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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 13.
Kinetic modeling and scale up of lipoic acid (LA) production from Saccharomyces cerevisiae in a stirred tank bioreactor.
Abstract Scale up studies for production of lipoic acid (LA) from Saccharomyces cerevisiae have been reported in this paper for the first time. LA production in batch mode was carried out in a stirred tank bioreactor at varying agitation and aeration with maximum LA production of 512 mg/L obtained at 350 rpm and 25 % dissolved oxygen in batch culture conditions. Thus, LA production increased from 352 mg/L in shake flask to 512 mg/L in batch mode in a 5 L stirred tank bioreactor. Biomass production under these conditions was mathematically explained using logistic equation and data obtained for LA production a...
Source: Bioprocess and Biosystems Engineering - November 24, 2012 Category: Biomedical Engineering Authors: Jayakar SS, Singhal RS Tags: Bioprocess Biosyst Eng Source Type: research
Real-time estimation of biomass and specific growth rate in physiologically variable recombinant fed-batch processes.
Abstract The real-time measurement of biomass has been addressed since many years. The quantification of biomass in the induction phase of a recombinant bioprocess is not straight forward, since biological burden, caused by protein expression, can have a significant impact on the cell morphology and physiology. This variability potentially leads to poor generalization of the biomass estimation, hence is a very important issue in the dynamic field of process development with frequently changing processes and producer lines. We want to present a method to quantify "biomass" in real-time which avoids off-line sampling...
Source: Bioprocess and Biosystems Engineering - November 23, 2012 Category: Biomedical Engineering Authors: Wechselberger P, Sagmeister P, Herwig C Tags: Bioprocess Biosyst Eng Source Type: research
Enhanced plasmid production in miniaturized high-cell-density cultures of Escherichia coli supported with perfluorinated oxygen carrier.
Abstract A simple method for plasmid minipreps in closed 1.5 mL microcentrifuge tubes using a cultivation medium with internal substrate delivery (EnBase(®)) in combination with a two-phase perfluorodecalin (PFD) system supplying additional oxygen to the E. coli culture is described. The procedure can simply be performed on a thermoshaker using only 50 μL cultivation volume. Twenty and twenty-five percent higher cell densities and plasmid concentration, respectively, were obtained with the additional oxygen delivery system when compared to cultures without PFD. Compared to standard 2 mL LB cultures ninefold h...
Source: Bioprocess and Biosystems Engineering - November 23, 2012 Category: Biomedical Engineering Authors: Pilarek M, Brand E, Hillig F, Krause M, Neubauer P Tags: Bioprocess Biosyst Eng Source Type: research
Control of cultured human cells with femtosecond laser ablated patterns on steel and plastic surfaces.
Abstract The purpose of the present study is to explore topographical patterns produced with femtosecond laser pulses as a means of controlling the behaviour of living human cells (U2OS) on stainless steel surfaces and on negative plastic imprints (polycarbonate). The results show that the patterns on both types of material strongly affect cell behaviour and are particularly powerful in controlling cell spreading/elongation, localization and orientation. Analysis by fluorescence and scanning electron microscopy shows that on periodic 1D grating structures, cells and cell nuclei are highly elongated and aligned, whe...
Source: Biomedical Microdevices - November 23, 2012 Category: Biomedical Engineering Authors: Nuutinen T, Silvennoinen M, Päiväsaari K, Vahimaa P Tags: Biomed Microdevices Source Type: research
Irreversible Electroporation: An In Vivo Study with Dorsal Skin Fold Chamber.
In this study, we investigate the effect of IRE in a human prostate cancer (LNCaP) grown in a thin, essentially two-dimensional, dorsal skin fold chamber system. Detailed experimental characterizations of the electrical and thermal responses of the tissue were performed yielding the first thermal response measurement in vivo of its kind that we are aware of. The interaction and coupling of electrical and thermal responses were further discussed. The threshold of the tumor injury was determined for human prostate tumor model, and the threshold value (600-1300 V cm(-1)) is dependent on the IRE parameters including pulse du...
Source: Annals of Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Qin Z, Jiang J, Long G, Lindgren B, Bischof JC Tags: Ann Biomed Eng Source Type: research
A Computational Approach to Understand Phenotypic Structure and Constitutive Mechanics Relationships of Single Cells.
Abstract The goal of this study is to construct a representative 3D finite element model (FEM) of individual cells based on their sub-cellular structures that predicts cell mechanical behavior. The FEM simulations replicate atomic force microscopy (AFM) nanoindentation experiments on live vascular smooth muscle cells. Individual cells are characterized mechanically with AFM and then imaged in 3D using a spinning disc confocal microscope. Using these images, geometries for the FEM are automatically generated via image segmentation and linear programming algorithms. The geometries consist of independent structures re...
Source: Annals of Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Wood ST, Dean BC, Dean D Tags: Ann Biomed Eng Source Type: research
Surface Curvature as a Classifier of Abdominal Aortic Aneurysms: A Comparative Analysis.
Abstract An abdominal aortic aneurysm (AAA) carries one of the highest mortality rates among vascular diseases when it ruptures. To predict the role of surface curvature in rupture risk assessment, a discriminatory analysis of aneurysm geometry characterization was conducted. Data was obtained from 205 patient-specific computed tomography image sets corresponding to three AAA population subgroups: patients under surveillance, those that underwent elective repair of the aneurysm, and those with an emergent repair. Each AAA was reconstructed and their surface curvatures estimated using the biquintic Hermite finite el...
Source: Annals of Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Lee K, Zhu J, Shum J, Zhang Y, Muluk SC, Chandra A, Eskandari MK, Finol EA Tags: Ann Biomed Eng Source Type: research
Endothelial Dysfunction, Arterial Stiffening, and Intima-Media Thickening in Large Arteries from HIV-1 Transgenic Mice.
This study employed NL4-3Δ gag/pol transgenic mice (HIV-Tg), which contain the genetic sequence for the HIV-1 proteins env, tat, nef, rev, vif, vpr, and vpu but lacks the gag and pol genes and reports that HIV-Tg mice have impaired aortic endothelial function, increased c-IMT, and increased arterial stiffness. Further, HIV-Tg arteries show decreased elastin content, increased cathepsin K and cathepsin S activity, and increased mechanical residual stress. Thus, mice that express HIV proteins exhibit pre-clinical markers of atherosclerosis and these markers correlate with changes in markers of vascular remodeling. These fin...
Source: Annals of Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Hansen L, Parker I, Sutliff RL, Platt MO, Gleason RL Tags: Ann Biomed Eng Source Type: research
Transtibial Amputee Joint Motion has Increased Attractor Divergence During Walking Compared to Non-Amputee Gait.
Abstract The amputation and subsequent prosthetic rehabilitation of a lower leg affects gait. Dynamical systems theory would predict the use of a prosthetic device should alter the functional attractor dynamics to which the system self-organizes. Therefore, the purpose of this study was to compare the largest Lyapunov exponent (a nonlinear tool for assessing attractor dynamics) for amputee gait compared to healthy non-amputee individuals. Fourteen unilateral, transtibial amputees and fourteen healthy, non-amputee individuals ambulated on a treadmill at preferred, self-selected walking speed. Our results showed that...
Source: Annals of Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Wurdeman SR, Myers SA, Stergiou N Tags: Ann Biomed Eng Source Type: research
The effect of implant design of linked total elbow arthroplasty on stability and stress: a finite element analysis.
Abstract Several linked total elbow arthroplasty designs exist, which function similar to a loose hinge joint. Constraint behaviour is an important design consideration, as it affects joint stability, or how much secondary [e.g. varus-valgus (VV)] motion is permitted. Implant durability is also a concern, as bearing failures have been reported. This finite element analysis investigates the constraint characteristics and ultra high molecular weight polyethylene bearing stresses of three linked elbow design concepts [cylindrical (CY), hourglass (HG) and concave cylinder (CC)]. The bearing of the CY design was subject...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Willing R, King GJ, Johnson JA Tags: Comput Methods Biomech Biomed Engin Source Type: research
Finite element modelling of human auditory periphery including a feed-forward amplification of the cochlea.
Abstract A three-dimensional finite element model is developed for the simulation of the sound transmission through the human auditory periphery consisting of the external ear canal, middle ear and cochlea. The cochlea is modelled as a straight duct divided into two fluid-filled scalae by the basilar membrane (BM) having an orthotropic material property with dimensional variation along its length. In particular, an active feed-forward mechanism is added into the passive cochlear model to represent the activity of the outer hair cells (OHCs). An iterative procedure is proposed for calculating the nonlinear response ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 22, 2012 Category: Biomedical Engineering Authors: Wang X, Wang L, Zhou J, Hu Y Tags: Comput Methods Biomech Biomed Engin Source Type: research
Assessment of inter-examiner agreement and variability in the manual classification of auditory brainstem response
Conclusions: Our results quantify the inter-examiner agreement and variability of the manual analysis of ABR data, and they also allows for the determination of different patterns of manual ABR analysis.
Source: BioMedical Engineering OnLine - November 22, 2012 Category: Biomedical Engineering Authors: Kheline NavesAdriano PereiraSlawomir NasutoIeda RussoAdriano Andrade Source Type: research
The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion
Conclusions: The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration.
Source: BioMedical Engineering OnLine - November 22, 2012 Category: Biomedical Engineering Authors: Chung-Ying TsaiChien-Ju LinYueh-Chu HuangPo-Chou LinFong-Chin Su Source Type: research
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Source: Elsevier Updates: Engineering - November 21, 2012 Category: Biomedical Engineering Source Type: news
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Source: Elsevier Updates: Engineering - November 21, 2012 Category: Biomedical Engineering Source Type: news
A Finite Element Model of the Lower Limb for Simulating Automotive Impacts.
Abstract A finite element (FE) model of a vehicle occupant's lower limb was developed in this study to improve understanding of injury mechanisms during traffic crashes. The reconstructed geometry of a male volunteer close to the anthropometry of a 50th percentile male was meshed using mostly hexahedral and quadrilateral elements to enhance the computational efficiency of the model. The material and structural properties were selected based on a synthesis of current knowledge of the constitutive models for each tissue. The models of the femur, tibia, and leg were validated against Post-Mortem Human Surrogate (PMHS)...
Source: Annals of Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Untaroiu CD, Yue N, Shin J Tags: Ann Biomed Eng Source Type: research
Characterizing the Collagen Fiber Orientation in Pericardial Leaflets Under Mechanical Loading Conditions.
Abstract When implanted inside the body, bioprosthetic heart valve leaflets experience a variety of cyclic mechanical stresses such as shear stress due to blood flow when the valve is open, flexural stress due to cyclic opening and closure of the valve, and tensile stress when the valve is closed. These types of stress lead to a variety of failure modes. In either a natural valve leaflet or a processed pericardial tissue leaflet, collagen fibers reinforce the tissue and provide structural integrity such that the very thin leaflet can stand enormous loads related to cyclic pressure changes. The mechanical response o...
Source: Annals of Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Alavi SH, Ruiz V, Krasieva T, Botvinick EL, Kheradvar A Tags: Ann Biomed Eng Source Type: research
Error Mechanisms of the Oscillometric Fixed-Ratio Blood Pressure Measurement Method.
This study may have important implications when using the fixed-ratio method, particularly in subjects with arterial disease. PMID: 23180030 [PubMed - as supplied by publisher]
Source: Annals of Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Liu J, Hahn JO, Mukkamala R Tags: Ann Biomed Eng Source Type: research
Analytical study of a microfludic DNA amplification chip using water cooling effect.
Abstract A novel continuous-flow polymerase chain reaction (PCR) chip has been analyzed in our work. Two temperature zones are controlled by two external controllers and the other temperature zone at the chip center is controlled by the flow rate of the fluid inside a channel under the glass chip. By employing a water cooling channel at the chip center, the sequence of denaturation, annealing, and extension can be created due to the forced convection effect. The required annealing temperature of PCR less than 313 K can also be demonstrated in this chip. The Poly(methyl methacrylate) (PMMA) cooling channel with the...
Source: Biomedical Microdevices - November 21, 2012 Category: Biomedical Engineering Authors: Chen JJ, Shen CM, Ko YW Tags: Biomed Microdevices Source Type: research
IB-LBM simulation of the haemocyte dynamics in a stenotic capillary.
Abstract To study the behaviour of a haemocyte when crossing a stenotic capillary, the immersed boundary-lattice Boltzmann method was used to establish a quantitative analysis model. The haemocyte was assumed to be spherical and to have an elastic cell membrane, which can be driven by blood flow to adopt a highly deformable character. In the stenotic capillary, the spherical blood cell was stressed both by the flow and the wall dimension, and the cell shape was forced to be stretched to cross the stenosis. Our simulation investigated the haemocyte crossing process in detail. The velocity and pressure were anatomise...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Yuan-Qing X, Xiao-Ying T, Fang-Bao T, Yu-Hua P, Yong X, Yan-Jun Z Tags: Comput Methods Biomech Biomed Engin Source Type: research
Computational framework to model and design surgical meshes for hernia repair.
Abstract Surgical procedures for hernia surgery are usually performed using prosthetic meshes. In spite of all the improvements in these biomaterials, the perfect match between the prosthesis and the implant site has not been achieved. Thus, new designs of surgical meshes are still being developed. Previous to implantation in humans, the validity of the meshes has to be addressed, and to date experimental studies have been the gold standard in testing and validating new implants. Nevertheless, these procedures involve long periods of time and are expensive. Thus, a computational framework for the simulation of pros...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Hernández-Gascón B, Espés N, Peña E, Pascual G, Bellón JM, Calvo B Tags: Comput Methods Biomech Biomed Engin Source Type: research
Modelling of global boundary effects on harmonic motion imaging of soft tissues.
In this study, a finite element (FE) model is developed to investigate the effect of global boundary conditions on the dynamic response of a soft tissue during HMI. The direct-solution steady-state dynamic analysis procedure is used to compute the harmonic displacement amplitude in FE simulations. The model is parameterised in terms of boundary conditions and viscoelastic properties, and the corresponding raster-scan displacement amplitudes are captured to examine its response. The effect of the model's global dimensions on the harmonic response is also investigated. It is observed that the dynamic response of soft tissue ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Zhao X, Pelegri AA Tags: Comput Methods Biomech Biomed Engin Source Type: research
Nonlinear numerical analysis of the structural response of the intervertebral disc to impact loading.
In this study, the contribution of the characteristic structure of the disc to its dynamic response has been evaluated. The influence of several model features on the dynamic response was investigated. A hyperelastic large deformation formulation was used to describe the nonlinear behaviour of the soft tissues. The material parameters were determined by the fitting of experimental data from the literature. The model demonstrated pressure wave propagation and reflection through the disc, with a periodic oscillation of the system in response to a single impulse load, and highlighted a potential primary role played by the col...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Marini G, Ferguson SJ Tags: Comput Methods Biomech Biomed Engin Source Type: research
Force and torque modelling of drilling simulation for orthopaedic surgery.
Abstract The advent of haptic simulation systems for orthopaedic surgery procedures has provided surgeons with an excellent tool for training and preoperative planning purposes. This is especially true for procedures involving the drilling of bone, which require a great amount of adroitness and experience due to difficulties arising from vibration and drill bit breakage. One of the potential difficulties with the drilling of bone is the lack of consistent material evacuation from the drill's flutes as the material tends to clog. This clogging leads to significant increases in force and torque experienced by the sur...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 21, 2012 Category: Biomedical Engineering Authors: Macavelia T, Ghasempoor A, Janabi-Sharifi F Tags: Comput Methods Biomech Biomed Engin Source Type: research
Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.
Abstract The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the elect...
Source: Bioprocess and Biosystems Engineering - November 20, 2012 Category: Biomedical Engineering Authors: Hakoda M, Hirota Y Tags: Bioprocess Biosyst Eng Source Type: research
Preparing spherical lignin from rice husk.
In this study, the regular sphere of lignin can be simply prepared from rice husk (RH) under certain conditions. Namely, RH is mixed with 35 % ethanol aqueous solution in the proportion of 1:10 (g:mL), non-isothermally heated to 493 K and kept for 5 h. After filtration and air-drying at room temperature, the regular lignin sphere with the diameter of 100-400 nm is obtained. The regular sphere of lignin has the potential utilization in fields such as reactive functional materials, photo sensing materials and surface active materials in cosmetics. The mechanism of formation of the regular spherical lignin is proposed and...
Source: Bioprocess and Biosystems Engineering - November 20, 2012 Category: Biomedical Engineering Authors: Zhang H, Zhao X, Ding X, Lei H, Wang Z Tags: Bioprocess Biosyst Eng Source Type: research
Using fluorochemical as oxygen carrier to enhance the growth of marine microalga Nannochloropsis oculata.
In this study, we proposed to use fluorochemical as oxygen carrier to overcome the challenge where four liquid fluorochemicals namely perfluorooctyl bromide, perfluorodecalin, methoxynonafluorobutane, and ethoxynonafluorobutane were investigated separately. Our results showed that the microalgal proliferation with different fluorinated liquids was similar and comparable to the culture without a fluorochemical. When cultured in the photobioreactor with 60 % oxygen atmosphere, the N. oculata can grow up in all the fluorochemical photobioreactors, but completely inhibited in the chamber without a fluorochemical. Moreover, th...
Source: Bioprocess and Biosystems Engineering - November 20, 2012 Category: Biomedical Engineering Authors: Lee YH, Yeh YL, Lin KH, Hsu YC Tags: Bioprocess Biosyst Eng Source Type: research
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Source: Elsevier Updates: Engineering - November 19, 2012 Category: Biomedical Engineering Source Type: news
Probabilistic neural network approach for the detection of SAHS from overnight pulse oximetry
In this study, a novel multivariate system is proposed for SAHS detection from the analysis of overnight blood oxygen saturation (SpO2). 115 subjects with SAHS suspicion were studied. A starting set of 17 time domain, stochastic, frequency-domain and nonlinear features were initially computed from SpO2 recordings. Sequential forward feature selection and a probabilistic neural network with leave-one-out cross-validation were applied. Oxygen desaturations below a 4 % threshold within 30 s (ODI430), restorations of 4 % within 10 s (RES4), median value (Sat50), SD1 Poincaré descriptor and the relative ...
Source: Medical and Biological Engineering and Computing - November 19, 2012 Category: Biomedical Engineering Tags: Medical and Biological Engineering and Computing Source Type: research
Optic disc detection in color fundus images using ant colony optimization
Abstract Diabetic retinopathy has been revealed as the most common cause of blindness among people of working age in developed countries. However, loss of vision could be prevented by an early detection of the disease and, therefore, by a regular screening program to detect retinopathy. Due to its characteristics, the digital color fundus photographs have been the easiest way to analyze the eye fundus. An important prerequisite for automation is the segmentation of the main anatomical features in the image, particularly the optic disc. Currently, there are many works reported in the literature with the purpo...
Source: Medical and Biological Engineering and Computing - November 19, 2012 Category: Biomedical Engineering Tags: Medical and Biological Engineering and Computing Source Type: research
Ovarian Tumor Characterization and Classification Using Ultrasound—A New Online Paradigm
The objective of this work is to develop an adjunct computer-aided diagnostic technique that uses 3D ultrasound images of the ovary to accurately characterize and classify benign and malignant ovarian tumors. In this algorithm, we first extract features based on the textural changes and higher-order spectra information. The significant features are then selected and used to train and evaluate the decision tree (DT) classifier. The proposed technique was validated using 1,000 benign and 1,000 malignant images, obtained from ten patients with benign and ten with malignant disease, respectively. On evaluating the classif...
Source: Journal of Digital Imaging - November 19, 2012 Category: Radiology Tags: Journal of Digital Imaging Source Type: research
Clustering gene expression data using a diffraction-inspired framework
Conclusion: The results of the diffraction-based clustering algorithm presented in this paper suggest that the method can provide researchers with a new tool for successfully analysing microarray data.
Source: BioMedical Engineering OnLine - November 19, 2012 Category: Biomedical Engineering Authors: Steven DingerMichael Van WykSergio CarmonaDavid Rubin Source Type: research
Accelerometry Reveals Differences in Gait Variability Between Patients with Multiple Sclerosis and Healthy Controls.
Abstract Variability of movement reflects important information for the maintenance of the health of the system. For pathological populations, changes in variability during gait signal the presence of abnormal motor control strategies. For persons with multiple sclerosis (PwMS), extensive gait problems have been reported including changes in gait variability. While previous studies have focused on footfall variability, the present study used accelerometers on the trunk to measure variability during walking. Thus, the purpose of this study was to examine the variability of the acceleration pattern of the upper and l...
Source: Annals of Biomedical Engineering - November 18, 2012 Category: Biomedical Engineering Authors: Huisinga JM, Mancini M, St George RJ, Horak FB Tags: Ann Biomed Eng Source Type: research
Guest editorial introduction to the Special Issue on bio-hybrid systems and living machines.
PMID: 23160841 [PubMed - as supplied by publisher]
Source: Biomedical Microdevices - November 18, 2012 Category: Biomedical Engineering Authors: Ricotti L, Menciassi A, Morishima K Tags: Biomed Microdevices Source Type: research
hERG drug response measured in droplet bilayers.
Abstract We show measurements of the human cardiac potassium ion channel K(v)11.1 (hERG) in droplet bilayers incorporated directly from commercial membrane preparations of HEK293 cells. Although we do not obtain ensemble conductance kinetics and rectification observed in patch clamp measurements of hERG, ensemble currents measured in our system showed inhibition dependent on astemizole and E-4031 concentration, with IC(50) values similar to those found with patch clamp. The availability of engineered HEK cells expressing a variety of ion channels, combined with the simplicity of the inhibition measurement, suggest ...
Source: Biomedical Microdevices - November 18, 2012 Category: Biomedical Engineering Authors: Portonovo SA, Salazar CS, Schmidt JJ Tags: Biomed Microdevices Source Type: research
Quantification of Biomechanical Interaction of Transcatheter Aortic Valve Stent Deployed in Porcine and Ovine Hearts.
Abstract Success of the deployment and function in transcatheter aortic valve replacement is heavily reliant on the tissue-stent interaction. The present study quantified important tissue-stent contact variables of self-expanding transcatheter aortic valve stents when deployed into ovine and porcine aortic roots, such as the stent radial expansion force, stent pullout force, the annulus deformation response and the coefficient of friction on the tissue-stent contact interface. Braided Nitinol stents were developed, tested to determine stent crimped diameter vs. stent radial force from a stent crimp experiment, and ...
Source: Annals of Biomedical Engineering - November 17, 2012 Category: Biomedical Engineering Authors: Mummert J, Sirois E, Sun W Tags: Ann Biomed Eng Source Type: research
Linking the Development of Ventilator-Induced Injury to Mechanical Function in the Lung.
Abstract Management of ALI/ARDS involves supportive ventilation at low tidal volumes (V (t)) to minimize the rate at which ventilator induced lung injury (VILI) develops while the lungs heal. However, we currently have few details to guide the minimization of VILI in the ALI/ARDS patient. The goal of the present study was to determine how VILI progresses with time as a function of the manner in which the lung is ventilated in mice. We found that the progression of VILI caused by over-ventilating the lung at a positive end-expiratory pressure of zero is accompanied by progressive increases in lung stiffness a...
Source: Annals of Biomedical Engineering - November 16, 2012 Category: Biomedical Engineering Authors: Smith BJ, Grant KA, Bates JH Tags: Ann Biomed Eng Source Type: research
Intermittent, moderate-intensity aerobic exercise for only eight weeks reduces arterial stiffness: evaluation by measurement of stiffness parameter and pressure–strain elastic modulus by use of ultrasonic echo tracking
Conclusions For healthy young subjects, β and E p were reduced by intermittent, moderate-intensity exercise training for only 8 weeks. Content Type Journal ArticleCategory Original ArticlePages 1-6DOI 10.1007/s10396-012-0408-1Authors Midori Tanaka, Faculty of Health Care Sciences, Himeji Dokkyo University, 7-2-1 Kamiohno, Himeji, Hyogo 670-8524, JapanMotoaki Sugawara, Faculty of Health Care Sciences, Himeji Dokkyo University, 7-2-1 Kamiohno, Himeji, Hyogo 670-8524, JapanYasuo Ogasawara, Department of Medical Engineering, Kawasaki University of Medical Welfare, Kurashiki, JapanTadafumi Izumi, Faculty...
Source: Journal of Medical Ultrasonics - November 14, 2012 Category: Radiology Tags: Journal of Medical Ultrasonics Source Type: research
Simulation of bone remodelling in orthodontic treatment.
This study was aimed at investigating the effect of orthodontic loading on both tooth movement and neighbouring bone density distribution. A set of computational algorithms incorporating both external and internal remodelling mechanisms was implemented into a patient-specific 3D finite element (FE) model to investigate and analyse orthodontic treatment under four typical modes of orthodontic loading. The consequence of orthodontic treatment was reproduced numerically by using this FE-based technique. The results indicated that the diverse modes of orthodontic loading would result in different magnitudes of tooth movement a...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 14, 2012 Category: Biomedical Engineering Authors: Wang C, Han J, Li Q, Wang L, Fan Y Tags: Comput Methods Biomech Biomed Engin Source Type: research
Mechanical performance of endodontic restorations with prefabricated posts: sensitivity analysis of parameters with a 3D finite element model.
In this study, a validated 3D biomechanical model of the restored tooth was used for an exhaustive sensitivity analysis. The individual influence of 20 different parameters on the mechanical performance of an endodontic restoration with prefabricated posts was studied. The results bring up the remarkable importance of the loading angle on the final restoration strength. Flexural loads are more critical than compressive or tensile loads. Young's modulus of the post and its length and diameter are the most influential parameters for strength, whereas other parameters such as ferrule geometry or core and crown characteristics...
Source: Computer Methods in Biomechanics and Biomedical Engineering - November 14, 2012 Category: Biomedical Engineering Authors: González-Lluch C, Pérez-González A, Sancho-Bru JL, Rodríguez-Cervantes PJ Tags: Comput Methods Biomech Biomed Engin Source Type: research
Print-to-print: a facile multi-object micro-patterning technique.
Abstract In recent years, micropatterning techniques have gained increasing popularity from a broad range of engineering and biology communities for the promise to establish highly quantitative investigations on miniature biological objects (e.g., cells and bacteria) with spatially defined microenvironments. However, majority of the existing techniques rely on cleanroom-based microfabrication and cannot be easily extended to a regular biological laboratory. In this paper, we present a simple versatile printing-based method, referred to as Print-to-Print (P2P), to form multi-object micropatterns for potential biolog...
Source: Biomedical Microdevices - November 14, 2012 Category: Biomedical Engineering Authors: Xing S, Zhao S, Pan T Tags: Biomed Microdevices Source Type: research
A micro blood sampling system for catheterized neonates and pediatrics in intensive care unit.
Abstract A new micro blood sampling system has been designed, fabricated, and characterized to reduce iatrogenic blood loss from the catheterized neonates and pediatrics in intensive care unit by providing micro-volume of blood to analytical biomedical microdevices which can do point-of-care testing for their critical care. The system can not only save enormous iatrogenic blood loss through 1 to 10 μL of blood sampling and re-infusion of 1 to 5 mL of discard blood but also reduce the infection risk through the closed structure while satisfying the key criteria of the blood sampler. The sampled blood preserved it...
Source: Biomedical Microdevices - November 14, 2012 Category: Biomedical Engineering Authors: Jung W, Ahn CH Tags: Biomed Microdevices Source Type: research
A mechanical model for predicting the probability of osteoporotic hip fractures based in DXA measurements and finite element simulation
Conclusion: The FE model allowed to obtain detailed maps of damage and fracture probability, identifying high-risk local zones at femoral neck and intertrochanteric and subtrochanteric areas, which are the typical locations of osteoporotic hip fractures.The developed model is suitable for being used in individualized cases. The model might better identify at-risk individuals in early stages of osteoporosis and might be helpful for treatment decisions.
Source: BioMedical Engineering OnLine - November 14, 2012 Category: Biomedical Engineering Authors: Enrique LópezElena IbarzAntonio HerreraJesús MateoAntonio Lobo-EscolarSergio PuértolasLuis Gracia Source Type: research
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Source: Elsevier Updates: Engineering - November 13, 2012 Category: Biomedical Engineering Source Type: news
Adaptive Segmentation of Vertebral Bodies from Sagittal MR Images Based on Local Spatial Information and Gaussian Weighted Chi-Square Distance
We present a novel method for the automatic segmentation of the vertebral bodies from 2D sagittal magnetic resonance (MR) images of the spine. First, a new affinity matrix is constructed by incorporating neighboring information, which local intensity is considered to depict the image and overcome the noise effectively. Second, the Gaussian kernel function is to weight chi-square distance based on the neighboring information, which the vital spatial structure of the image is introduced to improve the accuracy of the segmentation task. Third, an adaptive local scaling parameter is utilized to facilitate the image segment...
Source: Journal of Digital Imaging - November 13, 2012 Category: Radiology Tags: Journal of Digital Imaging Source Type: research
Interview: Leading the way in biomedical engineering: an interview with Robert Langer
Nanomedicine , October 2012, Vol. 7, No. 10, Pages 1483-1484.
Source: Future Medicine: Nanomedicine - November 13, 2012 Category: Nanotechnology Tags: article Source Type: research
Comparison of Non-Invasive Methods for Measurement of Local Pulse Wave Velocity Using FSI-Simulations and In Vivo Data.
Abstract In the search for better predictors of cardiovascular events, pulse wave velocity (PWV) has gained considerable interest. We compared three single-location methods to locally estimate PWV based on simultaneous measurements of pressure (P), velocity (U) or arterial diameter (D): the PU, ln(D)U and QA-method. First, the performance of these methods was analyzed using 3D fluid-structure interaction simulations (FSI) in a tube and patient-specific carotid artery. We demonstrated that the outcome was dependent on whether the methods were tested in the ideal conditions of a 3D axisymmetrical and reflection-free ...
Source: Annals of Biomedical Engineering - November 13, 2012 Category: Biomedical Engineering Authors: Swillens A, Taelman L, Degroote J, Vierendeels J, Segers P Tags: Ann Biomed Eng Source Type: research
Temporal Healing in Rat Achilles Tendon: Ultrasound Correlations.
Abstract The purpose of this study was to explore whether a new ultrasound-based technique correlates with mechanical and biological metrics that describe the tendon healing. Achilles tendons in 32 rats were unilaterally transected and allowed to heal without repair. At 7, 9, 14, or 29 days post-injury, tendons were collected and examined for healing via ultrasound image analysis, mechanical testing, and immunohistochemistry. Consistent with previous studies, we observe that the healing tendons are mechanically inferior (ultimate stress, ultimate load, and normalized stiffness) and biologically altered (cellular a...
Source: Annals of Biomedical Engineering - November 13, 2012 Category: Biomedical Engineering Authors: Chamberlain CS, Duenwald-Kuehl SE, Okotie G, Brounts SH, Baer GS, Vanderby R Tags: Ann Biomed Eng Source Type: research
Respiratory Flow-Sound Relationship During Both Wakefulness and Sleep and Its Variation in Relation to Sleep Apnea.
In this study, we recorded tracheal sound, respiratory flow, and head position from eight non-OSA and 10 OSA individuals during sleep and wakefulness. We compared the flow-sound relationship and variations in model parameters from wakefulness to sleep within and between the two groups. The results show that during both wakefulness and sleep, flow-sound relationship follows a power law but with different parameters. Furthermore, the variations in model parameters may be representative of the OSA pathology. The other objective of this study was to examine the accuracy of respiratory flow estimation algorithms during sleep: w...
Source: Annals of Biomedical Engineering - November 13, 2012 Category: Biomedical Engineering Authors: Yadollahi A, Montazeri A, Azarbarzin A, Moussavi Z Tags: Ann Biomed Eng Source Type: research