International Journal for Numerical Methods in Biomedical Engineering最新文献

{"title":"Fluid–structure interaction analysis of a healthy aortic valve and its surrounding haemodynamics","authors":"Zhongjie Yin,&nbsp;Chlöe Armour,&nbsp;Harkamaljot Kandail,&nbsp;Declan P. O'Regan,&nbsp;Toufan Bahrami,&nbsp;Saeed Mirsadraee,&nbsp;Selene Pirola,&nbsp;Xiao Yun Xu","doi":"10.1002/cnm.3865","DOIUrl":"10.1002/cnm.3865","url":null,"abstract":"<p>The opening and closing dynamics of the aortic valve (AV) has a strong influence on haemodynamics in the aortic root, and both play a pivotal role in maintaining normal physiological functions of the valve. The aim of this study was to establish a subject-specific fluid–structure interaction (FSI) workflow capable of simulating the motion of a tricuspid healthy valve and the surrounding haemodynamics under physiologically realistic conditions. A subject-specific aortic root was reconstructed from magnetic resonance (MR) images acquired from a healthy volunteer, whilst the valve leaflets were built using a parametric model fitted to the subject-specific aortic root geometry. The material behaviour of the leaflets was described using the isotropic hyperelastic Ogden model, and subject-specific boundary conditions were derived from 4D-flow MR imaging (4D-MRI). Strongly coupled FSI simulations were performed using a finite volume-based boundary conforming method implemented in FlowVision. Our FSI model was able to simulate the opening and closing of the AV throughout the entire cardiac cycle. Comparisons of simulation results with 4D-MRI showed a good agreement in key haemodynamic parameters, with stroke volume differing by 7.5% and the maximum jet velocity differing by less than 1%. Detailed analysis of wall shear stress (WSS) on the leaflets revealed much higher WSS on the ventricular side than the aortic side and different spatial patterns amongst the three leaflets.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.3865","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114359","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":"A semi-automatic method for block-structured hexahedral meshing of aortic dissections","authors":"Domagoj Bošnjak,&nbsp;Antonio Pepe,&nbsp;Richard Schussnig,&nbsp;Jan Egger,&nbsp;Thomas-Peter Fries","doi":"10.1002/cnm.3860","DOIUrl":"10.1002/cnm.3860","url":null,"abstract":"<p>The article presents a semi-automatic approach to generating structured hexahedral meshes of patient-specific aortas ailed by <i>aortic dissection</i>. The condition manifests itself as a formation of two blood flow channels in the aorta, as a result of a tear in the inner layers of the aortic wall. Subsequently, the morphology of the aorta is greatly impacted, making the task of domain discretization highly challenging. The meshing algorithm presented herein is automatic for the individual lumina, whereas the tears require user interaction. Starting from an input (triangle) surface mesh, we construct an <i>implicit surface representation</i> as well as a <i>topological skeleton</i>, which provides a basis for the generation of a <i>block-structure</i>. Thereafter, the mesh generation is performed via <i>transfinite maps</i>. The meshes are structured and fully hexahedral, exhibit good quality and reliably match the original surface. As they are generated with computational fluid dynamics in mind, a fluid flow simulation is performed to verify their usefulness. Moreover, since the approach is based on valid block-structures, the meshes can be made very coarse (around 1000 elements for an entire aortic dissection domain), and thus promote using solvers based on the geometric multigrid method, which is typically reliant on the presence of a hierarchy of coarser meshes.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.3860","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114358","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":"A comparison of machine learning methods for recovering noisy and missing 4D flow MRI data","authors":"Hunor Csala,&nbsp;Omid Amili,&nbsp;Roshan M. D'Souza,&nbsp;Amirhossein Arzani","doi":"10.1002/cnm.3858","DOIUrl":"10.1002/cnm.3858","url":null,"abstract":"<p>Experimental blood flow measurement techniques are invaluable for a better understanding of cardiovascular disease formation, progression, and treatment. One of the emerging methods is time-resolved three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI), which enables noninvasive time-dependent velocity measurements within large vessels. However, several limitations hinder the usability of 4D flow MRI and other experimental methods for quantitative hemodynamics analysis. These mainly include measurement noise, corrupt or missing data, low spatiotemporal resolution, and other artifacts. Traditional filtering is routinely applied for denoising experimental blood flow data without any detailed discussion on why it is preferred over other methods. In this study, filtering is compared to different singular value decomposition (SVD)-based machine learning and autoencoder-type deep learning methods for denoising and filling in missing data (imputation). An artificially corrupted and voxelized computational fluid dynamics (CFD) simulation as well as in vitro 4D flow MRI data are used to test the methods. SVD-based algorithms achieve excellent results for the idealized case but severely struggle when applied to in vitro data. The autoencoders are shown to be versatile and applicable to all investigated cases. For denoising, the in vitro 4D flow MRI data, the denoising autoencoder (DAE), and the Noise2Noise (N2N) autoencoder produced better reconstructions than filtering both qualitatively and quantitatively. Deep learning methods such as N2N can result in noise-free velocity fields even though they did not use clean data during training. This work presents one of the first comprehensive assessments and comparisons of various classical and modern machine-learning methods for enhancing corrupt cardiovascular flow data in diseased arteries for both synthetic and experimental test cases.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.3858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142082453","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":"Personalized optimization strategy for electrode array layout in TTFields of glioblastoma","authors":"Liang Wang,&nbsp;Chunxiao Chen,&nbsp;Yueyue Xiao,&nbsp;Rongfang Gong,&nbsp;Jun Shen,&nbsp;Ming Lu","doi":"10.1002/cnm.3859","DOIUrl":"10.1002/cnm.3859","url":null,"abstract":"<p>Tumor treating fields (TTFields) is a novel therapeutic approach for the treatment of glioblastoma. The electric field intensity is a critical factor in the therapeutic efficacy of TTFields, as stronger electric field can more effectively impede the proliferation and survival of tumor cells. In this study, we aimed to improve the therapeutic effectiveness of TTFields by optimizing the position of electrode arrays, resulting in an increased electric field intensity at the tumor. Three representative head models of real glioblastoma patients were used as the research subjects in this study. The improved subtraction-average-based optimization (ISABO) algorithm based on circle chaos mapping, opposition-based learning and golden sine strategy, was employed to optimize the positions of the four sets of electrode arrays on the scalp. The electrode positions are dynamically adjusted through iterative search to maximize the electric field intensity at the tumor. The experimental results indicate that, in comparison to the conventional layout, the positions of the electrode arrays obtained by the ISABO algorithm can achieve average electric field intensity of 1.7887, 2.0058, and 1.3497 V/cm at the tumor of three glioblastoma patients, which are 23.6%, 29.4%, and 8.5% higher than the conventional layout, respectively. This study demonstrates that optimizing the location of the TTFields electrode array using the ISABO algorithm can effectively enhance the electric field intensity and treatment coverage in the tumor area, offering a more effective approach for personalized TTFields treatment.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001204","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":"Solid-state laser (266 nm) as an alternative to ArF excimer laser (193 nm) for corneal reshaping: Comparative numerical study of the thermal effect","authors":"Ibrahim Abdelhalim,&nbsp;Aziza Ahmed Hassan,&nbsp;Salwa Abdelkawi,&nbsp;Salah Hassab Elnaby,&nbsp;Sahar Rahbar,&nbsp;Omnia Hamdy","doi":"10.1002/cnm.3861","DOIUrl":"10.1002/cnm.3861","url":null,"abstract":"<p>Laser corneal reshaping is a safe and effective technique utilized to treat common vision disorders. An advanced laser delivery system equipped with a pulsed UV laser with specific parameters is used to ablate parts of the cornea surface to correct the existing refractive error. The argon fluoride (ArF) excimer pulsed gas laser at 193 nm is the most employed type in the commercial devices for such treatments. This laser is generated using a mixture of Argon, Fluorine, and a significant amount of Neon gases. However, due to the ongoing Russian-Ukraine war, the availability of Neon gas is currently very limited, as this region is considered the primary supplier of pure Neon gas. Consequently we suggest replacing the common ArF laser source in the commercial devices with a solid-state (forth harmonic neodymium-doped yttrium aluminum garnet laser at 266 nm). This replacement uses the same operation parameters, optics, and scanning algorithm. Parameters from five commercial devices (Zeiss MEL 90, Technolas TENEO 317, Alcon Wave Light EX 500, Schwind Amaris 750 s, OptoSystems MICROSCAN VISUM) were compared with those of the i-ablation device, a research device that uses a 266 nm laser source. Our goal is to reduce production costs through a simple modification that has a significant impact. Consequently, the present study aims to find an alternative laser source for the current ArF laser without exchanging the complete system's design. This recommendation is based on a numerical simulation study. The thermal effect on a human cornea model was numerically evaluated using finite-element solutions of Pennes' bioheat equation on the COMSOL platform by applying two laser wavelengths. The results demonstrated that changing the laser source significantly impacts the thermal effect, even with the same laser settings. All studied devices showed a reduction in the thermal effect to below 40°C, compared with nearly 100°C under ordinary conditions.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001183","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":"Reduced order modelling of intracranial aneurysm flow using proper orthogonal decomposition and neural networks","authors":"Michael MacRaild,&nbsp;Ali Sarrami-Foroushani,&nbsp;Toni Lassila,&nbsp;Alejandro F. Frangi","doi":"10.1002/cnm.3848","DOIUrl":"10.1002/cnm.3848","url":null,"abstract":"<p>Reduced order modelling (ROMs) methods, such as proper orthogonal decomposition (POD), systematically reduce the dimensionality of high-fidelity computational models and potentially achieve large gains in execution speed. Machine learning (ML) using neural networks has been used to overcome limitations of traditional ROM techniques when applied to nonlinear problems, which has led to the recent development of reduced order models augmented by machine learning (ML-ROMs). However, the performance of ML-ROMs is yet to be widely evaluated in realistic applications and questions remain regarding the optimal design of ML-ROMs. In this study, we investigate the application of a non-intrusive parametric ML-ROM to a nonlinear, time-dependent fluid dynamics problem in a complex 3D geometry. We construct the ML-ROM using POD for dimensionality reduction and neural networks for interpolation of the ROM coefficients. We compare three different network designs in terms of approximation accuracy and performance. We test our ML-ROM on a flow problem in intracranial aneurysms, where flow variability effects are important when evaluating rupture risk and simulating treatment outcomes. The best-performing network design in our comparison used a two-stage POD reduction, a technique rarely used in previous studies. The best-performing ROM achieved mean test accuracies of 98.6% and 97.6% in the parent vessel and the aneurysm, respectively, while providing speed-up factors of the order <span></span><math>\u0000 <mrow>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>5</mn>\u0000 </msup>\u0000 </mrow></math>.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.3848","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001182","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":"Biomechanical behavior of temporomandibular joint movements driven by mastication muscles","authors":"Kang-jie Cheng,&nbsp;Qing-qing Zhang,&nbsp;Feng Zhang,&nbsp;Russell Wang,&nbsp;Yun-feng Liu","doi":"10.1002/cnm.3862","DOIUrl":"10.1002/cnm.3862","url":null,"abstract":"<p>Surgery of jawbones has a high potential risk of causing complications associated with temporomandibular joint disorder (TMD). The objective of this study was to investigate the effects of two drive modeling methods on the biomechanical behavior of the temporomandibular joint (TMJ) including articular disc during mandibular movements. A finite element (FE) model from a healthy human computed tomography was used to evaluate TMJ dynamic using two methods, namely, a conventional spatial-oriented method (displacement-driven) and a compliant muscle-initiated method (masticatory muscle-driven). The same virtual FE model was 3D printed and a custom designed experimental platform was established to validate the accuracy of experimental and theoretical results of the TMJ biomechanics during mandibular movements. The results show that stress distributed to TMJ and articular disc from mandibular movements provided better representation from the muscle-driving approach than those of the displacement-driven modeling. The simulation and experimental data exhibited significant strong correlations during opening, protrusion, and laterotrusion (with canonical correlation coefficients of 0.994, 0.993, and 0.932, respectively). The use of muscle-driven modeling holds promise for more accurate forecasting of stress analysis of TMJ and articular disc during mandibular movements. The compliant approach to analyze TMJ dynamics would potentially contribute to clinic diagnosis and prediction of TMD resulting from occlusal disease and jawbone surgery such as orthognathic surgery or tumor resection.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141983777","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":"Stem to prevent periprosthetic fracture after notching in total knee arthroplasty","authors":"Qian Wan,&nbsp;Aobo Zhang,&nbsp;Yang Liu,&nbsp;Hao Chen,&nbsp;Xue Zhao,&nbsp;Qing Han,&nbsp;Jincheng Wang","doi":"10.1002/cnm.3842","DOIUrl":"10.1002/cnm.3842","url":null,"abstract":"<p>Improper osteotomy during total knee arthroplasty (TKA) can lead to anterior femoral notching, which increases the risk of periprosthetic fractures due to stress concentration. One potential solution is the addition of an intramedullary stem to the femoral component. However, the optimal stem length remains unclear. In this study, we aimed to determine the optimal stem length using finite element models. Finite element models of femurs were developed with unstemmed prostheses and prostheses with stem lengths of 50, 75, and 100 mm. Under squat loading conditions, the von Mises stress at the notch and stress distribution on four transversal sections of the femur were analyzed. Additionally, micromotion of the prosthesis–bone interface was evaluated to assess initial stability. The unstemmed prosthesis exhibited a von Mises stress of 191.8 MPa at the notch, which decreased to 43.1, 8.8, and 23.5 MPa for stem lengths of 50, 75, and 100 mm, respectively. The stress reduction on four selected femoral transversal sections compared with the unstemmed prosthesis was 40.0%, 84.4%, and 67.1% for stem lengths of 50, 75, and 100 mm, respectively. Micromotion analysis showed a maximum of 118.8 μm for the unstemmed prosthesis, which decreased significantly with the application of stems, particularly at the anterior flange. Intramedullary stems effectively reduced stress concentration at the femoral notch. The 50-mm stem length provided the optimal combination of reduced notch stress, minimized stress-shielding effect, and decreased micromotion at the anterior flange.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141890703","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":"Flow reduction due to arterial catheterization during stroke treatment – A computational study using a distributed compartment model","authors":"Aseem Pradhan,&nbsp;Fernando Mut,&nbsp;Medhini Sosale,&nbsp;Juan Cebral","doi":"10.1002/cnm.3853","DOIUrl":"10.1002/cnm.3853","url":null,"abstract":"<p>The effectiveness of various stroke treatments depends on the anatomical variability of the cerebral vasculature, particularly the collateral blood vessel network. Collaterals at the level of the Circle of Willis and distal collaterals, such as the leptomeningeal arteries, serve as alternative avenues of flow when the primary pathway is obstructed during an ischemic stroke. Stroke treatment typically involves catheterization of the primary pathway, and the potential risk of further flow reduction to the affected brain area during this treatment has not been previously investigated. To address this clinical question, we derived the lumped parameters for catheterized blood vessels and implemented a corresponding distributed compartment (0D) model. This 0D model was validated against an experimental model and benchmark test cases solved using a 1D model. Additionally, we compared various off-center catheter trajectories modeled using a 3D solver to this 0D model. The differences between them were minimal, validating the simplifying assumption of the central catheter placement in the 0D model. The 0D model was then used to simulate blood flows in realistic cerebral arterial networks with different collateralization characteristics. Ischemic strokes were modeled by occlusion of the M1 segment of the middle cerebral artery in these networks. Catheters of different diameters were inserted up to the obstructed segment and flow alterations in the network were calculated. Results showed up to 45% maximum blood flow reduction in the affected brain region. These findings suggest that catheterization during stroke treatment may have a further detrimental effect for some patients with poor collateralization.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cnm.3853","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141876561","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 model-based hemodynamic comparisons of traditional and modified idealized models of autologous radiocephalic fistula","authors":"Fan Wang,&nbsp;Baohui Wang,&nbsp;Jinfeng Guo,&nbsp;Tian Zhang,&nbsp;Weina Mu,&nbsp;Chunhui Liu","doi":"10.1002/cnm.3856","DOIUrl":"10.1002/cnm.3856","url":null,"abstract":"<p>Autologous arteriovenous fistula (AVF) is a commonly used vascular access (VA) for hemodialysis, and hemodynamic changes are one of the main factors for its failure. To explore the effect of geometry on the hemodynamics in the AVF, a modified model is built with a gradual and smooth turn at the anastomosis and is compared with the traditional model, which has an abrupt sharp turn at the anastomisis. Transient computational fluid dynamics (CFD) simulations were performed for the comparison and analysis of the hemodynamic fields of the two models at different stages of the pulse cycle. The results showed that the low shear stress region and high oscillatory shear stress region in the modified AVF model coincided with regions of intimal hyperplasia that have been identified by previous studies. A comparison with the blood flow velocities measured in vivo was performed, and the error between the simulation results and the medical data was reduced by 22% in the modified model, which verifies the rationality and utility of the modified model.</p>","PeriodicalId":50349,"journal":{"name":"International Journal for Numerical Methods in Biomedical Engineering","volume":"40 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141793972","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}