Biomedical Engineering Biomedical Engineering RSS feedThis is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

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

Distributed Online Learning via Cooperative Contextual Bandits
In this paper, we propose a novel framework for decentralized, online learning by many learners. At each moment of time, an instance characterized by a certain context may arrive to each learner; based on the context, the learner can select one of its own actions (which gives a reward and provides information) or request assistance from another learner. In the latter case, the requester pays a cost and receives the reward but the provider learns the information. In our framework, learners are modeled as cooperative contextual bandits. Each learner seeks to maximize the expected reward from its arrivals, which involves trad...
Source: IEEE Transactions on Signal Processing - June 12, 2015 Category: Biomedical Engineering Source Type: research

Distributed Inference in Tree Networks Using Coding Theory
In this paper, we consider the problem of distributed inference in tree based networks. In the framework considered in this paper, distributed nodes make a 1-bit local decision regarding a phenomenon before sending it to the fusion center (FC) via intermediate nodes. We propose the use of coding theory based techniques to solve this distributed inference problem in such structures. Data is progressively compressed as it moves towards the FC. The FC makes the global inference after receiving data from intermediate nodes. Data fusion at nodes as well as at the FC is implemented via error correcting codes. In this context, we...
Source: IEEE Transactions on Signal Processing - June 12, 2015 Category: Biomedical Engineering Source Type: research

Data-Efficient Quickest Change Detection in Sensor Networks
The objective is to detect the change in distribution as quickly as possible, subject to constraints on the false alarm rate, the cost of observations taken at each sensor, and the cost of communication between the sensors and the fusion center. Minimax formulations are proposed for the above problem and distributed algorithms are proposed in which on-off observation control and censoring is used at each sensor to meet the constraints on data. It is shown that the proposed algorithms are asymptotically optimal for the proposed formulations, as the false alarm rate goes to zero. The asymptotic optimality of the proposed alg...
Source: IEEE Transactions on Signal Processing - June 12, 2015 Category: Biomedical Engineering Source Type: research

A Generalized Spatial Correlation Model for 3D MIMO Channels Based on the Fourier Coefficients of Power Spectrums
Previous studies have confirmed the adverse impact of fading correlation on the mutual information (MI) of two-dimensional (2D) multiple-input multiple-output (MIMO) systems. More recently, the trend is to enhance the system performance by exploiting the channels degrees of freedom in the elevation, which necessitates the derivation and characterization of three-dimensional (3D) channels in the presence of spatial correlation. In this paper, an exact closed-form expression for the Spatial Correlation Function (SCF) is derived for 3D MIMO channels. The proposed method resorts to the spherical harmonic expansion (SHE) of pla...
Source: IEEE Transactions on Signal Processing - June 12, 2015 Category: Biomedical Engineering Source Type: research

UTSA grads notch another win for animal stem cell startup
A pair of UTSA graduate students took top honors in an immigrant-founded startup competition on Friday, June 12, at Cafe Commerce. Ramon Coronado and Tony Yuan, graduate students in the UTSA College of Engineering’s Department of Biomedical Engineering, walked away with $1,500 in the first SATX Global Innovators Pitch Challenge. The pair won for their Mobile Stem Care firm that continues to impress judges and investors alike. Coronado and Yuan had previously taken first place at the 2015 Emerging… (Source: bizjournals.com Health Care:Hospitals headlines)
Source: bizjournals.com Health Care:Hospitals headlines - June 12, 2015 Category: Hospital Management Authors: Mike W. Thomas Source Type: news

UTSA grads notch another win for animal stem cell startup
A pair of UTSA graduate students took top honors in an immigrant-founded startup competition on Friday, June 12, at Cafe Commerce. Ramon Coronado and Tony Yuan, graduate students in the UTSA College of Engineering’s Department of Biomedical Engineering, walked away with $1,500 in the first SATX Global Innovators Pitch Challenge. The pair won for their Mobile Stem Care firm that continues to impress judges and investors alike. Coronado and Yuan had previously taken first place at the 2015 Emerging… (Source: bizjournals.com Health Care:Biotechnology headlines)
Source: bizjournals.com Health Care:Biotechnology headlines - June 12, 2015 Category: Biotechnology Authors: Mike W. Thomas Source Type: news

Transdermal Delivery of Functional Collagen Via Polyvinylpyrrolidone Microneedles.
Abstract Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcin...
Source: Annals of Biomedical Engineering - June 12, 2015 Category: Biomedical Engineering Authors: Sun W, Inayathullah M, Manoukian MA, Malkovskiy AV, Manickam S, Marinkovich MP, Lane AT, Tayebi L, Seifalian AM, Rajadas J Tags: Ann Biomed Eng Source Type: research

Computational modeling of peripheral pain: a commentary
This commentary is intended to find possible explanations for the low impact of computational modeling on pain research. We discuss the main strategies that have been used in building computational models for the study of pain. The analysis suggests that traditional models lack biological plausibility at some levels, they do not provide clinically relevant results, and they cannot capture the stochastic character of neural dynamics. On this basis, we provide some suggestions that may be useful in building computational models of pain with a wider range of applications. (Source: BioMedical Engineering OnLine)
Source: BioMedical Engineering OnLine - June 11, 2015 Category: Biomedical Engineering Authors: Erick ArgüelloRicardo SilvaMónica HuertaRené Avila Source Type: research

Individual and combined effects of OA-related subchondral bone alterations on proximal tibial surface stiffness: a parametric finite element modeling study
Subchondral changes during the osteoarthritic (OA) disease process have become a controversial and growing area of focus in OA research. OA-related changes to subchondral cortical and trabecular bone are theorized to initiate and accelerate cartilage degeneration by increasing subchondral bone surface stiffness (i.e., stiffness normal to the subchondral bone surface), which will alter load and stress distributions in cartilage, leading to cartilage degeneration and eventual OA [1–3]. Stiffness gradients arising from variations in local stiffness are also thought to increase cartilage shear stresses [2]. (Source: Medical ...
Source: Medical Engineering and Physics - June 11, 2015 Category: Biomedical Engineering Authors: Morteza Amini, S. Majid Nazemi, Joel L. Lanovaz, Saija Kontulainen, Bassam A. Masri, David R. Wilson, Walerian Szyszkowski, James D. Johnston Source Type: research

The effects of knee joint kinematics on anterior cruciate ligament injury and articular cartilage damage.
This study determined which knee joint motions lead to anterior cruciate ligament (ACL) rupture with the knee at 25° of flexion. The knee was subjected to internal and external rotations, as well as varus and valgus motions. A failure locus representing the relationship between these motions and ACL rupture was established using finite element simulations. This study also considered possible concomitant injuries to the tibial articular cartilage prior to ACL injury. The posterolateral bundle of the ACL demonstrated higher rupture susceptibility than the anteromedial bundle. The average varus angular displacement required ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - June 11, 2015 Category: Biomedical Engineering Authors: Orsi AD, Chakravarthy S, Canavan PK, Peña E, Goebel R, Vaziri A, Nayeb-Hashemi H Tags: Comput Methods Biomech Biomed Engin Source Type: research

Experimental Investigation of Pressure Applied on the Lower Leg by Elastic Compression Bandage.
The objective of this study was to investigate the influence of bandage mechanical properties, application technique and subject morphology on the interface pressure, which is the key of this treatment. Bandage stretch and interface pressure measurements (between the bandage and the leg) were performed on 30 healthy subjects (15 men and 15 women) at two different heights on the lower leg and in two positions (supine and standing). Two bandages were applied with two application techniques by a single operator. The statistical analysis of the results revealed: no significant difference in pressure between men and women, exce...
Source: Annals of Biomedical Engineering - June 11, 2015 Category: Biomedical Engineering Authors: Chassagne F, Martin F, Badel P, Convert R, Giraux P, Molimard J Tags: Ann Biomed Eng Source Type: research

Seattle in Deep Sleep This Week
Seattle wasn't sleepless this week. Not after more than 4,000 sleep experts from around the world descended upon the Emerald City for SLEEP 2015, an annual conference sponsored by the American Academy of Sleep Medicine and the Sleep Research Society. Topics and research on all things related to sleep -- how much we need, how much we don't get, how much is disrupted by undiagnosed sleep disorders and how a better, cheaper, less obtrusive way to detect sleep apnea is needed -- were discussed. "Right now we don't have enough sleep clinics, sleep laboratories and sleep specialists in the country to address all the sleep apn...
Source: Healthy Living - The Huffington Post - June 10, 2015 Category: Consumer Health Advice Source Type: news

Stress–Strain Measurements in Vitrified Arteries Permeated With Synthetic Ice Modulators
This study measures the Young's modulus in vitrified blood vessels below the glass transition temperature in conditions relevant to cryogenic storage and focuses on the cryoprotective agents (CPAs) cocktail DP6 mixed with synthetic ice modulators (SIMs). Small steplike strain changes were observed during the loading without affecting the bulk behavior, suggesting microfracture occurrences resembling previous observation on microfracture formation under compression in crystallized blood vessels. Young's modulus was measured to be 0.92–3.01 GPa, with no clear indication of SIM dependency on the Young's modulus. Instead, ...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Analysis of the Constraint Joint Loading in the Thumb During Pipetting
Dynamic loading on articular joints is essential for the evaluation of the risk of the articulation degeneration associated with occupational activities. In the current study, we analyzed the dynamic constraint loading for the thumb during pipetting. The constraint loading is considered as the loading that has to be carried by the connective tissues of the joints (i.e., the cartilage layer and the ligaments) to maintain the kinematic constraints of the system. The joint loadings are solved using a classic free-body approach, using the external loading and muscle forces, which were obtained in an inverse dynamic approach co...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Dynamic Properties of Tympanic Membrane in a Chinchilla Otitis Media Model Measured With Acoustic Loading
Otitis media is the most common infectious disease in young children, which results in changes in the thickness and mechanical properties of the tympanic membrane (TM) and induces hearing loss. However, there are no published data for the dynamic properties of the TM in otitis media ears, and it is unclear how the mechanical property changes are related to TM thickness variation. This paper reports a study of the measurement of the dynamic properties of the TM in a chinchilla acute otitis media (AOM) model using acoustic loading and laser Doppler vibrometry (LDV). AOM was created through transbullar injection of Haemophilu...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties
Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to mod...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Development and Validation of a Musculoskeletal Model of the Fully Articulated Thoracolumbar Spine and Rib Cage
We developed and validated a fully articulated model of the thoracolumbar spine in opensim that includes the individual vertebrae, ribs, and sternum. To ensure trunk muscles in the model accurately represent muscles in vivo, we used a novel approach to adjust muscle cross-sectional area (CSA) and position using computed tomography (CT) scans of the trunk sampled from a community-based cohort. Model predictions of vertebral compressive loading and trunk muscle tension were highly correlated to previous in vivo measures of intradiscal pressure (IDP), vertebral loading from telemeterized implants and trunk muscle myoelectric ...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Characterization of Mechanical Properties of Tissue Scaffolds by Phase Contrast Imaging and Finite Element Modeling
In tissue engineering, the cell and scaffold approach has shown promise as a treatment to regenerate diseased and/or damaged tissue. In this treatment, an artificial construct (scaffold) is seeded with cells, which organize and proliferate into new tissue. The scaffold itself biodegrades with time, leaving behind only newly formed tissue. The degradation qualities of the scaffold are critical during the treatment period, since the change in the mechanical properties of the scaffold with time can influence cell behavior. To observe in time the scaffold's mechanical properties, a straightforward method is to deform the scaff...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation
Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordi...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

The Influence of Airway Tree Geometry and Ventilation Frequency on Airflow Distribution
The human lung is known to be asymmetric and heterogeneous which leads to an inhomogeneous distribution of air. Within the scope of this paper the influence of the upper airway tree geometry on ventilation distribution and the differences between conventional mechanical ventilation (CMV) and high frequency oscillatory ventilation (HFOV) will be analyzed. The comparison is carried out under the assumption of positive pressure ventilation. Thereby, the mechanics of lung tissue is expected to play a minor role. Oscillatory flow is therefore generated numerically at a 3D model geometry of the upper human airways. For large eno...
Source: Journal of Biomechanical Engineering - June 10, 2015 Category: Biomedical Engineering Source Type: research

Model of a Plasmonic Phase Interrogation Probe for Optical Sensing of Hemoglobin in Blood Samples
Abstract Phase interrogation based surface plasmon resonance (SPR) biosensor is proposed for the determination of Hb concentration. Previous experimental results describing variation of refractive index of human blood with Hb concentration at different wavelengths are considered for design simulations. The biosensor design with silica substrate and gold layer is considered. The sensor’s performance is closely analyzed in terms of phase sensitivity and resolution. The influence of operating wavelength on biosensor’s performance for Hb measurement is critically investigated, which points to carry out the Hb mea...
Source: Sensing and Imaging - June 10, 2015 Category: Biomedical Engineering Source Type: research

Macroscopic modelling of bioethanol production from potato peel wastes in batch cultures supplemented with inorganic nitrogen.
Abstract Inorganic nitrogen supplementation is commonly used to boost fermentation metabolism in yeast cultures. However, an excessive addition can induce an opposite effect. Hence, it is important to ensure that the ammonia supplemented to the culture leads to an improvement of the ethanol production while avoiding undesirable inhibition effects. To this end, a macroscopic model describing the influence of ammonia addition on Saccharomyces cerevisiae metabolism during bioethanol production from potato peel wastes has been developed. The model parameters are obtained by a simplified identification methodology in fi...
Source: Bioprocess and Biosystems Engineering - June 10, 2015 Category: Biomedical Engineering Authors: Richelle A, Ben Tahar I, Hassouna M, Bogaerts P Tags: Bioprocess Biosyst Eng Source Type: research

Microconfined flow behavior of red blood cells
In the microcirculation in vivo, red blood cells (RBCs) travel through microvessels with diameter smaller than the individual cell size in order to allow optimal gas transfer between blood and tissues [1]. The most important properties of RBC are deformability and aggregation. The high RBC deformability is mainly due to the viscoelastic properties of the cell membrane, especially shear modulus and surface viscosity [2]. Pathological alterations of RBC deformability are known to be implicated in several diseases, including diabetes, malaria, and sickle cell disease [3–6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - June 10, 2015 Category: Biomedical Engineering Authors: Giovanna Tomaiuolo, Luca Lanotte, Rosa D'Apolito, Antonio Cassinese, Stefano Guido Source Type: research

Joint Power and Admission Control: Non-Convex $L_{q}$ Approximation and An Effective Polynomial Time Deflation Approach
In an interference limited network, joint power and admission control (JPAC) aims at supporting a maximum number of links at their specified signal-to-interference-plus-noise ratio (SINR) targets while using minimum total transmission power. Various convex approximation deflation approaches have been developed for the JPAC problem. In this paper, we propose an effective polynomial time non-convex approximation deflation approach for solving the problem. The approach is based on the non-convex $ell _{q}~(0< q< 1)$ approximation of an equivalent sparse $ell _{0}$ reformulation of the JPAC problem. We show that, for any...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

New Integer Normalized Carrier Frequency Offset Estimators
Carrier frequency offset (CFO) introduces spectrum misalignment of the transmit and receive filters, causing energy loss and distortion of received signal. A recent study presents an accurate signal model that incorporates these characteristics. However, CFO estimators in the existing literature were developed based on the signal models without these characteristics. This paper generalizes the accurate signal model with CFO to include timing offset and sampling offset and then studies what effects the accurate signal model bring to the CFO estimation and how to address them. We investigate different existing CFO estimators...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Cooperative Joint Synchronization and Localization in Wireless Sensor Networks
In this paper, cooperative sensor localization using asynchronous time-of-arrival measurements is investigated. It is well known that localization performance in wireless networks using time-based ranging or pseudo-ranging methods is greatly affected by the accuracy of the timing synchronization between the nodes involved in the estimation. Commonly, the original estimation problem is broken down into two subproblems, the synchronization problem and the localization problem, in what is known as a two-step approach. However, in this paper, the joint synchronization and localization problem is considered and examined for use...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Exploiting Known Interference as Green Signal Power for Downlink Beamforming Optimization
We propose a data-aided transmit beamforming scheme for the multi-user multiple-input-single-output (MISO) downlink channel. While conventional beamforming schemes aim at the minimization of the transmit power subject to suppressing interference to guarantee quality of service (QoS) constraints, here we use the knowledge of both data and channel state information (CSI) at the transmitter to exploit, rather than suppress, constructive interference. More specifically, we design a new precoding scheme for the MISO downlink that minimizes the transmit power for generic phase shift keying (PSK) modulated signals. The proposed p...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Bayesian Conditional Monte Carlo Algorithms for Nonlinear Time-Series State Estimation
Bayesian filtering aims at estimating sequentially a hidden process from an observed one. In particular, sequential Monte Carlo (SMC) techniques propagate in time weighted trajectories which represent the posterior probability density function (pdf) of the hidden process given the available observations. On the other hand, conditional Monte Carlo (CMC) is a variance reduction technique which replaces the estimator of a moment of interest by its conditional expectation given another variable. In this paper, we show that up to some adaptations, one can make use of the time recursive nature of SMC algorithms in order to propo...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

A Multitask Learning Framework for Broadband Source-Location Mapping Using Passive Sonar
Underwater source localization via passive sonar is a challenging task due to the dynamic and complex nature of the acoustic environment. Different from approaches based on matched-field processing, this work explores broadband underwater source localization within a multitask learning (MTL) framework. Here, each task refers to a robust signal approximation problem over a single frequency. MTL provides a natural framework for exchanging information across the narrowband signal-approximation problems and constructing an aggregate (across frequencies) source-localization map. Efficient algorithms based on block coordinate de...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Quantization of Eigen Subspace for Sparse Representation
We propose sparse Karhunen–Loeve Transform (SKLT) method to sparse eigen subspaces. The sparsity (cardinality reduction) is achieved through the pdf-optimized quantization of basis function (vector) set. It may be considered an extension of the simple and soft thresholding (ST) methods. The merit of the proposed framework for sparse representation is presented for auto-regressive order one, AR(1), discrete process and empirical correlation matrix of stock returns for NASDAQ-100 index. It is shown that SKLT is efficient to implement and outperforms several sparsity algorithms reported in the literature. (Source: IEEE...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Properties and Power Spectral Densities of CP Based OQAM-OFDM Systems
Offset quadrature amplitude modulation OFDM (OQAM-OFDM) systems have low sidelobes but require complex receivers for broadband channels. To deal with this problem, cyclic prefix (CP)-based OQAM-OFDM systems have been proposed in the literature. In this paper, we study OQAM-OFDM and two existing CP based OQAM-OFDM systems and propose a new CP based system with good spectrum performance. We investigate their properties and analyze their power spectral densities (PSDs). We show that the continuous-time transmitted CP-OQAM-OFDM signal after the CP insertion is equivalent to a truncated signal obtained by inserting CP and cycli...
Source: IEEE Transactions on Signal Processing - June 9, 2015 Category: Biomedical Engineering Source Type: research

Low-intensity functional electrical stimulation can increase multidirectional trunk stiffness in able-bodied individuals during sitting
The inability to voluntarily control the trunk musculature is a major problem following spinal cord injury as it can compromise functional independence and produce unwanted secondary complications. Recent developments suggest that neuroprostheses utilizing functional electrical stimulation (FES) may be able to facilitate or restore trunk control during sitting, standing, and other tasks involving postural control. In spite of these efforts, no study to date has used low-intensity FES to increase multidirectional trunk stiffness and damping in an attempt to bolster stability while minimizing muscle fatigue. (Source: Medical...
Source: Medical Engineering and Physics - June 9, 2015 Category: Biomedical Engineering Authors: Albert H. Vette, Noel Wu, Kei Masani, Milos R. Popovic Source Type: research

Advanced Prosthetics Provide More Functional Limbs
In an experiment at the University of Pittsburgh, a woman with quadriplegia uses her thoughts to operate a robotic arm to eat a piece of chocolate (Wodlinger B et al. J Neural Eng. doi:10.1088/1741-2560/12/1/016011 [published online December 16, 2014]). In a study at Case Western Reserve University, a man who lost his hand in an accident senses the texture of a cotton ball swept along the back of his prosthetic hand (Tan DW et al. Sci Transl Med. doi: 10.1126/scitranslmed.3008669 [published online October 8, 2014]). These remarkable feats demonstrate what advances in biomedical engineering have made possible for people liv...
Source: JAMA - June 9, 2015 Category: Journals (General) Source Type: research

A dynamic multibody model of the physiological knee to predict internal loads during movement in gravitational field.
Abstract Obtaining tibio-femoral (TF) contact forces, ligament deformations and loads during daily life motor tasks would be useful to better understand the aetiopathogenesis of knee joint diseases or the effects of ligament reconstruction and knee arthroplasty. However, methods to obtain this information are either too simplified or too computationally demanding to be used for clinical application. A multibody dynamic model of the lower limb reproducing knee joint contact surfaces and ligaments was developed on the basis of magnetic resonance imaging. Several clinically relevant conditions were simulated, includin...
Source: Computer Methods in Biomechanics and Biomedical Engineering - June 9, 2015 Category: Biomedical Engineering Authors: Bersini S, Sansone V, Frigo CA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Marker-Free Tracking of Facet Capsule Motion Using Polarization-Sensitive Optical Coherence Tomography.
Abstract We proposed and tested a method by which surface strains of biological tissues can be captured without the use of fiducial markers by instead, utilizing the inherent structure of the tissue. We used polarization-sensitive optical coherence tomography (PS OCT) to obtain volumetric data through the thickness and across a partial surface of the lumbar facet capsular ligament during three cases of static bending. Reflectivity and phase retardance were calculated from two polarization channels, and a power spectrum analysis was performed on each a-line to extract the dominant banding frequency (a measure of deg...
Source: Annals of Biomedical Engineering - June 9, 2015 Category: Biomedical Engineering Authors: Claeson AA, Yeh YJ, Black AJ, Akkin T, Barocas VH Tags: Ann Biomed Eng Source Type: research

Testicular biodistribution of silica-gold nanoparticles after intramuscular injection in mice.
This study investigated whether gold-silica nanoparticles could be detected in mouse testes after intramuscular injection, with a particular focus on their ability to cross the blood-testis barrier. To that purpose, well-characterized 70-nm gold core-silica shell nanoparticles were used to ensure sensitive detection using high-resolution techniques. Testes were collected at different time points corresponding to spermatogenesis stages in mice. Transmission electron microscopy and confocal microscopy were used for nanoparticle detection, and nanoparticle quantification was performed by atomic emission spectroscopy. All thes...
Source: Biomedical Microdevices - June 7, 2015 Category: Biomedical Engineering Authors: Leclerc L, Klein JP, Forest V, Boudard D, Martini M, Pourchez J, Blanchin MG, Cottier M Tags: Biomed Microdevices Source Type: research

A bio-inspired attachment mechanism for long-term adhesion to the small intestine.
Abstract To achieve long-term attachment of capsule endoscopes (CEs) and miniature biosensors in the human gastrointestinal (GI) tract, a tissue attachment mechanism (TAM) was designed, optimized and tested for safety and adhesive capabilities on excised tissue in vitro and in vivo on a live pig model. Six TAMs were tested for their attachment strength in an in vitro attachment tensile experiment in which each TAM was tested on three different proximal intestine tissue samples. The maximum strength and average value are 8.09 N and 4.54 N respectively. The initial attachment damage was tested for 10 min using a s...
Source: Biomedical Microdevices - June 7, 2015 Category: Biomedical Engineering Authors: Xie W, Kothari V, Terry BS Tags: Biomed Microdevices Source Type: research

Pump-free gradient-based micro-device enables quantitative and high-throughput bacterial growth inhibition analysis.
Abstract Antibiotic susceptibility testing is very important in antibiotic therapy. Traditional methods to determine antibiotic susceptibility include disk diffusion and broth dilution. However, these tests are always labor intensive, time-consuming, and need large amounts of reagents. In this paper, we demonstrated a novel pump-free micro-device that enables quantitative and high-throughput bacterial growth inhibition analysis. This device consists of a series of wells and diffusion-based antibiotic gradient channels. The wells serve as antibiotic sources and buffer sinks, and we could easily observe the bacterial...
Source: Biomedical Microdevices - June 7, 2015 Category: Biomedical Engineering Authors: Ran M, Wang Y, Wang S, Luo C Tags: Biomed Microdevices Source Type: research

The effect of AZD2171- or sTRAIL/Apo2L-loaded polylactic-co-glycolic acid microspheres on a subcutaneous glioblastoma model.
In this study, we investigated the potential of the highly hydrophobic AZD2171, released from modified polylactic-co-glycolic acid microspheres (PLGA-MS), to treat glioblastoma. To further demonstrate the versatile loading capacity of this system, the same PLGA formulation, which was found optimal for the loading and release of AZD2171, was tested with sTRAIL/Apo2L-a biologic drug that is very different than AZD2171 in its molecular weight, solubility, and charge. AZD2171 released from PLGA-MS was at least effective as the free drug in inhibiting endothelial growth and proliferation (in vitro), and, surprisingly, had a pro...
Source: Biomedical Microdevices - June 7, 2015 Category: Biomedical Engineering Authors: Shivinsky A, Bronshtein T, Haber T, Machluf M Tags: Biomed Microdevices Source Type: research

Identification of aldehyde reductase catalyzing the terminal step for conversion of xylose to butanetriol in engineered Escherichia coli.
Abstract Biosynthetic pathways for the production of biofuels often rely on inherent aldehyde reductases (ALRs) of the microbial host. These native ALRs play vital roles in the success of the microbial production of 1,3-propanediol, 1,4-butanediol, and isobutanol. In the present study, the main ALR for 1,2,4-butanetriol (BT) production in Escherichia coli was identified. Results of real-time PCR analysis for ALRs in EWBT305 revealed the increased expression of adhP, fucO, adhE, and yqhD genes during BT production. The highest increase of expression was observed up to four times in yqhD. Singular deletion of adhP, f...
Source: Bioprocess and Biosystems Engineering - June 6, 2015 Category: Biomedical Engineering Authors: Valdehuesa KN, Lee WK, Ramos KR, Cabulong RB, Choi J, Liu H, Nisola GM, Chung WJ Tags: Bioprocess Biosyst Eng Source Type: research

Mechanical Properties of Porcine Brain Tissue in the Coronal Plane: Interregional Variations of the Corona Radiata.
Abstract Most biomechanical models that aim to investigate traumatic brain injury consider the corona radiata as a homogeneous structure. To verify this, indentation-relaxation tests using a custom-designed indentation device were performed on the anterior, superior, and posterior region of the corona radiata in the coronal plane of the porcine brain. Using Boltzmann hereditary integral, a linear viscoelastic model with a Prony series approximation was fitted to the time-dependent shear modulus for different regions of the corona radiata, and the fit parameters were generated. The posterior region was the stiffest ...
Source: Annals of Biomedical Engineering - June 6, 2015 Category: Biomedical Engineering Authors: Chen F, Zhou J, Li Y, Wang Y, Li L, Yue H Tags: Ann Biomed Eng Source Type: research

Recognition of activities of daily living in healthy subjects using two ad-hoc classifiers
Conclusions: The performance of the classifiers varied significantly and shows that the classifier plays an important role in ADL recognition. Both RBI and CAR classifier performed better than existing state-of-the-art (NB, RF) on all ADL. Of the two ad-hoc classifiers, the CAR classifier was more accurate and is likely to be better suited than the RBI for distinguishing and recognizing complex ADL. (Source: BioMedical Engineering OnLine)
Source: BioMedical Engineering OnLine - June 6, 2015 Category: Biomedical Engineering Authors: Prabitha UrwylerLuca RampaReto StuckiMarcel BüchlerRené MüriUrs MosimannTobias Nef Source Type: research