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

Flow analysis comparison of network solid and sheet solid structures for Schwarz Primitive. Schwarz Primitive网固和片固结构的流动分析比较。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251348696

Derya Karaman, Hojjat Ghahramanzadeh Asl

{"title":"Flow analysis comparison of network solid and sheet solid structures for Schwarz Primitive.","authors":"Derya Karaman, Hojjat Ghahramanzadeh Asl","doi":"10.1177/09544119251348696","DOIUrl":"https://doi.org/10.1177/09544119251348696","url":null,"abstract":"Scaffolds developed from Triply Periodic Minimal Surface (TPMS) structures effectively mimic the geometric, mechanical, and fluid transport characteristics of human bones. These porous architectures facilitate fluid flow and augment bone cell adhesion and proliferation through their substantial surface area. In this study, the potential of network solid and sheet solid TPMS scaffolds with the same Schwarz Primitive architecture was compared for bone regeneration. Both types were modeled at 50%, 60%, 70%, and 80% porosity. A computational fluid dynamics (CFD) analysis was conducted to assess parameters such as surface area, pore size, permeability, wall shear stress, and flow rate. These parameters are known to exert a significant influence on the behavior of bone cells. The results demonstrated that network solids exhibited enhanced permeability and augmented pore sizes, thereby facilitating cell migration and nutrient delivery. Conversely, sheet solids exhibited elevated surface areas, thereby fostering cell adhesion and proliferation. Despite exhibiting equivalent porosity, the two structures manifested discernible disparities in geometry and flow performance. Network solid structures generally provided more favorable conditions for fluid flow and mechanical stimulation. Nevertheless, the selection of network or sheet architectures should be informed by specific clinical needs and tissue requirements. The findings demonstrate that architectural differences significantly affect scaffold performance, and understanding these effects can help optimize scaffold design for bone tissue engineering applications.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251348696"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576047","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 finite element study of the effect of cross-link stabilisation in a lumbar spine tumour model. 腰椎肿瘤模型中交联稳定效应的有限元研究。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251348279

Juntong Lai, James Tomlinson, Lee Breakwell, Damien Lacroix

{"title":"A finite element study of the effect of cross-link stabilisation in a lumbar spine tumour model.","authors":"Juntong Lai, James Tomlinson, Lee Breakwell, Damien Lacroix","doi":"10.1177/09544119251348279","DOIUrl":"https://doi.org/10.1177/09544119251348279","url":null,"abstract":"Spinal metastases can increase the risks of vertebral fracture due to bony destruction and instability in the spine. There are concerns that cross-links may impair adjuvant treatments, such as radiotherapy and proton beam therapy. The aim of this study was to assess the biomechanical effects of cross-link stabilisation for a growing tumour in order to provide recommendations on the use and placement of the cross-link. A finite element (FE) model of a fixation device was developed. The device was inserted virtually into a FE model of the lumbar spine (L1-S1) between L2 and L4. Tumour deposit of either 1.3%, 10.1%, 38.3%, 71.5% and 92.1% of the vertebral body was simulated. A 1000 N compressive, a 10° lateral bending and a 7.5 Nm torsional load were simulated on the top of L1. Results indicate that the stabilisation is capable of reducing the stress of the L3 lumbar spine under torsion with a growing tumour. However, compressive loading is concentrated in the L3 anterior vertebra when the tumour volume was greater than 10.1% of the vertebra volume. The cross-link stabilisation reduced the stress of the posterior body within the stabilised segments (L2-L4), especially under torsion. The position of the cross-link does affect the ability of stabilisation to reduce concentrated stress of both vertebrae and screws, which indicates that the position of the cross-link should be considered in clinical surgery to refine the stress concentration, spinal stability and structural stiffness, without compromising adjuvant treatments.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251348279"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144584593","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

Novel methods to quantify gait rehabilitation following ankle-foot fractures. 量化踝足骨折后步态康复的新方法。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251348490

Imran Mahmood, Anam Raza, Tayyaba Sultana, Abbas A Dehghani-Sanij

{"title":"Novel methods to quantify gait rehabilitation following ankle-foot fractures.","authors":"Imran Mahmood, Anam Raza, Tayyaba Sultana, Abbas A Dehghani-Sanij","doi":"10.1177/09544119251348490","DOIUrl":"https://doi.org/10.1177/09544119251348490","url":null,"abstract":"Lower limb fragility fractures included a break in bone from the pelvis to the foot. Weight-bearing and walking stability stand as key performance indicators to quantify fracture restoration. Normally, progress in fracture rehabilitation is observed through clinical assessments and patients' responses, and modern research also presents instrumented gait analysis. There exists a gap to statistically compute the regaining in patients' weight-bearing ability and walking stability following fractures. This study introduces methods to advance the analysis of instrumented signals and evaluate walking stability in fracture-healing patients. The centre of pressure (CoP) signals were captured for four conditions: tibia/fibula/talus fracture near the ankle (AF), lower-leg shaft fracture (LF), calcaneus fractures (CF), and normal ankle (NA). The time derivative for CoP signals showed impulsive responses during the loading and unloading transitions which were then modelled and transformed to the frequency domain. The developed models were further analysed by applying Nyquist and Bode methods and margins of stability were calculated for the fractured and healthy subjects. Results showed a substantial decline (Kruskal-Wallis's test, p < 0.001) in the intralimb stability of all three fractures. Also, there was a strong interlimb dependency (p < 0.001) observed between fractured and intact limbs applying Spearman's correlation during double limb support periods. Overall, the calcaneus fracture (CF) exhibited minimum intralimb stability and increased interlimb dependency. These methods stand clinically important in monitoring patients' rehabilitation and in decision-making about alternative treatment plans.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251348490"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576058","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

Deep learning based time-dependent reliability analysis of an underactuated lower-limb robot exoskeleton for gait rehabilitation. 基于深度学习的欠驱动下肢机器人外骨骼步态康复可靠性分析。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251349362

Fahad Hussain, Tanishka Goyal, Shahid Hussain, Prashant Jamwal, Roland Goecke

{"title":"Deep learning based time-dependent reliability analysis of an underactuated lower-limb robot exoskeleton for gait rehabilitation.","authors":"Fahad Hussain, Tanishka Goyal, Shahid Hussain, Prashant Jamwal, Roland Goecke","doi":"10.1177/09544119251349362","DOIUrl":"https://doi.org/10.1177/09544119251349362","url":null,"abstract":"This study evaluates the reliability of an underactuated wearable lower-limb exoskeleton designed to assist with gait rehabilitation. Recognizing the complexity of system reliability, a deep learning framework augmented with Long short-term Memory (LSTM) was utilized for the time-dependent reliability analysis of dynamic systems. The research commenced with the development of a lower-limb gait robot, modeled on a Stephenson III six-bar linkage mechanism. Following the mechanical design, computer-aided design (CAD) tools were employed to conceptualize a lower-limb robotic exoskeleton for rehabilitation purposes. The design incorporated two metallic materials (aluminum and steel), and a composite material (carbon fiber) tested using SolidWorks®. The prototype achieved a lightweight design (~1.63 kg) for carbon fiber material. An LSTM-enhanced deep neural network algorithm was implemented to predict the time-dependent reliability of joint displacements and end-effector trajectories. Finally, conditional probability methods were applied to complete the time-dependent system reliability assessment. The designed mechanical system for gait rehabilitation demonstrated high reliability (R ≈ 0.87). Over 200 simulation runs, reliability trends showed consistent and robust predictions.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251349362"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576046","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

Investigating the effects of geometrical parameters of an artificial cervical disc in vulnerable neck positions on the stress distribution in the spine using 3D finite element analysis. 采用三维有限元分析方法研究颈椎脆弱位置人工颈椎间盘几何参数对脊柱应力分布的影响。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251351175

Yalda Nasiri, Amir Khosravifard

{"title":"Investigating the effects of geometrical parameters of an artificial cervical disc in vulnerable neck positions on the stress distribution in the spine using 3D finite element analysis.","authors":"Yalda Nasiri, Amir Khosravifard","doi":"10.1177/09544119251351175","DOIUrl":"https://doi.org/10.1177/09544119251351175","url":null,"abstract":"One of the most common diseases of the spine is the degenerative intervertebral disc, which in extreme cases requires surgery. Replacing a damaged disc with an artificial disc (AD) is a common treatment method. Nowadays, due to the extensive use of smartphones and other similar devices, our cervical spine is often in a vulnerable position, such as a bent position, which results in more stress on the components of the spine, especially intervertebral discs. In this research, the effects of geometrical parameters of an AD on the biomechanics of the cervical spine are investigated in a bent neck position, using the finite element method. In this regard, computed tomography scans of the neck of a 29-year-old male in two states of straight and bent neck are used. Nine different AD geometries are generated by varying three geometric design variables, including the height, position of the centre of rotation and rotation radius of the AD. The results of stress distribution in the spine for the straight and bent neck positions are compared, and the maximum von Mises stress on the AD and healthy discs are assessed to choose an optimum geometry. The results show that proper selection of the geometrical parameters of the AD can lead to up to an 85% reduction in the AD's maximum von Mises stress for a bent neck position. The sensitivity analysis shows that the location of the rotation centre has the highest impact on the distribution of von Mises stress in the artificial disc.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251351175"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576056","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 biodegradable PCL cog threads for prolapse rehabilitation. 生物可降解PCL螺纹脱垂康复的生物力学评价。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-07 DOI: 10.1177/09544119251343371

Fábio Pinheiro, Abílio Manuel Pinho de Jesus, Ana Colette Maurício, Nuno Alves, António Augusto Fernandes, Elisabete Maria Elisabete Teixeira da Silva

{"title":"Biomechanical evaluation of biodegradable PCL cog threads for prolapse rehabilitation.","authors":"Fábio Pinheiro, Abílio Manuel Pinho de Jesus, Ana Colette Maurício, Nuno Alves, António Augusto Fernandes, Elisabete Maria Elisabete Teixeira da Silva","doi":"10.1177/09544119251343371","DOIUrl":"https://doi.org/10.1177/09544119251343371","url":null,"abstract":"Pelvic organ prolapse (POP) is a prevalent pelvic floor dysfunction (PFD) that significantly impacts women's quality of life, driving the need for innovative and less invasive treatment options. Surgical intervention remains the primary treatment for POP; however, it is often associated with high invasiveness, substantial risks, and a notable rate of failure. In this study, we investigate the potential of biodegradable cog threads, commonly used in cosmetic facial lifting, as an alternative surgical solution for reinforcing vaginal wall defects. Specifically, we evaluate the performance of commercially available 360° 4D barb threads made of polycaprolactone (PCL) under simulated physiological conditions. The degradation and mechanical properties of the threads were analyzed after immersion in Phosphate Buffer Solution (PBS) and Potassium Hydrogen Phthalate (KHP) for periods of 90 and 180 days, with comparisons to a control group. Fourier-transform infrared (FTIR) spectroscopy revealed mild to moderate degradation of the threads over 180 days in both mediums. Tensile strength tests indicated a reduction in maximum load-bearing capacity, with declines of 13% to 19%, more pronounced in the PBS medium. Despite this, cyclic tests demonstrated that the threads retained sufficient mechanical integrity to endure 100 loading cycles across all conditions, suggesting their durability under repetitive stress. These preliminary in vitro findings highlight the potential of biodegradable cog threads as a promising material for developing a novel, minimally invasive technique for POP correction. The threads' ability to maintain mechanical strength despite degradation supports their viability for long-term pelvic floor reinforcement.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251343371"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144584594","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

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 : 2025-07-07 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":"https://doi.org/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":"9544119251344437"},"PeriodicalIF":1.7,"publicationDate":"2025-07-07","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

An auxetic insole design with reverse graded-stiffness to relieve detrimental tissue stresses under bony prominence of calcaneus in diabetic foot. 一种具有反向分级刚度的增塑型鞋垫设计，以减轻糖尿病足跟骨突出处的有害组织应力。

IF 1.7 4区医学

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine Pub Date : 2025-07-03 DOI: 10.1177/09544119251350412

Xingyu Zhang, Xiang Geng, Xin Ma, Wen-Ming Chen

{"title":"An auxetic insole design with reverse graded-stiffness to relieve detrimental tissue stresses under bony prominence of calcaneus in diabetic foot.","authors":"Xingyu Zhang, Xiang Geng, Xin Ma, Wen-Ming Chen","doi":"10.1177/09544119251350412","DOIUrl":"https://doi.org/10.1177/09544119251350412","url":null,"abstract":"To effectively mitigate detrimental tissue stresses of the diabetic foot for preventing ulceration, contemporary strategies frequently utilize pressure-relief insoles. In this study, we have developed an innovative enhanced pressure-relief insole that integrate auxetic structures with a reverse graded-stiffness property. We introduce a novel modification to the insole internal structure, exhibiting untraditional regional stiffness from the center to the periphery. We utilize a validated finite element (FE) heel model of a diabetic patient to evaluate the effectiveness of the insole, computing internal stress of the heel (peak stresses, total stress concentration exposure, pressure on the fat pad, and tensile stress on the skin) and insole deformation. In addition, we conduct in-vitro uniaxial compression and in-vivo biomechanical experiments to assess its effects in static and gait. The FE results showed a significant reduction in internal stress within high-risk ulcer areas of the heel, with peak internal stresses reduced to 232.9 kPa (without insole: 374.6 kPa), and notable changes in the deformation across the insole's coronal plane. Additionally, uniaxial tensile tests demonstrated optimal energy dissipation at 28.76%. During gait, the auxetic insole resulted in a 19.72% reduction in peak pressure and 15.37% reduction in peak pressures-time integral compared to the conventional insole. A novel insole with auxetic structure and reverse graded-stiffness appear to better relieve the internal loads, gait-related pressure as well as enhanced energy dissipation for the plantar soft tissue under bony prominence of calcaneus of human foot. This research also holds substantial promise for optimizing other pressure-relief orthotic devices.","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119251350412"},"PeriodicalIF":1.7,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560876","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