Journal of Biomechanical Engineering This 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.

On Stability of Specific Adhesion of Particles to Membranes in Simple Shear Flow
Adhesion of carrier particles to the luminal surface of endothelium under hemodynamic flow conditions is critical for successful vascular drug delivery. Endothelial cells (ECs) line the inner surface of blood vessels. The effect of mechanical behavior of this compliant surface on the adhesion of blood-borne particles is unknown. In this contribution, we use a phase-plane method, first developed by Hammer and Lauffenburger (1987, “A Dynamical Model for Receptor-Mediated Cell Adhesion to Surfaces,” Biophys. J.,52(3), p. 475), to analyze the stability of specific adhesion of a spherical particle to a compliant interface l...
Source: Journal of Biomechanical Engineering - October 17, 2018 Category: Biomedical Engineering Source Type: research

A Computational Model for the Dynamics of Cerebrospinal Fluid in the Spinal Subarachnoid Space
Global models for the dynamics of coupled fluid compartments of the central nervous system (CNS) require simplified representations of the individual components which are both accurate and computationally efficient. This paper presents a one-dimensional model for computing the flow of cerebrospinal fluid (CSF) within the spinal subarachnoid space (SSAS) under the simplifying assumption that it consists of two coaxial tubes representing the spinal cord and the dura. A rigorous analysis of the first-order nonlinear system demonstrates that the system is elliptic-hyperbolic, and hence ill-posed, for some values of parameters,...
Source: Journal of Biomechanical Engineering - October 17, 2018 Category: Biomedical Engineering Source Type: research

Bulk Flow and Near Wall Hemodynamics of the Rabbit Aortic Arch and Descending Thoracic Aorta: A 4D PC-MRI Derived Computational Fluid Dynamics Study
Animal models offer a flexible experimental environment for studying atherosclerosis. The mouse is the most commonly used animal, however, the underlying hemodynamics in larger animals such as the rabbit are far closer to that of humans. The aortic arch is a vessel with complex helical flow and highly heterogeneous shear stress patterns which may influence where atherosclerotic lesions form. A better understanding of intraspecies flow variation and the impact of geometry on flow may improve our understanding of where disease forms. In this work, we use magnetic resonance angiography (MRA) and 4D phase contrast magnetic res...
Source: Journal of Biomechanical Engineering - October 17, 2018 Category: Biomedical Engineering Source Type: research

Supraspinatus Tendons Have Different Mechanical Properties Across Sex
The objective of this study was to determine how sex and hormone differences in rats affect supraspinatus tendon and muscle properties. We hypothesized that male supraspinatus tendons would have increased cross-sectional area but no differences in tendon material properties or muscle composition when compared to supraspinatus tendons from female or ovariectomized (OVX) female rats. Uninjured supraspinatus tendons and muscles from male, female, and OVX female rats were collected and mechanical and histological properties were determined. Our analysis demonstrated decreased dynamic modulus and increased hysteresis and cross-...
Source: Journal of Biomechanical Engineering - October 17, 2018 Category: Biomedical Engineering Source Type: research

Forecasting Postflight Hip Fracture Probability Using Probabilistic Modeling
A probabilistic model predicts hip fracture probability for postflight male astronauts during lateral fall scenarios from various heights. A biomechanical representation of the hip provides impact load. Correlations relate spaceflight bone mineral density (BMD) loss and postflight BMD recovery to bone strength (BS). Translations convert fracture risk index (FRI), the ratio of applied load (AL) to BS, to fracture probability. Parameter distributions capture uncertainty and Monte Carlo simulations provide probability outcomes. The fracture probability for a 1 m fall 0 days postflight is 15% greater than preflight and remains...
Source: Journal of Biomechanical Engineering - October 17, 2018 Category: Biomedical Engineering Source Type: research

On Rate Boundary Conditions for Soft Tissue Bifurcation Analysis
Mechanical instability of soft tissues can either risk their normal function or alternatively trigger patterning mechanisms during growth and morphogenesis processes. Unlike standard stability analysis of linear elastic bodies, for soft tissues undergoing large deformations it is imperative to account for the nonlinearities induced by the coupling between load and surface changes at onset of instability. The related issue of boundary conditions, in context of soft tissues, has hardly been addressed in the literature, with most of available research employing dead-load conditions. This paper is concerned with the influence ...
Source: Journal of Biomechanical Engineering - October 1, 2018 Category: Biomedical Engineering Source Type: research

Erratum: “The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies” (ASME J. Biomech. Eng., 2017, 139 (5), p. 051002; DOI: 10.1115/1.4036146 ) to Paper Number BIO-16-1363
(Source: Journal of Biomechanical Engineering)
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Prediction of Anterior Cruciate Ligament Force Produced by Tibiofemoral Compression During Controlled Knee Flexion: A New Robotic Testing Methodology
Application of tibiofemoral compression force (TCF) has been shown to produce anterior cruciate ligament (ACL) injuries in a laboratory setting. A new robotic testing methodology was utilized to predict ACL forces generated by TCF without directly loading the ligament. We hypothesized that ACL force, directly recorded by a miniature load cell during an unconstrained test, could be predicted by measurements of anterior tibial restraining force (ARF) recorded during a constrained test. The knee was first flexed under load control with 25 N TCF (tibial displacements and rotations unconstrained) to record a baseline kinematic ...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Tibial Contact Force and Contact Location Errors of the VERASENSE
The OrthoSensor VERASENSE knee system is a commercially available instrumented tibial insert that provides real-time intraoperative measurements of tibial contact force and contact location to guide surgeons toward improving outcomes in total knee arthroplasty (TKA). However, the device has been used contrary to the manufacturer's instructions in several studies and lacks published information on accuracy. Therefore, the primary objectives of this study were to evaluate the device's error in tibial contact force when used according to and contrary to the manufacturer's instructions, and also to evaluate the device's error ...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Day-to-Day Reliability of Nonlinear Methods to Assess Walking Dynamics
The present study investigated the day-to-day reliability (quantified by the absolute and relative reliability) of nonlinear methods used to assess human locomotion dynamics. Twenty-four participants of whom twelve were diagnosed with knee osteoarthritis completed 5  min of treadmill walking at self-selected preferred speed on two separate days. Lower limb kinematics were recorded at 100 Hz and hip, knee, and ankle joint angles, three-dimensional (3D) sacrum marker displacement and stride time intervals were extracted for 170 consecutive strides. The larges t Lyapunov exponent and correlation dimension were calculated ...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Finite Element Formulation of Multiphasic Shell Elements for Cell Mechanics Analyses in FEBio
This study presents a novel formulation of multiphasic shell elements and its implementation in FEBio. The shell model includes front- and back-face nodal degrees-of-freedom for the solid displacement, effective fluid pressure and effective solute concentrations, and a linear interpolation of these variables across the shell thickness. This formulation was verified against classical models of cell physiology and validated against reported experimental measurements in chondrocytes. This implementation of passive transport of fluid and solutes across multiphasic membranes makes it possible to model the biomechanics of isolat...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Effect of Longitudinal Variation of Vocal Fold Inner Layer Thickness on Fluid-Structure Interaction During Voice Production
A three-dimensional fluid-structure interaction computational model was used to investigate the effect of the longitudinal variation of vocal fold inner layer thickness on voice production. The computational model coupled a finite element method based continuum vocal fold model and a Navier –Stokes equation based incompressible flow model. Four vocal fold models, one with constant layer thickness and the others with different degrees of layer thickness variation in the longitudinal direction, were studied. It was found that the varied thickness resulted in up to 24% stiffness reducti on at the middle and up to 47% stiffn...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

Distribution of Brain Strain in the Cerebrum for Laboratory Impacts to Ice Hockey Goaltender Masks
Concussions are among the most common injuries sustained by goaltenders. Concussive injuries are characterized by impairment to neurological function which can affect many different brain regions. Understanding how different impact loading conditions (event type and impact site) affect the brain tissue response may help identify what kind of impacts create a high risk of injury to specific brain regions. The purpose of this study was to examine the influence of different impact conditions on the distribution of brain strain for ice hockey goaltender impacts. An instrumented headform was fitted with an ice hockey goaltender...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research

A Fluid –Structure Interaction Model of the Left Coronary Artery
A fluid –structure interaction (FSI) model of a left anterior descending (LAD) coronary artery was developed, incorporating transient blood flow, cyclic bending motion of the artery, and myocardial contraction. The three-dimensional (3D) geometry was constructed based on a patient's computed tomography an giography (CTA) data. To simulate disease conditions, a plaque was placed within the LAD to create a 70% stenosis. The bending motion of the blood vessel was prescribed based on the LAD spatial information. The pressure induced by myocardial contraction was applied to the outside of the blood vessel wall. The fluid doma...
Source: Journal of Biomechanical Engineering - September 25, 2018 Category: Biomedical Engineering Source Type: research