Journal of Biomechanical Engineering 
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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.Evaluation and Prediction of Human Lumbar Vertebrae Endplate Mechanical Properties Using Indentation and Computed Tomography
Current implant materials and designs used in spinal fusion show high rates of subsidence. There is currently a need for a method to predict the mechanical properties of the endplate using clinically available tools. The purpose of this study was to develop a predictive model of the mechanical properties of the vertebral endplate at a scale relevant to the evaluation of current medical implant designs and materials. Twenty vertebrae (10 L1 and 10 L2) from 10 cadavers were studied using dual-energy X-ray absorptiometry to define bone status (normal, osteopenic, or osteoporotic) and computed tomography (CT) to study endplate...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
A Thermal and Biological Analysis of Bone Drilling
With the introduction of high-speed cutting tools, clinicians have recognized the potential for thermal damage to the material being cut. Here, we developed a mathematical model of heat transfer caused by drilling bones of different densities and validated it with respect to experimentally measured temperatures in bone. We then coupled these computational results with a biological assessment of cell death following osteotomy site preparation. Parameters under clinical control, e.g., drill diameter, rotational speed, and irrigation, along with patient-specific variables such as bone density were evaluated in order to unders...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Poly(Propylene Fumarate) –Hydroxyapatite Nanocomposite Can Be a Suitable Candidate for Cervical Cages
A wide range of materials have been used for the development of intervertebral cages. Poly(propylene fumarate) (PPF) has been shown to be an excellent biomaterial with characteristics similar to trabecular bone. Hydroxyapatite (HA) has been shown to enhance biocompatibility and mechanical properties of PPF. The purpose of this study was to characterize the effect of PPF augmented with HA (PPF:HA) and evaluate the feasibility of this material for the development of cervical cages. PPF was synthesized and combined with HA at PPF:HA wt:wt ratios of 100:0, 80:20, 70:30, and 60:40. Molds were fabricated for testing PPF:HA bulk ...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
A New Growth Model for Aortic Valve Calcification
Calcific aortic valve disease (CAVD) is a progressive disease in which minerals accumulate in the tissue of the aortic valve cusps, stiffening them and preventing valve opening and closing. The process of valve calcification was found to be similar to that of bone formation including cell differentiation to osteoblast-like cells. Studies have shown the contribution of high strains to calcification initiation and growth process acceleration. In this paper, a new strain-based calcification growth model is proposed. The model aims to explain the unique shape of the calcification and other disease characteristics. The calcific...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Numerical Parametric Study of Paravalvular Leak Following a Transcatheter Aortic Valve Deployment Into a Patient-Specific Aortic Root
This study demonstra ted that a rigorously developed patient-specific computational model can provide useful insights into underlying mechanisms causing PVL and potentially assist in pre-operative planning for TAVR to minimize PVL. (Source: Journal of Biomechanical Engineering)
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Analysis of Spatial and Temporal Step Parameters During Crutch-Assisted Gait as a Dual-Task: A Pilot Study
The main objective was to analyze the changes in the spatial and temporal step parameters during a dual-task: walking with a forearm crutch to partially unload the body weight of the subject. The secondary objective was to determine the influence of the use of the crutch with the dominant or nondominant hand in the essential gait parameters. Seven healthy subjects performed gait without crutches (GWC) and unilateral assisted gait (UAG) with the crutch carried out by dominant hand (dominant crutch (DC)) and nondominant hand (nondominant crutch (NDC)). Gait was recorded using a Vicon System; the GCH System 2.0 and the GCH Co...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Statistical Characterization of Human Brain Deformation During Mild Angular Acceleration Measured In Vivo by Tagged Magnetic Resonance Imaging
Understanding of in vivo brain biomechanical behavior is critical in the study of traumatic brain injury (TBI) mechanisms and prevention. Using tagged magnetic resonance imaging, we measured spatiotemporal brain deformations in 34 healthy human volunteers under mild angular accelerations of the head. Two-dimensional (2D) Lagrangian strains were examined throughout the brain in each subject. Strain metrics peaked shortly after contact with a padded stop, corresponding to the inertial response of the brain after head deceleration. Maximum shear strain of at least 3% was experienced at peak deformation by an area fraction (me...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Laboratory Validation of a Wearable Sensor for the Measurement of Head Acceleration in Men's and Women's Lacrosse
Mild traumatic brain injuries, or concussions, can result from head acceleration during sports. Wearable sensors like the GForceTrackerTM (GFT) can monitor an athlete's head acceleration during play. The purpose of this study was to evaluate the accuracy of the GFT for use in boys' and girls' lacrosse. The GFT was mounted to either a strap connected to lacrosse goggles (helmetless) or a helmet. The assembly was fit to a Hybrid III (HIII) headform instrumented with sensors and impacted multiple times at different velocities and locations. Measurements of peak linear acceleration and angular velocity were obtained from both ...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Optimal Estimation of Anthropometric Parameters for Quantifying Multisegment Trunk Kinetics
Kinetics assessment of the human head-arms-trunk (HAT) complex via a multisegment model is a useful tool for objective clinical evaluation of several pathological conditions. Inaccuracies in body segment parameters (BSPs) are a major source of uncertainty in the estimation of the joint moments associated with the multisegment HAT. Given the large intersubject variability, there is currently no comprehensive database for the estimation of BSPs for the HAT. We propose a nonlinear, multistep, optimization-based, noninvasive method for estimating individual-specific BSPs and calculating joint moments in a multisegment HAT mode...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
The Multi-Axial Failure Response of Porcine Trabecular Skull Bone Estimated Using Microstructural Simulations
The development of a multi-axial failure criterion for trabecular skull bone has many clinical and biological implications. This failure criterion would allow for modeling of bone under daily loading scenarios that typically are multi-axial in nature. Some yield criteria have been developed to evaluate the failure of trabecular bone, but there is a little consensus among them. To help gain deeper understanding of multi-axial failure response of trabecular skull bone, we developed 30 microstructural finite element models of porous porcine skull bone and subjected them to multi-axial displacement loading simulations that spa...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
A Finite Element Bendo-Tensegrity Model of Eukaryotic Cell
Mechanical interaction of cell with extracellular environment affects its function. The mechanisms by which mechanical stimuli are sensed and transduced into biochemical responses are still not well understood. Considering this, two finite element (FE) bendo-tensegrity models of a cell in different states are proposed with the aim to characterize cell deformation under different mechanical loading conditions: a suspended cell model elucidating the global response of cell in tensile test simulation and an adherent cell model explicating its local response in atomic force microscopy (AFM) indentation simulation. The force-el...
Source: Journal of Biomechanical Engineering - June 21, 2018 Category: Biomedical Engineering Source Type: research
Changes in Intervertebral Disk Mechanical Behavior During Early Degeneration
Intervertebral disk (IVD) degeneration is commonly described by loss of height and hydration. However, in the first stage of IVD degeneration, this loss has not yet occurred. In the current study, we use an ex vivo degeneration model to analyze the changes in IVDs mechanical behavior in the first phase of degeneration. We characterize these changes by stretched-exponential fitting, and suggest the fitted parameters as markers for early degeneration. Enzymatic degeneration of healthy lumbar caprine IVDs was induced by injecting 100μL of Chondro ïtinase ABC (Cabc) into the nucleus. A no-intervention and phosphate buffered ...
Source: Journal of Biomechanical Engineering - May 24, 2018 Category: Biomedical Engineering Source Type: research
Electromyography-Driven Forward Dynamics Simulation to Estimate In Vivo Joint Contact Forces During Normal, Smooth, and Bouncy Gaits
This study created a full-body musculoskeletal model using data from the “Sixth Grand Challenge Competition to Predict in vivo Knee Loads.” This model incorporates subject-specific geometries of the right leg in order to concurrently predict knee contact forces, ligament forces, muscle forces, and ground contact forces. The objectives of this paper are twofold: (1) t o describe an electromyography (EMG)-driven modeling methodology to predict knee contact forces and (2) to validate model predictions by evaluating the model predictions against known values for a patient with an instrumented total knee replacement (TKR) f...
Source: Journal of Biomechanical Engineering - May 18, 2018 Category: Biomedical Engineering Source Type: research
Determination of Elastic Modulus in Mouse Bones Using a Nondestructive Micro-Indentation Technique Using Reference Point Indentation
The determination of the elastic modulus of bone is important in studying the response of bone to loading and is determined using a destructive three-point bending method. Reference point indentation (RPI), with one cycle of indentation, offers a nondestructive alternative to determine the elastic modulus. While the elastic modulus could be determined using a nondestructive procedure for ex vivo experiments, for in vivo testing, the three-point bending technique may not be practical and hence RPI is viewed as a potential alternative and explored in this study. Using the RPI measurements, total indentation distance (TID), c...
Source: Journal of Biomechanical Engineering - May 10, 2018 Category: Biomedical Engineering Source Type: research
Selecting Sensitive Parameter Subsets in Dynamical Models With Application to Biomechanical System Identification
We present an application identifying a biomechanical parametric model of a head position-tracking task for ten human subjects. Using measured data, our method (1) reduced model complexity by only requiring five out of twelve parameters to be estimated, (2) significantly reduced parameter 95% confidence intervals by up to 89% of the original confidence interval, (3) maintained goodness of fit measured by variance accounted for (VAF) at 82%, (4) reduced computation time, where our FIM method was 164 times faster than the LASSO method, and (5) selected similar sensitive parameters to the LASSO method, where three out of five...
Source: Journal of Biomechanical Engineering - May 8, 2018 Category: Biomedical Engineering Source Type: research
