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Computer Methods in Biomechanics and Biomedical Engineering

Emilia Anna Kiryk, Konrad Kamieniecki, Monika Kwacz
This paper presents the process of designing a new elastic element replacing a membrane in the chamber stapes prosthesis (ChSP). The results of the study are volume displacement characteristics obtained for the prosthesis and physiological stapes. Simulation tests on a 3D CAD model have confirmed that a properly designed ring can stimulate perilymph with the same or greater efficacy as the physiological stapes footplate placed on the elastic annular ligament. The ChSP with a new elastic element creates a good chance of improving hearing in patients suffering from otosclerosis...
November 9, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Michael Sandberg, Kwong Ming Tse, Long Bin Tan, Heow Pueh Lee
In the present study, the free fall impact test in accordance with the EN1078 standard for certification of bicycle helmets is replicated using numerical simulations. The impact scenario is simulated using an experimentally validated, patient-specific head model equipped with and without a bicycle helmet. Head accelerations and intracranial biomechanical injury metrics during the impacts are recorded. It is demonstrated that wearing the bicycle helmet during the impact reduces biomechanical injury metrics, with the biggest reduction seen in the metric for skull fracture...
November 8, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Chi-Lun Lin, Guan-Jhong Lan
The rotational cutting method has been used in needle biopsy technologies to sample tough tissues, such as calcifications in the breast. The rotational motion of the needle introduces shear forces to the cutting surface such that the cutting force in the axial direction is reduced. As a result, tissue samples with large volume and better quality can be obtained. In order to comprehensively understand the effect of the needle rotation to the axial cutting force under a wide range of the needle insertion speed, this paper demonstrates a computational approach that incorporates the surface-based cohesive behavior to simulate a rotating needle cutting soft tissue...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Nithin Babu Rajendra Kurup, Markus Puchinger, Margit Gföhler
Push-rim wheelchair propulsion is biomechanically inefficient and physiologically stressful to the musculoskeletal structure of human body. This study focuses to obtain a new, optimized propulsion shape for wheelchair users, which is within the ergonomic ranges of joint motion, thus reducing the probability of injuries. To identify the propulsion movement, forward dynamic optimization was performed on a 3D human musculoskeletal model linked to a handle based propulsion mechanism, having shape and muscle excitations as optimization variables...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
R Eberle, D Heinrich, A J van den Bogert, M Oberguggenberger, W Nachbauer
ACL-injuries are one of the most common knee injuries in noncontact sports. Kinematic data of injury prone situations provide important information to study the underlying ACL-injury mechanisms. However, these data are rare. In this work an approach is presented to generate injury prone situations for noncontact ACL-injuries on a computer. The injury prone situations are generated by a musculoskeletal simulation model using kinematic data of a non-injury situation and the method of Monte Carlo simulation. The approach is successfully applied to generate injury prone landings in downhill ski racing...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
John T Wilson, Lowell T Edgar, Saurabh Prabhakar, Marc Horner, Raoul van Loon, James E Moore
The secondary lymphatic valve is a bi-leaflet structure frequent throughout collecting vessels that serves to prevent retrograde flow of lymph. Despite its vital function in lymph flow and apparent importance in disease development, the lymphatic valve and its associated fluid dynamics have been largely understudied. The goal of this work was to construct a physiologically relevant computational model of an idealized rat mesenteric lymphatic valve using fully coupled fluid-structure interactions to investigate the relationship between three-dimensional flow patterns and stress/deformation within the valve leaflets...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
B Kathirgamanathan, P Silva, J Fernandez
Obesity causes increased loading on the foot which can damage the soft tissue and bone ultimately leading to foot problems. Experimental and computational methods were used to analyse the chain of biomechanical changes in the lower limb due to obesity. The experimental study shows some changes in foot posture and gait where obese subjects were more likely to have pronated feet, smaller joint angles in the sagittal and frontal planes, smaller cadence, and smaller stride length. Anatomically correct finite element models generated on obese subjects showed increased and altered internal and plantar stress...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Willeke A Traa, Mark C van Turnhout, Kevin M Moerman, Jules L Nelissen, Aart J Nederveen, Gustav J Strijkers, Dan L Bader, Cees W J Oomens
Pressure ulcers occur due to sustained mechanical loading. Deep tissue injury is a severe type of pressure ulcer, which is believed to originate in subcutaneous tissues adjacent to bony prominences. In previous experimental-numerical studies the relationship between internal tissue state and damage development was investigated using a 2D analysis. However, recent studies suggest that a local analysis is not sufficient. In the present study we developed a method to create animal-specific 3D finite element models of an indentation test on the tibialis anterior muscle of rats based on MRI data...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Alexis D Gidley, Anthony P Marsh, Brian R Umberger
The purpose of this study was to identify one or more performance-based criteria that may be used to generate predictive optimal control simulations of submaximal pedaling. Two-legged pedaling simulations were generated based on minimizing muscle activation, muscle stress, metabolic energy, time derivative of muscle force, and minimizing metabolic energy while pedaling smoothly. The simulations based on minimizing muscle activation and muscle stress most closely matched experimental pedaling data, with the activation criterion better matching experimental muscle activation timing...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Yue Qiu, Ding Yuan, Ye Wang, Jun Wen, Tinghui Zheng
This paper describes a systematic investigation on the hemodynamic environment in a patient-specific AAA with tortuous common iliac artery(CIA) and external iliac artery (EIA). 3D reconstructions from CT scans and subsequent computational simulation are carried out. It is found out that the Newtonian and non-Newtonian models have very similar flow field and WSS distribution. More importantly, it is revealed that the torturous CIA maintained its helical flow. It is concluded that the assumption of Newtonian blood is adequate in capturing the intra-aneurysmal hemodynamics...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Marcello Iasiello, Kambiz Vafai, Assunta Andreozzi, Nicola Bianco
Boundary layer effects for Low-Density Lipoprotein (LDL) concentration problems in a multi-layer artery model are analyzed in this work. Both a straight artery and aorta-iliac bifurcation are analyzed. Mass, momentum and species governing equations are based on the porous media theory and solved with the commercial finite-element based code COMSOL Multiphysics. For the straight artery, various inlet velocities, arterial sizes and intramural pressure values are investigated. Results are presented in terms of concentration profiles close to the lumen/endothelium interface and boundary layer thickness...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Danilo S Catelli, Mariska Wesseling, Ilse Jonkers, Mario Lamontagne
Most musculoskeletal models (MSKM) are designed to evaluate gait and running, which have limited range of motion (ROM). The purpose of this study was to examine the effect of wrapping surfaces (WS) at the knee and hip joints in a MSKM, on the muscle moment arms (MA) and activations during squatting. The MSKM was then customized by changing parameters of the original WS and by implementing additional WS. The WS prevent muscles from crossing into the bones, providing realistic muscle MA for large ROM. The modified MSKM is suitable for analysis up to 138° hip and 145° knee flexions...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Debao Zhou, Xuehuan He
Patient pain caused by a colonoscope is one of the main complications in completing a colonoscopy. Currently, randomized controlled trial (RCT) is one of the most used methods to evaluate the efficacy of small-caliber (SC) colonoscopes in reducing patient pain during a colonoscopy, compared with a standard colonoscope (SDC). However, many disturbing factors, including endoscopists' skills, characteristics of patients and new technical features of the colonoscope (passive bending and high force transmission shaft), limit the reliability and generalizability of each finding in current RCTs...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Wookjin Lee, Jaiyoung Ryu, Hangsik Shin, Hong Sun Ryou, Seong Wook Cho
Arterial tonometry is a widely used non-invasive blood pressure measurement method. In contrast to the cuff-based method, it is possible to obtain a continuous pressure profile with respect to systolic and diastolic pressures using this method. However, due to a requirement of arterial tonometry-that a sensor needs to be placed directly above a blood vessel-placement error is inevitable if the measurement device is only capable of measuring local regions. This study assumed that the plate sensor is flexible, thus reducing the placement error...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
N Barléon, R J Clarke, H Ho
One challenge for hepatic flow simulation is to divide the hepatic vasculature into individual Couinaud segments, and to simulate flow at both segmental and organ levels. We propose to integrate a segment simulation algorithm with the flow solver in a Constructive Constraint Optimisation (CCO) algorithm to address this problem. In this way blood flow simulations can be conducted for large segment-specific vasculatures as relevant to surgical procedures. In this short communication we outline the methods and present some preliminary results...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Benedikt Schlager, Frank Niemeyer, Fabio Galbusera, David Volkheimer, René Jonas, Hans-Joachim Wilke
The kinematics of a spinal motion segment is determined by the material properties of the soft-tissue and the morphology. The material properties can vary within subjects and between vertebral levels, leading to a wide possible range of motion of a spinal segment independently on its morphology. The goal of this numerical study was to identify the most influential material parameters concerning the kinematics of a spinal motion segment and their plausible ranges. Then, a method was tested to deduce the material properties automatically, based on a given ROM and morphology...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Ryszard Uklejewski, Mariusz Winiecki, Adam Patalas, Piotr Rogala
The multispiked connecting scaffold (MSC-scaffold) prototype is an essential innovation in the fixation of components of resurfacing arthroplasty (RA) endoprostheses, providing their entirely non-cemented and bone-tissue-preserving fixation in peri-articular bone. An FE study is proposed to evaluate the influence of geometrical features of the MSC-scaffold on the transfer of mechanical load in peri-implant bone. For this study, an FE model of Ti-Alloy MSC-scaffold prototype embedded in a bilinear elastic, transversely isotropic bone material was built...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Daniel Viggiani, Jeff M Barrett, Kayla M Fewster, Jack Callaghan
An adaptable method of computing muscle co-activity is presented. Instantaneous muscle activities from multiple muscles are reduced into commonality and activity level dimensions. Both dimensions are weighted independently and combined into a co-activation measure, Φ. Myoelectric data from relaxed and braced simulated rear vehicle impacts were used to compare Φ to two existing co-activity measures in muscle pair and multi-muscle cases, Φ showed greater sensitivity in the muscle pair case and could better discriminate the relaxed and braced conditions in the multi-muscle case than previous measures...
November 6, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Tomohiro Otani, Masao Tanaka
The present study proposes a computational method to identify the unloaded corneal shape based on the prescribed surface profile of the cornea acquired from in vivo measurements. Variational shape optimization of the unloaded corneal shape was formulated to satisfy that the corneal shape at the mechanical equilibrium state in the physiological situation corresponded to the prescribed surface profile. The shape variation was calculated using the Lagrange multiplier method with a finite element solution. Numerical solution showed that the optimized corneal shape was in excellent agreement with the prescribed surface profile of the cornea without μm-scale surface irregularities...
October 27, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Gustavo Souto de Sá E Souza, Adriano O Andrade, Marcus Fraga Vieira
Gait variability has been used to evaluate the ability to control gait. Several studies approached this topic by analysing the influence of different conditions on gait variability, such as different walk speeds, inclined surfaces, load carriage, or comparing characteristics of subject groups, such as age, sedentarism and impairment level. The aim of this study was to develop and assess a new method, based on the property of the Hilbert transform of easily creating a phase portrait from a single time series, capable of estimating variability within gait cycles...
October 27, 2018: Computer Methods in Biomechanics and Biomedical Engineering
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