International Journal for Numerical Methods in Biomedical Engineering最新文献

{"title":"Characterization of the In Situ Stress State of Blood Clots in Ischemic Stroke: The Effect of Initial Conditions and Arterial Interaction","authors":"Jose L. Monclova,&nbsp;Scott D. Simon,&nbsp;Keefe B. Manning,&nbsp;Francesco Costanzo","doi":"10.1002/cnm.70094","DOIUrl":"10.1002/cnm.70094","url":null,"abstract":"<p>Ischemic stroke, caused by a blood clot lodging in cerebral vasculature, is a leading cause of death worldwide. The mechanics of vessel occlusion and the influence of residual stress on thrombectomy outcomes remain poorly understood. Most computational studies neglect arterial residual stress and the deformation a clot undergoes as it lodges, both of which elevate system stresses. Here, we introduce a method to simulate the initial state of a clot lodged in an idealized artery with residual stress. In this study, the artery is formulated as two concentric right cylinders with fibers embedded in an isotropic mesh, with a pre-deformation used to incorporate residual stress. A base equilibrium state of an elastic clot is simulated in continuous contact with the arterial wall. The opening angle of the artery, un-lodged-to-lodged dimensional ratios, and stiffness of the clot are varied in parametric sweeps to characterize the traction forces of the clot into the arterial wall. An aspiration pressure is applied to the proximal end of the clot to determine the pressures necessary to begin tensile detachment of the clot. As the artery opening angle increased, removal aspiration pressures increased, while the pressures decreased with increasing artery fiber orientation. The stress-free-to-lodged length ratio of the clot influenced the removal aspiration pressure, with pressures increasing nearly a thousand-fold with increased ratio. By incorporating different factors that contribute to the stress state of the system, this study provides a library of realistic initial conditions for simulating aspiration thrombectomy and validating new surgical techniques.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 10","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.70094","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-Phase Blood Flow in a Stenosed Coronary Artery: A Clinical Model-Based Experimental and Numerical Study","authors":"Orhan Yildirim,&nbsp;Sendogan Karagoz,&nbsp;Fatin Sonmez,&nbsp;Ilker Firat","doi":"10.1002/cnm.70102","DOIUrl":"10.1002/cnm.70102","url":null,"abstract":"<div>\u0000 \u0000 <p>This study aims to develop an experimental platform that emulates the human cardiovascular system to investigate the effects of varying pulse rates and fluid properties on pressure drop, peristaltic pump output pressure, and power consumption. To support the experimental findings, computational fluid dynamics (CFD) simulations were conducted to analyze single-phase blood flow dynamics. Idealized arterial geometries representing healthy (0% stenosis) and diseased (65% stenosis) conditions were reconstructed from computed tomography (CT) images. A non-Newtonian blood-mimicking fluid (XSCN) was formulated to better replicate the rheological behavior of blood, while distilled water was used as the Newtonian reference fluid. Experiments were conducted at six different pulse rates: 72, 84, 96, 114, 132, and 156 beats per minute (bpm). The experimental setup was replicated in a virtual environment using ANSYS Fluent to simulate flow behavior under identical boundary conditions. The results demonstrate that increasing pulse rate leads to an increase in pressure drop (Δ<i>P</i>), pump output pressure, and power consumption for both arterial models. These effects were more pronounced in the stenosed artery due to flow constriction. Elevated turbulence intensity was observed at higher pulse rates, with notable differences between Newtonian and non-Newtonian fluids, particularly in terms of flow resistance and shear-dependent viscosity. Power consumption was found to be directly correlated with fluid viscosity, which varied with shear rate in the non-Newtonian fluid. The 65% stenosed model consistently exhibited higher pressure drops and flow irregularities. Fractional flow reserve (FFR) analysis confirmed that a 65% luminal narrowing poses significant hemodynamic risk. The highest wall shear stress (WSS) values were localized in the stenotic region, contributing to disturbed flow patterns and increased turbulence downstream. The non-Newtonian fluid model revealed that WSS was more sensitive to flow alterations, emphasizing the role of shear-dependent viscosity in vascular hemodynamics. These findings underscore the critical influence of hemodynamic parameters—such as pulse rate, viscosity, and arterial geometry—on cardiovascular performance. The study further highlights the detrimental impact of arterial stenosis on blood flow behavior and energy expenditure, with implications for clinical diagnosis and treatment planning in cardiovascular diseases.</p>\u0000 </div>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 10","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Computationally Efficient and Causal Frequency Domain Formalism for Hemodynamics Allowing for Nonlinearities and Generalized Coupling Conditions.","authors":"Mikael Karlsson, Mina Nashed, Tamer Elnady, Mats Åbom","doi":"10.1002/cnm.70104","DOIUrl":"https://doi.org/10.1002/cnm.70104","url":null,"abstract":"<p><p>Reduced order hemodynamic models are an increasingly important complementary tool to in vivo measurements. They enable effective creation of large datasets with well-defined parameter variations, which can be used, for example, for training machine learning models, conducting virtual studies of intervention strategies, or for the development of pulse wave analysis algorithms. Here, a 1D frequency domain formalism for pulse wave propagation in the cardiovascular system is presented. Using the scattering matrix formulation, a computationally efficient and causal solution is obtained, including possible source terms and nonideal coupling conditions. Local nonlinear effects, as those seen in stenoses or aneurysms, are introduced via an iterative procedure, achieving as good accuracy as state-of-the-art time-domain solvers while being significantly more computationally efficient. The new formalism has been successfully validated against well-documented reference cases from the literature.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 10","pages":"e70104"},"PeriodicalIF":2.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145240174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Pressure Drop in Arterial Models With Stenoses Using Numerical and Experimental In Vitro Approaches: Effect of Elasticity","authors":"B. Chernyavsky,&nbsp;N. Mouzali,&nbsp;V. Glanz,&nbsp;A. Velikorodny","doi":"10.1002/cnm.70099","DOIUrl":"10.1002/cnm.70099","url":null,"abstract":"<div>\u0000 \u0000 <p>An experimental and numerical investigation of the blood flow across the stenosis embedded in the elastic artery had been carried out within a framework of a project aimed at the development of the decision support system for the diagnostics of stable coronary artery disease, using a novel hybrid physics-informed machine learning (ML) and computational fluid dynamics (CFD) approach. Integration of CFD equations into a ML framework requires the development and validation of a CFD model optimized for this specific task. The values of empirical coefficients required for the implementation of the CFD component of the project were obtained by collecting experimental data on a pressure drop in elastic arterial models with stenoses in the physiologically relevant range of flow conditions, and the results were used for the validation of the numerical solver. Analysis of the experimental data also demonstrated a strong impact of the vessels' elasticity on the pressure drop across a stenosis, as well as a substantial role of the time-dependent (pulsative) flow parameters. It has been shown that fine-tuning of the values of the viscous and turbulent resistance coefficients to account for the elasticity of the vessels surrounding the stenosis can substantially improve the accuracy of the pressure drop prediction in the intermediate lesions, specifically relevant for clinical applications.</p>\u0000 </div>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145126198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Study of Two Generations of Lumbar Disc Prostheses","authors":"Moussa Amadji","doi":"10.1002/cnm.70100","DOIUrl":"10.1002/cnm.70100","url":null,"abstract":"<div>\u0000 \u0000 <p>Total disc replacement (TDR) is an emerging technique for addressing degenerated intervertebral discs. However, the first generation of TDR has been associated with the generation of wear debris, which may adversely affect surrounding biological tissues, and they fail to fully replicate the range of motion (ROM) of a healthy intervertebral disc. This study aims to compare two generations of TDRs to determine which more effectively mimics the biomechanical behavior of a biological disc while minimizing associated complications. Four finite element models (healthy L4-L5, Prodisc-L, SB-Charité, and a second-generation TDR) were studied using Ansys under specific loads and moments: 7.5 Nm and 1175 N in flexion, 7.5 Nm and 500 N in extension, 7.8 Nm and 700 N in lateral bending, and 5.5 Nm and 720 N in axial rotation. First-generation TDRs reduce ROM in flexion (−61% for Prodisc-L, −65% for SB-Charité) and in extension (−59.37% and −79%). However, they increase ROM in lateral inclination (+121% and +100%) and in axial rotation (+129.41% and +111.76%). The second-generation TDR shows minimal deviations from the intact model, except in extension. First-generation of disc prostheses do not maintain 100% ROM of an intact intervertebral disc and generate wear debris during operation, potentially compromising surrounding biological tissues. In contrast, second-generation of disc prostheses closely mimic the ROM of an intact disc due to the hyperelastic properties of their core and eliminate wear debris production through to its monobloc design.</p>\u0000 </div>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145126188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Assessment of a Novel Generic Finite Element Spine Model for Clinical Applications","authors":"Yifan Su,&nbsp;Athanasios I. Tsirikos,&nbsp;Vasileios Koutsos,&nbsp;Pankaj Pankaj","doi":"10.1002/cnm.70098","DOIUrl":"https://doi.org/10.1002/cnm.70098","url":null,"abstract":"<p>Numerical modeling has been extensively employed to understand the biomechanics of the spine. Often, patient-specific models developed from medical scans, which are specific to an individual and their particular clinical case, are used. The aim of this study was to develop a generic model of the full adolescent spine, which includes ribs, muscles, and ligaments, that can effectively simulate realistic spinal biomechanics. The model was developed using computer-aided design, incorporating anatomical parameters to represent a 15-year-old adolescent full-spine geometry. Essential components like the ribcage and related musculature were included to capture realistic biomechanics. The model appraisal involved mesh sensitivity analysis and tests on selected functional spinal units (FSUs) in each spinal region to assess the biomechanics of specific components of the full spine. Biomechanical responses, including range of motion, intradiscal pressure, and facet joint forces, were evaluated across multiple simulated loading tasks. Results were compared to previous in vitro and in silico studies. Our model demonstrated good agreement with previous experimental and numerical studies. The ribcage inclusion simulated the stiffening effect observed in vivo satisfactorily. Ligamentous effect tests on thoracic and lumbar FSUs indicated that the model satisfactorily replicated expected biomechanical responses. The study shows that the developed model can be employed effectively to simulate real-life spine motions. The developed model will be used for future AIS research, enabling the investigation of surgical treatment outcomes across diverse clinical scenarios.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.70098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Modelling Using Uncertainty Quantification and Global Sensitivity for the Risk of Hernia Repair Fixation Failure","authors":"Katarzyna Szepietowska,&nbsp;Izabela Lubowiecka","doi":"10.1002/cnm.70096","DOIUrl":"10.1002/cnm.70096","url":null,"abstract":"<div>\u0000 \u0000 <p>Despite being a common procedure, abdominal hernia treatments still require improvement due to the number of relapses and other postoperative issues. In silico testing can be employed to predict the behavior of the complex abdominal wall and implant systems. Here, uncertainty quantification and sensitivity analysis are required in order to optimize the parameters of hernia repair models. This paper concerns the modeling of an abdominal wall and implant using the finite element method. A Gasser-Ogden-Holzapfel (GOH) material model is used for the abdominal wall and an orthotropic material model for the implant. The parameters of the GOH model and the orientation of the implant are assumed to be uncertain. Regression-based polynomial chaos expansion is used as a meta-modeling method for uncertainty propagation and global sensitivity analysis. The maximum force in the connection between the implant and native tissue is considered as the quantity of interest. A failure risk criterion is also defined and presented. It has been found that the significance of the material parameters depends on the type of implant that is analyzed. Likewise, the risk of connection failure varies considerably depending on the implant used. Models with different types of implant produce very diverse results. Moreover, these differences also appear in the global sensitivity index and the risk of connection failure. This would indicate that specific implant designs and material properties are crucial to the success of hernia repair surgery.</p>\u0000 </div>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Analysis of Three Different Intramedullary Nails for Fixture of Unstable Intertrochanteric Fractures","authors":"Chao-qing Huang,&nbsp;Xiao-wei Huang,&nbsp;Xing Wu","doi":"10.1002/cnm.70093","DOIUrl":"10.1002/cnm.70093","url":null,"abstract":"<div>\u0000 \u0000 <p>We aimed to analyze the effects of PFNA, InterTAN, and Gamma nails for the fixture of unstable intertrochanteric fractures (UIFs) by finite element analysis. 3D reconstruction models fixed with PFNA, InterTAN, and Gamma nail of the normal femur and unstable intertrochanteric fractures were created. Boundary conditions and load were set in advance, and finite element analysis was performed. Interfragmentary strain theory (IFS) was used to simulate the growth of callus. The Python language was used for the secondary development of ABAQUS to simulate the fracture healing process. The principal strain of the femur and the Von Mises stress of the device component were evaluated and compared by three nail fixation methods under four load conditions. There was no significant difference between InterTAN and Gamma nails in terms of peak strain within the implanted bone and maximum device stress values, and both bone strain and implant stress state were lower in the femur after implantation of PFNA nail fixation. Finite element analyses show that the Gamma nail is more suitable for fixing 31A2.2 intertrochanteric fracture. PFNA is more suitable for fixing UIFs except for 31A2.2 intertrochanteric fracture. Therefore, the implantation of PFNA nails in the femur can withstand more forces during exercise than InterTAN and Gamma nails, which have a faster pre-healing phase and are therefore more suitable for small fractures.</p>\u0000 </div>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145082311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Analysis of Laser Thermal Ablation for Gingival and Peri-Implant Inflammation Using Various Laser Irradiation Angles","authors":"Donghyuk Kim,&nbsp;Hyunjung Kim,&nbsp;Hee-Sun Kim","doi":"10.1002/cnm.70080","DOIUrl":"https://doi.org/10.1002/cnm.70080","url":null,"abstract":"<p>Because of tooth decay and loss, many people use dental implants as tooth replacements. However, careless management can trigger an inflammatory reaction to an implant. Recently, various studies have been conducted on the sterilization and purification of implant surfaces using diodes, Er:YAG lasers, and CO₂ lasers. In this study, the therapeutic effect of photothermal therapy, a laser treatment method for peri-implantitis, was analyzed through numerical analysis based on heat-transfer theory. The numerical simulation conditions included laser power values in the range of 0.0–4.0 W, laser irradiation angles ranging from 15° to 40°, and laser irradiation durations of 100–500 s. In addition, the Arrhenius damage integral was used to quantitatively verify the therapeutic effects of the photothermal therapy. An analysis of the results confirmed that the Arrhenius thermal damage ratio and normal tissue Arrhenius thermal damage ratio decreased as the laser irradiation angle increased. However, for the same normal tissue Arrhenius thermal damage ratio, the effective laser intensity increased with the laser angle. Finally, the effectiveness of photothermal therapy for peri-implantitis under various conditions was confirmed. These results are expected to optimize the clinical treatment of peri-implantitis in the future.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.70080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Numerical Evaluation of Wall Shear Stress Using the Finite Element Method","authors":"Jana Brunátová,&nbsp;Jørgen S. Dokken,&nbsp;Kristian Valen-Sendstad,&nbsp;Jaroslav Hron","doi":"10.1002/cnm.70086","DOIUrl":"https://doi.org/10.1002/cnm.70086","url":null,"abstract":"<p>Wall shear stress (WSS) is a crucial hemodynamic quantity extensively studied in cardiovascular research, yet its numerical computation is not straightforward. This work compares WSS results obtained from two different finite element discretizations, quantifies the differences between continuous and discontinuous stresses, and introduces a modified variationally consistent method for WSS evaluation through the formulation of a boundary-flux problem. Two benchmark problems are considered: a 2D Stokes flow on a unit square and a 3D Poiseuille flow through a cylindrical pipe. These are followed by investigations of steady-state Navier–Stokes flow in two image-based, patient-specific aneurysms. The study focuses on P1/P1 stabilized and Taylor–Hood P2/P1 mixed finite elements for velocity and pressure. WSS is computed using either the proposed boundary-flux method or as a projection of tangential traction onto first order Lagrange (P1), discontinuous Galerkin first order (DG-1), or discontinuous Galerkin zero order (DG-0) space. For the P1/P1 stabilized element, the boundary-flux and P1 projection methods yielded equivalent results. With the P2/P1 element, the boundary-flux evaluation demonstrated faster convergence in the Poiseuille flow example but showed increased sensitivity to pressure field inaccuracies in image-based geometries compared to the projection method. Furthermore, a paradoxical degradation in WSS accuracy was observed when combining the P2/P1 element with fine boundary-layer meshes on a cylindrical geometry, an effect attributed to inherent geometric approximation errors. In aneurysm geometries, the P2/P1 element exhibited superior robustness to mesh size when evaluating average WSS and low shear area (LSA), outperforming the P1/P1 stabilized element. Projecting discontinuous finite element functions into continuous spaces can introduce artifacts, such as the Gibbs phenomenon. Consequently, it is crucial to carefully select the finite element space for boundary stress calculations, not only in applications involving WSS computations for aneurysms.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"41 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.70086","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}