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Biomedical Engineering

This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 13.

Optimal Periodic Sensor Scheduling in Networks of Dynamical Systems
We consider the problem of finding optimal time-periodic sensor schedules for estimating the state of discrete-time dynamical systems. We assume that multiple sensors have been deployed and that the sensors are subject to resource constraints, which limits the number of times each can be activated over one period of the periodic schedule. We seek an algorithm that strikes a balance between estimation accuracy and total sensor activations over one period. We make a correspondence between active sensors and the nonzero columns of the estimator gain. We formulate an optimization problem in which we minimize the trace of the e...
Source: IEEE Transactions on Signal Processing - May 20, 2014 Category: Biomedical Engineering Source Type: research

Discrete Signal Processing on Graphs: Frequency Analysis
Signals and datasets that arise in physical and engineering applications, as well as social, genetics, biomolecular, and many other domains, are becoming increasingly larger and more complex. In contrast to traditional time and image signals, data in these domains are supported by arbitrary graphs. Signal processing on graphs extends concepts and techniques from traditional signal processing to data indexed by generic graphs. This paper studies the concepts of low and high frequencies on graphs, and low-, high- and band-pass graph signals and graph filters. In traditional signal processing, these concepts are easily define...
Source: IEEE Transactions on Signal Processing - May 20, 2014 Category: Biomedical Engineering Source Type: research

Consensus-based Distributed Particle Filtering With Distributed Proposal Adaptation
We develop a distributed particle filter for sequential estimation of a global state in a decentralized wireless sensor network. A global state estimate that takes into account the measurements of all sensors is computed in a distributed manner, using only local calculations at the individual sensors and local communication between neighboring sensors. The paper presents two main contributions. First, the likelihood consensus scheme for distributed calculation of the joint likelihood function (used by the local particle filters) is generalized to arbitrary local likelihood functions. This generalization overcomes the restr...
Source: IEEE Transactions on Signal Processing - May 20, 2014 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Biomedical Engineering Associate Editors
Provides a listing of current committee members and society officers. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Biomedical Engineering information for authors
Provides instructions and guidelines to prospective authors who wish to submit manuscripts. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

JBHI Special Issue of “Big-Data for Health”
Describes the above-named upcoming special issue or section. May include topics to be covered or calls for papers. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society-Discovering, Innovating and Engineering
Describes the above-named upcoming conference event. May include topics to be covered or calls for papers. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Corrections to “Atrial Fibrillation Detection Using an iPhone 4S”
(Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Patient-Specific Coronary Stenoses Can Be Modeled Using a Combination of OCT and Flow Velocities to Accurately Predict Hyperemic Pressure Gradients
This study developed a new approach to generate CFD models by combining high-fidelity, patient-specific coronary anatomy models derived from optical coherence tomography (OCT) imaging with patient-specific pressure and velocity phasic data. Additionally, we used a new technique which does not require the catheter to be used to determine the centerline of the vessel. The CFD data were then compared with invasively measured pressure and velocity. Angiography imaging data of 21 vessels collected from 19 patients were fused with OCT visualizations of the same vessels using an algorithm that produces reconstructions inheriting ...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Design and Evaluation of a 1.1-GHz Surface Coil Resonator for Electron Paramagnetic Resonance-Based Tooth Dosimetry
This paper describes an optimized design of a surface coil resonator for in vivo electron paramagnetic resonance (EPR)-based tooth dosimetry. Using the optimized resonator, dose estimates with the standard error of the mean of approximately 0.5 Gy were achieved with irradiated human teeth. The product of the quality factor and the filling factor of the resonator was computed as an index of relative signal intensity in EPR tooth dosimetry by the use of 3-D electromagnetic wave simulator and radio frequency circuit design environment (ANSYS HFSS and Designer). To verify the simulated results of the signal intensity in...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

MRI Induced Torque and Demagnetization in Retention Magnets for a Bone Conduction Implant
Performing magnetic resonance imaging (MRI) examinations in patients who use implantable medical devices involve safety risks both for the patient and the implant. Hearing implants often use two permanent magnets, one implanted and one external, for the retention of the external transmitter coil to the implanted receiver coil to achieve an optimal signal transmission. The implanted magnet is subjected to both demagnetization and torque, magnetically induced by the MRI scanner. In this paper, demagnetization and a comparison between measured and simulated induced torque is studied for the retention magnet used in a bone con...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Feasibility of Long-Term Monitoring of Multifrequency and Multisegment Body Impedance by Portable Devices
In this study, we evaluated the feasibility of unobtrusive multisegment BIS with small portable devices by presenting and testing a DSP-based prototype specifically designed to minimize weight, size, and power consumption of BIS systems. The prototype consists in 1) a tetrapolar electrodes setup; 2) an analog board with a transconductance amplifier which injects the stimulation current and an instrumentation amplifier which senses the associated voltage drop; and 3) a digital board with a digital signal processor for data processing, for system calibration and for generation of the stimulating waveforms. To optimize the de...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Novel Electrodes for Underwater ECG Monitoring
We have developed hydrophobic electrodes that provide all morphological waveforms without distortion of an ECG signal for both dry and water-immersed conditions. Our electrode is comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS). For feasibility testing of the CB/PDMS electrodes, various tests were performed. One of the tests included evaluation of the electrode-to-skin contact impedance for different diameters, thicknesses, and different pressure levels. As expected, the larger the diameter of the electrodes, the lower the impedance and the difference between the large sized CB/PDMS and th...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Bioimpedance-Based Respiration Monitoring With a Defibrillator
Defibrillators often use an ac measurement to ensure safe electrode placement. Some defibrillators also utilize impedance measurements for ventilation monitoring. This paper investigates how such measurements can be optimized for high respiration sensitivity and finds that it is beneficial to add two extra electrodes in addition to the two defibrillator electrodes. This four electrode setup increases sensitivity and also allows respiration measurements at lower frequencies than the two electrode setup. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Novel Noninvasive Approach for Detecting Arteriovenous Fistula Stenosis
In this study, a noninvasive approach based on stethoscope auscultation for monitoring AVF stenosis was proposed. Here, a wireless blood flow sound recorder was designed to record blood flow sounds wirelessly. In order to effectively extract the varying feature of blood flow sounds for AVF stenosis, the 2-D feature pattern built from S-transform was also proposed as the feature in the AVF stenosis detecting algorithm. Different from other frequency-related coefficients, the feature pattern can contain the information of blood flow sounds in time and frequency domains simultaneously. Preliminary findings showed that the pro...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Catheter-Induced Errors in Pressure Measurements in Vessels: An In-Vitro and Numerical Study
Accurate measurement of blood pressure is important because it is a biomarker for cardiovascular disease. Diagnostic catheterization is routinely used for pressure acquisition in vessels despite being subject to significant measurement errors. To investigate these errors, this study compares pressure measurement using two different techniques in vitro and numerical simulations. Pressure was acquired in a pulsatile flow phantom using a 6F fluid-filled catheter and a 0.014′′ pressure wire, which is considered the current gold standard. Numerical simulations of the experimental set-up with and without a catheter...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Evaluation of Conoscopic Holography for Estimating Tumor Resection Cavities in Model-Based Image-Guided Neurosurgery
Surgical navigation relies on accurately mapping the intraoperative state of the patient to models derived from preoperative images. In image-guided neurosurgery, soft tissue deformations are common and have been shown to compromise the accuracy of guidance systems. In lieu of whole-brain intraoperative imaging, some advocate the use of intraoperatively acquired sparse data from laser-range scans, ultrasound imaging, or stereo reconstruction coupled with a computational model to drive subsurface deformations. Some authors have reported on compensating for brain sag, swelling, retraction, and the application of pharmaceutic...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Scanning Electrochemical Microscopy as a Novel Proximity Sensor for Atraumatic Cochlear Implant Insertion
A growing number of minimally invasive surgical and diagnostic procedures require the insertion of an optical, mechanical, or electronic device in narrow spaces inside a human body. In such procedures, precise motion control is essential to avoid damage to the patient's tissues and/or the device itself. A typical example is the insertion of a cochlear implant which should ideally be done with minimum physical contact between the moving device and the cochlear canal walls or the basilar membrane. Because optical monitoring is not possible, alternative techniques for sub millimeter-scale distance control can be very u...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Design and Evaluation of a Quasi-Passive Knee Exoskeleton for Investigation of Motor Adaptation in Lower Extremity Joints
In this study, we describe the mechanical design and control scheme of a quasi-passive knee exoskeleton intended to investigate the biomechanical behavior of the knee joint during interaction with externally applied impedances. As the human knee behaves much like a linear spring during the stance phase of normal walking gait, the exoskeleton implements a spring across the knee in the weight acceptance (WA) phase of the gait while allowing free motion throughout the rest of the gait cycle, accomplished via an electromechanical clutch. The stiffness of the device is able to be varied by swapping springs, and the timing of en...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Time-Variant, Frequency-Selective, Linear and Nonlinear Analysis of Heart Rate Variability in Children With Temporal Lobe Epilepsy
The major aim of our study is to demonstrate that a concerted combination of time-variant, frequency-selective, linear and nonlinear analysis approaches can be beneficially used for the analysis of heart rate variability (HRV) in epileptic patients to reveal premonitory information regarding an imminent seizure and to provide more information on the mechanisms leading to changes of the autonomic nervous system. The quest is to demonstrate that the combined approach gains new insights into specific short-term patterns in HRV during preictal, ictal, and postictal periods in epileptic children. The continuous Morlet-wavelet t...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Real-time Microwave Imaging of Differential Temperature for Thermal Therapy Monitoring
A microwave imaging system for real-time 3-D imaging of differential temperature has been developed for the monitoring and feedback of thermal therapy systems. Design parameters are constrained by features of a prototype-focused microwave thermal therapy system for the breast, operating at 915 MHz. Real-time imaging is accomplished with a precomputed linear inverse scattering solution combined with continuous vector network analyzer (VNA) measurements of a 36-antenna, HFSS-modeled, cylindrical cavity. Volumetric images of differential change of dielectric constant due to temperature are formed with a refresh rate as...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Feature Selection and Activity Recognition System Using a Single Triaxial Accelerometer
Activity recognition is required in various applications such as medical monitoring and rehabilitation. Previously developed activity recognition systems utilizing triaxial accelerometers have provided mixed results, with subject-to-subject variability. This paper presents an accurate activity recognition system utilizing a body worn wireless accelerometer, to be used in the real-life application of patient monitoring. The algorithm utilizes data from a single, waist-mounted triaxial accelerometer to classify gait events into six daily living activities and transitional events. The accelerometer can be worn at any location...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Automatic Ingestion Monitor: A Novel Wearable Device for Monitoring of Ingestive Behavior
Objective monitoring of food intake and ingestive behavior in a free-living environment remains an open problem that has significant implications in study and treatment of obesity and eating disorders. In this paper, a novel wearable sensor system (automatic ingestion monitor, AIM) is presented for objective monitoring of ingestive behavior in free living. The proposed device integrates three sensor modalities that wirelessly interface to a smartphone: a jaw motion sensor, a hand gesture sensor, and an accelerometer. A novel sensor fusion and pattern recognition method was developed for subject-independent food intake reco...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Miniature Electrical Stimulator for Hemorrhage Control
Noncompressible hemorrhage is currently the most common cause of preventable death in battlefield and in civilian trauma injuries. Tourniquets, specialized wound dressings, and hemorrhage-inhibiting biomaterials are not sufficiently effective in arrest of noncompressible hemorrhage and often cause collateral tissue damage. An effective, easy-to-use, portable device is needed to reduce blood loss in trauma patients immediately following injury and to maintain hemorrhage control up to several hours—until the injured is evacuated to a medical facility. We developed a miniature electrical stimulator to induce vascular c...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Abnormal Dynamics of EEG Oscillations in Schizophrenia Patients on Multiple Time Scales
This study aims to reveal the abnormal amplitude dynamics of electroencephalogram (EEG) oscillations in schizophrenia patients on multiple time scales. EEGs were recorded from schizophrenia patients ($n$ = 19) and healthy controls ($n$ = 16) while they were at resting state with eyes closed, at resting state with eyes open, and at watching video. Detrended fluctuation analysis and measures of life-time and waiting-time were used to characterize the abnormal dynamics of EEG oscillations on both long (1–20 s) and short (≤1 s) time scales. Abnormal dynamics of EEG oscillations in alph...
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

Differentiating Between Psychogenic Nonepileptic Seizures and Epilepsy Based on Common Spatial Pattern of Weighted EEG Resting Networks
In this study, we develop an approach for discriminating between PNES and epilepsy using the common spatial pattern extracted from the brain network topology (SPN). The study reveals that 92% accuracy, 100% sensitivity, and 80% specificity were reached for the classification between PNES and focal epilepsy. The newly developed SPN of resting EEG may be a promising tool to mine implicit information that can be used to differentiate PNES from epilepsy. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research

A Reconstruction Algorithm of Magnetoacoustic Tomography With Magnetic Induction for an Acoustically Inhomogeneous Tissue
In this study, we proposed a new algorithm for MAT-MI to image the impedance distribution in tissues with inhomogeneous acoustic speed distributions. With a computer head model constructed from MR images of a human subject, a series of numerical simulation experiments were conducted. The present results indicate that the inhomogeneous acoustic properties of tissues in terms of speed variation can be incorporated in MAT-MI imaging. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - May 20, 2014 Category: Biomedical Engineering Source Type: research