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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 20.

Extracting a Cardiac Signal From the Extracorporeal Pressure Sensors of a Hemodialysis Machine
Although patients undergoing hemodialysis treatment often suffer from cardiovascular disease, monitoring of cardiac rhythm is not performed on a routine basis. Without requiring any extra sensor, this study proposes a method for extracting a cardiac signal from the built-in extracorporeal venous pressure sensor of the hemodialysis machine. The extraction is challenged by the fact that the cardiac component is much weaker than the pressure component caused by the peristaltic blood pump. To further complicate the extraction problem, the cardiac component is difficult to separate when the pump and heart rates coincide. The pr...
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

Examination of Poststroke Alteration in Motor Unit Firing Behavior Using High-Density Surface EMG Decomposition
This study provides direct evidence of motor unit firing behavior alterations poststroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

An Ultrasonic-Adaptive Beamforming Method and Its Application for Trans-skull Imaging of Certain Types of Head Injuries; Part I: Transmission Mode
A new adaptive beamforming algorithm for imaging via small-aperture 1-D ultrasonic-phased arrays through composite layered structures is reported. Such structures cause acoustic phase aberration and wave refraction at undulating interfaces and can lead to significant distortion of an ultrasonic field pattern produced by conventional beamforming techniques. This distortion takes the form of defocusing the ultrasonic field transmitted through the barrier and causes loss of resolution and overall degradation of image quality. To compensate for the phase aberration and the refractional effects, we developed and examined an ada...
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

Front Cover
Presents the front cover for this issue of the publication. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Biomedical Engineering publication information
Provides a listing of the editors, board members, and current staff for this issue of the publication. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

Table of Contents
Presents the table of contents for this issue of the publication. (Source: IEEE Transactions on Biomedical Engineering)
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

A Microwave Imaging-Based Technique to Localize an In-Body RF Source for Biomedical Applications
In some biomedical applications such as wireless capsule endoscopy, the localization of an in-body radio-frequency (RF) source is important for the positioning of any abnormality inside the gastrointestinal tract. With knowledge of the location, therapeutic operations can be performed precisely at the position of the abnormality. Electrical properties (relative permittivity and conductivity) of the tissues and their distribution are utilized to estimate the position. This paper presents a method for the localization of an in-body RF source based on microwave imaging. The electrical properties of the tissues and their distr...
Source: IEEE Transactions on Biomedical Engineering - April 21, 2015 Category: Biomedical Engineering Source Type: research

The influence of stem taper re-use upon the failure load of ceramic heads
The use of ceramic heads in total hip arthroplasty is constantly increasing due to their good wear characteristics, biocompatibility and reduction of fretting corrosion risk [1,2]. They are used especially in young patients and clinical results are very good [3]. However, ceramic is a brittle material and fractures of the components can occur in unfavorable situations. The probability of these fractures is very low (0.004–0.35% for alumina heads) but they do happen [4–11]. The main reasons for head fracture are local stress concentrations caused by taper interface contamination or damage [12] or due to loosening of the...
Source: Medical Engineering and Physics - April 20, 2015 Category: Biomedical Engineering Authors: Julian Gührs, Annika Krull, Florian Witt, Michael M. Morlock Source Type: research

Precision of image-based registration for intraoperative navigation in the presence of metal artifacts: Application to corrective osteotomy surgery
Bone fractures are very common [1] and are mostly treated by closed reduction. In this procedure the aim of the physician is to align the bone segments without surgical intervention. Approximately 5% of the distal radius fractures [2,3] result in a symptomatic malunion. Such a malunion [4] may lead to a reduced function of the limb, chronic pain, and may finally lead to early osteoarthritis. In severe malunion cases the bone segments may be realigned by surgical treatment with a procedure called a corrective osteotomy [4]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - April 20, 2015 Category: Biomedical Engineering Authors: J.G.G. Dobbe, F. Curnier, X. Rondeau, G.J. Streekstra Source Type: research

Ultrananocrystalline diamond-CMOS device integration route for high acuity retinal prostheses.
Abstract High density electrodes are a new frontier for biomedical implants. Increasing the density and the number of electrodes used for the stimulation of retinal ganglion cells is one possible strategy for enhancing the quality of vision experienced by patients using retinal prostheses. The present work presents an integration strategy for a diamond based, high density, stimulating electrode array with a purpose built application specific integrated circuit (ASIC). The strategy is centered on flip-chip bonding of indium bumps to create high count and density vertical interconnects between the stimulator ASIC and...
Source: Biomedical Microdevices - April 19, 2015 Category: Biomedical Engineering Authors: Ahnood A, Escudie MC, Cicione R, Abeyrathne CD, Ganesan K, Fox KE, Garrett DJ, Stacey A, Apollo NV, Lichter SG, Thomas CD, Tran N, Meffin H, Prawer S Tags: Biomed Microdevices Source Type: research

Synthesis of a hybrid polymer-inorganic biomimetic support incorporating in situ pectinase from Aspergillus niger ATCC 9642.
Abstract The hybrid alginate/gelatin/calcium oxalate (AGOCa) support was successfully synthesized through the biomimetic mineralization method for immobilization in situ of a pectinolytic extract from Aspergillus niger ATCC 9642 via entrapment technique. The efficiency of immobilization reached 72.7 %. Sodium oxalate buffer (100 mM, pH 5.5) was selected as adjuvant of the immobilization process by allowing the formation of a calcified shell around the calcium alginate capsule, significantly increasing the stability to storage, thermal and recycling of the enzymatic immobilized pectinolytic extract. The pH and tem...
Source: Bioprocess and Biosystems Engineering - April 19, 2015 Category: Biomedical Engineering Authors: Bustamante-Vargas CE, Mignoni ML, de Oliveira D, Venquiaruto LD, Valduga E, Toniazzo G, Dallago RM Tags: Bioprocess Biosyst Eng Source Type: research

Sensing and Recognition When Primary User Has Multiple Transmit Power Levels
In this paper, a new cognitive radio (CR) scenario called Multiple Primary Transmit Power (MPTP) is investigated where the primary user (PU) could possibly work on more than one discrete transmit power levels. Different from most existing literatures where PU is assumed to operate with a constant transmit power only, this new consideration well matches the practical standards, e.g., IEEE 802.11 Series, GSM, LTE, LTE-A, etc., as well as the adaptive powering concept that a user would vary its transmit power under different situations. The primary target of CR under MPTP may still be detecting the presence of PU. However, th...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Source Enumeration in Array Processing Using a Two-Step Test
We investigate the problem of enumerating source signals impinging on an array of sensors given noisy, limited observations. The assumption of a large sample size is indispensable for most of the existing approaches so that they suffer significant performance degradation when only a small number of samples is available. Random matrix theory can capture the asymptotic distributions of the eigenvalues accurately and provide good approximations even for a finite sample size. In this paper, we take into account the relationship and distributions of the noise and signal eigenvalues based on random matrix theory and derive a sim...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Constrained and Preconditioned Stochastic Gradient Method
We consider stochastic approximations that arise from such applications as data communications and image processing. We demonstrate why constraints are needed in a stochastic approximation and how a constrained approximation can be incorporated into a preconditioning technique to derive the preconditioned stochastic gradient method (PSGM). We perform convergence analysis to show that the PSGM converges to the theoretical best approximation under some simple assumptions on the preconditioner and on the independence of samples drawn from a stochastic process. Simulation results are presented to demonstrate the effectiveness ...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Performance Tradeoffs for Networked Jump Observer-Based Fault Diagnosis
In this paper, we address the fault diagnosis problem for discrete-time multi-sensor systems over communication networks with measurement dropouts. We use the measurement outcomes to model the measurement reception scenarios. Based on this, we propose the use of a jump observer to diagnose multiple faults. We model the faults as slow time-varying signals and introduce this dynamic in the observer to estimate the faults and to generate a residual. The fault detection is assured by comparing the residual signal with a prescribed threshold. We design the jump observer, the residual and the threshold to attain disturbance atte...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Performance Analysis of Time-Reversal MUSIC
In this paper, we study the performance of multiple signal classification (MUSIC) in computational time-reversal (TR) applications. The analysis builds upon classical results on first-order perturbation of singular value decomposition. The closed form of mean-squared error (MSE) matrix of TR-MUSIC is derived for the single-frequency case in both multistatic co-located and non co-located scenarios. The proposed analysis is compared with Cramér–Rao lower-bound (CRLB), and it is exploited for comparison of TR-MUSIC when linear and (nonlinear) multiple-scattering is present. Finally, a numerical analysis is provi...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Subspace Learning and Imputation for Streaming Big Data Matrices and Tensors
Extracting latent low-dimensional structure from high-dimensional data is of paramount importance in timely inference tasks encountered with “Big Data” analytics. However, increasingly noisy, heterogeneous, and incomplete datasets, as well as the need for real-time processing of streaming data, pose major challenges to this end. In this context, the present paper permeates benefits from rank minimization to scalable imputation of missing data, via tracking low-dimensional subspaces and unraveling latent (possibly multi-way) structure from incomplete streaming data. For low-rank matrix data, a subspace estimat...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Asymptotically Efficient Estimation of a Nonlinear Model of the Heteroscedasticity and the Calibration of Measurement Systems
The measurement system calibration includes the estimation of the sensor error models in order to get an optimal estimation of the measured parameters. The paper is devoted to the estimation of a nonlinear parametric model of the heteroscedasticity and its application to the calibration of measurement systems. The heteroscedasticity occurs in regression when the measurement noise variance is nonconstant. The maximum likelihood (ML) estimation of variance function parameters leads to a system of nonlinear equations. The iterative solution of these nonlinear equations is based entirely on a successful choice of initial condi...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Robust Joint Source-Relay-Destination Design Under Per-Antenna Power Constraints
This paper deals with joint source-relay-destination beamforming (BF) design for an amplify-and-forward (AF) relay network. Considering the channel state information (CSI) from the relay to the destination is imperfect, we first aim to maximize the worst case received SNR under per-antenna power constraints. The associated optimization problem is then solved in two steps. In the first step, by revealing the rank-one property of the optimal relay BF matrix, we establish the semi-closed form solution of the joint optimal BF design that only depends on a vector variable. Based on this result, in the second step, we propose a ...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Estimation of Spatially Correlated Random Fields in Heterogeneous Wireless Sensor Networks
We develop new algorithms for spatial field reconstruction, exceedance level estimation and classification in heterogeneous (mixed analog & digital sensors) Wireless Sensor Networks (WSNs). We consider spatial physical phenomena which are observed by a heterogeneous WSN, meaning that it consists partially of sparsely deployed high-quality sensors and partially of low-quality sensors. The high-quality sensors transmit their (continuous) noisy observations to the Fusion Centre (FC), while the low-quality sensors first perform a simple thresholding operation and then transmit their binary values over imperfect wireless ch...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

On Decentralized Estimation With Active Queries
We consider the problem of decentralized 20 questions with noise for multiple players/agents under the minimum entropy criterion in the setting of stochastic search over a parameter space, with application to target localization. We propose decentralized extensions of the active query-based stochastic search strategy that combines elements from the 20 questions approach and social learning. We prove convergence to correct consensus on the value of the parameter. This framework provides a flexible and tractable mathematical model for decentralized parameter estimation systems based on active querying. We illustrate the effe...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

Sparsity-Aware Sensor Collaboration for Linear Coherent Estimation
In the context of distributed estimation, we consider the problem of sensor collaboration, which refers to the act of sharing measurements with neighboring sensors prior to transmission to a fusion center. While incorporating the cost of sensor collaboration, we aim to find optimal sparse collaboration schemes subject to a certain information or energy constraint. Two types of sensor collaboration problems are studied: minimum energy with an information constraint; and maximum information with an energy constraint. To solve the resulting sensor collaboration problems, we present tractable optimization formulations and prop...
Source: IEEE Transactions on Signal Processing - April 18, 2015 Category: Biomedical Engineering Source Type: research

A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells
The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken...
Source: BioMedical Engineering OnLine - April 18, 2015 Category: Biomedical Engineering Authors: Ahmed AlrifaiyJohan BorgOlof LindahlKerstin Ramser Source Type: research

Brief histories of medical physics in Asia-Oceania
Abstract The history of medical physics in Asia-Oceania goes back to the late nineteenth century when X-ray imaging was introduced, although medical physicists were not appointed until much later. Medical physics developed very quickly in some countries, but in others the socio-economic situation as such prevented it being established for many years. In others, the political situation and war has impeded its development. In many countries their medical physics history has not been well recorded and there is a danger than it will be lost to future generations. In this paper, brief histories of the development of me...
Source: Australasian Physical and Engineering Sciences in Medicine - April 18, 2015 Category: Biomedical Engineering Source Type: research

Stimulating Brain Waves May Boost Creativity And Ease Depression
The secret to stimulating creativity may be to literally stimulate the brain. In a new study, scientists at the University of North Carolina at Chapel Hill were able to measurably increase creativity by altering electrical activity in the brain -- a finding that may have significant implications for the treatment of depression. The researchers stimulated the brains of 20 healthy individuals with a low dose of electric currents, transmitted safely and non-invasively through electrodes attached to the scalp. Afterward, the participants performed an average of 7.4 percent better on a test of creative thinking. The elect...
Source: Science - The Huffington Post - April 17, 2015 Category: Science Source Type: news

Stimulating Brain Waves May Boost Creativity And Ease Depression
The secret to stimulating creativity may be to literally stimulate the brain. In a new study, scientists at the University of North Carolina at Chapel Hill were able to measurably increase creativity by altering electrical activity in the brain -- a finding that may have significant implications for the treatment of depression. The researchers stimulated the brains of 20 healthy individuals with a low dose of electric currents, transmitted safely and non-invasively through electrodes attached to the scalp. Afterward, the participants performed an average of 7.4 percent better on a test of creative thinking. The elect...
Source: Healthy Living - The Huffington Post - April 17, 2015 Category: Consumer Health Advice Source Type: news

[In Brief] This week's section
In science news around the world, the World Health Organization calls for the public release of clinical trials data, Brazil approves the first commercial planting of genetically modified eucalyptus trees, a review panel convened by the Scientific Committee of the International Whaling Commission gives Japanese research whaling a thumbs-down, and the death of monkeys at a Harvard University primate research facility prompts an investigation. Also, a thoracic surgeon who famously transplanted artificial tracheae into patients—and then faced misconduct charges—has been cleared in one of two investigations. And biomedical...
Source: Science: Current Issue - April 17, 2015 Category: Science Authors: Science Magazine (mailto:soleditor at aaas.org) Source Type: research

Three-dimensional cardiac computational modelling: methods, features and applications
The combination of computational models and biophysical simulations can help to interpret an array of experimental data and contribute to the understanding, diagnosis and treatment of complex diseases such as cardiac arrhythmias. For this reason, three-dimensional (3D) cardiac computational modelling is currently a rising field of research. The advance of medical imaging technology over the last decades has allowed the evolution from generic to patient-specific 3D cardiac models that faithfully represent the anatomy and different cardiac features of a given alive subject. Here we analyse sixty representative 3D cardiac com...
Source: BioMedical Engineering OnLine - April 17, 2015 Category: Biomedical Engineering Authors: Alejandro Lopez-PerezRafael SebastianJose Ferrero Source Type: research

Roles of the Fibrous Superficial Zone in the Mechanical Behavior of TMJ Condylar Cartilage.
This study aims to elucidate the roles of this fibrous zone in the mechanical behaviors, particularly lubrication, of TMJ under physiological loading regimes. Mechanical tests on porcine condylar cartilage demonstrated that the superficial and middle-deep zones exhibit tension-compression nonlinearity. The tensile and compressive moduli of the superficial zone are 30.73 ± 12.97 and 0.028 ± 0.016 MPa, respectively, while those for the middle-deep zone are 2.43 ± 1.75 and 0.14 ± 0.09 MPa. A nonlinear finite element model of condylar cartilage was built to simulate sliding of a spherical probe over the articular...
Source: Annals of Biomedical Engineering - April 17, 2015 Category: Biomedical Engineering Authors: Ruggiero L, Zimmerman BK, Park M, Han L, Wang L, Burris DL, Lu XL Tags: Ann Biomed Eng Source Type: research

Biomedical Engineering Accredited Undergraduate Programs: 4 Decades of Growth.
PMID: 25893510 [PubMed - as supplied by publisher] (Source: Annals of Biomedical Engineering)
Source: Annals of Biomedical Engineering - April 17, 2015 Category: Biomedical Engineering Authors: Hart RT Tags: Ann Biomed Eng Source Type: research

Validation of a Quantitative Single-Subject Based Evaluation for Rehabilitation-Induced Improvement Assessment.
In this study, we propose an automatic comprehensive method of combining multiple measures in order to assess a functional improvement. As test-bed, a functional electrical stimulation based treatment for foot drop correction performed with chronic post-stroke participants is presented. Patients were assessed on five relevant outcome measures before, after intervention, and at a follow-up time-point. A novel algorithm based on variables minimum detectable change is proposed and implemented in a custom-made software, combining the outcome measures to obtain a unique parameter: capacity score. The difference between capacity...
Source: Annals of Biomedical Engineering - April 17, 2015 Category: Biomedical Engineering Authors: Gandolla M, Molteni F, Ward NS, Guanziroli E, Ferrigno G, Pedrocchi A Tags: Ann Biomed Eng Source Type: research

Reducing Neointima Formation in a Swine Model with IVUS and Sirolimus Microbubbles.
Abstract Potent therapeutic compounds with dose dependent side effects require more efficient and selective drug delivery to reduce systemic drug doses. Here, we demonstrate a new platform that combines intravascular ultrasound (IVUS) and drug-loaded microbubbles to enhance and localize drug delivery, while enabling versatility of drug type and dosing. Localization and degree of delivery with IVUS and microbubbles was assessed using fluorophore-loaded microbubbles and different IVUS parameters in ex vivo swine arteries. Using a swine model of neointimal hyperplasia, reduction of neointima formation following balloo...
Source: Annals of Biomedical Engineering - April 17, 2015 Category: Biomedical Engineering Authors: Kilroy JP, Dhanaliwala AH, Klibanov AL, Bowles DK, Wamhoff BR, Hossack JA Tags: Ann Biomed Eng Source Type: research

A Generalized Method for the Analysis of Planar Biaxial Mechanical Data Using Tethered Testing Configurations
Simulation of the mechanical behavior of soft tissues is critical for many physiological and medical device applications. Accurate mechanical test data is crucial for both obtaining the form and robust parameter determination of the constitutive model. For incompressible soft tissues that are either membranes or thin sections, planar biaxial mechanical testing configurations can provide much information about the anisotropic stress–strain behavior. However, the analysis of soft biological tissue planar biaxial mechanical test data can be complicated by in-plane shear, tissue heterogeneities, and inelastic changes in spec...
Source: Journal of Biomechanical Engineering - April 16, 2015 Category: Biomedical Engineering Source Type: research

Noninvasive In Vivo Determination of Residual Strains and Stresses
Vascular growth and remodeling during embryonic development are associated with blood flow and pressure induced stress distribution, in which residual strains and stresses play a central role. Residual strains are typically measured by performing in vitro tests on the excised vascular tissue. In this paper, we investigated the possibility of estimating residual strains and stresses using physiological pressure–radius data obtained through in vivo noninvasive measurement techniques, such as optical coherence tomography or ultrasound modalities. This analytical approach first tested with in vitro results using experimental...
Source: Journal of Biomechanical Engineering - April 16, 2015 Category: Biomedical Engineering Source Type: research

Mechanical and Microstructural Investigation of the Cyclic Behavior of Human Amnion
In this study, the mechanical response of human amnion to repeated loading and the microstructural mechanisms determining its behavior were investigated. Inflation and uniaxial cyclic tests were combined with corresponding in situ experiments in a multiphoton microscope (MPM). Fresh unfixed amnion was imaged during loading and changes in thickness and collagen orientation were quantified. Mechanical and in situ experiments revealed differences between the investigated configurations in the deformation and microstructural mechanisms. Repeated inflation induces a significant but reversible volume change and is characterized ...
Source: Journal of Biomechanical Engineering - April 16, 2015 Category: Biomedical Engineering Source Type: research

Symmetric Toeplitz-Structured Compressed Sensing Matrices
Abstract How to construct a suitable measurement matrix is an important topic in compressed sensing. A significant part of the recent work is that the measurement matrices are not completely random on the entries but exhibit some considerable structures. In this paper, we proved that a symmetric Toeplitz matrix and its variant can be used as measurement matrices and recovery signal with high probability. Compared with random matrices (e.g. Gaussian and Bernoulli matrices) and some structured matrices (e.g. Toeplitz and circulant matrices), we need to generate fewer independent entries to obtain the measurement ma...
Source: Sensing and Imaging - April 16, 2015 Category: Biomedical Engineering Source Type: research