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

{"title":"Impact-Based Analysis Method (IBAM) to evaluate the primary stability of the pedicle screw: A proof of concept.","authors":"Julie Gabriel, Yvan Petit, Giuseppe Rosi, Éric Wagnac, Michel Dagher, Arnaud Dubory, Charles-Henri Flouzat-Lachaniette, Guillaume Haïat","doi":"10.1177/09544119261444102","DOIUrl":"https://doi.org/10.1177/09544119261444102","url":null,"abstract":"<p><p>The long-term success of spinal instrumentation depends on the initial stability of pedicle screws (PS), yet current intraoperative assessments rely on surgeon subjectivity. This study introduces a quantitative, non-invasive approach-the Impact-Based Analysis Method (IBAM)-to support intraoperative decision-making. The IBAM measures screw stability using low-amplitude impacts delivered with an instrumented hammer on the surgical screwdriver after screw insertion. An IBAM indicator, defined as the average time difference between the two earliest local maxima in the force signal, was analyzed under varying stability conditions in artificial bone samples. Experimental factors included bone density (ρ), insertion depth (<i>D</i>), and pilot hole diameter (<i>ϕ</i>). The IBAM indicator was compared with the PS pull-out force for each configuration. Although the main effects showed opposite trends for the pull-out force and the IBAM indicator, their relative magnitudes were similar (<i>ρ</i>∼35%, <i>D</i>∼25%, <i>ϕ</i>∼15%). The relationship between the pull-out force and the IBAM indicator followed a power-law model (adjusted <i>R</i>² = 0.85) with a negative exponent. As screw stability increased, the pull-out force rose while the IBAM indicator decreased, demonstrating complementary sensitivity to bone-implant interface changes. While results are promising, the simplified experimental design limited the ability to fully capture bone-implant interaction complexity. Future studies should aim to validate IBAM in vivo to confirm its clinical applicability.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261444102"},"PeriodicalIF":1.5,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147842059","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":"Biomechanical effects of intra-abdominal pressure and genital hiatus on the pelvic floor in initial injury.","authors":"Qiuyu Zheng, Ling Li, Zhenhua Gao, Jihong Shen, Tingqiang Yao","doi":"10.1177/09544119261434622","DOIUrl":"https://doi.org/10.1177/09544119261434622","url":null,"abstract":"<p><p>The biomechanical mechanism between <i>genital hiatus</i> (GH), intra-abdominal pressure (IAP) and pelvic organ prolapse (POP) is currently unclear. Therefore, two biomechanical models for comparative analysis are developed to discuss the biomechanical relations of IAP and GH with prolapse of <i>anterior</i> and <i>posterior vaginal walls</i> (AVW and PVW) in the injured pelvic floor system. Based on the magnetic resonance imaging (MRI) of the pelvic floor of a healthy woman, we developed two 2D finite element models by using mechanical equivalence to represent the physiological and pathological states respectively. Both models contain hollow structure <i>rectum</i>. We simulated biomechanical characteristics of POP progression under different IAP and GH values in the PVW injury. In the pathological state with an IAP of 83.9 cmH₂O, the descending displacement of the <i>cervix</i> increased from 14.3 to 20.9 mm when the GH increased from 10 to 40 mm. The maximum stress of AVW and <i>perineal body</i> (PB) rose from 0.343 to 0.611 MPa, from 0.190 to 0.974 MPa, respectively. Compared with the physiological state, the initial GH is a significant influence on POP progression. The increase of GH leads to a reduction or loss of biomechanical support for the <i>bladder</i>. The influence of IAPs and GH interaction exacerbates the injury and mechanical imbalance in the pathological state, which triggers increased stress in the AVW and PB, the descending displacements of the cervix and PVM, and exacerbates POP progression.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261434622"},"PeriodicalIF":1.5,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147842141","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":"Mechanism and control strategy design of a multi-position nursing bed for bedridden elderly care.","authors":"Shiyuan Ren, Haoyu Zhou, Xuan Xi, Lei Yu, Chipu Zhang, Yongfei Feng, Hongbo Wang","doi":"10.1177/09544119261441028","DOIUrl":"https://doi.org/10.1177/09544119261441028","url":null,"abstract":"<p><p>Nursing beds equipped with multi-position adjustment capabilities play a crucial role in preventing pressure ulcers and promoting blood circulation in bedridden patients. This study presents a multi-position nursing bed that integrates back-lifting, leg-bending, and lateral positioning functions, ensuring smooth and stable transitions between various care postures. The back-lifting and leg-bending modules are designed using planar linkage mechanisms, while the lateral positioning module combines planar linkage mechanisms with a flexible bedsheet, enabling more compliant posture adjustments. Kinematic analysis of the back-lifting and leg-bending modules is performed using the generalized transmission ratio method, followed by the development of the corresponding dynamic model. For the lateral positioning module, a comprehensive geometric analysis of the positioning process is carried out, leading to the derivation of the input-output motion mapping. In the control system design, an adaptive fast nonsingular terminal sliding mode control (AFNTSMC) strategy is proposed for the back-lifting and leg-bending modules, while a PID control strategy is employed for the lateral positioning module. Finally, a functional prototype of the nursing bed is developed, and its posture transformation capabilities are validated.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261441028"},"PeriodicalIF":1.5,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147819989","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":"Influence of the camera calibration process on the accuracy of vision-based 3D reconstruction for human gait analysis.","authors":"Juan C Arellano-González, Hugo I Medellín-Castillo, Mauro E Maya-Méndez, Carlos Soubervielle-Montalvo, Mario G Bernal-Torres","doi":"10.1177/09544119261444092","DOIUrl":"https://doi.org/10.1177/09544119261444092","url":null,"abstract":"<p><p>The camera calibration process (CCP) is an essential procedure in computer vision techniques (CVT) affecting the 3D reconstruction accuracy as it involves computing the parameters needed to determine 3D information from 2D images. The CCP performance depends on the model used to approximate the camera behavior, and on the intrinsic and extrinsic conditions used. Inadequate CCP conditions may result in large 3D reconstruction errors. Although in human gait analysis (HGA) applications some works have focused on studying the influence of CCP conditions on the reconstruction accuracy, there is a lack of methodological guidelines on optimal calibration conditions. In order to bridge this research gap, in this paper an investigation to evaluate the influence of the CCP conditions, such as the number of calibration points, camera type, image size and calibration pattern size, on the accuracy of 3D reconstruction for HGA, is presented. A linear CVT based on the Direct Linear Transformation (DLT) algorithm was selected. The results have shown that the 3D reconstruction accuracy increases with the number of calibration points, the quality of the cameras, the image size and the calibration pattern size. Adequate reconstruction errors for HGA (smaller than 1%) can be obtained when using the homogeneous CVT, 24 calibration points, conventional cameras, image size of 1280 pixels × 1024 pixels, and a large calibration pattern (1.2 m × 0.7 m × 1.0 m). This CVT and CCP conditions can be obtained with relatively low-cost equipment, making it attractive for clinical use in low-income countries.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261444092"},"PeriodicalIF":1.5,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147779403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite element framework for investigating the mechanical response of podiatric insole: A pilot study.","authors":"Vaissaud Yoko, Nicolas Clercx, Schumacher Faustine, Tits Pierre-Olivier, Pierre D'Ans, Busegnies Yves","doi":"10.1177/09544119261434625","DOIUrl":"https://doi.org/10.1177/09544119261434625","url":null,"abstract":"<p><p>In podiatry, polymeric orthopedic insoles are widespread, to optimize athletic performances or for diabetic care. Despite computer-aided design development, the choice of materials, their distribution in the sole and their thickness is empirical. The research question of this study is to determine the relationship between the properties of the materials of a sole, the stacking of these materials, and the overall mechanical response of the sole. Cohort studies are inefficient to solve this complex problem, due to numerous parameters, nor to elucidate the effort transmission through the insoles. In this study, finite element simulations are used for the prediction of the pressure distribution at the interface between the foot and the insole for a range of commercial podiatric insole materials with Shore hardness between 18 and 60 (3 ethylene vinyl acetate copolymers, Poron© polyurethane and an elastomer). After measuring the mechanical properties of these materials, the simulated pressure distribution under various insoles was compared to measured pressure distribution. For 15 configurations, simulated pressure agrees with measured pressure for 84% of the sensors. In addition to validating the finite element methodology for podiatric insoles, the hyper foam law parameters determined for each material in this study can be used to predict the mechanical reaction of insole - foot systems.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261434625"},"PeriodicalIF":1.5,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147779411","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":"Unified modeling of pelvic transverse rotations across walking, jogging, running, and sprinting using a single-sensor: Minimal limit cycle approach.","authors":"Maede Alavikia, Ahmad Reza Arshi","doi":"10.1177/09544119261441022","DOIUrl":"https://doi.org/10.1177/09544119261441022","url":null,"abstract":"<p><p>This study investigated transverse pelvis rotations across walking, jogging, running, and sprinting using minimal limit cycle (MLC) modeling. Ten soccer players performed four gaits while a sacrum-mounted inertial measurement unit (IMU) recorded kinematics. We hypothesized that one expression could capture control mechanisms across gaits. A unified MLC model described all gait types within a common dynamical structure, with differences explained by coefficient modulation rather than distinct control strategies. Nonlinearity decreased from walking to sprinting, consistent with energetic differences between pendulum-like walking and spring-mass running dynamics. Stiffness coefficients (linear and nonlinear) varied significantly: linear stiffness was higher in sprinting than walking and jogging, while nonlinear stiffness was reduced in sprinting compared to jogging. These adaptations suggest gait-specific modulation of pelvis rotational velocity within an overarching shared framework, consistent with (but not directly demonstrating) central pattern generator (CPG)-based control architecture. Damping coefficients showed less sensitivity across gaits. Nonlinear stiffness (Duffing) and damping (Van der Pol) coefficients were consistent with stabilization mechanisms related to momentum preservation and energy recycling. Model fit improved from ∼63% in walking to ∼93% in sprinting, without changing equation structure, highlighting parameter modulation as the key mechanism. Quantifying gait transitions with a single pelvis sensor supports field-based monitoring, rehabilitation, and movement-quality screening related to injury risk, while informing bipedal robotics and rehabilitation devices requiring unified control architectures. To our knowledge, this is the first study to report unified gait modeling across four gait types using MLC with a single sensor, underscoring translational value in biomechanics, clinical practice, and robotics.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261441022"},"PeriodicalIF":1.5,"publicationDate":"2026-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723538","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":"Superior longitudinal strength of auxetic stents: A comparative numerical study.","authors":"Xiang Shen, Jianwei Gao, Huilin Yao, Yizhe Wang, Zewen He, Jiahao Chen, Hongyu Liang","doi":"10.1177/09544119261443827","DOIUrl":"https://doi.org/10.1177/09544119261443827","url":null,"abstract":"<p><p>Longitudinal stent deformation (LSD) caused by insufficient longitudinal strength of stent has become one of the serious complications of stent intervention. Although an auxetic stent, as highly promising stent, has already been widely used in the interventional field, its resistance to longitudinal deformation has not yet been studied. In this study, three types of stents were designed and their LSD were studied and compared with conventional stents. Finite element analysis was used to investigate the effects of Poisson's ratio, stent structural design, tensile force application location, circumferential cell number, and expansion diameter on LSD. The results showed that a more pronounced auxetic tendency contributes to enhancing the stent's capability to resist longitudinal deformation. Auxetic stents exhibited superior longitudinal strength compared to conventional stents. Increasing the number of connecting struts was found to enhance longitudinal strength. A cell design featuring a convex hexagonal shape was shown to improve the longitudinal strength of stents. Moreover, an increase of the number of circumferential cells led to an increase of longitudinal strength. It was also observed that the stent ends were more susceptible to longitudinal deformation than the midsection. Additionally, longitudinal strength was found to decrease with the increase of stent expansion diameter. This study may provide insights for the structural design of high-performance stents and rational selection of stents with resistance to LSD.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261443827"},"PeriodicalIF":1.5,"publicationDate":"2026-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723494","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":"Mechanobiological design strategy for additively manufacturable tibial ankle implant for enhanced biomechanical and osseointegration performance: A finite element and machine learning approach.","authors":"Minku, Rajesh Ghosh","doi":"10.1177/09544119261439570","DOIUrl":"https://doi.org/10.1177/09544119261439570","url":null,"abstract":"<p><p>The leading cause of revision surgeries in ankle arthroplasty is aseptic loosening of the tibial implant, resulting from adverse bone remodelling and insufficient osseointegration. Aseptic loosening depends on multiple factors, such as the design of the implant, the porous surface of the implant, the quality of bone, implant positioning, wear debris, etc. The extent to which the design of porous architecture and its relationship with aseptic loosening failure mechanisms remains unexplored. The study aims to identify the lattice design of porous rhombic dodecahedron architecture of tibial implants that would be able to maximise bone formation and reduce stress shielding using macro-micro finite element (FE) analysis with machine learning (ML) approach. The study entails the macro-microscale FE modelling of four porous rhombic dodecahedron tibial implants (PRDTI), referred as PRDTI50, PRDTI60, PRDTI70, and PRDTI80. Based on macro-micro-FE determined dataset, four artificial neural network (ANN)-based ML algorithms were trained and validated for faster prediction of bone ingrowth. Results evidenced that von Mises stress in the tibia exhibited elevated stresses for PRDTI80 and PRDTI70 implants compared to PRDTI60, PRDTI50, and solid implant. Bone ingrowth results indicated that the PRDTI70 implant exhibited higher amounts of bone formation. The study proposes the PRDTI70 implant is a viable option for designing tibial implants to simultaneously reduce stress shielding and maximises bone ingrowth. This preclinical analysis sheds light on the role of porous structure design in bone formation for the development of porous tibial prostheses for TAR to prevent revision instances.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261439570"},"PeriodicalIF":1.5,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147699573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and in vitro testing of an innovative orthodontic bracket debonding force measurement device.","authors":"Varadaraju Magesh, Pandurangan Harikrishnan","doi":"10.1177/09544119261441343","DOIUrl":"https://doi.org/10.1177/09544119261441343","url":null,"abstract":"<p><p>Orthodontic brackets are removed from the teeth surfaces after fixed appliance therapy using debonding pliers, but the applied forces are unknown. There is a need for clinicians to know the debonding forces and so this study was aimed to develop an orthodontic debonding force measurement device and to test it in vitro. The device consists of an Orthodontic debonding plier with 3D printed handle covers to adapt the Force Sensitive Resistors (FSRs) which in-turn is attached to an electronic circuit made with a Printed Circuit Board (PCB) connected with a microcontroller. The forces applied by the plier during removal of orthodontic brackets were captured through an Integrated Development Environment (IDE) software display. The device was tested using 20 artificial lower premolar teeth with brackets bonded on the labial (outer) surface of the teeth. Forces generated from both the handles of the plier were recorded for each sample. The descriptive statistics along with Intraclass Correlation Coefficient (ICC) was performed. Between the tested samples, the least debonding force at the tip of the plier was 66.67 N and highest was 141.26 N with a mean of 111.61 N. Higher forces were recorded in the plier's upper handle which had contact with palm and thumb finger than the lower handle with the remaining finger's contact. The preliminary in vitro testing of the developed orthodontic debonding force measurement device was found functionally satisfactory. The device is simple to use and will be beneficial to the clinicians in monitoring the debonding forces.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261441343"},"PeriodicalIF":1.5,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147691788","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":"Automated SEM image analysis of electrospun PVA nanofibers for skin tissue engineering: Integrating morphological, fractal, and statistical characterization using MATLAB App Designer.","authors":"Muna M Kareem, Hussain A Jaber, Basma A Al-Ghali, İlyas Çankaya","doi":"10.1177/09544119261441368","DOIUrl":"https://doi.org/10.1177/09544119261441368","url":null,"abstract":"<p><p>Electrospun nanofiber scaffolds are important in biomedicine, especially skin tissue engineering, in which scaffold porosity and fiber orientation significantly affect cell penetration, nutrition diffusion, and biomechanical integration. Despite progress on image-based, non-destructive methods for SEM analysis, integrating quantitative metrics from multiple morphological descriptors into a unified and automated workflow remains challenging. In this paper, we present a software tool developed using MATLAB App Designer, which facilitates SEM image analysis for non-destructive characterization of electrospun nanofiber scaffolds. This application provides capability to determine porosity, pore size, fiber diameter and fractal dimension as well as estimation of BET surface area and Barrett-Joyner-Halenda (BJH) volume based on geometric models. Eight independently electrospun nanofiber scaffolds, fabricated at identical electrospinning parameters, were analyzed using a combination of automated thresholding, morphological processing, and skeletonization. For each sample, five SEM images were analyzed (total = 40 images). Estimated BET and BJH data were extrapolated from image-based parameters, considering cylindrical-like scaffold geometry to assess internal consistency. High correlations were observed between porosity and surface area, and pore size with BJH volume highlight that the model is appropriate for relative scaffold screening. Statistical comparison detected various methods (Otsu and morphological thresholding) were significantly different from each other (<i>p</i> < 0.05), indicating importance of method choices on results. A user-friendly GUI allows users to access techniques and view metric outputs easily. Although strong <i>R</i> values were observed, they reflect internal coherence, not external validation. The tool offers a replicable platform for early-stage scaffold assessment in tissue engineering and nanomaterial research.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261441368"},"PeriodicalIF":1.5,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147676043","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}