Medical Engineering & Physics最新文献

{"title":"Aortic strain, flow pattern and wall shear stress in a patient-specific compliant aorta replica using Shake-the-Box","authors":"Xiaolin Wu ,&nbsp;Kaspar M.B. Jansen ,&nbsp;Jos J.M. Westenberg ,&nbsp;Hildo J. Lamb ,&nbsp;Saša Kenjereš","doi":"10.1016/j.medengphy.2024.104263","DOIUrl":"10.1016/j.medengphy.2024.104263","url":null,"abstract":"<div><div>High-fidelity <em>in vitro</em> flow simulator in combination with high-dimensional flow visualization techniques can offer precise and comprehensive evaluation of aortic hemodynamics. However, it is particularly challenging to create a fully transparent aorta replica that faithfully mimics the aortic curvature and stiffness. In this study, we successfully manufactured a patient-specific compliant aorta phantom with a dilated ascending aorta that can be used <em>in vitro</em> hemodynamic study. We conducted pulsatile flow measurement on the deformable aorta replica using advanced 4D particle tracking velocimetry – Shake-the-Box. The aortic distensibility, circumferential strain, flow pattern, wall shear stress (WSS), and turbulent kinetic energy were assessed. Furthermore, the peak velocity field and WSS distribution were compared to <em>in vivo</em> MRI measurements. We found that the distensibility and circumferential strain of our aortic replica fell within the physiological range of young patients. The aortic diameter changed as much as 5.4 mm (42 %) in a cardiac cycle and the aortic distensibility was 9.9 × 10^–3 mmHg^-1. In addition, the obtained flow pattern and WSS distribution were found in a good agreement with <em>in vivo</em> MRI measurement. In conclusion, the compliant aorta phantom replicated the aortic wall material well. It also faithfully simulated the aortic flow and near-wall hemodynamics. The relatively large lumen dimension change (5.4 mm) in a cardiac cycle suggests the necessity of considering wall deformation in aortic flow simulations. We propose employing this approach for future studies, such as medical treatment training, validation of <em>in silico</em> fluid-structure interaction models, or as a complement to <em>in vivo</em> measurements.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"135 ","pages":"Article 104263"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135690","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":"Long-duration electrocardiogram classification based on Subspace Search VMD and Fourier Pooling Broad Learning System","authors":"Xiao-li Wang ,&nbsp;Run-jie Wu ,&nbsp;Qi Feng ,&nbsp;Jian-bin Xiong","doi":"10.1016/j.medengphy.2024.104267","DOIUrl":"10.1016/j.medengphy.2024.104267","url":null,"abstract":"<div><div>Detecting early stages of cardiovascular disease from short-duration Electrocardiogram (ECG) signals is challenging. However, long-duration ECG data are susceptible to various types of noise during acquisition. To tackle the problem, Subspace Search Variational Mode Decomposition (SSVMD) was proposed, which determines the optimal solution by continuously narrowing the parameter subspace and implements data preprocessing by removing baseline drift noise and high-frequency noise modes. In response to the unclear spatial characteristics and excessive data dimension in long-duration ECG data, a Fourier Pooling Broad Learning System (FPBLS) is proposed. FPBLS integrates a Fourier feature layer and a broad pooling layer to express the input data with more obvious features, reducing the data dimension and maintaining effective features. The theory is verified using the MIT-BIH arrhythmia database and achieves better results compared to the latest literature method.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"135 ","pages":"Article 104267"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135691","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":"Hearing the unheard: Fundamentals of acoustic emission signals as predictors of total hip arthroplasty implant loosening","authors":"Magnus Reulbach ,&nbsp;Longwei Cong ,&nbsp;Bernd-Arno Behrens ,&nbsp;Eike Jakubowitz","doi":"10.1016/j.medengphy.2024.104266","DOIUrl":"10.1016/j.medengphy.2024.104266","url":null,"abstract":"<div><div>Implant loosening remains a primary cause of failure of total hip arthroplasty<span><span>¹</span></span> (THA) and is often detected late, when pain occurs. Acoustic emission<span><span>²</span></span> (AE) analysis is a promising method for early loosening detection, on the supposition that relative movements at the bone–implant interface induce detectable AE signals. To distinguish loosening-induced AE signals from those of stable THA components <em>in vitro</em> investigations are necessary. Substituting human with animal bone for such testing could enable simplified and cost-effective sample preparation. The aim of this study was to investigate whether AE signals differ between bone tissues of different species. AE signals generated by relative movements between TiAl₆V₄ and human, bovine, and porcine cortical bone were investigated. Per species, 125 movements were analyzed, with 26 AE features identified for each movement. The most important time and frequency features of AE signals from human bone differed significantly from those of both animal species. Signals of human origin were longer and exhibited higher rise time. The main frequency components of human AE signals were in a lower frequency range, with a centroid frequency of 113.7 kHz. Based on these differences, it is not advisable to replace human cortical bone with animal bone for AE-related <em>in vitro</em> studies.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104266"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748412","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":"Merging mixed reality and computational modeling for enhanced visualization of cardiac biomechanics","authors":"Eleonora Costagliola ,&nbsp;Francesco Musumeci ,&nbsp;Caterina Gandolfo ,&nbsp;Michele Pilato ,&nbsp;Salvatore Pasta","doi":"10.1016/j.medengphy.2024.104258","DOIUrl":"10.1016/j.medengphy.2024.104258","url":null,"abstract":"<div><div>Mixed reality (MR) has the potential to complement numerical simulations for enhanced post-processing and integrate digital models into the daily clinical practice of healthcare professionals. In complex cardiac anatomies, the decision-making process for bioprosthesis implantation involves the challenging analysis of heart valve distribution, positioning, and sealing. This study proposes a framework to visualize computational modeling results in an immersive environment for comprehensive analysis of the geometric implications of implanted devices on human heart function. After computational analysis, the biomechanical behavior of the Living Heart Human Model (LHHM) was used to develop MR content for the immersive visualization of the heart kinematics and the electrical field. Additionally, MR content was developed to assess the spatial implications of left ventricular outflow tract (LVOT) obstruction as observed in transcatheter mitral valve replacement (TMVR). Findings demonstrated that augmented exploration of cardiac biomechanics can be used for a better understanding of the electrical field of the beating heart. In the case of TMVR simulation, MR-related analysis of LVOT obstruction can result in improved visualization and manipulation of 3D anatomies and assessment of device-induced anatomic constraints. We conclude that the synergy between in-silico modeling and MR can potentially enhance physicians' ability to visualize the implications of biomedical device implants in complex cardiac anatomies, benefiting both physicians and simulation experts.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104258"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756716","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":"Effect of excitation sequence of myocardial contraction on the mechanical response of the left ventricle","authors":"Giorgos Troulliotis ,&nbsp;Alison Duncan ,&nbsp;Xiao Yun Xu ,&nbsp;Alessandro Gandaglia ,&nbsp;Fillipo Naso ,&nbsp;Hendrik Versteeg ,&nbsp;Saeed Mirsadraee ,&nbsp;Sotiris Korossis","doi":"10.1016/j.medengphy.2024.104255","DOIUrl":"10.1016/j.medengphy.2024.104255","url":null,"abstract":"<div><div>In the past two decades there has been rapid development in the field of computational cardiac models. These have included either (i) mechanical models that assumed simultaneous myocardial activation, or (ii) electromechanical models that assumed time-varying myocardial activation. The influence of these modelling assumptions of myocardial activation on clinically relevant metrics, like myocardial strain, commonly used for validation of cardiac models has yet to be systematically examined, leading to uncertainty over their influence on the predictions of these models. This study examined the effects of simultaneous (mechanical), uniform endocardial, 3-patch endocardial (simulating the fascicles of the His-Purkinje system) and 1-patch endocardial (simulating the atrioventricular node) excitation sequences on the mechanical response of a synthetic human left ventricular model. The influence of the duration of the activation and time-to-peak contraction was also investigated. The electromechanical and mechanical models produced different strain distributions in early systole. However, these differences decayed as systole progressed. Using the same activation duration (74 ms) the average peak-systolic circumferential strain difference between the models was 0.65±0.37 %. A slightly prolonged activation duration (134 ms) resulted in no substantial difference increase (0.76±0.47 %). Differences up to 3.5 % were observed for prolonged activation durations (200 ms). Endocardial excitation produced non-physiological cumulative activation time distributions compared to the other models. Septal 1-patch excitation resulted in early systolic strain response that resembled pathological left bundle branch block. Decreased time-to-peak contraction exaggerated the effects of electrophysiology. The study found that excitation sequence minimally affects strain distributions at peak systole for physiological and even slightly pathological activation durations. However, electromechanical models with (patho)physiologically informed activation sequences are important for the accurate prediction of early systolic and pathological late systolic responses.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104255"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748413","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":"Medial and lateral knee contact forces and muscle forces during sit-to-stand in patients one year after unilateral total knee arthroplasty","authors":"Erik Kowalski ,&nbsp;Alexandre R.M. Pelegrinelli ,&nbsp;Danilo S. Catelli ,&nbsp;Geoffrey Dervin ,&nbsp;Mario Lamontagne","doi":"10.1016/j.medengphy.2024.104262","DOIUrl":"10.1016/j.medengphy.2024.104262","url":null,"abstract":"<div><div>Understanding how forces are transmitted through the knee after TKA is essential, as it may explain why many patients experience pain or functional limitations during various activities. This study compared knee muscle forces and knee contact forces (KCF) during sit-to-stand in patients one year after unilateral total knee arthroplasty (TKA) with either a medial ball-and-socket (MBS) or posterior stabilized (PS) implant and compared them to a group of similarly healthy aged controls (CTRL). A musculoskeletal model and static optimization estimated lower limb kinematics, knee kinetics, muscle forces, and KCFs. The normalized sit-to-stand cycle was compared among the groups using statistical nonparametric mapping, and peak between-limb differences were compared using discrete statistics. The PS group required greater forward lean during the sit-to-stand task, causing greater spine flexion, posterior pelvic tilt, and decreased hip flexion on the operated limb. PS and MBS groups favoured their non-operated limb, resulting in less range of motion throughout the lower limb, lower knee kinetics, muscle forces, and KCFs on the operated limb. Compared to the controls, the MBS and PS groups had reduced medial compartment KCF. The control group did favour their dominant limb over their non-dominant limb. Post-operative rehabilitation should continue to promote greater use of the operated knee to have more symmetrical loading between operated and non-operated limbs and improve strength and mobility at the hip and ankle joints. One year after surgery, TKA patients remain with reduced muscle forces and KCF on their operated limb during a sit-to-stand task, regardless whether they received an MBS or PS implant.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104262"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142822894","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":"Effect of plantar fascia stiffness on plantar windlass mechanism and arch: Finite element method and dual fluoroscopic imaging system verification","authors":"Qiaolin Zhang ,&nbsp;Dong Sun ,&nbsp;Meizi Wang ,&nbsp;Viktória Tafferner-Gulyás ,&nbsp;Hairong Chen ,&nbsp;István Bíró ,&nbsp;Yaodong Gu","doi":"10.1016/j.medengphy.2024.104259","DOIUrl":"10.1016/j.medengphy.2024.104259","url":null,"abstract":"<div><div>This study explored the relationship between the foot arch stiffness and windlass mechanism, focusing on the contribution of the posterior transverse arch. Understanding the changing characteristics of foot stiffness is critical for providing a scientific basis for treating foot-related diseases. Based on a healthy male's computed tomography, kinematic, and dynamics data, a foot musculoskeletal finite element model with a dorsiflexion angle of 30°of metatarsophalangeal joint was established. Analyze the changes in stress distribution of the plantar fascia, metatarsophalangeal joint angle, arch height, and length during barefoot walking as the stiffness of the plantar fascia varies from 25 % to 200 %. For validation, the simulated arch parameters were compared with the dual fluorescence imaging system measurements. The width of transverse arch, height, and length of longitudinal arch measured by the dual fluorescence imaging system were 45.14 ± 1.63 mm, 29.29 ± 1.57 mm, and 155.16 ± 2.69 mm, respectively. The results of the simulation were 46.51 mm, 29.96 mm, and 156.71 mm, respectively. With the increase of plantar fascia stiffness, the effect of the windlass mechanism increased, the flexion angle of the metatarsophalangeal joint decreased, the distal stress of plantar fascia decreased gradually, while the proximal and middle stress increased, the transverse arch angle increased, but when the plantar fascia stiffness exceeds 150 %, the transverse arch angle decreases. The increase of plantar fascia stiffness will increase the effect of the windlass mechanism but decrease the flexion angle of the metatarsophalangeal joint. The stiffness of the plantar fascia influences the behavior of the plantar fascia. The plantar fascia stiffness affects the distal tension of the plantar fascia by affecting the flexion of the metatarsophalangeal joint in the plantar windlass mechanism. It affects the stiffness of the transverse arch of the foot together with the ground reaction force acting on the distal metatarsal.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104259"},"PeriodicalIF":1.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698491","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":"The effect of the length of chimney's protrusion on the hemodynamics of abdominal aorta stent graft after endovascular aneurysm repair","authors":"Moshe Brand ,&nbsp;Hila Ben-Gur ,&nbsp;Moshe Halak","doi":"10.1016/j.medengphy.2024.104256","DOIUrl":"10.1016/j.medengphy.2024.104256","url":null,"abstract":"<div><h3>Introduction</h3><div>Abdominal aortic aneurysms present a significant clinical challenge, particularly when located near the renal arteries. In cases of infra-renal abdominal aortic aneurysms, the main stent graft may occlude the renal arteries, disrupting blood supply. To prevent this, two 'chimney' stent grafts can be implanted to maintain renal artery perfusion.</div></div><div><h3>Method</h3><div>This study investigates the impact of chimney stent graft protrusion length on the hemodynamics of stent graft using computational fluid dynamics (CFD). Two chimney configurations were analyzed, with the chimney protruding 10 and 30 mm above the upper part of the main stent graft. Key hemodynamic parameters were compared, including wall shear stress, blood flow velocity, and pathlines.</div></div><div><h3>Results</h3><div>The CFD analysis showed no substantial differences in hemodynamic parameters between these configurations.</div></div><div><h3>Conclusions</h3><div>The findings indicate negligible hemodynamic differences between the two chimney configurations. A chimney that protrudes 30 mm above the main stent graft is a viable option and may help reduce procedure time and patient risk.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104256"},"PeriodicalIF":1.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697999","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":"Thermal simulation of the lower limb in vascular medicine: A proof-of-concept by using computed tomography images","authors":"Tomppa Pakarinen ,&nbsp;Eko Hakala ,&nbsp;Otso Arponen ,&nbsp;Emppu Kuokkanen ,&nbsp;Niku Oksala ,&nbsp;Antti Vehkaoja","doi":"10.1016/j.medengphy.2024.104260","DOIUrl":"10.1016/j.medengphy.2024.104260","url":null,"abstract":"<div><div>Simulations of physiology based on patient-specific anatomical structures have several potential applications in medicine. A few fields, such as radiotherapy and neurophysiology already utilize such methods in clinical practice, yet a number of disciplines could benefit from similar technologies, especially when imaging data is already available. The major problem in patient-specific simulation is the data conversion to simulation-compatible form i.e., data preparation and the coupling of the underlying physics to the anatomical model. In this work we present such a methodology in the context of vascular medicine, consisting of a three-dimensional blood flow-temperature simulation model of the lower limb built from computed tomography data. We also simulate a clinical condition of chronic limb-threatening ischemia, a severe complication of peripheral arterial disease. This proof-of-concept model simulates the limb's surface temperature with respect to the vascular structure. The methodology, depicting accurate patient anatomy, is a promising step towards individualized physiological simulations in vascular medicine, although more research and validation are required. Such a model could eventually outline a deeper understanding of the relation between vascular changes and peripheral thermal behavior.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104260"},"PeriodicalIF":1.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722594","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":"Open laminectomy plus posterolateral fusion versus open laminectomy plus transforaminal lumbar interbody fusion surgical approaches for fusing degenerated L4-L5 segment: A comparative finite element study","authors":"Kishore Pradeep,&nbsp;Bidyut Pal","doi":"10.1016/j.medengphy.2024.104261","DOIUrl":"10.1016/j.medengphy.2024.104261","url":null,"abstract":"<div><div>Various finite element (FE) studies reported the biomechanical effects of fusion surgeries in the lumbar spine. However, a comparative study on Open laminectomy plus Posterolateral Fusion (OL-PLF) and Open Laminectomy plus Transforaminal Lumbar Interbody Fusion (OL-TLIF) for fusing an L4-L5 segment has not been reported in the literature. The present comparative FE study evaluates the biomechanical variations in an L4-L5 segment fused using OL-PLF and OL-TLIF surgical approaches. The three-dimensional implanted models were constructed from a computed-tomography scan dataset using image processing software. The models were simulated for the physiological movements such as lateral bending, flexion and extension. The OL-TLIF model had a considerably larger peak equivalent strain than the OL-PLF model under extension (126 %), lateral bending (88 %) and flexion (13 %). However, in both implanted models, a peak equivalent strain above the compressive yield strain limit of the vertebra (0.007) was observed over 60 % of the L4-L5 fused segment, indicating an imminent post-operative bone failure under the imposed loading conditions. The maximum equivalent strain observed in the disc and endplates of the L3-L4 segment was substantially larger to initiate the adjacent segment degeneration. No discernible biomechanical benefits were observed for the OL-TLIF or OL-PLF approaches in fusing the L4-L5 segment.</div></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"134 ","pages":"Article 104261"},"PeriodicalIF":1.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697998","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}