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.

Flow –Structure Interaction Simulations of the Aortic Heart Valve at Physiologic Conditions: The Role of Tissue Constitutive Model
The blood flow patterns in the region around the aortic valve depend on the geometry of the aorta and on the complex flow –structure interaction between the pulsatile flow and the valve leaflets. Consequently, the flow depends strongly on the constitutive properties of the tissue, which can be expected to vary between healthy and diseased heart valves or native and prosthetic valves. The main goal of this work is to qualitatively demonstrate that the choice of the constitutive model of the aortic valve is critical in analysis of heart hemodynamics. To accomplish that two different constitutive models were used in curvili...
Source: Journal of Biomechanical Engineering - January 23, 2018 Category: Biomedical Engineering Source Type: research

Nanoparticle Optimization for Enhanced Targeted Anticancer Drug Delivery
This study applies rigorous optimization to the design of NPs. A preliminary investigation revealed that delivery efficiency increases monotonically witha and AR. However, maximizinga and AR results in nonuniform drug distribution, which impairs tumor regression. Therefore, a multiobjective optimization (MO) problem is formulated to quantify the trade-off between NPs accumulation and distribution. The MO is solved using the derivative-free mesh adaptive direct search algorithm. Theoretically, the Pareto-optimal set consists of an infinite number of mathematically equivalent solutions to the MO problem. However, interesting...
Source: Journal of Biomechanical Engineering - January 19, 2018 Category: Biomedical Engineering Source Type: research

Operator Bias Errors Are Reduced Using Standing Marker Alignment Device for Repeated Visit Studies
When optical motion capture is used for motion analysis, reflective markers or a digitizer are typically used to record the location of anatomical landmarks identified through palpation. The landmarks are then used to construct anatomical coordinate systems. Failure to consistently identify landmarks through palpation over repeat tests creates artifacts in the kinematic waveforms. The purpose of this work was to improve intra- and inter-rater reliability in determining lower limb anatomical landmarks and the associated anatomical coordinate systems using a marker alignment device (MAD). The device aids the subject in recre...
Source: Journal of Biomechanical Engineering - January 19, 2018 Category: Biomedical Engineering Source Type: research

A Potential Tool for the Study of Venous Ulcers: Blood Flow Responses to Load
Venous ulcers are deep wounds that are located predominantly on the lower leg. They are prone to infection and once healed have a high probability of recurrence. Currently, there are no effective measures to predict and prevent venous ulcers from formation. Hence, the goal of this work was to develop a Windkessel-based model that can be used to identify hemodynamic parameters that change between healthy individuals and those with wounds. Once identified, these parameters have the potential to be used as indicators of when internal conditions change, putting the patient at higher risk for wound formation. In order to achiev...
Source: Journal of Biomechanical Engineering - January 18, 2018 Category: Biomedical Engineering Source Type: research

Dynamic Simulation of Human Gait Model With Predictive Capability
In this paper, it is proposed that the central nervous system (CNS) controls human gait using a predictive control approach in conjunction with classical feedback control instead of exclusive classical feedback control theory that controls based on past error. To validate this proposition, a dynamic model of human gait is developed using a novel predictive approach to investigate the principles of the CNS. The model developed includes two parts: a plant model that represents the dynamics of human gait and a controller that represents the CNS. The plant model is a seven-segment, six-joint model that has nine degrees-of-free...
Source: Journal of Biomechanical Engineering - January 18, 2018 Category: Biomedical Engineering Source Type: research

Multibody Kinematics Optimization for the Estimation of Upper and Lower Limb Human Joint Kinematics: A Systematized Methodological Review
The objective of this review was to identify the numerical methods, their validation and performance for the estimation of the human joint kinematics using MKO. Seventy-four papers were extracted from a systematized search in five databases and cross-referencing. Model-derived kinematics were obtained using either constrained optimization or Kalman filtering to minimize the difference between measured (i.e., by skin markers, electromagnetic or inertial sensors) and model-derived positions and/or orientations. While hinge, universal, and spherical joints prevail, advanced models (e.g., parallel and four-bar mechanisms, elas...
Source: Journal of Biomechanical Engineering - January 18, 2018 Category: Biomedical Engineering Source Type: research

Time Course Response of the Heart and Circulatory System to Active Postural Changes
In conclusion, when compared to active stand up, HR and CO responded significant faster initially when subjects were lying down (p <  0.05); there were no significant differences in response times between male and female subjects. These data will be used during evaluation of physiological control systems for RBPs, which may improve patient outcomes for end-stage heart failure patients. (Source: Journal of Biomechanical Engineering)
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

A Small Deformation Thermoporomechanics Finite Element Model and Its Application to Arterial Tissue Fusion
Understanding the impact of thermally and mechanically loading biological tissue to supraphysiological levels is becoming of increasing importance as complex multiphysical tissue –device interactions increase. The ability to conduct accurate, patient specific computer simulations would provide surgeons with valuable insight into the physical processes occurring within the tissue as it is heated or cooled. Several studies have modeled tissue as porous media, yet fully coupl ed thermoporomechanics (TPM) models are limited. Therefore, this study introduces a small deformation theory of modeling the TPM occurring within biol...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Determinant Factors for Arterial Hemodynamics in Hypertension: Theoretical Insights From a Computational Model-Based Study
Hypertension is a well-documented predictive factor for cardiovascular events. Clinical studies have extensively demonstrated the differential hemodynamic consequences of various antihypertensive drugs, but failed to clearly elucidate the underlying mechanisms due to the difficulty in performing a quantitative deterministic analysis based on clinical data that carry confounding information stemming from interpatient differences and the nonlinearity of cardiovascular hemodynamics. In the present study, a multiscale model of the cardiovascular system was developed to quantitatively investigate the relationships between hemod...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Shoe –Floor Interactions in Human Walking With Slips: Modeling and Experiments
We present results for both soft and hard sole material. The computational approaches for slip and friction force distributions are pr esented using a spring-beam networks model. The model predictions match the experimentally observed sole deformations with large soft sole deformation at the beginning and the end stages of the stance, which indicates the increased risk for slip. The experiments confirm that both the previously repo rted required coefficient of friction (RCOF) and the deformation measurements in this study can be used to predict slip occurrence. Moreover, the deformation and force distribution results repor...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Foot and Ankle Joint Biomechanical Adaptations to an Unpredictable Coronally Uneven Surface
Coronally uneven terrain, a common yet challenging feature encountered in daily ambulation, exposes individuals to an increased risk of falling. The foot-ankle complex may adapt to improve balance on uneven terrains, a recovery strategy which may be more challenging in patients with foot-ankle pathologies. A multisegment foot model (MSFM) was used to study the biomechanical adaptations of the foot and ankle joints during a step on a visually obscured, coronally uneven surface. Kinematic, kinetic and in-shoe pressure data were collected as ten participants walked on an instrumented walkway with a surface randomly positioned...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Mechanical Fatigue of Bovine Cortical Bone Using Ground Reaction Force Waveforms in Running
Stress fractures are a common overuse injury among runners associated with the mechanical fatigue of bone. Several in vivo biomechanical studies have investigated specific characteristics of the vertical ground reaction force (vGRF) in heel-toe running and have observed an association between increased loading rate during impact and individuals with a history of stress fracture. The purpose of this study was to examine the fatigue behavior of cortical bone using vGRF-like loading profiles, including those that had been decomposed into their respective impact and active phase components. Thirty-eight cylindrical cortical bo...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Development of a Single-Degree-of-Freedom Mechanical Model for Predicting Strain-Based Brain Injury Responses
In this study, a single-degree-of-freedom (sDOF) mechanical analog was developed to parametrically investigate the link between rotational head kinematics and brain deformation. Model efficacy was assessed by comparing the maximum magnitude of displacement to strain-based brain injury predictors from finite element (FE) human head models. A series of idealized rotational pulses covering a broad range of acceleration and velocity magnitudes (0.1 –15 krad/s2 and 1 –100 rad/s) with durations between 1 and 3000 ms were applied to the mechanical models about each axis of the head. Results show that brain deformation ma...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

Validation of the Strain Assessment of a Phantom of Abdominal Aortic Aneurysm: Comparison of Results Obtained From Magnetic Resonance Imaging and Stereovision Measurements
Predicting aortic aneurysm ruptures is a complex problem that has been investigated by many research teams over several decades. Work on this issue is notably complex and involves both the mechanical behavior of the artery and the blood flow. Magnetic resonance imaging (MRI) can provide measurements concerning the shape of an organ and the blood that flows through it. Measuring local distortion of the artery wall is the first essential factor to evaluate in a ruptured artery. This paper aims to demonstrate the feasibility of this measure using MRI on a phantom of an abdominal aortic aneurysm (AAA) with realistic shape. The...
Source: Journal of Biomechanical Engineering - January 17, 2018 Category: Biomedical Engineering Source Type: research

A Short History of Bioengineering Research in Ireland
In July 2018, Ireland will host the World Congress of Biomechanics in Dublin. This Congress is held once every 4  yr and is the premier meeting worldwide in its field, with over 3000 people expected to visit Dublin in July. The awarding of the 2018 Congress to Ireland is a reflection of the strength of biomechanics and bioengineering research in this country. To mark this event, herein we describe the develo pment of biomechanics and bioengineering research in Ireland over the past 40 yr, which has grown in parallel with the medical device industry as well as the expansion of Government investment in science, innovatio...
Source: Journal of Biomechanical Engineering - January 12, 2018 Category: Biomedical Engineering Source Type: research