Blood transfusion prediction using restricted Boltzmann machines.
Abstract The availability of blood transfusion has been a recurrent concern for medical institutions and patients. Efficient management of this resource represents an important challenge for many hospitals. Likewise, rapid reaction during transfusion decisions and planning is a critical factor to maximize patient care. This paper proposes a novel strategy for predicting the blood transfusion need, based on available information, by means of Restricted Boltzmann Machines (RBM). By extracting and analyzing high-level features from 4831 patient records, RBM can deal with complex patterns recognition, helping supervis...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 24, 2020 Category: Biomedical Engineering Authors: Cifuentes J, Yao Y, Yan M, Zheng B Tags: Comput Methods Biomech Biomed Engin Source Type: research

Simulated brain strains resulting from falls differ between concussive events of young children and adults.
This study examined peak and cumulative brain strain from 20 cases of concussion in both young children and adults using physical reconstructions and finite element modelling of the brain response to impacts. The child group showed lower impact kinematics as well as strain metrics. Results suggest children may suffer concussive injuries with lower brain strains compared to adults. PMID: 32207335 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 24, 2020 Category: Biomedical Engineering Authors: Koncan D, Gilchrist M, Vassilyadi M, Hoshizaki TB Tags: Comput Methods Biomech Biomed Engin Source Type: research

Lattice Boltzmann simulation of swelling of an implant for microtia manufactured with IPN hydrogel.
Abstract The swelling characteristics of an implant for microtia treatment manufactured with IPN hydrogel was achieved using a three-dimensional lattice Boltzmann model. Dimensionless units of length and mass were employed. Comparisons between computational data and experimental values obtained by an adsorption isotherm test of a hydrogel implant immersed in Ringer's solution at a constant temperature of 310.15 K achieve coefficients of determination between 0.98782 and 0.99669. The results demonstrate that the thickness of the sample has a great impact on the time required to achieve thermodynamic equilibr...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 23, 2020 Category: Biomedical Engineering Authors: Boschetti PJ, Pelliccioni O, Da Costa K, Sabino MA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Numerical simulation of lateral and transforaminal lumbar interbody fusion, two minimally invasive surgical approaches.
es JM Abstract The present study aims to compare spinal stability after two different minimally invasive techniques, the lateral lumbar interbody fusion (LLIF) and the transforaminal lumbar interbody fusion (TLIF) approaches. Two nonlinear three-dimensional finite element (FE) models of the L4-L5 functional spinal unit (FSU) were subjected to the loads that usually act on the lumbar spine. Findings show that the LLIF approach yields better results for torsion load case, due to the larger surface area of the implant. For extension, flexion and lateral bending loads, the TLIF approach presents smaller displacements ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 19, 2020 Category: Biomedical Engineering Authors: Areias B, Caetano SC, Sousa LC, Parente M, Jorge RN, Sousa H, Gonçalves JM Tags: Comput Methods Biomech Biomed Engin Source Type: research

Biomechanical analysis of segmental lumbar lordosis and risk of cage subsidence with different cage heights and alternative placements in transforaminal lumbar interbody fusion.
The objective was to numerically assess the resulting segmental lumbar lordosis (SLL) and stresses at the bone-cage interface as functions of cage height (8- vs. 10-mm) and cage placement (oblique asymmetric, vs. anterior symmetric) for normal and osteoporotic bone quality. A L4-L5 detailed finite element model of TLIF was subjected to the functional loadings of 10 Nm in the physiological planes after the application of a 400 N follower-load. The SLL was increased by 0.9° (11%) and 1.0° (13%), respectively in oblique asymmetric and anterior symmetric cage placement with 8-mm height; they were 1.4°...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 13, 2020 Category: Biomedical Engineering Authors: Rastegar S, Arnoux PJ, Wang X, Aubin CÉ Tags: Comput Methods Biomech Biomed Engin Source Type: research

The effect of hemodynamic parameters in patient-based coronary artery models with serial stenoses: normal and hypertension cases.
In this study, we entirely use open source tools and techniques for coronary computed tomography angiography (CCTA) image segmentation, 3D reconstruction, grid generation and hemodynamic simulations. The results yield different hemodynamic parameters such as velocity magnitude, mean arterial pressure difference, flow-pressure linear relation, wall shear stress (WSS) and eventually virtual fractional flow reserve (vFFR) allowing for the prediction and the assessment of lumen area severity conditions in MSS coronaries. PMID: 32159397 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 11, 2020 Category: Biomedical Engineering Authors: Hoque KE, Ferdows M, Sawall S, Tzirtzilakis EE Tags: Comput Methods Biomech Biomed Engin Source Type: research

Simulated anterior translation and medial rotation of the talus affect ankle joint contact forces during vertical hopping.
Abstract The purpose of the present study was to identify the effects of anterior translation and medial rotation of the talus on ankle joint contact forces (AJF) during double-limb vertical hopping. A computational musculoskeletal model was used to calculate AJF under 225 different combinations of 0-10 mm (in 10/15 mm increments) anterior translation and 0-5° (in 5/15° increments) medial rotation for ten subjects. The results show anteroposterior AJF was moderately affected by anterior translation, while mediolateral AJF was strongly affected by medial rotation. Future research should invest...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 11, 2020 Category: Biomedical Engineering Authors: Kim H, Kipp K Tags: Comput Methods Biomech Biomed Engin Source Type: research

Hybrid triad provides fracture plane stability in a computational model of a Pauwels Type III hip fracture.
Abstract The study utilized finite element method to determine displacements and stresses in a set of Pauwels Type III femoral neck fractures repaired using 3 techniques (cannulated screws (Triad), sliding hip screw (SHS), and a Hybrid (SHS + cannulated screws). The research found that shear displacement doubled between the 65° and 75° fracture angles regardless of fixation construct. The SHS alone was the least stable construct, with highest construct stresses and shear displacement along the fracture plane. The stability of the Hybrid and Triad constructs were similar, but stress in the Hyb...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 11, 2020 Category: Biomedical Engineering Authors: Cordeiro M, Caskey S, Frank C, Martin S, Srivastava A, Atkinson T Tags: Comput Methods Biomech Biomed Engin Source Type: research

On biological availability dependent bone remodeling.
Abstract Modeling the evolution of bone density is relevant for understanding, simulation and possible prediction of bone response to external and internal influences. In this work we present a formulation for the bone density evolution process that takes into account not only the commonly considered mechanical stimulus, but, as novelty, also the influence of the availability of nutrients and hormones, with its implementation pursued within the finite element method. A simple uni-axial extension test is used to illustrate and compare our novel model against the classical approach. The results of the proposed modif...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 4, 2020 Category: Biomedical Engineering Authors: Papastavrou A, Schmidt I, Steinmann P Tags: Comput Methods Biomech Biomed Engin Source Type: research

Atomistic to continuum model for studying mechanical properties of RNA nanotubes.
Abstract With rapid advancements in the emerging field of RNA nanotechnology, its current and potential applications, new important problems arise in our quest to better understand properties of RNA nanocomplexes. In this paper, our focus is on the modeling of RNA nanotubes which are important for many biological processes. These RNA complexes are also important for human beings, with their theurapeutical and biomedical applications discussed vigorously in the literature over the recent years. Here, we develop a continuum model of RNA nanotubes, originally obtained from self assembly of RNA building blocks in the ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 2, 2020 Category: Biomedical Engineering Authors: Badu S, Prabhakar S, Melnik R, Singh S Tags: Comput Methods Biomech Biomed Engin Source Type: research

Assessment of stress/strain in dental implants and abutments of alternative materials compared to conventional titanium alloy-3D non-linear finite element analysis.
Abstract The aim of this study was to assess the stress/strain in dental implant/abutments with alternative materials, in implants with different microgeometry, through finite element analysis (FEA). Three-dimensional models were created to simulate the clinical situation of replacement of a maxillary central incisor with implants, in a type III bone, with a provisional single crown, loaded with 100 N in a perpendicular direction. The FEA parameters studied were: implant materials-titanium, porous titanium, titanium-zirconia, zirconia, reinforced fiberglass composite (RFC), and polyetheretherketone (PEEK); ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 2, 2020 Category: Biomedical Engineering Authors: Tretto PHW, Dos Santos MBF, Spazzin AO, Pereira GKR, Bacchi A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Finite element submodeling technique to analyze the contact pressure and wear of hard bearing couples in hip prosthesis.
Abstract Finite element (FE) simulation plays a major role in computing stress and predicting the failure of biomedical components. Normally in past, researchers focused on developing a global computational model from the scanned data of patients to analyze the stresses and deformations. To compute the wear of the hip prosthesis, mostly the global model (GM) is used to predict the expected life for million cycles using nodal updating technique which leads to high computational effort and time. The proposed work utilizes a submodeling finite element technique to analyze the contact pressure and wear of biomaterials...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 2, 2020 Category: Biomedical Engineering Authors: Shankar S, Nithyaprakash R, Santhosh BR, Uddin MS, Pramanik A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Is it possible to detect a true rotation axis of the temporomandibular joint with common pantographic methods? A fundamental kinematic analysis.
Abstract The location of the terminal hinge axis of the temporomandibular joint is still a very wide-spread procedure in dentistry in order to replicate the movement in various articulator devices. Especially pantographic methods are claimed to provide accurate measurements and, additionally, are seen to be able to separate a pure rotation of the joint from a movement with an arbitrary combined shift and rotation. In the latter application, these methods were used in a lot of studies as a reference standard. The aim of this study was to analyze, whether common pantographic methods in general are able to distinguis...
Source: Computer Methods in Biomechanics and Biomedical Engineering - March 2, 2020 Category: Biomedical Engineering Authors: Mehl A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Computational fluid dynamic simulation of two-fluid non-Newtonian nanohemodynamics through a diseased artery with a stenosis and aneurysm.
This article presents a two-dimensional theoretical study of hemodynamics through a diseased permeable artery with a mild stenosis and an aneurysm present. The effect of metallic nanoparticles on the blood flow is considered, motivated by drug delivery (pharmacology) applications. Two different models are adopted to mimic non-Newtonian characteristics of the blood flow; the Casson (viscoplastic) fluid model is deployed in the core region and the Sisko (viscoelastic) fluid model employed in the peripheral (porous) region. The revised Buongiorno two-component nanofluid model is utilized for nanoscale effects. The blood is co...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 26, 2020 Category: Biomedical Engineering Authors: Dubey A, Vasu B, Anwar Bég O, Gorla RSR, Kadir A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Minimally invasive transforaminal and anterior lumbar interbody fusion surgery at level L5-S1.
es JM Abstract This paper presents a finite element analysis to investigate the biomechanical changes caused by transforaminal (TLIF) and anterior lumbar interbody fusion (ALIF) at the L5-S1 level, applying two different implants: T_PAL (TLIF) and SynFix (ALIF). The main objective is to determine which one is more stable for patients. Numerical simulations of segmental motion show that, in the early postoperative phase, displacements and rotation angles obtained in ALIF are greater than the corresponding ones obtained in TLIF, as well as the principal stress values on the ligaments. So, TLIF performed with T_PAL i...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 25, 2020 Category: Biomedical Engineering Authors: Fidalgo DS, Areias B, Sousa LC, Parente M, Jorge RN, Sousa H, Gonçalves JM Tags: Comput Methods Biomech Biomed Engin Source Type: research

Null strain analysis of submerged aneurysm analogues using a novel 3D stereomicroscopy device.
Abstract To measure the inhomogeneous 3D-strain fields present during inflation-extension testing of physiologically submerged micro-aneurysms, a Stereo Digital Image Correlation (StereoDIC) microscopy system is developed that revolves 15° stereo-angle cameras around a centrally-mounted target. Calibration is performed using submerged dot patterns and system accuracy verified using strain and deformation analyses for rigid body motions of speckle-patterned, micro-aneurysmal surrogates. In terms of the Green-Lagrange strain tensor and the 3D displacement fields, the results are stable even after 120 minu...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 18, 2020 Category: Biomedical Engineering Authors: Lane BA, Lessner SM, Vyavahare NR, Sutton MA, Eberth JF Tags: Comput Methods Biomech Biomed Engin Source Type: research

Studying the effects of asymmetry on freestyle swimming using smoothed particle hydrodynamics.
In this study, the asymmetrical freestyle swimming performance of a male elite level swimmer who breathed every second arm stroke (unilaterally) was investigated. A laser body scan and multi-angle video footage of the athlete were used to generate a swimming biomechanical model. This model was then used in a Smoothed Particle Hydrodynamics (SPH) fluid simulation of swimming through a virtual pool. The results from this study enabled the kinematic asymmetry to be related to the consequential fluid dynamic asymmetry. The intra-cyclic fluctuations in the streamwise forces and speed were also examined. Hand angles of attack we...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 13, 2020 Category: Biomedical Engineering Authors: Cohen RCZ, Cleary PW, Mason BR, Pease DL Tags: Comput Methods Biomech Biomed Engin Source Type: research

Analysis of fiber strain in the human tongue during speech.
This study investigates mechanical cooperation among tongue muscles. Five volunteers were imaged using tagged magnetic resonance imaging to quantify spatiotemporal kinematics while speaking. Waveforms of strain in the line of action of fibers (SLAF) were estimated by projecting strain tensors onto a model of fiber directionality. SLAF waveforms were temporally aligned to determine consistency across subjects and correlation across muscles. The cohort exhibited consistent patterns of SLAF, and muscular extension-contraction was correlated. Volume-preserving tongue movement in speech generation can be achieved through multip...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 7, 2020 Category: Biomedical Engineering Authors: Gomez AD, Stone ML, Woo J, Xing F, Prince JL Tags: Comput Methods Biomech Biomed Engin Source Type: research

Comparison of two different bowel anastomosis types using finite volume method.
uml;k A Abstract The purpose of this study was to compare side-to-side and functional end-to-end anastomosis techniques that are commonly used in bowel surgery. Considering the dimensions of these two different anastomosis models, SolidWorks program was used for 3 D studies. Intra-intestinal flow analyzes were performed based on the finite volume method using Ansys Fluent, a computational fluid Dynamics (CFD) program. The flow velocity, pressure, turbulent knetic energy, turbulence vortex distribution, vortex viscosity and wall shear stresses for each model were calculated in results of the analysis for the...
Source: Computer Methods in Biomechanics and Biomedical Engineering - February 3, 2020 Category: Biomedical Engineering Authors: Pirhan Y, Gök K, Gök A Tags: Comput Methods Biomech Biomed Engin Source Type: research

A biomechanical model of the pathological aortic valve: simulation of aortic stenosis.
uez A Abstract Aortic stenosis (AS) disease is a narrowing of the aortic valve (AV) opening which reduces blood flow from the heart causing several health complications. Although a lot of work has been done in AV simulations, most of the efforts have been conducted regarding healthy valves. In this article, a new three-dimensional patient-specific biomechanical model of the valve, based on a parametric formulation of the stenosis that permits the simulation of different degrees of pathology, is presented. The formulation is based on a double approach: the first one is done from the geometric point of view, reducin...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 29, 2020 Category: Biomedical Engineering Authors: Loureiro-Ga M, Veiga C, Fdez-Manin G, Jimenez VA, Calvo-Iglesias F, Iñiguez A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Optimizing neotissue growth inside perfusion bioreactors with respect to culture and labor cost: a multi-objective optimization study using evolutionary algorithms.
In this study, we use a previously published computationally efficient model, describing the neotissue growth (cells + their extracellular matrix) inside 3D scaffolds in a perfusion bioreactor. In order to find the most cost-effective medium refreshment strategy for the bioreactor culture, a multi-objective optimization strategy was developed aimed at maximizing the neotissue growth while minimizing the total cost of the experiment. Four evolutionary optimization algorithms (NSGAII, MOPSO, MOEA/D and GDEIII) were applied to the problem and the Pareto frontier was computed in all methods. All algorithms led to...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 29, 2020 Category: Biomedical Engineering Authors: Mehrian M, Geris L Tags: Comput Methods Biomech Biomed Engin Source Type: research

Biomechanical effects of corticotomy facilitated orthodontic anterior retraction: a 3-dimensional finite element analysis.
CONCLUSIONS: Varied corticotomy designs can change the biomechanical effects on dento-alveolar structures. The incision near the periphery of apical and bilateral incision combined with palatal incision may be the optimized design used for retraction of anterior teeth. PMID: 31985276 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 27, 2020 Category: Biomedical Engineering Authors: Liu Y, Wu Y, Yang C, Song J, Fan Y Tags: Comput Methods Biomech Biomed Engin Source Type: research

Occlusal load modelling significantly impacts the predicted tooth stress response during biting: a simulation study.
The objectives of this study were two-fold: (i) develop a computational model to calculate the stress response of the first molar during biting of a rubber sample and (ii) evaluate the influence of different occlusal load models on the stress response of dental structures. A three-dimensional finite element model was developed comprising the mandible, first molar, associated dental structures, and the articular fossa and discs. Simulations of a maximum force bite on a rubber sample were performed by applying muscle forces as boundary conditions on the mandible and computing the contact between the rubber and molars (GS cas...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 22, 2020 Category: Biomedical Engineering Authors: Saini H, Ackland DC, Gong L, Cheng LK, Röhrle O Tags: Comput Methods Biomech Biomed Engin Source Type: research

Characterization of hyperelastic and damage behavior of tendons.
The objective of this study was to explore different mathematical models to determine which would be the best option to predict the behavior of tendons and ligaments in complex biological systems using Finite Elements (FE) models. Therefore, we took into account accuracy as well as computational features. We considered the model proposed by Shearer and coupled it with a sigmoid function, which governs the evolution of damage in tendons, as the most appropriate for the fitting of the experimental data. The achieved solution shows to be of high interest attributable to the simplicity of the damage law function and its low co...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 20, 2020 Category: Biomedical Engineering Authors: López-Campos JA, Ferreira JPS, Segade A, Fernández JR, Natal RM Tags: Comput Methods Biomech Biomed Engin Source Type: research

Multisite pacing and myocardial scars: a computational study.
Abstract Cardiac resynchronization therapy (CRT) is a frequently effective treatment modality for dyssynchronous heart failure, however, 30% of patients do not respond, usually due to suboptimal activation of the left ventricle (LV). Multisite pacing (MSP) may increase the response rate, but its effect in the presence of myocardial scars is not fully understood. We use a computational model to study the outcome of MSP in an LV with scars in two different locations and of two different sizes. The LV was stimulated from anterior, posterior and lateral locations individually and in pairs, while a septal stimulation s...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 20, 2020 Category: Biomedical Engineering Authors: Albatat M, Bergsland J, Arevalo H, Odland HH, Wall S, Sundnes J, Balasingham I Tags: Comput Methods Biomech Biomed Engin Source Type: research

Effect of asymmetry on the flow behavior in an idealized arterial bifurcation.
In this study, hemodynamics for steady and pulsatile flow of blood has been investigated in an idealized carotid artery bifurcation having all the vessels in the same plane for a range of bifurcation angles for symmetric and asymmetric bifurcation. The simulations reveal the presence of a pair of helical vortices, symmetric about the bifurcation plane, in each daughter tube near the bifurcation. PMID: 31931612 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 14, 2020 Category: Biomedical Engineering Authors: Nagargoje M, Gupta R Tags: Comput Methods Biomech Biomed Engin Source Type: research

Biomechanical study of medial meniscus after posterior horn injury: a finite element analysis.
Abstract We established an effective finite element model of knee joint for observation of stress and displacement of meniscus related changes after medial meniscus injury. Different types of medial meniscus injury can lead to varied meniscus stress and displacement changes. Stress and displacement concentration were found in fissure tip of meniscus tear compared to normal meniscus. The posterior horn injury of medial meniscus may initiate combined injury of medial meniscus posterior horn (MMPH) and that of medial meniscus body, and combined injury of MMPH and that of lateral meniscus anterior horn; fissure expans...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 13, 2020 Category: Biomedical Engineering Authors: Jiang P, Cui J, Chen Z, Dai Z, Zhang Y, Yi G Tags: Comput Methods Biomech Biomed Engin Source Type: research

An in silico pipeline for subject-specific hemodynamics analysis in liver surgery planning.
Abstract The progresses in fast simulations of the hepatic flow in subject-specific vascular tree have created new toolkits for pre-surgical planning. The aim of this short communication is to introduce a computational pipeline that integrates several recently developed in silico liver models and algorithms. Firstly, a semi-automatic segmentation pipeline is used to digitise hepatic vessels. Then, a constructive constraint optimisation (CCO) algorithm is used to extend the digitised vascular tree, and also to compute the blood pressure and flow velocity in the tree. Couinaud segments are simulated from the diffusi...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 11, 2020 Category: Biomedical Engineering Authors: Ho H, Yu HB, Bartlett A, Hunter P Tags: Comput Methods Biomech Biomed Engin Source Type: research

Analytical and computational sliding wear prediction in a novel knee implant: a case study.
The objective of this paper is to develop a computational model which can be used to assess the wear arising at the implant articulating surfaces. Experimental wear coefficients were determined from physical testing, the results of which were verified using a semi-analytical model. Experimental results were incorporated into an anatomically correct computational model of the knee and implant. The wear-rate predicted for the implant was 27.74 mm3 per million cycles (MC) and the wear depth predicted was 1.085 mm/MC. Whereas the wear-rate is comparable to that seen in conventional knee implants, the wear depth i...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 11, 2020 Category: Biomedical Engineering Authors: Hussin MS, Fernandez J, Ramezani M, Kumar P, Kelly PA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Occupant kinematics and biomechanics during frontal collision in autonomous vehicles-can rotatable seat provides additional protection?
Abstract In a highly autonomous vehicle (HAV), the rotatable seat is likely to be designed to facilitate ease of communication between the occupants. We hypothesize that the protective effects of current restraint systems vary among different seating configurations and that by using the rotational seat to alter the occupant's orientation in accordance with the direction of impact, occupants will be better protected. Moreover, in HAVs, it's likely that an imminent impact could be detected at a time of 200 ms, or even longer, prior to the initial contact. The availability of this additional time could be used...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 11, 2020 Category: Biomedical Engineering Authors: Wu H, Hou H, Shen M, Yang KH, Jin X Tags: Comput Methods Biomech Biomed Engin Source Type: research

The influence of the elastic modulus of the plaque in carotid artery on the computed results of FFRCT.
Abstract To study the effect of carotid plaque elastic modulus on hemodynamic parameters such as fractional flow reserve derived from computed tomography angiography (FFRCT), so as to provide a more accurate modeling method for the calculation of FFRCT of the carotid artery stenosis, three clinical cases with different ages were used to establish the three-dimensional fluid-structure interaction (FSI) model with different elastic modulus of the vessel wall and the plaque according to their age. Hemodynamic parameters were obtained by numerical simulations of the FSI models. Comparing the results from the three pat...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 8, 2020 Category: Biomedical Engineering Authors: Xu K, Yu L, Wan J, Wang S, Lu H Tags: Comput Methods Biomech Biomed Engin Source Type: research

Influence of Socket-shield technique on the biomechanical response of dental implant: three-dimensional finite element analysis.
This study evaluated the bone microstrain, displacement, and stress distribution according to the surgical technique (conventional or Socket-shield) and evaluation period (immediately after implant installation or after healing). Each condition was modeled for the finite element analysis, totaling four groups, with a morse-taper implant and a cemented prosthesis. The maximum displacement, von Mises stress, and bone microstrain yielded higher values during the immediate stage, without a difference between Socket-shield and conventional treatments. The use of the Socket-shield technique does not negatively impact the biomech...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 8, 2020 Category: Biomedical Engineering Authors: Tribst JPM, Dal Piva AMO, Borges ALS, Bottino MA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Individualized prediction of pedicle screw fixation strength with a finite element model.
Abstract Pedicle screws are used for the treatment of a wide variety of spinal pathologies. A good screw holding power in bone is required for treatment success, but has so far not been predictable computationally. The goal of this study was to develop an automated tool able to predict patient-specific screw fixation strength through finite element simulation. We compared the simulation results with results from biomechanical pull-out tests performed on animal lumbar specimens. Experimental and simulation pull-out strengths were highly correlated [Formula: see text] and the mean error was 20.25%. The fixation stre...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 7, 2020 Category: Biomedical Engineering Authors: Widmer J, Fasser MR, Croci E, Spirig J, Snedeker JG, Farshad M Tags: Comput Methods Biomech Biomed Engin Source Type: research

In silico study of glenoid perforation during total shoulder arthroplasty: the effects on stress & micromotion.
In silico study of glenoid perforation during total shoulder arthroplasty: the effects on stress & micromotion. Comput Methods Biomech Biomed Engin. 2020 Jan 07;:1-9 Authors: Wahab AHA, Saad APM, Syahrom A, Kadir MRA Abstract Glenoid perforation is not the intended consequence of the surgery and must be avoided. The analysis on biomechanical aspect of glenoid vault perforation remains unknown. The purpose of this study is to determine the impact of glenoid perforation towards stress distribution and micromotion at the interfaces. Eight glenoid implant models had been constructed with various size,...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 7, 2020 Category: Biomedical Engineering Authors: Wahab AHA, Saad APM, Syahrom A, Kadir MRA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Assessment of the shock adsorption properties of bike helmets: a numerical/experimental approach.
Abstract In this paper, a numerical and experimental study of the shock absorption properties of bike helmets is presented. Laboratory compression and tensile tests were carried out on samples of expanded polystyrene (EPS) and polycarbonate (PC), respectively constituting the internal shock absorption layer and the external hard shell of composite helmets. The measured responses of the two materials were then exploited to calibrate the relevant elasto-plastic constitutive models, adopted in full-scale finite element analyses of a helmet subject to standardized impacts. The simulations allowed assessing the time ev...
Source: Computer Methods in Biomechanics and Biomedical Engineering - January 6, 2020 Category: Biomedical Engineering Authors: Bocciarelli M, Carvelli V, Mariani S, Tenni M Tags: Comput Methods Biomech Biomed Engin Source Type: research

Personalized hip joint kinetics during deep squatting in young, athletic adults.
Abstract The goal of this study was to report deep squat hip kinetics in young, athletic adults using a personalized numerical model solution based on inverse dynamics. Thirty-five healthy subjects underwent deep squat motion capture acquisitions and MRI scans of the lower extremities. Musculoskeletal models were personalized using each subject's lower limb anatomy. The average peak hip joint reaction force was 274 percent bodyweight. Average peak hip and knee flexion angles were 107° and 112° respectively. These new findings show that deep squatting kinetics in the younger population differ substantially ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 12, 2019 Category: Biomedical Engineering Authors: Van Houcke J, Galibarov PE, Van Acker G, Fauconnier S, Allaert E, Van Hoof T, Almeida DF, Steenackers G, Pattyn C, Audenaert EA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Finite element modeling and static/dynamic validation of thoracolumbar-pelvic segment.
In this study, a three-dimensional finite element model of thoracolumbar structure including complete pelvis (T12-pelvis) was built using computed tomography technology. The modeling process has been explained in detailed. During the process of validation, the model was assigned with non-linear material property for static or dynamic analyses. In static analysis, the vertebral geometry parameters of T12-L5, the axial displacement, the posterior disc bulge and the intradiscal pressure of intervertebral disc, range of motion under six loading cases and facet joint forces were obtained and compared with the experimental data....
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 9, 2019 Category: Biomedical Engineering Authors: Guo LX, Li WJ Tags: Comput Methods Biomech Biomed Engin Source Type: research

Relating mechanical properties of vertebral trabecular bones to osteoporosis.
This study could be useful for a better understanding of the elastic behavior of trabecular bones in human vertebral bodies, allowing an estimation of bone answer under stress in different directions and the risk of fracture associated with osteoporosis.HighlightsDescribing the elastic behavior of trabecular bones in human vertebral bodies at the micro and macroscopic.Allow a better estimation of the stress in different directions and risk of fracture associated with osteoporosis.Model request a very low computational cost.Offer a better understand the global effective coefficients of samples of trabecular bone, from the m...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 9, 2019 Category: Biomedical Engineering Authors: Cesar R, Bravo-Castillero J, Ramos RR, Pereira CAM, Zanin H, Rollo JMDA Tags: Comput Methods Biomech Biomed Engin Source Type: research

Effect of axial prestretch and adipose tissue on the inflation-extension behavior of the human abdominal aorta.
ný L Abstract Our study aims to show that perivascular adipose tissue may significantly change the mechanical state of the abdominal aorta. To this end, uniaxial tensile tests with perivascular fat tissue were carried out. In the subsequent regression analysis, stress-strain data were fitted by the polynomial strain energy density. A constitutive model of adipose tissue was used in the analytical simulation of the inflation-extension behavior of the human abdominal aorta. The computational model was based on the theory of the bi-layered thick-walled tube. In addition to the effect of perivascular tissue, th...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 9, 2019 Category: Biomedical Engineering Authors: Voňavková T, Horný L Tags: Comput Methods Biomech Biomed Engin Source Type: research

Influence of population variability in ligament material properties on the mechanical behavior of ankle: a computational investigation.
This study demonstrated the feasibility of biofidelic models in investigating individual difference at the material level, and emphasized the importance of probabilistic description of individual difference when identifying the injury mechanism of a broad spectrum. PMID: 31809575 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 6, 2019 Category: Biomedical Engineering Authors: Liu Y, Zhou Q, Gan S, Nie B Tags: Comput Methods Biomech Biomed Engin Source Type: research

Elementwise material assignment in reconstructed or transformed patient-specific FEA models developed from CT scans.
Abstract In patient-specific finite element modeling, elementwise material assignment calculates local mechanical properties from the underlying CT data. If meshes must be transformed, for example to reconstruct broken bones, this elementwise material mapping is not possible using commercial software. Accordingly, we developed an algorithm to transform and reconstruct CT scans and fill gaps at discontinuities. Virtual mechanical testing showed that iterative reconstruction retains material heterogeneity with minimal strain artifacts and achieves whole-bone mechanics clinically equivalent (within 5%) to homogeneous...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 6, 2019 Category: Biomedical Engineering Authors: Schwarzenberg P, Dailey HL Tags: Comput Methods Biomech Biomed Engin Source Type: research

A computational fluid dynamics study pre- and post-fistula closure in a coronary artery fistula.
This study numerically investigated the hemodynamics of a patient-specific coronary artery fistula (CAF) before and after the fistula closure. The results indicated that the dilated fistula result in inadequate perfusion to other healthy aortas. Disturbed blood flow, aberrant WSSs, local negative pressure gradients and sharp pressure changes are shown in both untreated and occluded fistula. Furthermore, extreme high WSS appeared at the fistula bending after the terminal closure. It was concluded that the fistula closure may effectively improve the phenomenon of stealing blood but worsen the unfavorable hemodyanmics predisp...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 5, 2019 Category: Biomedical Engineering Authors: Cao H, Qiu Y, Yuan D, Yu J, Li D, Jiang Y, Su L, Peng L, Zheng T Tags: Comput Methods Biomech Biomed Engin Source Type: research

Modeling and simulation of musculoskeletal system of human lower limb based on tensegrity structure.
Abstract In this paper, a mechanical model of the skeletal muscle of human lower limb system is established by using the Hill muscle model and kinetic equation of the movement of lower extremities according to the attachment positions of skeletal muscle. State vector and neural control are delineated by the direct configuration method. Changes of gait and skeletal muscle stress during walking process are analyzed with energy consumption as objective function. Results illustrate that simulation data are in good agreement with actual walking gait data. Feasibility and correctness of the designed model and control be...
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 27, 2019 Category: Biomedical Engineering Authors: Wang Z, Yang C, Feng K, Qin X Tags: Comput Methods Biomech Biomed Engin Source Type: research

Influence of needling conditions on the corneal insertion force.
Abstract Needle insertion plays an important part in the process of corneal graft surgery. In this paper, a three-dimensional symmetry model of the human cornea is constructed using the finite element method. Simplification of specific optic physiology is defined for the model: The cornea constrained by the sclera is presented as two layers consisting of epithelium and stroma. A failure criterion based on the distortion energy theory has been proposed to predict the insertion process of the needle. The simulation results show a good agreement with the experimental data reported in the literature. The influence of ...
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 27, 2019 Category: Biomedical Engineering Authors: Han SF, Yang Y Tags: Comput Methods Biomech Biomed Engin Source Type: research

Investigation of effective intrusion and extrusion force for maxillary canine using finite element analysis.
This study revised and complemented orthodontic biomechanical behaviours of tooth movement with intrusive-extrusive force and could further help optimize orthodontic treatment. PMID: 31553278 [PubMed - in process] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 27, 2019 Category: Biomedical Engineering Authors: Wu J, Liu Y, Wang D, Zhang J, Dong X, Jiang X, Xu X Tags: Comput Methods Biomech Biomed Engin Source Type: research

Modeling the effects of musculoskeletal geometry on scapulohumeral muscle moment arms and lines of action.
Abstract Biomechanical investigations examining shoulder function commonly observe a high degree of inter-individual variability in muscle activity and kinematic patterns during static and dynamic upper extremity exertions. Substantial differences in musculoskeletal geometry between individuals can alter muscle moment arms and lines of action that, theoretically, alter muscle activity and shoulder kinematics. The purposes of this research were to: (i) quantify model-predicted functional roles (moment arms, lines of action) of the scapulohumeral muscles, (ii) compare model predictions to experimental data in the li...
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 27, 2019 Category: Biomedical Engineering Authors: Mulla DM, Hodder JN, Maly MR, Lyons JL, Keir PJ Tags: Comput Methods Biomech Biomed Engin Source Type: research

Separate modeling of cortical and trabecular bone offers little improvement in FE predictions of local structural stiffness at the proximal tibia.
The objective of this research was to evaluate different QCT-FE modeling and thresholding approaches to identify the method which best predicted experimentally measured local subchondral structural stiffness with highest explained variance and least error. Our results showed that separate modeling of proximal tibial cortical and trabecular bone offered little improvement in QCT-FE-predicted stiffness (0% to +3% improvement in explained variance) when compared to modeling the proximal tibia as a single structure. Based on the results of this study, we do not recommend separate modeling of cortical bone and trabecular bone w...
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 11, 2019 Category: Biomedical Engineering Authors: Hosseini Kalajahi SM, Nazemi SM, Johnston JD Tags: Comput Methods Biomech Biomed Engin Source Type: research

Comparison of computational modelling techniques for braided stent analysis.
In this study, two commonly utilised methods of computationally modelling filament interaction in braided stents are investigated: the join method and the weave method. Three different braided stent designs are experimentally tested and computationally modelled in both radial and v-block configurations. The results of the study indicate that while both methods are capable of capturing braided stent performance to some degree, the weave method is much more robust. PMID: 31502888 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 10, 2019 Category: Biomedical Engineering Authors: Kelly N, McGrath DJ, Sweeney CA, Kurtenbach K, Grogan JA, Jockenhoevel S, O'Brien BJ, Bruzzi M, McHugh PE Tags: Comput Methods Biomech Biomed Engin Source Type: research

Subject-specific geometry affects acetabular contact pressure during gait more than subject-specific loading patterns.
This study investigated how subject-specific boundary conditions and joint geometry affect acetabular cartilage contact mechanics using a multi-scale workflow. For two healthy subjects, musculoskeletal models calculated subject-specific hip kinematics and loading, which were used as boundary conditions for FEM. Cartilage contact mechanics were predicted using either generic or subject-specific FEM and boundary conditions. A subject-specific mesh resulted in a more lateral contact. Effects of subject-specific boundary conditions varied between both subjects. Results highlight the complex interplay between loading and kinema...
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 9, 2019 Category: Biomedical Engineering Authors: Wesseling M, Van Rossom S, Jonkers I, Henak CR Tags: Comput Methods Biomech Biomed Engin Source Type: research

Bone remodelling around the tibia due to total ankle replacement: effects of implant material and implant-bone interfacial conditions.
This study also indicates that proper bonding between implant and bone is essential for long-term survival of the prosthetic components. PMID: 31497997 [PubMed - as supplied by publisher] (Source: Computer Methods in Biomechanics and Biomedical Engineering)
Source: Computer Methods in Biomechanics and Biomedical Engineering - September 9, 2019 Category: Biomedical Engineering Authors: Mondal S, Ghosh R Tags: Comput Methods Biomech Biomed Engin Source Type: research