency has a positive correlation in total healthy subjects. This result imply there are inter-individual difference in functional efficiency in healthy subjects. In addition, there was a significant positive correlation between functional efficiency and education year in younger healthy subjects, and there was no significant correlation in older healthy subjects. This implies there are alterations when age-related pathology increases.
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14:50-15:05, Paper ThCT14.3 | Add to My Program |
Applications of Deep Learning in Medical Image Analysis (I) |
Suk, Heung-Il | Korea Univ |
Keywords: Image feature extraction, Image classification, Multivariate image analysis
Abstract: Over the last decades, we have witnessed the importance of medical imaging for the early detection, diagnosis, and treatment of diseases. In the clinic, human experts such as radiologists and physicians have mostly performed the medical image interpretation. However, due to large variations in pathology and potential fatigue of human experts, researchers and doctors have recently begun to benefit from computer-assisted interventions. While, compared to the advances in medical imaging technologies per se, it is belated for the advances in computational medical image analysis; machine learning has been enhancing the improvement. In the use of machine learning for medical image analysis, discovering meaningful features or representations inherent in images lies at the heart of its success to accomplish target tasks. Conventionally, task-related features were mostly designed by human experts based on their knowledge about the target domains, which thus made it challenging for non-experts to exploit machine learning for their own studies. However, deep learning has relieved such obstacles by absorbing the feature-engineering step into a learning step. That is, instead of extracting features in a hand-designed manner, deep learning requires only a set of data with minor preprocessing, if necessary, and then discovers the informative representations in a self-taught manner. So, now the burden of feature engineering has shifted from a human-side to a computer-side, thus allowing non-experts in machine learning to effectively use deep learning for their own researches and/or applications, especially in medical image analysis. In this talk, I will briefly introduce the fundamental concepts of deep learning and then, present our recent work that exploited deep models for different applications in medical imaging such as brain disease diagnosis, brain pathology detection and segmentation, and pulmonary detection by using MRI, PET, or CT.
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15:05-15:20, Paper ThCT14.4 | Add to My Program |
Connectomics Image Analysis Using Deep Learning (I) |
Quan, Tran Minh | Ulsan National Inst. of Science and Tech. (UNIST) |
Hildebrand, David G. C. | The Rockefeller Univ |
Jeong, Won-Ki | Ulsan National Inst. of Science and Tech. (UNIST) |
Keywords: Image segmentation, Brain image analysis
Abstract: In this paper, we introduce a novel deep neural network architecture, for the automatic segmentation of neuronal structures in connectomics data. Our method leverages the latest advances in machine learning, such as semantic segmentation and residual neural networks, with the summation-based skip connections to allow a much deeper network architecture for a more accurate segmentation.
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15:20-15:35, Paper ThCT14.5 | Add to My Program |
Deep Learning for Medical Image Reconstruction (I) (withdrawn from program) |
Ye, Jong Chul | Korea Advanced Inst. of Science & Tech. |
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ThCT15 Minisymposium, Webster Room |
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Bioengineering Advances in the Diagnosis and Treatment of Sleep Apnea III
(Issues in Therapeutic Modalities for Sleep-Disordered Breathing) |
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Chair: Khoo, Michael | Univ. of Southern California |
Co-Chair: Penzel, Thomas | Charite Univ. Berlin |
Organizer: Khoo, Michael | Univ. of Southern California |
Organizer: Penzel, Thomas | Charite Univ. Berlin |
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14:20-14:35, Paper ThCT15.1 | Add to My Program |
An Industry Perspective on the Growth of Connected Care and Its Evolution to Personalised Treatment of Sleep-Disordered Breathing (I) |
Armitstead, Jeffrey Peter | Res. Ltd., Univ. of Sydney |
Liu, Dongquan | Res. Asia Operations |
Schindhelm, Klaus | Univ. of New South Wales |
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14:35-14:50, Paper ThCT15.2 | Add to My Program |
Personalizing the Treatment of Sleep Apnea – Using Physiology to Better Predict Treatment Success and Guide Therapy Choice (I) |
Edwards, Bradley Allan | Monash Univ |
Sands, Scott Aaron | Brigham and Women's Hospital and Harvard Medical School |
Joosten, Simon | Monash Health and Monash Univ |
Landry, Shane | Monash Univ |
Terrill, Philip Ian | Univ. of Queensland |
Owens, Robert | Harvard Medical School |
Malhotra, Atul | Brigham and Women's Hospital and Harvard Medical School |
White, David P | Brigham and Women's Hospital and Harvard Medical School |
Wellman, David Andrew | Harvard Medical School |
Hamilton, Garun | Department of Res. and Sleep Medicine, Monash Medical Cen |
Keywords: Sleep - Obstructive sleep apnea, Sleep - Sleep apnea therapy, Cardiovascular and respiratory system modeling - Respiratory Control models
Abstract: Obstructive sleep apnea (OSA) is a very common sleep disorder associated with serious health consequences. Despite the existence of several treatments for the disorder, the major limitations facing clinicians are that they are often either poorly tolerated or only resolve OSA in a proportion of patients, making it difficult to know which therapy to recommend for a particular individual. The key to offering newer treatments that are both effective and tolerable to the patient, is to recognize that OSA is a multifactorial disorder. Recent evidence clearly establishes that in addition to a collapsible upper airway, a large majority of patients have at least three non-anatomical traits contributing to the pathogenesis of their OSA, including a high loop gain, a low arousal threshold and a poor pharyngeal muscle response. Importantly, tools (both invasive and non-invasive) have now been developed to quantify deficits in the specific physiological traits contributing to OSA in a given individual. In the current report, we examine the evidence surrounding whether information about an OSA patients underlying physiological abnormalities can inform which treatment (pharmacologically, surgery or using oral appliances) is likely to resolve OSA in that individual. Overall, the emerging evidence suggests that measurement of phenotypic traits helps better predict responders to alternative OSA therapies than currently available screening tools, a finding which shows promise in taking us one-step closer to individualizing therapy for patients with OSA.
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14:50-15:05, Paper ThCT15.3 | Add to My Program |
Does CPAP Therapy Reduce Secondary Major Cardiovascular Events in OSA Patients with Cardiovascular Disease? � Highlights from the SAVE Study (I) |
McEvoy, R. Doug | Adelaide Inst. for Sleep Health |
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15:05-15:20, Paper ThCT15.4 | Add to My Program |
Effects of CPAP and Adaptive Servo-Ventilation on Cardiovascular Function in CHF-CSR: A Computer Simulation Study (I) |
Khoo, Michael | Univ. of Southern California |
Hu, Wen-Hsin | Univ. of Southern California |
Keywords: Sleep - Periodic breathing & central apnea, Sleep - Sleep apnea therapy, Sleep - Cardiovascular & Metabolic consequences of sleep disorders
Abstract: Recent multi-center trials of the application of continuous positive airway pressure (CPAP) and adaptive servo-ventilation (ASV) therapy in patients with congestive heart failure (CHF) and Cheyne-Stokes respiration (CSR) have found no beneficial long-term effect on cardiovascular function. To better understand the physiological mechanisms underlying these clinical outcomes, we employed an integrative computer model of cardiorespiratory control to simulate both modes of ventilatory assistance on patients with different severities of heart failure and sleep-disordered breathing. Model simulations predicted the clinically-observed decreases in apnea-hypopnea index and left ventricle afterload. However, there were consistent reductions in stroke volume and elevation of heart rate, with little change in mean SaO2 and PaCO2 in all treatment groups. Cardiac output was increased during treatment with CPAP but not ASV. Our simulation findings suggest that CSR serves as compensatory mechanism to CHF by augmenting both stroke volume and heart rate, and thus eliminating CSR with ASV may not be as beneficial as initially expected.
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ThCT17 Invited Session, Einthoven Hall |
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Signal Processing and Modelling Techniques for Fetal Monitoring |
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Chair: Khandoker, Ahsan Habib | Khalifa Univ. of Science, Tech. and Res |
Organizer: Khandoker, Ahsan Habib | Khalifa Univ. of Science, Tech. and Res |
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14:20-14:35, Paper ThCT17.1 | Add to My Program |
Investigating Fetal Myocardial Function in Heart Anomalies by Doppler Myocardial Performance Indices |
Khandoker, Ahsan Habib | Khalifa Univ. of Science, Tech. and Res |
Alangari, Haitham M. | Khalifa Univ |
Marzbanrad, Faezeh | The Univ. of Melbourne |
Kimura, Yoshitaka | Tohoku Univ |
Keywords: Time-frequency and time-scale analysis - Wavelets, Time-frequency and time-scale analysis - Time-frequency analysis, Signal pattern classification - Markov models
Abstract: Fetal myocardial performance index are used to assess aspects of systolic and diastolic function in developing fetal heart. The aim of this study was to determine normal values of fetal left ventricular (LV) Tei Index (TI) for measuring systolic performance and K-Index (KI) for diastolic performance in early (<32 weeks), Mid (32-35 weeks) and late trimester (35-41 weeks) normal fetuses and fetuses with congenital heart diseases (CHD). Simultaneous recordings of Doppler Ultrasound Signal (DUS) of the LV outflow tracts and fetal electrocardiogram signals were obtained in 57 normal and 14 fetuses with CHD. CHDs were categorized in two types (conduction pathway abnormalities [8 cases] and structural anomalies [6 cases]). The LV isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ventricular ejection time (VET) and ventricular filling time (VFT) were measured from amplitudes and peaks of high frequency component of DUS signals by an automated model. The TI and the new index were calculated by using the formula (ICT + IRT)/VET and (ICT + IRT)/VFT respectively. The TI did not show any significant change from CHD (conduction) to CHD (structural) fetuses (0.72± 0.09 vs 0.76±0.02; NS). On the other hand, KI showed significant decline in values (0.82±0.24 vs 0.49±0.34; p<0.05) during normal development period and CHD with structural anomalies particularly. The correlation of KI with gestational ages was found to be negative and significant (r=-0.29; p=0.025). Both TI and KI can be easily obtained in the fetus from DUS recording without the need for precise anatomic imaging. In conclusion, KI may be a useful tool to explore the healthy development of fetal myocardial function and identify fetuses with CHD (structural). More research is needed to check if KI could recognize the compromised fetuses from normal ones in future.
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14:35-14:50, Paper ThCT17.2 | Add to My Program |
Detecting Fetal Heart Sounds by Means of Fractal Dimension Analysis in the Wavelet Domain |
Koutsiana, Elisavet | Lab. of Medical Informatics, the Medical School, Aristotle Univ |
Hadjileontiadis, Leontios | Aristotle Univ. of Thessaloniki |
Chouvarda, Ioanna | Aristotle Univ. EL090049627 |
Khandoker, Ahsan Habib | Khalifa Univ. of Science, Tech. and Res |
Keywords: Time-frequency and time-scale analysis - Wavelets
Abstract: Phonocardiography is a low-cost technique for the detection of fetal heart sounds (FHS) that can extend clinical auscultation in mobile and home care setups. The work presented here examines the transferability of a Wavelet Transform (WT)-based method that combines also Fractal Dimension (FD) analysis, previously proposed as WT-FD for the cases of lung and bowel sound analysis [4], to the extraction of FHSs. The WT-FD method has been evaluated with 12 simulated FHS signals and has shown promising results in terms of accuracy and performance (89%) in indentifying the location of heartbeat, even with cases of signals with additive noise up to (6dB). This robustness paves the way for WT-FD testing in real FHSs, recorded under clinical setting, clearly contributing to better evaluation of the fetal heart functionality.
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ThCT18 Oral Session, Montgomery Hall |
Add to My Program |
Kalman Filtering |
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Chair: Almeida, Vania | Aston Univ |
Co-Chair: Hamid, Laith | Univ. of Kiel |
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14:20-14:35, Paper ThCT18.1 | Add to My Program |
Self-Reported Well-Being Score Modelling and Prediction: Proof-Of-Concept of an Approach Based on Linear Dynamic Systems |
Li, Xinyang | National Univ. of Singapore |
Poli, Riccardo | Univ. of Essex |
Valenza, Gaetano | Univ. of Pisa |
Scilingo, Enzo Pasquale | Univ. of Pisa |
Citi, Luca | Univ. of Essex |
Keywords: Kalman filtering, Parametric filtering and estimation, Signal pattern classification - Markov models
Abstract: Assessment and recognition of perceived well-being has wide applications in the development of assistive healthcare systems for people with physical and mental disorders. In practical data collection, these systems need to be less intrusive, and respect users' autonomy and willingness as much as possible. As a result, self-reported data are not necessarily available at all times. Conventional classifiers, which usually require feature vectors of a prefixed dimension, are not well suited for this problem. To address the issue of non-uniformly sampled measurements, in this study we propose a method for the modelling and prediction of self-reported well-being scores based on a linear dynamic system. Within the model, we formulate different features as observations, making predictions even in the presence of inconsistent and irregular data. We evaluate the proposed method with synthetic data, as well as real data from two patients diagnosed with cancer. In the latter, self-reported scores from three well-being-related scales were collected over a period of approximately 60 days. Prompted each day, the patients had the choice whether to respond or not. Results show that the proposed model is able to track and predict the patients' perceived well-being dynamics despite the irregularly sampled data.
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14:35-14:50, Paper ThCT18.2 | Add to My Program |
Removal of Spurious Phase Variations in Oscillatory Signals |
Mortezapouraghdam, Zeinab | Saarland Univ |
Strauss, Daniel J. | Saarland Univ. Medical Faculty |
Keywords: Kalman filtering, Physiological systems modeling - Signals and systems, Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: The study of oscillatory electroencephalogram (EEG) data has been one of the main sources for the analysis of different brain functions and decoding a variety of cognitive processes. One of the interesting features that has been the focus of study in the last decades is the study of instantaneous phase information in EEG. Phase synchronization techniques are among the main analysis tools that measure the degree of phase re-organization in signals. In phase re-organization approach, the phase alignment in stimulus induced potentials has been shown to be informative for decoding cognitive processes. Despite the developments in this area, the precision of the measures may vary based on the level of noise. Phase distortion due to artefacts and a variety of pre-processing steps that are applied on data, can introduce artificial phase alignment. These artificial phase variations (that is referred to spurious phase changes, are not correlated to any stimulus or event. In a new study, it has been showed that a low instantaneous envelope lead to abrupt changes in IP, which could distort the results of phase synchronization. In this work, we propose a method that is able to estimate the true phase based on the measurements and estimate a standard deviation for the computed phase. The method enables to remove the effect of artificial phase changes due to low envelope. In this approach the analytic signal is modeled by a Kalman smoother, and estimates a more reliable version of the IP from the measurements. At last, we evaluate the model on different synthetic data sets.
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14:50-15:05, Paper ThCT18.3 | Add to My Program |
Spatial Projection As a Preprocessing Step for EEG Source Reconstruction Using Spatiotemporal Kalman Filtering |
Hamid, Laith | Univ. of Kiel |
Al Farawn, Ali | Univ. of Kufa |
MERLET, Isabelle | INSERM - Univ. De Rennes 1 |
Japaridze, Natia | Department of Neuropediatrics, Christian-Albrechts-Univ. Of |
Heute, Ulrich | Univ. of Kiel |
Stephani, Ulrich | Christian-Albrechts-Univ. of Kiel |
Galka, Andreas | Christian-Albrechts-Univ. of Kiel |
WENDLING, Fabrice | INSERM - Univ. De Rennes 1 |
Siniatchkin, Michael | Univ. of Kiel |
Keywords: Kalman filtering, Physiological systems modeling - Signal processing in physiological systems, Physiological systems modeling - Signal processing in simulation
Abstract: The reconstruction of brain sources from noninvasive electroencephalography (EEG) or magnetoencephalography (MEG) via source imaging can be distorted by information redundancy in case of high-resolution recordings. Dimensionality reduction approaches such as spatial projection may be used to alleviate this problem. In this proof-of-principle paper we apply spatial projection to solve the problem of information redundancy in case of source reconstruction via spatiotemporal Kalman filtering (STKF), which is based on state-space modeling. We compare two approaches for incorporating spatial projection into the STKF algorithm and select the best approach based on its performance in source localization with respect to accurate estimation of source location, lack of spurious sources, computational speed and small number of required optimization steps in state-space model parameter estimation. We use state-of-the-art simulated EEG data based on neuronal population models, for which the number and location of sources is known, to validate the source reconstruction results of the STKF. The incorporation of spatial projection into the STKF algorithm solved the problem of information redundancy, resulting in correct source localization with no spurious sources, and decreased the overall computational time in STKF analysis. The results help make STKF analyses of high-density EEG, MEG or simultaneous MEG-EEG data more feasible.
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15:05-15:20, Paper ThCT18.4 | Add to My Program |
Source Reconstruction Via the Spatiotemporal Kalman Filter and LORETA from EEG Time Series with 32 or Fewer Electrodes |
Hamid, Laith | Univ. of Kiel |
Al Farawn, Ali | Univ. of Kufa |
MERLET, Isabelle | INSERM - Univ. De Rennes 1 |
Japaridze, Natia | Department of Neuropediatrics, Christian-Albrechts-Univ. Of |
Heute, Ulrich | Univ. of Kiel |
Stephani, Ulrich | Christian-Albrechts-Univ. of Kiel |
Galka, Andreas | Christian-Albrechts-Univ. of Kiel |
WENDLING, Fabrice | INSERM - Univ. De Rennes 1 |
Siniatchkin, Michael | Univ. of Kiel |
Keywords: Kalman filtering, Physiological systems modeling - Signal processing in physiological systems, Physiological systems modeling - Signal processing in simulation
Abstract: The clinical routine of non-invasive electroencephalography (EEG) is usually performed with 8-40 electrodes, especially in long-term monitoring, infants or emergency care. There is a need in clinical and scientific brain imaging to develop inverse solution methods that can reconstruct brain sources from these low-density EEG recordings. In this proof-of-principle paper we investigate the performance of the spatiotemporal Kalman filter (STKF) in EEG source reconstruction with 9-, 19- and 32- electrodes. We used simulated EEG data of epileptic spikes generated from lateral frontal and lateral temporal brain sources using state-of-the-art neuronal population models. For validation of source reconstruction, we compared STKF results to the location of the simulated source and to the results of low-resolution brain electromagnetic tomography (LORETA) standard inverse solution. STKF consistently showed less localization bias compared to LORETA, especially when the number of electrodes was decreased. The results encourage further research into the application of the STKF in source reconstruction of brain activity from low-density EEG recordings.
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15:20-15:35, Paper ThCT18.5 | Add to My Program |
Detecting Dynamical Changes in Vital Signs Using Switching Kalman Filter |
Almeida, Vania | Aston Univ |
Nabney, Ian T. | Aston Univ |
Keywords: Kalman filtering, Time-frequency and time-scale analysis - Nonstationary processing
Abstract: Vital signs contain valuable information about patients' health status during their stay in general wards, when the deterioration process begins. The use of methods to predict and detect regime changes such as switching models can help to understand how vital sign dynamics are altered in disease conditions. However, time series of vital signs are remarkably non-stationary in these scenarios. The objective of this study is to quantify the potential bias of switching models in the presence of non-stationarities, when the inputs are spectral, symbolic and entropy indices. To distinguish stationary from non-stationary periods, a test was used to verify the stability of the mean and variance over short periods. Then, we compared the results from a switching Kalman filter (SKF) model trained using indices obtained over stationary periods with a model trained solely over non-stationary periods. It was observed that indices measured over stationary and non-stationary periods were significantly different. The results of switching models were highly dependent on the indices that were used as inputs. The multi-scale entropy (MSE) approach presented the highest correlation values between non-stationary and stationary switches, an average correlation coefficient of 38%.
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15:35-15:50, Paper ThCT18.6 | Add to My Program |
A Kalman Filter Approach with State Inequality Constraints for Real-Time Prediction of Intradialytic Hypotension Using a PVDF Sensor |
Ansari, Sardar | Univ. of Michigan |
Molaei, Somayeh | Univ. of Michigan |
Oldham, Kenn | Univ. of Michigan |
Heung, Michael | Univ. of Michigan |
Ward, Kevin | Univ. of Michigan |
Najarian, Kayvan | Univ. of Michigan - Ann Arbor |
Keywords: Kalman filtering, Signal pattern classification
Abstract: Intradialytic hypotension (IDH) is the most common complication of hemodialysis, affecting 15-50% of all dialysis sessions. Previously, we had presented a non-invasive Polyvinylidene Fluoride (PVDF) based sensor in the form of a ring to measure vascular tone and we showed that the morphology of the signal can be utilized to predict IDH. This paper presents an approach for analyzing the PVDF signal using extended Kalman filter (EKF) and a synthetic model that has previously been used to model the ECG signal with Gaussian functions. Moreover, a novel approach for incorporating state inequality constraints into the EKF process using a gradient projection method is introduced. The taut string algorithm was first used to estimate the outline of the signal and remove it to highlight the reflection waves. Then, the EKF was used to characterize the morphology of the signal using Gaussian functions. The amplitudes of the Gaussian functions were used as features to train a classifier. The results indicated that the PPV and NPV for the prediction were 83.33% and 100%, respectively.
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ThDT1 |
Roentgen Hall |
Ignite Session T-01 |
Ignite Session |
Chair: Sajib, Saurav Z K | Kyung Hee Univ |
Co-Chair: Haider, Clifton | Mayo Clinic | |
16:10-16:18, Subsession ThDT1-01, Roentgen Hall | |
Adaptive filtering I Poster Session, 4 papers |
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16:10-16:20, Subsession ThDT1-02, Roentgen Hall | |
Connectivity analysis I Poster Session, 5 papers |
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16:10-16:24, Subsession ThDT1-03, Roentgen Hall | |
Data mining I Poster Session, 7 papers |
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16:10-16:28, Subsession ThDT1-04, Roentgen Hall | |
Nonlinear dynamic analysis III Poster Session, 9 papers |
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ThDT1-01 Poster Session, Roentgen Hall |
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Adaptive Filtering I |
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16:10-16:12, Paper ThDT1-01.1 | Add to My Program |
EEG-Based Emotion Estimation Using Adaptive Tracking of Discriminative Frequency Components |
Liu, Shuang | Tianjin Univ |
Zhang, Di | Tianjin Univ |
Tong, Jingjing | Tianjin Univ |
He, Feng | Tianjin Univ |
QI, Hongzhi | Tianjin Univ |
Zhang, Lixin | Tianjin Univ |
Ming, Dong | Tianjin Univ |
Keywords: Signal pattern classification, Data mining and processing - Pattern recognition, Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: EEG-based emotion recognition has received increasing attention in advanced human-computer interaction, the frequency components that give effective discrimination between different types of emotion states are subject specific and identification of these subject-specific discriminative frequency components (DFCs) is important for the accurate classification of emotional activities. This paper investigated the potential of adaptive tracking of discriminative frequency components (DFCs) as an effective method for choosing the discriminative bands of EEG patterns and improving emotion recognition performance. 13 healthy volunteers were emotionally elicited by pictures selected from the International Affective Picture System (IAPS). Discriminative frequency components were tracked and analyzed for each subject and classification of three emotions (pleasant/high arousal, neutral, unpleasant/high arousal) was performed by employing a Hidden Markov Model (HMM) and a Support Vector Machine (SVM). Our results showed that adaptive tracking of DFCs improved classification accuracies significantly and the highest average accuracy of 82.85% was achieved by SVM.
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16:12-16:14, Paper ThDT1-01.2 | Add to My Program |
A Template Subtraction Method for the Removal of Cardiogenic Oscillations on Esophageal Pressure Signals |
Graßhoff, Jan | Univ. of Luebeck |
Petersen, Eike | Univ. of Lübeck |
Eger, Marcus | Dräger Medical |
Bellani, Giacomo | Department of Experimental Medicine, Univ. of Milan-Bicocca |
Rostalski, Philipp | Inst. for Electrical Engineering in Medicine, Univ. Of |
Keywords: Adaptive filtering, Data mining and processing in biosignals
Abstract: Esophageal pressure is usually measured in patients receiving mechanical ventilation and is used for the assessment of lung mechanics. However, its interpretation is complicated by the presence of cardiogenic oscillations (CGO). In this article we present a novel method for the reduction of CGO based on the identification of pressure templates. Similar approaches are known for the removal of electrocardiographic (ECG) artifacts from the electromyogram (EMG). The proposed method is tested on clinical recordings of patients under assisted spontaneous ventilation. Besides the improvement of the respiratory signals, the identified CGO templates can be used diagnostically when viewed in relation to corresponding ECG data. This approach is illustrated on a few sample datasets.
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16:14-16:16, Paper ThDT1-01.3 | Add to My Program |
FPGA Implementation of Adaptive Beamforming in Hearing Aids |
Samtani, Kartik | National Inst. of Tech. Karnataka |
Thomas, Jobin | National Inst. of Tech. Karnataka |
Varma, Abhinav | National Inst. of Tech. Karnataka |
DAVID S., SUMAM | NATIONAL Inst. OF Tech. KARNATAKA, SURATHKAL |
S. P., Deepu | National Inst. of Tech. Karnataka |
Keywords: Adaptive filtering, Directionality, Physiological systems modeling - Signal processing in simulation
Abstract: Beamforming is a spatial filtering technique used in hearing aids to improve target sound reception by reducing interference from other directions. In this paper we propose improvements in an existing architecture present for two omnidirectional microphone array based adaptive beamforming for hearing aid applications and implement the same on Xilinx Artix 7 FPGA using VHDL coding and Xilinx Vivado 2015.2. The nulls are introduced in particular directions by combination of two fixed polar patterns. This combination can be adaptively controlled to steer the null in the direction of noise. The beamform patterns and improvements in SNR values obtained from experiments in a conference room environment are analyzed.
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16:16-16:18, Paper ThDT1-01.4 | Add to My Program |
Detection of User Independent Single Trial ERPs in Brain Computer Interfaces: An Adaptive Spatial Filtering Approach |
Leza Lahuerta, Cristina | Univ. Pol. De Madrid |
Puthusserypady, Sadasivan | Tech. Univ. of Denmark |
Keywords: Adaptive filtering, Time-frequency and time-scale analysis - Wavelets, Signal pattern classification
Abstract: Brain Computer Interfaces (BCIs) use brain sig- nals to communicate with the external world. The main challenges to address are speed, accuracy and adaptability. Here, a novel algorithm for P300 based BCI spelling system is presented, specifically suited for single-trial detection of Event- Related Potentials (ERPs) by combining spatial filtering and new feature extraction methods. The adaptive spatial filtering technique, axDAWN, removes the need for calibration of the system thereby improving the overall speed of the system. Besides, axDAWN enhances the P300 response to target stimuli. The wavelet decomposition and entropy of the recorded ERPs are shown to be correlated with the presence of the P300 responses. The proposed scheme is validated thoroughly in a P300 speller and provides a solution to achieve high accuracy results for single-trial detection of ERPs, being the system user independent.
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ThDT1-02 Poster Session, Roentgen Hall |
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Connectivity Analysis I |
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16:10-16:12, Paper ThDT1-02.1 | Add to My Program |
Low-Latency VLSI Architecture for Neural Cross-Frequency Coupling Analysis |
O Leary, Gerard | Univ. of Toronto |
Valiante, Taufik A. | Univ. of Toronto |
Genov, Roman | Univ. of Toronto |
Keywords: Coupling and synchronization - Coherence in biomedical signal processing, Connectivity measurements, Signal pattern classification
Abstract: Growing evidence suggests that cross-frequency coupling (CFC) is a key mechanism in neuronal computation, communication, and learning in the brain. Abnormal CFC has been implicated in pathological brain states such as epilepsy and Parkinson’s disease. A reduction in excessive coupling has been shown in effective neuromodulation treatments, suggesting that CFC may be a useful feedback measure in closed-loop neural stimulation devices. However, processing latency limits the responsiveness of such systems. A VLSI architecture is presented which implements three selectable measures of CFC to enable the application specific trade-off between low-latency and high-accuracy processing. The architecture is demonstrated using in-vitro human neocortical slice recordings, with a latency of 48ms.
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16:12-16:14, Paper ThDT1-02.2 | Add to My Program |
Neuronal Desynchronization As Marker of an Impaired Brain Network |
Schulz, Steffen | Univ. of Applied Sciences Jena |
Legorburu Cladera, Borja | Univ. Pol. De Catalunya |
Giraldo, Beatriz | Univ. Poiltècnica De Catalunya |
Bolz, Mathias | Univ. Hospital Jena |
Bär, Karl-Jürgen | Friedrich-Schiller-Univ. of Jena |
Voss, Andreas | Univ. of Applied Sciences Jena |
Keywords: Coupling and synchronization - Coherence in biomedical signal processing, Connectivity measurements, Physiological systems modeling - Signal processing in physiological systems
Abstract: Synchronization is a central key feature of neural information processing and communication between different brain areas. Disturbance of oscillatory brain rhythms and decreased synchronization have been associated with different disorders including schizophrenia. The aim of this study was to investigate whether synchronization (in relaxed conditions with no stimuli) between different brain areas within the delta, theta, alpha (alpha1, alpha2), beta (beta1, beta2), and gamma bands is altered in patients with a neurological disorder in order to generate significant cortical enhancements. To achieve this, we investigated schizophrenic patients (SZO; N=17, 37.5±10.4 years, 15 males) and compared them to healthy subjects (CON; N=21, 36.7±13.4 years, 15 males) applying the phase locking value (PLV). We found significant differences between SZO and CON in different brain areas of the theta, alpha1, beta2 and gamma bands. These areas are related to the central and parietal lobes for the theta band, the parietal lobe for the alpha1, the parietal and frontal for the beta2 and the frontal-central for the gamma band. The gamma band revealed the most significant differences between CON and SZO. PLV were 61.7% higher on average in SZO in most of the clusters when compared to CON. The related brain areas are directly related to cognition skills which are proved to be impaired in SZO. The results of this study suggest that synchronization in SZO is also altered when the patients were not asked to perform a task that requires their cognitive skills (i.e., no stimuli are applied - in contrast to other findings).
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16:14-16:16, Paper ThDT1-02.3 | Add to My Program |
Coherence Analysis of Invasive Blood Pressure and Its Noninvasive Indicators for Improvement of Cuffless Measurement Accuracy |
Ding, Xiao-Rong | The Chinese Univ. of Hong Kong |
Yan, Bryan P. | Prince of Wales Hospital, the Chinese Univ. of Hong Kong |
Zhang, Yuan-Ting | The Chinese Univ. of Hong Kong |
Liu, Jing | The Chinese Univ. of Hong Kong |
Su, Peng | The Chinese Univ. of Hong Kong |
Zhao, Ni | The Chinese Univ. of Hong Kong |
Keywords: Coupling and synchronization - Coherence in biomedical signal processing, Time-frequency and time-scale analysis - Time-frequency analysis, Physiological systems modeling - Multivariate signal processing
Abstract: Pulse transit time (PTT) is one of the most extensively studied indicators for measuring cuffless BP. However, PTT-based method has limited accuracy for BP estimation, particularly for long term monitoring, which roots probably in the incapability of PTT to reflect BP changes. To figure out the covariation of BP-related noninvasive indicators and BP, we propose to analyze the coherence of intra-arterial systolic BP (SBP) and noninvasive indicators including PTT, photoplethysmogram intensity ratio (PIR) and RR interval (RRI) of electrocardiogram (ECG) in time domain with singular spectrum analysis (SSA) and in frequency domain with cross-spectral analysis. SSA decomposed SBP and these indicators into slowing trend and fast oscillations, and showed that their fast variations oscillated at similar frequency but their slow variations were out of phase synchronization. Cross-spectra between SBP and these indicators further illustrated stronger coherence correlation in high frequency (HF, 0.15-0.40 Hz) (PTT: 0.54±0.30, PIR: 0.73±0.25, RRI: 0.63±0.25) than in low frequency (LF, 0.04-0.15 Hz) (PTT: 0.24±0.19, PIR: 0.37±0.23, RRI: 0.33±0.23). The results suggest that these indicators are inadequate to track LF component of BP. Therefore, it would be valuable to explore LF-related BP indicators and new models to integrate LF and HF information for improvement of cuffless measurement accuracy.
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16:16-16:18, Paper ThDT1-02.4 | Add to My Program |
Phase-Amplitude Coupling Analysis of Spontaneous EEG Activity in Alzheimer's Disease |
Poza, Jesus | Univ. of Valladolid |
Bachiller, Alejandro | Univ. of Valladolid |
Gomez, Carlos | Univ. of Valladolid, CIF: Q4718001C |
Garcia, Maria | Univ. of Valladolid, CIF: Q4718001C |
Núñez, Pablo | Univ. of Valladolid, CIF: Q4718001C |
Gomez-Pilar, Javier | Univ. of Valladolid, CIF: Q4718001C |
Tola-Arribas, Miguel A. | Department of Neurology, Hospital Univ. Río Hortega |
Cano, Mónica | Department of Clinical Neurophysiology, Hospital Univ. R |
Hornero, Roberto | Univ. of Valladolid |
Keywords: Coupling and synchronization - Nonlinear coupling, Coupling and synchronization - Coherence in biomedical signal processing, Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: This study was aimed at exploring phase-amplitude coupling (PAC) patterns of neural activity in dementia due to Alzheimer’s disease (AD). For this task, five minutes of spontaneous electroencephalographic (EEG) activity from 22 patients with mild AD and 16 cognitively healthy controls were studied. To assess PAC patterns, phase-locking value was computed between the phase of low frequencies and the power of high frequencies within each sensor. Our results showed that high-frequency gamma power is phase-locked to the alpha peak in EEG signals. Furthermore, statistically significant differences (p<0.05, permutation test) between patients with mild AD and elderly controls were observed at the lower left temporo-parietal area, suggesting that early stages of AD elicit a region-specific decrease of PAC in the neural activity.
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16:18-16:20, Paper ThDT1-02.5 | Add to My Program |
Study on the Effects of Brightness Contrast on Steady-State Motion Visual Evoked Potential |
Yan, Wenqiang | Xi'an Jiaotong Univ |
Xu, Guanghua | Xi'an Jiaotong Univ |
Xie, Jun | Xi'an Jiaotong Univ |
Li, Min | School of Mechanical Engineering, Xi’an Jiaotong Univ |
Zhang, Sicong | Xi’an Jiaotong Univ |
Luo, Ailing | Xi’an Jiaotong Univ |
Keywords: Causality, Data mining and processing in biosignals, Signal pattern classification
Abstract: Traditional steady - state visual evoked potential (SSVEP) using light flicker stimulation may easy cause visual fatigue with a consequent reduction of recognition accuracy. In the previous study, we proposed a steady - state motion visual evoked potential (SSMVEP) brain - computer interface (BCI) method. A black - white ring - shaped checkerboard was used as the visual stimulus paradigm in this study. The movement patterns of the checkerboard included contraction and expansion. Based on the signal-to-noise ratio (SNR), recognition accuracy and anti-fatigue properties, the effects of black-white brightness contrast on the brain response were investigated. Experimental results indicated that when the contrast ratio was the highest, it could obtain higher recognition accuracy and SNR, yet it was easy to cause visual fatigue. When the contrast was the lowest, the sensitivity of the eyes against flicker reduced to the lowest, and it could reduce visual fatigue. However the recognition accuracy and SNR were low. In contrast, the appropriate contrast could guarantee high SNR and recognition accuracy, and as much as possible to reduce the visual fatigue.
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ThDT1-03 Poster Session, Roentgen Hall |
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Data Mining I |
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16:10-16:12, Paper ThDT1-03.1 | Add to My Program |
Template-DTW Based on Inertial Signals: Preliminary Results for Step Characterization |
Mantilla, Juan | Univ. Paris Descartes |
Oudre, Laurent | L2TI, Univ. Paris 13 |
Barrios, Rémi | COGNAC G Univ. Paris Descartes |
Vienne, Aliénor | COGNACG, CNRS/SSA UMR 8257, Univ. Paris Descartes |
Ricard, Damien | COGNACG, CNRS/SSA UMR 8257, Univ. Paris Descartes |
Keywords: Signal pattern classification, Data mining and processing - Pattern recognition, Nonlinear dynamic analysis - Biomedical signals
Abstract: In this paper, we present a method for the creation of a library of inertial signals based on Dynamic Time Warping (DTW) for step characterization, with preliminary results in control subjects and patients with neurological diseases. Subjects performed a protocol including a 10 m straight walking, then turn back and walking for additional 10 m. The library is constructed with inertial signals (acceleration and angular velocities recorded in three directions) aligned with the DTW. Templates in the library are obtained for a specific cohort and for the different walking phases of the protocol. They are compared to the signal of a single subject by calculating a Pearson correlation coefficient. The method has been tested on a database of 864 exercises, obtained from 71 healthy controls, 24 patients with Parkinson disease and 48 patients with Radiation Induced Leukoencephalopathy (RIL). Pearson correlation classification reports a precision of about 85% for step detection. For exercise characterization the sensitivity is about 57%, 56% and 82% for Parkinson, RIL and control subjects respectively.
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16:12-16:14, Paper ThDT1-03.2 | Add to My Program |
Using Spatial Features for Classification of Combined Motions Based on Common Spatial Pattern |
Lu, Huiyang | School of Data and Computer Science, Sun Yat-Sen Univ |
Zhang, Haoshi | Shenzhen Inst. of Advanced Tech |
Wang, Zhong | School of Data and Computer Science, Sun Yat-Sen Univ |
Wang, Ruomei | School of Data and Computer Science, Sun Yat-Sen Univ |
Li, Guanglin | Shenzhen Inst. of Advanced Tech |
Keywords: Signal pattern classification, Data mining and processing - Pattern recognition, Physiological systems modeling - Signals and systems
Abstract: Motion recognition is an important application of electromyography (EMG) analysis. While discrete motions such as hand open, hand close and wrist pronation have been extensively investigated, studies on combined motions involving two or more degrees of freedom (DOFs) are relatively few and the classification accuracy of the combined motions reported in previous studies is barely satisfactory. To improve the accuracy of the combined motion recognition, common spatial pattern (CSP) was employed in this study to extract spatial features. 18 forearm motion classes, consisted of 8 discrete motions and 10 combined motions, were classified by the proposed method. Our results showed that the accuracy rate of CSP features was 96.3%, which outperformed the commonly used time-domain (TD) features by 2.4% and TD combined with auto-regression coefficients (TDAR) by 0.6%. Moreover, CSP features cost noticeable much less time than TDAR and quite less time than TD in testing. These results suggest that CSP features could be a better feature set for multi-DOF myoelectric control than conventional features.
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16:14-16:16, Paper ThDT1-03.3 | Add to My Program |
Surgical Gesture Classification Using Dynamic Time Warping and Affine Velocity |
Cifuentes Quintero, Jenny Alexandra | Univ. Nacional De Colombia |
Pham, Minh Tu | Inst. National Des Sciences Appliquées (INSA De Lyon) |
Moreau, Richard | INSA-Lyon |
Prieto, Flavio | Unversidad Nacional De Colombia |
Boulanger, Pierre | Univ. of Alberta |
Keywords: Signal pattern classification, Data mining and processing - Pattern recognition, Physiological systems modeling - Multivariate signal processing
Abstract: Minimally Invasive Surgery (MIS) has become widespread as an important surgical technique due to its advantages related to pain relief and short recovery time periods. However, this approach implies the acquisition of special surgical skills, which represents a challenge in the objective assessment of surgical gestures. In this way, several studies shown that kinematics and kinetic analysis of hand movement is a valuable assessment tool of basic surgical skills in MIS. In addition, recent researches proved that human motion performed during surgery can be described as a sequence of constant affine velocity movements. In this paper, we present a novel method to classify gestures based on an affine velocity analysis of 3D motion and an implementation of the Dynamic Time Warping algorithm. In particular, affine velocity calculation correlates kinematics and geometrical variables such as curvature, torsion, and euclidean velocity, reducing the dimension of the conventional 3D problem. In this way, using the simplicity of dynamic time warping algorithm allows us to perform an accurate classification, easier to implement and understand. Experimental validation of the algorithm is presented based on the position and orientation data of a laparoscope instrument, determined by six cameras. Results show the advantages of the proposed method, compared to conventional Multidimensional Dynamic Time Warping, to classify surgical gestures in MIS.
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16:16-16:18, Paper ThDT1-03.4 | Add to My Program |
Biological Tissues Identification from Their Raman Spectral Signals Acquired by a Raman Needle |
Yang, Tangwen | Beijing Jiaotong Univ |
Zheng, Jiawen | Beijing Jiaotong Univ |
Keywords: Signal pattern classification
Abstract: In this paper, biological tissues are discriminated based on their intrinsic Raman spectral features. First, a Raman needle, which comprises of a Raman probe and a puncture needle, is devised to insert into biological tissues and acquire their Raman spectral data. The Savitzky-Golay filter is used to remove the data noise, and an adaptive iterative penalized least squares method to rectify the baseline. To extract the spectral features from the data, the principal component analysis (PCA) is used. Then, a genetic algorithm (GA) based support vector machine (SVM) method is proposed to classify the biological tissues based on the spectral features. Experimental study was conducted with different animal specimens and approved that the proposed methods can identify efficiently the different biological tissues.
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16:18-16:20, Paper ThDT1-03.5 | Add to My Program |
Counting Malaria Parasites with a Two-Stage EM Based Algorithm Using Crowsourced Data |
Cabrera-Bean, Margarita | Univ. Pol. De Catalunya, UPC, BarcelonaTECH |
Pagès-Zamora, Alba | Univ. Pol. De Catalunya |
Diaz-Vilor, Carles | Univ. Pol. De Catalunya |
Postigo Camps, Maria | Tech. Univ. of Madrid |
Cuadrado Sanchez, Daniel | Tech. Univ. of Madrid |
Luengo-Oroz, Miguel Angel | Univ. Pol. De Madrid |
Keywords: Signal pattern classification, Data mining and processing - Pattern recognition
Abstract: Malaria eradication of the worldwide is currently one of the main WHO's global goals. In this work, we focus on the use of human-machine interaction strategies for low-cost fast reliable malaria diagnostic based on a crowdsourced approach. The addressed technical problem consists in detecting spots in images even under very harsh conditions when positive objects are very similar to some artifacts. The clicks or tags delivered by several annotators labeling an image are modeled as a robust finite mixture, and techniques based on the expectation-maximization (EM) algorithm are proposed for accurately counting malaria parasites on thick blood smears obtained by microscopic Giemsa-stained techniques. This approach outperforms other traditional methods as it is shown through experimentation with real data.
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16:20-16:22, Paper ThDT1-03.6 | Add to My Program |
Elastic Net Based Sparse Feature Learning and Classification for Alzheimer's Disease Identification |
Wang, Ling | Univ. of Electronic Science and Tech. of China |
Liu, Yan | Univ. of Chinese Acad. of Sciences |
zeng, xiangzhu | Peking Univ. Third Hospital, Beijing, China |
Wang, Zheng | Capital Univ. of Medical Sciences |
Keywords: Signal pattern classification - Genetic algorithms, Principal component analysis
Abstract: Magnetic resonance imaging (MRI) has been successfully applied to investigate neuron pathological changes. Since the high dimension of observation data, sparse feature learning plays an important role in overcoming the challenge of high variable dimension and low sample size problem among the disease identification. In this paper, sparse Elastic Net (EN) was used to extract low dimension features and to identify the Alzheimer's disease (AD). Compare with principal component analysis (PCA) method, the EN method can solve the problems of less samples and high correlations between variables. For those variables sharing the same biological phenomenon, it selected whole groups into the model automatically once one variable among them was selected. Unlike other subspace learning methods, the proposed method used less man-made feature setting. The problems of dimension reduction and classification were conducted into a similar formulation. Experimental results illustrated the effectiveness of the proposed method.
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16:22-16:24, Paper ThDT1-03.7 | Add to My Program |
Reducing False Asystole Alarms in Intensive Care |
Dekimpe, Remi | Univ. Catholique De Louvain |
Heldt, Thomas | Massachusetts Inst. of Tech |
Keywords: Signal pattern classification, Physiological systems modeling - Signal processing in physiological systems, Physiological systems modeling - Signals and systems
Abstract: High rates of false monitoring alarms in intensive care can desensitize staff and therefore pose a significant risk to patient safety. Like other critical arrhythmia alarms, asystole alarms require immediate attention by the care providers as a true asystole event can be acutely life threatening. Here, we demonstrate that most asystole alarms are caused by poor signal quality and propose and evaluate an algorithm to identify data windows of poor signal quality and thereby help suppress false asystole alarms. The algorithm combines intuitive signal-quality features (degree of signal saturation and baseline wander) and information from other physiological signals that might be available. Algorithm training and testing was performed on the MIMIC II and 2015 PhysioNet/Computing in Cardiology Challenge databases, respectively. The algorithm achieved an alarm specificity of 81.0% and sensitivity of 95.4%, missing only one out of 22 true asystole alarms. On a separate neonatal data set, the algorithm was able to reject 89.7% (890 out of 992) of false asystole alarms while keeping all 22 true events. The results show that the false asystole alarm rate can be significantly reduced through basic signal quality evaluation.
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ThDT1-04 Poster Session, Roentgen Hall |
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Nonlinear Dynamic Analysis III |
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16:10-16:12, Paper ThDT1-04.1 | Add to My Program |
Elimination of Power Line Interference from ECG Signals Using Recurrent Neural Networks |
Qiu, Yue | Zhejiang Univ |
Xiao, Feng | Zhejiang Univ |
Shen, Haibin | Zhejiang Univ |
Keywords: Nonlinear dynamic analysis - Nonlinear filtering, Neural networks and support vector machines in biosignal processing and classification
Abstract: This study proposed a method for the elimination of 50-Hz power line interference (PLI) in electrocardiogram (ECG) signals, using recurrent neural networks (RNN). The method is to preliminarily train an RNN-based model to obtain the signal pattern of PLI. The ECG signals are then filtered by subtracting the PLI signals extracted by the trained model. The results suggest that the proposed method could significantly relieve the distortion of QRS complex while filtering the ECG signals efficiently. The method was evaluated by comparing with a traditional IIR notch filter and an adaptive filtering method.
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16:12-16:14, Paper ThDT1-04.2 | Add to My Program |
A Novel Heart Rate Variability Analysis Using Lagged Poincaré Plot: A Study on Hedonic Visual Elicitation |
Nardelli, Mimma | Univ. of Pisa |
Greco, Alberto | Univ. of Pisa |
Valenza, Gaetano | Univ. of Pisa |
Lanata', Antonio | Univ. of Pisa |
Bailon, Raquel | Univ. of Zaragoza |
Scilingo, Enzo Pasquale | Univ. of Pisa |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Signal pattern classification
Abstract: This paper reports on a novel method for the analysis of Heart Rate Variability (HRV) through Lagged Poincaré Plot (LPP) theory. Specifically a hybrid method, LPPsymb, including LPP quantifiers and related symbolic dynamics was proposed. LPP has been applied to investigate the autonomic response to pleasant and unpleasant pictures extracted from the International Affective Picture System (IAPS). IAPS pictures are standardized in terms of level of arousal, i.e. the intensity of the evoked emotion, and valence, i.e. the level of pleasantness/ unpleasantness, according to the Circumplex model of Affects (CMA). Twenty-two healthy subjects were enrolled in the experiment, which comprised four sessions with increasing arousal level. Within each session, valence increased from negative to positive. An ad-hoc pattern recognition algorithm using a Leave-One-Subject-Out (LOSO) procedure based on a Quadratic Discriminant Classifier (QDC) was implemented. Our pattern recognition system was able to classify pleasant and unpleasant sessions with an accuracy of 71.59%. Therefore, we can suggest the use of the LPPsymb for emotion recognition.
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16:14-16:16, Paper ThDT1-04.3 | Add to My Program |
Pressure Ulcer Risk Detection from Complexity of Activity |
Padhye, Nikhil | Univ. of Texas Health Science Center |
Bergstrom, Nancy | The Univ. of Texas Health Science Center at Houston |
Rapp, Mary | Retired |
Etcher, LuAnn | Spring Arbor Univ. School of Human Services |
Redeker, Nancy | Yale School of Nursing |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Nonlinear dynamic analysis - Deterministic chaos
Abstract: Activity levels in nursing home residents were measured with accelerometers over one week as part of a multicenter randomized controlled trial, and complexity of the resulting activity patterns were characterized. Among 813 study participants on whom activity data had been collected, 16 participants developed pressure ulcers by the end of the study. The fractal dimension D0 of the activity series was lower (p=0.039) in residents who developed pressure ulcers than in controls matched on the basis of race, randomization group, score on the Braden scale, and diagnoses of cardiovascular disease and dementia. Hurst exponents indicated that the scaling of the power spectrum was close to 1/f in pressure ulcer cases. At timescales exceeding 30 minutes, approximate entropy tended to be higher in the controls than in the pressure ulcer cases. The fractal structure of the activity time series and its information content offer the ability to predict higher risk of development of pressure ulcers in nursing home residents.
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16:16-16:18, Paper ThDT1-04.4 | Add to My Program |
Feature Analysis of Dysphonia Speech for Monitoring Parkinson's Disease |
Rueda, Alice | Ryerson Univ |
Krishnan, Sridhar | Ryerson Univ |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Time-frequency and time-scale analysis - Nonstationary processing, Time-frequency and time-scale analysis - Empirical mode decomposition in biosignal analysis
Abstract: Parkinson's disease (PD) is a progressive neurodegenerative disorder that has no known cure and no known prevention. Early detection is crucial in order to slow down the progress. In the past 10 years, interest in PD analysis has visibly increased. Speech impairment affects the majority of people with Parkinson's (PWP). New features and machine learning algorithms were proposed to help diagnose PD and to measure a patient's progress. Using sustained vowel /a/ recordings, we identified a more prominent set of Mel-Frequency Cepstral Coefficient (MFCC) and Intrinsic Mode Functions (IMF), and other parameters that can best represent the characteristics of Parkinson's dysphonia to assist with the diagnosis process. For higher quality audio signals, there is a visible difference in the higher MFCC coefficients, the wider spectrum bandwidth in the first three IMFs of PWP, and higher power intensity in the healthy subjects. We also found that even the signals are downsampled into toll-quality, the distinguishable MFCC and IMFs features were largely maintained. This enabled a whole possibility of providing telemedicine for PWP.
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16:18-16:20, Paper ThDT1-04.5 | Add to My Program |
Heart Rate Variability in Patients with Major Depressive Disorder and Healthy Controls During Non-REM Sleep and REM Sleep |
Kwon, Hyunbin | Seoul National Univ |
Yoon, Heenam | Seoul National Univ |
Jung, Dawoon | Seoul National Univ |
Choi, Sangho | Seoul National Univ |
Choi, Jaewon | Seoul National Univ. Hospital |
Lee, Yujin | Seoul National Univ. Hospital |
Jeong, Do-Un | Seoul National Univ. Hospital |
Park, Kwang S. | Seoul National Univ |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Time-frequency and time-scale analysis - Empirical mode decomposition in biosignal analysis
Abstract: The objectives of this study are to investigate heart rate variability (HRV) in major depressive disorder patients (MDD) and healthy controls during different sleep stages, and to examine the association of HRV during sleep and depression severity. Polysomnography was recorded from 15 depressive patients with a higher beck depression inventory index (BDI > 25, H-BDI-D), 15 depressive patients with a lower BDI index (BDI≤25, L-BDI-D) and 15 healthy controls. HRV was calculated during the first three rapid eye movements (REM) periods and non-REM stages (i.e. sleep stage 2 and 3) with time domain, power spectral and fractal analysis. As a result, H-BDI-D patients showed the highest short-term fractal alpha-1 exponent during first REM period and healthy controls had the lowest values. Our results suggest an association between the depression severity and the autonomic nerve function, especially during the first REM sleep. The pathophysiological analysis for this property should be conducted in future prospective studies.
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16:20-16:22, Paper ThDT1-04.6 | Add to My Program |
Complexity Analysis of EEG under Magnetic Stimulation on Acupoint of Guangming(GB37) |
Geng, Yuehua | Hebei Univ. of Tech |
xing, yangyang | Hebei Univ. of Tech |
Zhang, Xin | Tianjin Pol. Univ |
Ge, Manling | Hebei Univ. of Tech |
Keywords: Nonlinear dynamic analysis - Biomedical signals
Abstract: In this study, changes in electroencephalogram (EEG) signals under repetitive magnetic stimulation at the acupoint of Guangming (GB37) were analyzed using nonlinear dynamics complexity. C0 complexity is a statistical indicators which can quantify time dynamics of EEG signals. The study compared the C0 complexity under magnetic stimulation at GB37 with those at a mock point, as well as the C0 complexity under visual stimulation before and after magnetic stimulation at GB37. The results showed that the C0 complexity values of EEG signals in the electrode F3,Cz,C4 and P3 were different depending on whether magnetic stimulation was at the GB37 or a mock point (P < 0.05),and the C0 complexity of magnetic stimulation on GB37 was generally higher than that on mock point. Moreover, EEG signals from visual stimulation before magnetic stimulation at GB37 were significantly different from those after magnetic stimulation at GB37 in two electrodes which were C4 and P3(P < 0.05).The conclusion of the study is that magnetic stimulation at GB37 has a significant impact on EEG signals. First, EEG complexity during magnetic stimulation at GB37 was significantly higher than that at the mock point in frontal area, central area and parietal area (electrodes F3, Cz, C4 and P3). Second, EEG signals in central area and parietal area (electrodes C4 and P3) resulting from visual stimulation differed depending on whether magnetic stimulation at GB37 was given. The study has important significance for the application of magnetic stimulation on acupoints.
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16:22-16:24, Paper ThDT1-04.7 | Add to My Program |
Higuchi Fractal Dimension of the Electroencephalogram As a Biomarker for Early Detection of Alzheimer's Disease |
Al-nuaimi, Ali H. Husseen | Univ. of Plymouth |
Jammeh, Emmanuel | Plymouth Univ. School of Computing and Mathematics |
Sun, Lingfen | Plymouth Univ. School of Computing and Mathematics |
Ifeachor, Emmanuel | Univ. of Plymouth |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Signal pattern classification
Abstract: It is widely accepted that early diagnosis of Alzheimer’s disease (AD) makes it possible for patients to gain access to appropriate health care services and would facilitate the development of new therapies. AD starts many years before its clinical manifestations and a biomarker that provides a measure of changes in the brain in this period would be useful for early diagnosis of AD. Given the rapid increase in the number of older people suffering from AD, there is a need for an accurate, low-cost and easy to use biomarkers that could be used to detect AD in its early stages. Potentially, the electroencephalogram (EEG) can play a vital role in this but at present, no reliable EEG biomarker exists for early diagnosis of AD. The gradual slowing of brain activity caused by AD starts from the back of the brain and spreads out towards other parts. Consequently, determining the brain regions that are first affected by AD may be useful in its early diagnosis. Higuchi fractal dimension (HFD) has characteristics which make it suited to capturing region-specific neural changes due to AD. The aim of this study is to investigate the potential of HFD of the EEG as a biomarker which is associated with the brain region first affected by AD. Mean HFD value was calculated for all channels of EEG signals recorded from 52 subjects (20-AD and 32-normal). Then, p-values were calculated between the two groups (AD and normal) to detect EEG channels that have a significant association with AD. k-nearest neighbor (KNN) algorithm was used to compute the distance between AD patients and normal subjects in the classification. Our results show that AD patients have significantly lower HFD values in the parietal areas. HFD values for channels in these areas were used to discriminate between AD and normal subjects with a sensitivity and specificity values of 100% and 80%, respectively.
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16:24-16:26, Paper ThDT1-04.8 | Add to My Program |
Comparison of Different Shielding Methods in Acquisition of Physiological Signals |
Jiang, Yanbing | Shenzhen Inst. of Advanced Tech |
Ji, Ning | Shenzhen Inst. of Advanced Tech |
Wang, Hui | Shenzhen Inst. of Advanced Tech. Chinese Acad. of S |
Liu, Xueyu | Chongqing Univ. of Tech |
Geng, Yanjuan | Shenzhen Inst. of Advanced Tech |
Li, Peng | The Third Affiliated Hospital of Sun Yat-Sen Univ |
Chen, Shixiong | Shenzhen Inst. of Advanced Tech |
Li, Guanglin | Shenzhen Inst. of Advanced Tech |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Time-frequency and time-scale analysis - Time-frequency analysis
Abstract: Power line interference in the surrounding environment could usually introduce many difficulties when collecting and analyzing physiological signals. Since power line interference is usually several orders of amplitude larger than the physiological electrical signals, methods of suppressing power line interference should be considered during the signal acquisition. Many studies used a hardware or software band-stop filter to suppress power line interference but it could easily cause attenuations and distortions to the signal of interest. In this study, two kinds of methods that used different signals to drive the shields of the electrodes were proposed to reduce the impacts of power line interference. Three channels of two physiological signals (ECG and EMG) were simultaneously collected when the electrodes were not shielded (No-Shield), shielded by ground signals (GND-Shield) and shielded by buffered signals of the corresponding electrodes (Active-Shield), respectively, on a custom hardware platform based on TI ADS1299. The results showed that power line interference would be significantly suppressed when using shielding approaches, and the Active-Shield method could achieve the best performance with a power line interference reduction up to 36dB. The study suggested that the Active-Shield method at the analog front-end was a great candidate to reduce power line interference in routine acquisitions of physiological signals.
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16:26-16:28, Paper ThDT1-04.9 | Add to My Program |
Investigation of Lagged Poincar´e Plot Reliability in Ultra-Short Synthetic and Experimental Heart Rate Variability Series |
Nardelli, Mimma | Univ. of Pisa |
Greco, Alberto | Univ. of Pisa |
Bolea, Juan | Inst. De Investigación En Ingeniería De Aragón (I3A)Univ |
Valenza, Gaetano | Univ. of Pisa |
Scilingo, Enzo Pasquale | Univ. of Pisa |
Bailon, Raquel | Univ. of Zaragoza |
Keywords: Nonlinear dynamic analysis - Biomedical signals, Physiological systems modeling - Signal processing in physiological systems
Abstract: This study reports on the reliability of Lagged Poincar´e Plot (LPP) parameters calculated from ultra-short cardiovascular time series (from 30 to 180 seconds). Recently, several studies have investigated on the accuracy of linear features extracted from ultra-short Heart Rate Variability (HRV) signals, whereas a few studies have studied nonlinear approaches. Particularly, methods derived from the phase-space theory, especially the ones employing multi-lag analyses, are usually considered to be inaccurate with a low number of samples. Here we propose a comprehensive study about LPP, using both synthetic and real RR series. Specifically, we considered 109 5-minutes HRV series: 60 synthetic series generated through the Integral Pulse Frequency Modulation (IPFM) model and 49 experimental series acquired from healthy subjects during resting-state. Three parameters have been extracted through the ellipse-fitting method, SD1, SD2 and S, using ten values of lag. All LPP parameters were estimated by averaging estimates gathered from segments of 30, 120 and 180 seconds, and compared with the once from 5-minute series. Results showed Spearman’s correlation coefficients higher than 0.9 in both synthetic and real series. In conclusion, SD1 gave promising results in terms of percentage absolute error, when it was extracted from series with a duration less than three minutes.
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ThDT2 |
Cho Room |
Ignite Session T-02 |
Ignite Session |
Chair: Oh, Junghwan | Pukyong National Univ |
Co-Chair: Yoo, Hongki | Hanyang Univ | |
16:10-16:30, Subsession ThDT2-01, Cho Room | |
Optical imaging Poster Session, 10 papers |
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16:10-16:16, Subsession ThDT2-02, Cho Room | |
Optical imaging - Coherence tomography Poster Session, 3 papers |
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16:10-16:12, Subsession ThDT2-03, Cho Room | |
Optical imaging - Confocal microscopy Poster Session, 1 paper |
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16:10-16:12, Subsession ThDT2-04, Cho Room | |
Optical imaging and microscopy - Fluorescence microscopy Poster Session, 1 paper |
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16:10-16:16, Subsession ThDT2-05, Cho Room | |
Optical imaging and microscopy - Microscopy Poster Session, 3 papers |
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16:10-16:14, Subsession ThDT2-06, Cho Room | |
Optical imaging and microscopy - Multi photon imaging Poster Session, 2 papers |
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16:10-16:14, Subsession ThDT2-07, Cho Room | |
Optical imaging and microscopy - Near infra-red spectroscopy Poster Session, 2 papers |
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16:10-16:14, Subsession ThDT2-08, Cho Room | |
Optical imaging and microscopy - Neuroimaging Poster Session, 2 papers |
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ThDT2-01 Poster Session, Cho Room |
Add to My Program |
Optical Imaging |
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16:10-16:12, Paper ThDT2-01.1 | Add to My Program |
Wound Scanning and Recovery Volume Prediction |
Kang, Juehyung | Hanyang Univ |
Yoo, Hongki | Hanyang Univ |
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16:12-16:14, Paper ThDT2-01.2 | Add to My Program |
Fiber-Based Rotary Joint for Ultra-High Resolution OCT |
Kim, JunYoung | Hanyang Univ |
Song, Joon Woo | Guro Hospital, Korea Univ |
Kim, Jin Won | Korea Univ. Guro Hospital |
Yoo, Hongki | Hanyang Univ |
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16:14-16:16, Paper ThDT2-01.3 | Add to My Program |
Reflective Spectral Probe Based on Microsphere |
Choi, Myunghwan | Sungkyunkwan Univ |
Jo, Yongjae | Sungkyunkwan Univ |
Keywords: Optical imaging, Optical imaging - Confocal microscopy
Abstract: Thin-film interference has been widely utilized to measure a layer thickness of a dielectric thin-film. Here we demonstrate that this phenomenon can be adopted to probe the diameter of microspheres at nanoscale precision. We further suggest a new concept that microspheres serve as a reflective optical probe for highly-multiplexed cellular labeling.
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16:16-16:18, Paper ThDT2-01.4 | Add to My Program |
Photoacoustic Imaging of Dental Implant |
Kim, Chulhong | Pohang Univ. of Science and Tech |
Lee, Donghyun | POSTECH |
Park, Sungjo | POSTECH |
Hyunjung, Kim | POSTECH |
Keywords: Optical imaging, Ultrasound imaging - Other organs
Abstract: Dental implants are general method to replace broken or decayed tooth. During the dental implant treatment, radiographic examinations are used to monitor and guide the dental implant treatment. Although radiographic examinations provide jawbone and near teeth’s three-dimensional anatomical information, it uses ionizing radiation that can be accumulated and can adversely affect the human body. In this study, we demonstrated photoacoustic imaging of dental implant with an implant embedded pig jawbone. Our study shows the potential clinical application of the photoacoustic imaging of dental implant.
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16:18-16:20, Paper ThDT2-01.5 | Add to My Program |
Intravital Fluorescence Imaging of Reactive Oxygen Species in Murine Carotid Atherosclerotic Plaque |
Kim, Chang-Soo | Hanyang Univ. Department of Biomedical Engineering |
Park, Eun Jin | Korea Univ. Guro Hospital, Cardiovascular Center, Multimoda |
Ryu, Jiheun | Korea Advanced Inst. of Science and Tech. Department O |
park, Kyeongsoon | Chung-Ang Univ. Department of Systems Biotechnology |
Kim, Jin Won | Korea Univ. Guro Hospital |
Yoo, Hongki | Hanyang Univ |
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16:20-16:22, Paper ThDT2-01.6 | Add to My Program |
Development of Handheld Optical-Resolution Photoacoustic Probe |
Park, Kyungjin | Pohang Univ. of Science and Tech |
Kim, Jin Young | POSTECH |
Lee, Changho | Chonnam National Univ. Medical School |
Ryu, Seon Young | POSTECH |
Kim, Sehui | POSTECH |
BAIK, Jin Woo | Pohang Univ. of Science and Tech |
Kim, Jongbeom | POSTECH |
Kim, Chulhong | Pohang Univ. of Science and Tech |
Keywords: Optical imaging, Optical imaging and microscopy - Microscopy
Abstract: We developed a portable optical resolution photoacoustic microscope (OR-PAM) probe using MEMS (Microelectromechanical Systems) technology to achieve high signal-to-noise ratio (SNR). All acoustic, optical and mechanical scanning elements are integrated into a 17 mm diameter probe.
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16:22-16:24, Paper ThDT2-01.7 | Add to My Program |
Development of Indocyanine Green Fluorescence Imaging System Using Near Infra-Red Light on Laparoscopic Surgery |
Park, Sunup | OSONG Medical Innovation Foundation |
Yoo, Sojeong | OSONG Medical Innovation Foundation |
Kang, Taegeon | OSONG Medical Innovation Foundation |
Kim, Seok-ki | National Cancer Center |
Lee, Seungrag | OSONG Medical Innovation Foundation |
Keywords: Optical imaging, Infra-red imaging, Image visualization
Abstract: INTRODUCTION Near infra-red (NIR) fluorescence optical imaging system using indocyanine green (ICG) was introduced to improve the visualization and provide detailed information during minimal invasive surgery. In this study, we describe the development of the fluorescence endoscopy system and identification of accurate tumor sites in stomach and colon surgery. MATERIALS AND METHODS We made an imaging agent mixture of ICG and macro-aggregated albumin (MMA) and it was diluted to different concentrations. We also prepared a near infrared fluorescence (NIR-F) laparoscopy system consisting of an integrated light sources (high powered white light emitting diode (LED) and a 780 nm laser diode), a filter set (820 +_ 20 nm) for collecting fluorescence and a standard rigid laparoscope with a customized camera assembly. The fluorescent agent was injected on the mucosa of the stomach and colons of a pig model. We intended that NIR-F laparoscopy system could run under conventional conditions in order to identify the fluorescent sites RESULTS The location of the fluorescent agent was fully detected in real time. The injected mixture was not diffused throughout mucosal surfaces. The NIRF laparoscopy system and imaging dye were able to provide accurate targeting in the resected specimens. DISCUSSION The laparoscopy system of ICG fluorescence imaging is a promising technique with advantages; safer, more cost effective and more convenient. This method would help to dissect the exact tumor lesions during minimal gastrointestinal surgery.
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16:24-16:26, Paper ThDT2-01.8 | Add to My Program |
Evaluation of Methods for Endoscopic 3D-Measurements Using the Example of Endometriosis Diagnosis |
Schuldt, Dennis | Univ. of Applied Sciences and Arts Dortmund |
Sutorma, Andreas | Univ. of Applied Sciences and Arts Dortmund |
Tanriverdi, Fatih | Univ. of Applied Sciences and Arts Dortmund |
Thiem, Jörg | Univ. of Applied Sciences and Arts Dortmund |
Keywords: Optical imaging, Image feature extraction
Abstract: This contribution deals with challenges concerning distance measurements with the help of an medical 3D-endoscope and means of Computer Vision algorithms. The aim is the analysis of accuracy aspects in medical video data of an endoscopic endometriosis diagnosis.
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16:26-16:28, Paper ThDT2-01.9 | Add to My Program |
Ex-Vivo Elasticity Assessment of Stroke Rat Brain Using ARFI-OCE |
Chang, Yeon Hee | DGIST |
Kim, Jihun | DGIST |
Hwang, Jae Youn | Daegu Gyeongbuk Inst. of Science and Tech |
Oh, Yong-Seok | DGIST |
Song, Cheol | DGIST |
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16:28-16:30, Paper ThDT2-01.10 | Add to My Program |
Physically-Synthesized Porous Gold Nanoparticles for Biological Applications |
Wi, Jung-Sub | Korea Res. Inst. of Standards and Science |
Park, Jisoo | Korea Res. Inst. of Standards and Science |
Kang, Heesung | Korea Res. Inst. of Standards and Science |
Lee, Sang-Won | Korea Res. Inst. of Standards and Science |
Lee, Tae Geol | Korea Res. Inst. of Standards and Science |
Keywords: Optical imaging, Optical imaging and microscopy - Multi photon imaging
Abstract: Physically-synthesized gold nanoparticles having a narrow size distribution and containing multiple nanopores have been utilized as photothermal converters and laser-based imaging contrast agents. Nanopores within the gold nanoparticles make it possible to increase the light-absorption cross-section and consequently to exhibit distinct improvements in photothermal conversion, photoacoustic imaging, and two-photon luminescence imaging efficiencies.
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ThDT2-02 Poster Session, Cho Room |
Add to My Program |
Optical Imaging - Coherence Tomography |
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16:10-16:12, Paper ThDT2-02.1 | Add to My Program |
Integrated Optical Coherence Tomography and Fluorescence Lifetime Imaging Catheter for Detecting Atherosclerotic Plaque in Vivo |
Lee, Min Woo | Hanyang Univ |
Kang, Woo Jae | KAIST |
Nam, Hyeong Soo | Hanyang Univ |
Song, Joon Woo | Guro Hospital, Korea Univ |
Kim, Jin Won | Korea Univ. Guro Hospital |
Oh, Wang-Yuhl | KAIST |
Yoo, Hongki | Hanyang Univ |
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16:12-16:14, Paper ThDT2-02.2 | Add to My Program |
Visualization of Bioresorbable Vascular Scaffold Disruption by ECG-Triggered Ultra-High Speed OCT System and Investigation of Its Detrimental Effect on Arterial Healing by Integrated OCT/NIRF System |
Nam, Hyeong Soo | Hanyang Univ |
Kim, Sunwon | Korea Univ. Guro Hospital |
Park, Hyun-Sang | KAIST |
Song, Joon Woo | Guro Hospital, Korea Univ |
Oh, Wang-Yuhl | KAIST |
Kim, Jin Won | Korea Univ. Guro Hospital |
Yoo, Hongki | Hanyang Univ |
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16:14-16:16, Paper ThDT2-02.3 | Add to My Program |
Design and Fabrication of Gastrointestinal OCT Probe with Extended Depth of Focus |
Xing, Jingchao | Hanyang Univ |
Yoo, Hongki | Hanyang Univ |
Keywords: Optical imaging - Coherence tomography
Abstract: We designed and fabricated a gastrointestinal (GI) OCT probe. We applied a binary phase spatial filter (BPSF) to extend the depth of focus (DOF) of the OCT probe. In the simulation result, the OCT probe with the optimized BPSF can extend the DOF to 6.83 mm, which is twice longer than that of the probe without BPSF. We fabricated the BPSF probe using replica molding lithography. We anticipate that this endoscopic OCT probe can provide detailed microstructural information of tissues with the extended imaging range.
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ThDT2-03 Poster Session, Cho Room |
Add to My Program |
Optical Imaging - Confocal Microscopy |
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16:10-16:12, Paper ThDT2-03.1 | Add to My Program |
Boundary Detection Method in Skin Diseases by Using Confocal Raman Micro-Spectroscopy |
Sohn, Wonbum | KyungHee Univ |
Shin, Younggwon | Kyung Hee Univ |
Kim, Soogeun | Kyung Hee Univ |
Lee, Soo Yeol | Kyung Hee Univ |
Keywords: Optical imaging - Confocal microscopy, Optical imaging and microscopy - Microscopy, Optical imaging
Abstract: Recently, there has been much interest in research to detect cancer boundary for accurate treatments. In this study, we report the method to detect disease boundary using a two-layer skin model. The estimated boundary positions using integral Raman intensity were almost similar to the actual boundary positions of the skin model. These results show the possibility of detection of the disease boundary in actual diagnosis.
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ThDT2-04 Poster Session, Cho Room |
Add to My Program |
Optical Imaging and Microscopy - Fluorescence Microscopy |
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16:10-16:12, Paper ThDT2-04.1 | Add to My Program |
Automatic Segmentation of Z-Lines in Cardiac Cells from Microscope Fluorescence Images |
Nolla-Colomer, Carme | Univ. Pol. De Catalunya |
Vallmitjana, Alex | Automatic Control Department, Univ. Pol. De Catalun |
Marchena, Miquel | Univ. Pol. De Catalunya |
Echebarria, Blas | Univ. Pol. De Catalunya |
Herrainz, Adela | Cardiovascular Res. Center from the Spanish National Res |
Hove-Madsen, Leif | Cardiovascular Res. Center from the Spanish National Res |
Chen, S.R. Wayne | Univ. of Calgary |
Benitez, Raul | Univ. Pol. De Catalunya |
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ThDT2-05 Poster Session, Cho Room |
Add to My Program |
Optical Imaging and Microscopy - Microscopy |
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16:10-16:12, Paper ThDT2-05.1 | Add to My Program |
HerNet: An Automated HER-2 Scoring Tool for Breast Cancer Screening Using Deep Learning |
Saha, Monjoy | Indian Inst. of Tech. Kharagpur |
Arun, Indu | TMC, West Bengal |
Chakraborty, Chandan | Indian Inst. of Tech. Kharagpur |
Keywords: Optical imaging and microscopy - Microscopy
Abstract: The aim of this manuscript is to develop an automated HER-2 scoring tool for the breast cancer screening. Henceforth, we proposed HerNet: a deep learning framework, which solves this purpose. Our proposed methodology achieved better performances in comparisons with the other existing techniques.
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16:12-16:14, Paper ThDT2-05.2 | Add to My Program |
3D Position Detection of Cell Nuclei in Hematoxylin-Stained Histological Sections |
Takano, Masashi | Shibaura Inst. of Tech |
Takahashi, Masanobu | Shibaura Inst. of Tech |
Nakano, Masayuki | Shonan Fujisawa Tokushukai Hospital |
Keywords: Image segmentation, Optical imaging and microscopy - Microscopy, Image feature extraction
Abstract: A method is proposed to detect the 3D positions of sphere-like shaped cell nuclei in 3D bright-field images of histological sections. Hematoxylin-staining was employed to obtain 3D bright-field images for thick histological sections. Both bright-field imaging and hematoxylin-staining are readily available for general pathologists. Preliminary results using a 30μm thick section show promising performance.
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16:14-16:16, Paper ThDT2-05.3 | Add to My Program |
Skin Cell Heat Damage Evaluation for the Safety of Laser Medical Devices |
Katagiri, Wataru | Keio Univ. Graduate School of Science and Tech |
Nyberg, Tobias | Royal Inst. of Tech. Sweden |
Keywords: Optical imaging and microscopy - Microscopy, Image segmentation
Abstract: A lot of laser medical devices have been developed over the past half-century. Particularly these days, low-level near infrared laser devices for epidermal tissue have been rapidly innovated. In terms of safety and efficacy of the therapies or the treatments, an accurate heat damage criterion is required. We showed the damage threshold of heat generated by near infrared laser irradiation with cultivated human epidermal keratinocytes. These results define the safe combinations of temperature and laser duration.
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ThDT2-06 Poster Session, Cho Room |
Add to My Program |
Optical Imaging and Microscopy - Multi Photon Imaging |
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16:10-16:12, Paper ThDT2-06.1 | Add to My Program |
Microfluidics-On-A-Tongue Imaging Chamber for Taste Mapping in Vivo |
Han, Jisoo | Sungkyunkwan Univ |
Choi, Myunghwan | Sungkyunkwan Univ |
Keywords: Optical imaging, Optical imaging and microscopy - Microscopy, Optical imaging and microscopy - Multi photon imaging
Abstract: The current understanding on cellular encoding process in the taste field has relied on studies using ex vivo model systems, which cannot fully recapitulate the native cellular microenvironment. To resolve this methodological limitation, we invented a new imaging window enabling simultaneous chemical and optical access to the mouse tongue in vivo. Using the imaging chamber, we recorded calcium activity of taste cells under various taste stimuli in live mice, and obtained a comprehensive cellular-level taste map. We believe our novel tool will promote deeper understanding of taste coding logic.
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16:12-16:14, Paper ThDT2-06.2 | Add to My Program |
Real-Time Two-Photon Fluorescence Lifetime Imaging Microscopy for Deep-Tissue Tomography |
Ryu, Jiheun | Korea Advance Inst. of Science and Tech. (KAIST) |
Jeong, Jae-Heon | Korea Advanced Inst. of Science and Tech. (KAIST) |
Yoo, Hongki | Hanyang Univ |
Gweon, Dae-Gab | Korea Advanced Inst. of Science and Tech. (KAIST) |
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ThDT2-07 Poster Session, Cho Room |
Add to My Program |
Optical Imaging and Microscopy - Near Infra-Red Spectroscopy |
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16:10-16:12, Paper ThDT2-07.1 | Add to My Program |
Measurement of Brain Hemodynamic Change According to Dietary Intake Using Near-Infrared Spectroscopy |
Fukuda, Keiko | Tokyo Metropolitan Coll. of Industrial Tech |
Yuki, Muramatsu | Tokyo Metropolitan Coll. of Industrial Tech |
Hasegawa, Masahiro | Tokyo Metropolitan Coll. of Industrial Tech |
Keywords: Optical imaging and microscopy - Near infra-red spectroscopy
Abstract: For evaluating associations between dietary intake and brain hemodynamic changes in prefrontal cerebral cortex, we measured local blood flow distribution with a short-term memory task using near-infrared spectroscopy. For the after-meal task period, local cerebral blood volume changes have a decreasing trend after meals and decreases in local cerebral blood volume occurred after meals despite increases in heart rate for promoting digestion.
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16:12-16:14, Paper ThDT2-07.2 | Add to My Program |
Design of an Endoscope for Thermal Inspection |
Kim, Keo-Sik | Electronics and Telecommunications Res. Inst. (ETRI) |
Min, Gihyeon | Electronics and Telecommunications Res. Inst. (ETRI) |
Son, Dong Hoon | Electronics and Telecommunications Res. Inst. (ETRI) |
Kang, Hyun Seo | Electronics and Telecommunications Res. Inst. (ETRI) |
Kim, Sung Chang | Electronics and Telecommunications Res. Inst. (ETRI) |
Keywords: Optical imaging and microscopy - Near infra-red spectroscopy, Multimodal imaging, Image visualization
Abstract: A new type of an endoscope which monitoring thermal distribution simultaneously with real 2D image has been developed. Both infrared (IR) imaging and visible (VIS) imaging parts were mounted together on one probe in this endoscope. The matching images produced by overlapping thermal distribution images with real 2D ones in parallel were recorded for evaluating its feasibility. It showed a good potential as a considerable tool for the early diagnosis of pathology and also non-destructive testing.
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ThDT2-08 Poster Session, Cho Room |
Add to My Program |
Optical Imaging and Microscopy - Neuroimaging |
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16:10-16:12, Paper ThDT2-08.1 | Add to My Program |
Spectral Reflectometry on the Myelinated Axon |
Kwon, Junhwan | Center for Neuroscience Imaging Res. Inst. of Basic Sci |
Choi, Myunghwan | Sungkyunkwan Univ |
Keywords: Optical imaging, Optical imaging and microscopy - Neuroimaging, Optical imaging - Confocal microscopy
Abstract: Myelin in the mammalian nervous system provides axonal integrity and efficient electrical conduction by insulating axons with multilayered cellular thin-films. Yet, current imaging techniques for the axons cannot provide sufficient subcellular resolution in a living samples, especially in vivo. This has restricted our understanding on the myelinated axon; especially their dynamic remodeling at nanoscale is largely veiled. Here, we report a new optical imaging technique providing a spatial resolution beyond diffraction-limit by using intrinsic reflective property of the myelinated axon in their natural living state. Our technique is based on spectral reflectometry, which has been widely utilized in silicon industry to measure thin-film coating at sub-nanometer accuracy. By bringing the technique on the murine nervous tissues, we demonstrate measurements of nanostructural change in the axon under traumatic brain injury, and the myelin under osmotic challenge. This technique provides new avenues to observe myelin dynamics in a nanoscale in vivo.
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16:12-16:14, Paper ThDT2-08.2 | Add to My Program |
Simultaneous Optical and Electrical Measurements of Neural Activities from Clustered Neural Networks |
Kim, Raeyoung | KAIST |
Nam, Yoonkey | Korea Advanced Insitiute of Science and Tech |
Keywords: Optical imaging and microscopy - Neuroimaging, Optical imaging and microscopy - Fluorescence microscopy
Abstract: Various electrophysiological techniques have been developed to study the electrical activities of neurons. The electrical measurement provides signals with high temporal resolution. However, the spatial resolution is low since the position of a microelectrode is fixed. Optical recording can complement the spatial limit by membrane potential imaging. Here, we constructed a simultaneous optical and electrical signal measurement system and measured the neural activities of clustered neural networks to relate subthreshold membrane potential variance and action potentials. Microelectrode arrays and voltage sensitive dye (VSD) were used for electrical and optical measurements, respectively.
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ThDT3 |
Park Room |
Ignite Session T-03 |
Ignite Session |
Chair: Joo, Segyeong | Asan Medical Center, Univ. of Ulsan Coll. Ofmedicine |
Co-Chair: Lee, Jae Sung | Seoul National Univ | |
16:10-16:16, Subsession ThDT3-01, Park Room | |
Cardiac imaging and image analysis Poster Session, 3 papers |
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16:10-16:12, Subsession ThDT3-02, Park Room | |
Dual-energy X-ray imaging Poster Session, 1 paper |
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16:10-16:16, Subsession ThDT3-03, Park Room | |
EEG imaging Poster Session, 3 papers |
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16:10-16:16, Subsession ThDT3-04, Park Room | |
Micro-CT imaging Poster Session, 3 papers |
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16:10-16:22, Subsession ThDT3-05, Park Room | |
PET and SPECT imaging Poster Session, 6 papers |
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16:10-16:16, Subsession ThDT3-06, Park Room | |
PET and SPECT Imaging applications Poster Session, 3 papers |
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16:10-16:12, Subsession ThDT3-07, Park Room | |
X-ray - Fluoroscopy Poster Session, 1 paper |
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16:10-16:22, Subsession ThDT3-08, Park Room | |
X-ray CT imaging Poster Session, 6 papers |
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16:10-16:16, Subsession ThDT3-09, Park Room | |
X-ray imaging applications Poster Session, 3 papers |
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ThDT3-01 Poster Session, Park Room |
Add to My Program |
Cardiac Imaging and Image Analysis |
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16:10-16:12, Paper ThDT3-01.1 | Add to My Program |
Cardiac Cycle Phase Classification for Four-Dimensional Imaging of Zebrafish Embryos |
He, Hengda | School of Optical and Electronic Information, Huazhong Univ |
Cheng, Chang-Chieh | National Chiao Tung Univ |
Chen, Yen-Ling | Department of Applied Chemistry and Department of Biological Sci |
Liau, Ian | Department of Applied Chemistry and Inst. of Molecular Scien |
Ching, YuTai | National Chiao Tung Univ |
Keywords: Image classification, Cardiac imaging and image analysis
Abstract: We propose a method to classify a set of four-dimensional (4D) cardiac images of a zebrafish embryo into four cardiac phases, i.e., the end of diastole, the contracting phase, the end of systole, and the expanding phase, such that further analysis can be facilitated such as the visualization of 4D volume data sets or the observation of cardiovascular system development. The method is based on the observation that the ventricle of a zebrafish covers larger image area than the atrium. We calculate the MSE (mean squared error) for each image with its neighbor images. The computed value is the “significance” of the image that can be used to decide whether the ventricle reach the largest or smallest volume. The experiment results show that the proposed method can successfully classify the real dataset that consists of 3100 images acquired by a confocal microscope.
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16:12-16:14, Paper ThDT3-01.2 | Add to My Program |
Fully Automated Lumen Morphology Segmentation and 3D Reconstruction Algorithms for Optical Coherence Tomography |
Yang, Su | Keimyung Univ |
Yoon, Hyuck-Jun | Keimyung Univ |
Kim, Seon-Chil | Keimyung Univ |
Lee, Jong-Ha | Keimyung Univ. School of Medicine |
Keywords: Cardiac imaging and image analysis, Optical imaging - Coherence tomography, Volume rendering
Abstract: Abstract—Intravascular Optical Coherence Tomography (IVOCT) is a medical imaging modality, which provides high images resolution (10-15 µm) cross sectional image of coronary artery. Clinically, irregular protrusions and thrombosis after stent deployment can be significant adverse outcomes such as thrombotic re-occlusion or restenosis. In this study, we propose an algorithm for automatically detect lumen morphology and analyze lumen shape features. Then, along the detected area, different features are depicted with different colors to visualize irregularity feature of lumen. In the results, we noticed that the lumen irregularity and location of the thrombosis can be analyzed in a few seconds and can lead to understanding of overall vascular status and help to determine cardiovascular diagnosis.
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16:14-16:16, Paper ThDT3-01.3 | Add to My Program |
An Interactive Biventricular Modelling Tool Using Subdivision Surface: Application to Congenital Heart Disease |
Mauger, Charlène Alice | Univ. of Auckland |
Gilbert, Kathleen | Univ. of Auckland |
Cowan, Brett | Univ. of Auckland |
Suinesiaputra, Avan | Univ. of Auckland |
Young, Alistair | Univ. of Auckland |
Keywords: Deformable image registration, Cardiac imaging and image analysis
Abstract: An interactive 3D+t biventricular analysis method using a subdivision surface model is introduced. Comparisons with a previous method using Bézier surfaces and manual contouring show that the proposed surface representation achieved comparable accuracy with the previous method. The main advantage of this method is a faster analysis of cardiac function in congenital heart disease. Similar accuracy was obtained with four times fewer parameters in each direction.
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ThDT3-02 Poster Session, Park Room |
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Dual-Energy X-Ray Imaging |
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16:10-16:12, Paper ThDT3-02.1 | Add to My Program |
Dual Energy-Based Metal Segmentation for Metal Artifact Reduction in Dental Computed Tomography |
Hegazy, Mohamed Abdalla Ahmed | Department of Biomedical Engineering, Kyung Hee Univ |
Eldib, Mohamed Elsayed | Department of Biomedical Engineering, Kyung Hee Univ |
Hernandez, Daniel | Kyung Hee Univ |
LEE, Jeong Seok | Korea Electrotechnology Res. Inst |
Mun, Yang Ji | Department of Biomedical Engineering, Kyung Hee Univ |
Cho, Myung Hye | Department of Biomedical Engineering, Kyung Hee Univ |
Cho, Min Hyoung | Kyung Hee Univ |
Lee, Soo Yeol | Kyung Hee Univ |
Keywords: Dual-energy X-ray imaging, Micro-CT imaging
Abstract: Metal artifact caused by dental filling and dental implant is one of the most challenging problems in dental computed tomography. To reduce this metal artifact we have two main steps, metal segmentation and metal replacement. Metal segmentation is not easy, especially in dental imaging because the tooth and bone is high density and may segmented as a metal in CT image. We propose a new method for MAR using dual energy imaging to enhance the performance of segmentation and have a new method in estimating metal information in the projection image. The initial result of this method showing that this method has a promising performance in metal artifact reduction.
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ThDT3-03 Poster Session, Park Room |
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EEG Imaging |
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16:10-16:12, Paper ThDT3-03.1 | Add to My Program |
SigViewer: Visualizing Multimodal Signals Stored in XDF (Extensible Data Format) Files |
Lin, Yida | Columbia Univ |
Brunner, Clemens | Univ. of Graz |
Sajda, Paul | Columbia Univ |
Faller, Josef | Columbia Univ |
Keywords: EEG imaging, MEG imaging, Image visualization
Abstract: Multimodal biosignal acquisition is facilitated by recently introduced software solutions such as Lab Streaming Layer (LSL) and its associated data format XDF (Extensible Data Format). However, there are no stand-alone applications that can visualize multimodal time series stored in XDF files. We extended SigViewer, an open source cross-platform Qt C++ application with the capability of loading, resampling, annotating, and visualizing signals stored in XDF files and successfully applied the tool for post-hoc visual verification of the accuracy of a system that aims to predict the phase of alpha oscillations within the electroencephalogram in real-time.
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16:12-16:14, Paper ThDT3-03.2 | Add to My Program |
A Comparison of Single-Trial EEG Classification and EEG-Informed Fmri across Three MR Compatible EEG Recording Systems |
Faller, Josef | Columbia Univ |
Hong, Linbi | Columbia Univ |
Cummings, Jennifer | Columbia Univ |
Sajda, Paul | Columbia Univ |
Keywords: EEG imaging, Magnetic resonance imaging - MR neuroimaging, Brain image analysis
Abstract: Simultaneously recorded electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) can be used to non-invasively measure the spatiotemporal dynamics of the human brain. One challenge is dealing with the artifacts that each modality introduces into the other when the two are recorded concurrently, for example the ballistocardiogram (BCG). We conducted a preliminary comparison of three different MR compatible EEG recording systems and assessed their performance in terms of single-trial classification of the EEG when simultaneously collecting fMRI. We found tradeoffs across all three systems, for example varied ease of setup and improved classification accuracy with reference electrodes (REF) but not for pulse artifact subtraction (PAS) or reference layer adaptive filtering (RLAF).
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16:14-16:16, Paper ThDT3-03.3 | Add to My Program |
Second Order Blind Identification and Support Vector Machine Technique towards Imagery Movement Identification from EEG Signals |
Kalogiannis, Gregory | Aristotle Univ. of Thessaloniki |
Hassapis, George | Aristotle Univ. of Thesaloniki |
Keywords: Independent component analysis, Principal and independent component analysis - Blind source separation
Abstract: During imagery motor movements tasks, the so called mu and beta event related desynchronization (ERD) and synchronization (ERS) are taking place, allowing us to determine human patient imagery movement. However, original recordings of electroencephalography (EEG) data contain environmental and system noise and interference which need to be removed in order to isolate the ERS/ERD events from the rest of the signal. This paper presents a new technique based on a reworked Second Order Blind Identification (SOBI) algorithm for noise removal while imagery movement classification is implemented using Support Vector Machine (SVM) technique.
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ThDT3-04 Poster Session, Park Room |
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Micro-CT Imaging |
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16:10-16:12, Paper ThDT3-04.1 | Add to My Program |
Automatic Optimization of Segmentation-Free Empirical Beam Hardening Correction |
Mun, Yang Ji | Department of Biomedical Engineering, Kyung Hee Univ |
Hernandez, Daniel | Kyung Hee Univ |
Hegazy, Mohamed Abdalla Ahmed | Department of Biomedical Engineering, Kyung Hee Univ |
Eldib, Mohamed Elsayed | Department of Biomedical Engineering, Kyung Hee Univ |
Cho, Min Hyoung | Kyung Hee Univ |
Lee, Soo Yeol | Kyung Hee Univ |
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