Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine最新文献_第4页

Multiphase fluid-solid interaction analysis of stent-vessel-blood based on type B aortic dissection. 基于B型主动脉夹层支架-血管血液的多相流固相互作用分析。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-01 Epub Date: 2025-07-07 DOI: 10.1177/09544119251344437

Shirun Zhong, Yang Ouyang, Geng'e Zhang, Shanshan Hu, Feixiang Xiong

{"title":"Multiphase fluid-solid interaction analysis of stent-vessel-blood based on type B aortic dissection.","authors":"Shirun Zhong, Yang Ouyang, Geng'e Zhang, Shanshan Hu, Feixiang Xiong","doi":"10.1177/09544119251344437","DOIUrl":"10.1177/09544119251344437","url":null,"abstract":"Thoracic endovascular aortic repair (TEVAR) is an effective treatment method for Stanford type B aortic dissection (TB-AD). In the investigation of treatment methods of TEVAR, numerical simulation technologies play a pivotal role. However, current finite element simulations of AD often use overly simplified vascular models and fail to adequately consider the complex interactions between stents, vessels, and blood. In this study, a Boolean operation was adopted to establish 3D models of TB-AD based on patient-specific CT images. The 3D software was used to construct 5, 6, and 8-peak stent grafts. A finite element method was applied to simulate the compression and release processing of stent graft deployment. Finally, a fluid-solid interaction module was constructed for the multiphase fluid-solid interaction simulation. The results showed that after stent graft deployment, the cross-sectional area of the vessels in the aortic coarctation region increased by 60.0%-65.5%. The maximum blood flow velocity in the true lumen decreased from 1.585 m/s to 1.125-1.238 m/s. The maximum blood pressure increased from 1574 Pa (true lumen) and 1853 Pa (false lumen) to 2021-2165 Pa (true lumen). The distribution of wall equivalent stress was more uniform, and the maximum value decreased from 0.5475 MPa to 0.1667-0.1758 MPa. The maximum equivalent stress of the stent was 3.815-4.315 MPa. Comprehensive comparisons showed that the eight-peak stent graft exhibited lower equivalent stress and superior improvement in vascular morphology, blood flow, and vessel stress, providing an optimal stent graft option for the clinical treatment of TB-AD.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"593-606"},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576057","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}

引用次数: 0

Investigation of cytotoxicity and genotoxicity properties of modified hemp fiber filled PLA biocomposites. 改性大麻纤维填充聚乳酸生物复合材料的细胞毒性和遗传毒性研究。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-01 Epub Date: 2025-07-15 DOI: 10.1177/09544119251351717

Nurhan Çevik Elen, Bünyamin Çiçek, Levent Elen, Büşra Moran, Musa Yıldırım, Yasin Kanbur

{"title":"Investigation of cytotoxicity and genotoxicity properties of modified hemp fiber filled PLA biocomposites.","authors":"Nurhan Çevik Elen, Bünyamin Çiçek, Levent Elen, Büşra Moran, Musa Yıldırım, Yasin Kanbur","doi":"10.1177/09544119251351717","DOIUrl":"10.1177/09544119251351717","url":null,"abstract":"This study aimed to investigate the biocompatibility and toxicity of biodegradable composites reinforced with hemp fibers in a polylactic acid (PLA) matrix. To enhance the compatibility of hemp fibers with PLA, various polymer structures, including maleic anhydride (MA), polybutylene succinate (PBS), and thermoplastic polyurethane (TPU), were incorporated. Additionally, surface modification of hemp fibers was carried out using sodium hydroxide (NaOH) and 3-(2-aminoethylamino) propyl trimethoxy silane (APTES) to improve interfacial adhesion. The in vitro biocompatibility and genotoxicity of the produced composites were evaluated using L-929 fibroblast and CHO-K1 cell lines. In the cytotoxicity tests, cells were exposed to composite extracts for 24 h, after which viability rates were determined to assess possible toxic effects. Genotoxicity tests were performed to examine potential DNA damage induced by the composites. The results demonstrated that the hemp fiber-reinforced PLA composites exhibited high biocompatibility, with cell viability reaching up to 120%, while no DNA damage was observed in genotoxicity analyses. These findings indicate that the developed composites are non-toxic and have promising potential for biomedical applications. However, further in vivo studies are required to gain a more comprehensive understanding of their long-term biocompatibility and safety profile.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"697-705"},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144637869","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}

引用次数: 0

A novel approach to flow visualization through mechanical heart valves. 一种通过机械心脏瓣膜血流可视化的新方法。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-06-25 DOI: 10.1177/09544119251342868

Dylan Goode, Ruby Dhaliwal, Jaymes Schmidt, Kibret Mequanint, Hadi Mohammadi

{"title":"A novel approach to flow visualization through mechanical heart valves.","authors":"Dylan Goode, Ruby Dhaliwal, Jaymes Schmidt, Kibret Mequanint, Hadi Mohammadi","doi":"10.1177/09544119251342868","DOIUrl":"10.1177/09544119251342868","url":null,"abstract":"Mechanical heart valves (MHVs) are indispensable in managing valvular disease, yet they often lack the hemodynamic efficiency of native valves and require lifelong anticoagulation therapy to mitigate thrombus formation. This study introduces a novel bileaflet mechanical heart valve (BMHV), the iValve, designed to address these challenges by more closely emulating native valve performance. Central to this research is the development of a custom-built steady-state flow simulator, which provides a cost-effective and innovative approach to visualizing flow dynamics through MHVs. Unlike traditional methods, this simulator allows for detailed observation of flow patterns, focusing on critical regions such as the central flow and hinge areas.Using the novel flow simulator, the flow through the iValve was compared to that of conventional BMHVs, including the SJM/Abbott Regent and On-X valves. The iValve exhibited significantly reduced flow disturbances and vortex formation in the central flow region and effective hinge washing during the forward flow phase. These preliminary findings suggest that the iValve design minimizes energy loss and shear stress on blood elements, potentially reducing or eliminating the need for anticoagulation therapy. The steady-state flow simulator proved invaluable in these assessments, offering precise, qualitative insights into flow behavior that would be challenging to achieve with other methods. Future work, including pulsatile flow simulations and in vivo testing, will further explore the iValve's clinical potential and validate these promising results.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"584-590"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12209540/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144497887","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}

引用次数: 0

The adverse effects of car seats and vibration frequencies on different lumbar intervertebral discs in different age groups. 汽车座椅及振动频率对不同年龄组不同腰椎间盘的不良影响。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-06-25 DOI: 10.1177/09544119251344365

KaiFeng Zhang, JingFang Zhang, RuiChun Dong, ShiFu Zheng, ChengZe Li, Qian Li

{"title":"The adverse effects of car seats and vibration frequencies on different lumbar intervertebral discs in different age groups.","authors":"KaiFeng Zhang, JingFang Zhang, RuiChun Dong, ShiFu Zheng, ChengZe Li, Qian Li","doi":"10.1177/09544119251344365","DOIUrl":"10.1177/09544119251344365","url":null,"abstract":"The prolonged whole-body vibration (WBV) may be one of the important factors contributing to low back pain. This study used a validated whole-body model and the WBV evaluation standard (ISO 2631-5:2018) to investigate the effects of car seat, frequency and age on the risk factors of the lumbar spine during prolonged exposure to WBV. The modal frequencies contributing more to the human resonance were first preliminarily predicted by modal analysis, and then sinusoidal excitations with frequencies of 1, 3, 5, 7, 9, 11 and 13 Hz were applied for transient analysis. On this basis, the adverse effects of long-term WBV on the lumbar spine were assessed based on the risk factors defined in the WBV evaluation standard (ISO 2631-5:2018). The transient analysis and risk factor calculation demonstrated that the responses exhibited a pronounced frequency dependence, with the highest response occurring at 4 Hz and 5 Hz excitation for elastic and rigid car seats, respectively. Rigid car seat increased disc von Mises stress and risk factors by 7.6% and 11%, respectively, compared with elastic one. After 5 years from the age of 25, the peak risk factors for human-body exposure to vibration were 0.73 and 0.81 for elastic and rigid car seats, respectively and continued to increase with age. From age 45 onwards, the adverse effects of vibration on the lumbar spine will reach a risk level considered dangerous after 5 years.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"501-514"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144497888","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}

引用次数: 0

The influence of arterial stenosis on blood damage under continuous flow. 连续血流条件下动脉狭窄对血液损伤的影响。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-05-25 DOI: 10.1177/09544119251341424

Shuai Li, Wangwang Su, Zhenling Wei, Zhuo Li, Chengyang Liu, Peng Wu, Liudi Zhang

{"title":"The influence of arterial stenosis on blood damage under continuous flow.","authors":"Shuai Li, Wangwang Su, Zhenling Wei, Zhuo Li, Chengyang Liu, Peng Wu, Liudi Zhang","doi":"10.1177/09544119251341424","DOIUrl":"10.1177/09544119251341424","url":null,"abstract":"Arterial stenosis, resulting from plaque accumulation, can lead to serious conditions such as thrombosis and von Willebrand syndrome. This study investigates how variations in stenosis shape and severity affect red blood cell (RBC) and von Willebrand factor (VWF) damage through simulations and experimental approaches. A continuous flow generation device was utilized to create a blood circulation platform. The effects of different stenosis shapes and severities under continuous flow conditions on RBC damage and VWF degradation were examined. Blood samples were then analyzed for plasma-free hemoglobin concentration and VWF degradation. The results indicated that increased stenosis severity correlated with elevated hemolysis and a higher degradation rate of high molecular weight VWF (HMW-VWF). Rectangular stenosis induced more severe hemolysis and VWF degradation compared to elliptical stenosis at equivalent stenosis degrees. Both stenosis types demonstrated varying VWF degradation rates at low and medium/high stenosis levels, with elliptical stenosis showing particularly low VWF degradation at lower stenosis levels. The study highlights that different stenosis shapes and severities significantly affect blood damage under continuous flow. Greater stenosis severity resulted in increased blood flow velocity and wall shear stress (WSS), leading to enhanced hemolysis and VWF degradation, with rectangular stenosis showing more pronounced effects.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"574-583"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144143399","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}

引用次数: 0

Synthesis of hydroxyapatite /Zeolite/Perlit hybrid coatings on human tooth by hydrothermal method and their in vitro behaviour. 水热法制备羟基磷灰石/沸石/Perlit牙体杂化涂层及其体外性能研究。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-06-18 DOI: 10.1177/09544119251342007

Büşra Tunç, Mehtap Muratoğlu

{"title":"Synthesis of hydroxyapatite /Zeolite/Perlit hybrid coatings on human tooth by hydrothermal method and their in vitro behaviour.","authors":"Büşra Tunç, Mehtap Muratoğlu","doi":"10.1177/09544119251342007","DOIUrl":"10.1177/09544119251342007","url":null,"abstract":"Hydroxyapatite (HA) is prevalently employed as a biomaterial, courtesy of its bone-like resemblance. For the purpose of counterbalancing the frail mechanical attributes of unadulterated HA, the creation of bioceramic composite materials has been instigated. The goal of this investigation revolves around the endeavor to encapsulate human teeth by utilizing a HA-based dental composite powder, procured from perlite in conjunction with zeolite obtained via hydrothermal synthesis methodologies. Human teeth were gathered from dental practitioners, underwent a calcination process at an exponentially high temperature of 850°C for three hours and subsequently transformed into a powdered state. Calcium nitrate (CaNO3) was indispensable as the calcium supplier, while phosphorus pentoxide (P2O5) was pivotal as the source of phosphorus. Different proportions (10%-50%) of perlite-converted zeolite were incorporated into the artificially synthesized Hydroxyapatite (HA). The prepared specimens were later subjected to a series of tests, including Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), investigation of surface roughness, and in vitro analyses. For in vitro test, samples were submerged in Ringer's solution and kept for periods of 1, 10, and 25 days. It became evident that an escalation in reinforcement quantity triggered a concurrent rise in parameters such as porosity and surface roughness value. It was also noted that a HA layer had established itself on the surface of the specimens according to the Ca/P proportion. With an increase in time spent submerged in the solution, a corresponding increase was observed in apatite formation.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"548-559"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144317785","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}

引用次数: 0

Research on the method of mucosal negative pressure electrocoagulation marking under gastrointestinal endoscopy. 胃肠内镜下粘膜负压电凝标记方法的研究。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-05-23 DOI: 10.1177/09544119251338437

Hongrui Wang, Jie Ren, Jiuzhou Zhao, Yu Zhou

{"title":"Research on the method of mucosal negative pressure electrocoagulation marking under gastrointestinal endoscopy.","authors":"Hongrui Wang, Jie Ren, Jiuzhou Zhao, Yu Zhou","doi":"10.1177/09544119251338437","DOIUrl":"10.1177/09544119251338437","url":null,"abstract":"With the development of medical equipment technology, minimally invasive surgery has become the core advancement direction in surgical treatment. There are still some issues with mucosal marking and injection under gastrointestinal endoscopy. This paper aims to study a novel negative pressure electrocoagulation marking technique. Using a negative pressure pump in conjunction with a radiofrequency energy emission platform, we compared the effects of conventional electrocoagulation marking and negative pressure electrocoagulation marking using porcine stomachs as experimental subjects. The experimental system includes a negative pressure electrocoagulation platform and a radiofrequency energy emission platform. The experimental materials are fresh porcine stomachs. Electrocoagulation marking of porcine stomach under no negative pressure and negative pressure conditions. An infrared thermal imaging camera was used to measure the temperature. The experimental results showed that the highest average temperature in the no negative pressure group was 78.2 ± 7.6°C, while in the negative pressure group it was 78.1 ± 7.9°C, with no significant difference between the two (p = 0.8557). During subsequent injection tests, the average burst pressure in the no negative pressure group was 66.40 ± 16.96 mmHg, while in the negative pressure group it was 83.48 ± 28.56 mmHg. The negative pressure group had a significantly higher burst pressure (p = 0.0135), indicating that the negative pressure electrocoagulation marking technique can significantly enhance mucosal elevation. The results suggest that the negative pressure electrocoagulation marking technique has great potential for application in gastrointestinal endoscopic surgery. It can improve the safety of the surgery without increasing thermal injury, helping to reduce the incidence of intraoperative complications.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"538-547"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144136336","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}

引用次数: 0

A simultaneous calibration method of robot kinematic parameters and hand-eye parameters for orthopedic surgical robot systems. 骨科手术机器人系统运动学参数和手眼参数的同步标定方法。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-06-13 DOI: 10.1177/09544119251342396

Haiping Liang, Yaoan Lu, Chengyong Wang

{"title":"A simultaneous calibration method of robot kinematic parameters and hand-eye parameters for orthopedic surgical robot systems.","authors":"Haiping Liang, Yaoan Lu, Chengyong Wang","doi":"10.1177/09544119251342396","DOIUrl":"10.1177/09544119251342396","url":null,"abstract":"Orthopedic surgical robot systems increasingly demand high-precision positioning and orientation. Low accuracy of positioning and orientation is a potential hazard during a surgery and also affects the surgical quality. The transformation relationship between the robot base coordinate system and the optical tracking system, which is called hand-eye calibration, is supposed to be calibrated accurately preoperatively. The hand-eye parameters identification is inevitably affected by the errors of robot kinematic parameters. Errors in robot kinematic parameters and hand-eye parameters significantly influence the accuracy of an orthopedic surgical robot system. To enhance the calibration accuracy, a simultaneous precise calibration method of the robot's kinematic parameters and hand-eye parameters for orthopedic surgical robot systems is proposed, eliminating the error accumulation caused by a step-by-step calibration procedure of hand-eye parameters and kinematic parameters. The objective function of the proposed simultaneous calibration method is defined as the weighted sum of the averages and variances of the positioning and orientation errors of the robot's end-effector, ensuring the difference between the errors of the robot poses after parameters calibration in its work space is small, and it is solved by using the Differential Evolution algorithm, avoiding complex gradient calculations. The proposed calibration method is verified by experiments, and a robot-assisted osteotomy experiment is also conducted to demonstrate the accuracy and effectiveness of the proposed calibration method.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"524-537"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144286396","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}

引用次数: 0

Biomechanical evaluation of temporomandibular joint implants and periprosthetic bone under unilateral and bilateral clenching. 单侧和双侧握紧对颞下颌关节种植体和假体周围骨的生物力学评价。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-05-27 DOI: 10.1177/09544119251342019

Rajdeep Ghosh, Girish Chandra, Vivek Verma, Kamalpreet Kaur, Ajoy Roychoudhury, Sudipto Mukherjee, Anoop Chawla, Kaushik Mukherjee

{"title":"Biomechanical evaluation of temporomandibular joint implants and periprosthetic bone under unilateral and bilateral clenching.","authors":"Rajdeep Ghosh, Girish Chandra, Vivek Verma, Kamalpreet Kaur, Ajoy Roychoudhury, Sudipto Mukherjee, Anoop Chawla, Kaushik Mukherjee","doi":"10.1177/09544119251342019","DOIUrl":"10.1177/09544119251342019","url":null,"abstract":"To ensure the long-term success of temporomandibular joint (TMJ) implants, it is imperative to understand their biomechanical performances. This study aims to compare the biomechanical performance of two stock implants (narrow and standard) under unilateral and bilateral clenching during both osseointegrated and non-osseointegrated conditions. Finite element models of a human mandible were developed from QCT data, with the left TMJ being replaced by the implants. Six clenching tasks were simulated to evaluate stress and strain distributions in the mandible and implants. Ipsilateral clenching produced higher mandibular strains, while contralateral clenching generated larger implant stresses. Furthermore, intercuspal biting was found to have produced the highest strain (1750-1880 µε) and stress (∼17 MPa) in the mandible. Osseointegration reduced stresses (up to 0.14 MPa) and strains (up to 30 µε) in mandible as well as stresses in mandibular components (up to 48 MPa) and screws (up to 71 MPa). However, during non-osseointegrated conditions, stresses in cortical bone were higher for standard TMJ implant as compared to narrow implant. This suggests possible preference of narrow implant over standard ones.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"560-573"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144151530","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}

引用次数: 0

Upper body instability in people with Parkinson's disease: A kinematic study. 帕金森病患者的上半身不稳定：一项运动学研究。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-06-01 Epub Date: 2025-05-27 DOI: 10.1177/09544119251343284

Saeed Daniali, Mohammed N Ashtiani, Sedighe Kahrizi

{"title":"Upper body instability in people with Parkinson's disease: A kinematic study.","authors":"Saeed Daniali, Mohammed N Ashtiani, Sedighe Kahrizi","doi":"10.1177/09544119251343284","DOIUrl":"10.1177/09544119251343284","url":null,"abstract":"Instabilities of the upper body affect posture and locomotion in people with Parkinson's disease (PD), but the responses of the torso to sudden perturbations have not yet been investigated. This study aimed to examine upper body stability using a wobbling seat encountering challenging perturbations in comparison to healthy age-matched controls. In this cross-sectional study, 12 people with PD and 12 healthy individuals sat on a wobbling seat and underwent quick release perturbations. Motion capture was used to assess upper body stability based on the kinematic data of sways in all directions. People with PD had greater upper body sways than the control group in all directions when faced with unexpected perturbations. The application of expected perturbations to people with PD caused approximately 2.4 times greater upper body sways in the flexion direction (p < 0.001). Maximum sway velocity was significantly greater (p = 0.001) and time-to-fall was significantly shorter (p = 0.004) in people with PD than in the control cohort. People with PD had upper body instability, specifically in the forward direction. They were unable to adapt their neuromuscular responses after repeated trials. Given the significance of upper body stability in performing daily physical activities, it is imperative to consider long-term trunk rehabilitation for people with PD.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"515-523"},"PeriodicalIF":1.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144151535","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}

引用次数: 0