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

{"title":"Measurement of the wear volumes generated within retrieved magnetically controlled growing rods.","authors":"Thomas J Joyce","doi":"10.1177/09544119261433151","DOIUrl":"10.1177/09544119261433151","url":null,"abstract":"<p><p>Magnetically controlled growing rods are used for the surgical treatment of early onset scoliosis. However, one of the key concerns around the use of these rods is the extensive titanium alloy metallosis seen at revision surgery. To quantify the wear causing this metallosis, for the first time the internal wear volumes from magnetically controlled growing rods have been measured. A cohort of 30 retrieved rods was measured, from 18 cases (6 single rods and 12 dual rod constructs) after an average time in vivo of 1120 days. Another pair of rods explanted after 30 days due to infection served as a negligible-wear datum to validate the methodology. From each retrieved rod, the wear volume of the extending bar component and of the outer casing component was measured. This was achieved through geometric measurements of the components, with the geometry of the internal aspect of the outer casings determined using a replicating compound and then measuring the replica. The average wear volume of the retrieved rods was 71.8 (21.2-201.9) mm³ which equated to an average wear rate of 23.4 (6.9-65.8) mm³/year. Of the 32 rods measured, 21 were 90 mm in length and 11 were 70 mm in length. The 90 mm rods showed a statistically significant greater wear than the 70 mm rods (<i>p</i> = 0.007); this may be attributed to the greater extension length available in the 90 mm rods, and thus for greater wear under boundary lubrication. The wear volumes measured from the retrieved growing rods are substantial and of concern in this paediatric population.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"467-480"},"PeriodicalIF":1.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13199638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147594023","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":"Data-driven optimal design of foam-padded vests for female protection against air blast.","authors":"Feng Zhu, George Wang, Zhiqing Cheng","doi":"10.1177/09544119261432726","DOIUrl":"10.1177/09544119261432726","url":null,"abstract":"<p><p>Blast-induced thoracic injuries pose a significant threat to military personnel, particularly during training and combat operations involving high-explosive weapons. While conventional body armor is primarily designed for ballistic protection, it is often inadequate for mitigating internal injuries caused by air blast waves. This study presents a data-driven approach for the optimal design of foam-padded protective vests tailored for female users exposed to air blast loading. A finite element (FE) model of the VIVA+ 50th percentile female torso was integrated with a multilayer foam vest model and subjected to simulated blast pressures ranging from 140 kPa to 1.4 MPa. The densities of three foam layers (inner, middle, outer) and the explosive charge mass were varied parametrically, and a surrogate model was developed to map these inputs to a biomechanical injury metric- peak chest wall velocity. The surrogate, based on second-order nonlinear regression, was validated against simulation data (<i>R</i>² = 0.98) and used in conjunction with a multi-objective genetic algorithm (NSGA-II) to identify optimal foam configurations. Results revealed that high-density inner and middle layers minimize local deformation, while the outer layer should have lower density to dissipate energy efficiently. Energy absorption analysis confirmed a shift in layer contributions with increasing blast intensity. Additionally, a simplified regression tree model (M5P) was developed to partition the design space and enhance interpretability without compromising accuracy. This study offers new insight into blast-specific armor design and demonstrates the value of surrogate-based optimization in protective equipment engineering.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"373-385"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513898","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":"Topological optimization and biomechanical analysis of porous fusion cage with TPMS structures.","authors":"Waseem Ur Rahman, Tianxiang Dong, Wei Jiang","doi":"10.1177/09544119261425378","DOIUrl":"10.1177/09544119261425378","url":null,"abstract":"<p><p>Porous fusion cages present a promising alternative to traditional solid fusion cages in anterior cervical decompression and fusion surgery (ACDF), offering improved bone in growth through interconnectivity and a reduced elastic modulus, which may reduce the risk of cage subsidence. This study employs an integrated topology optimization approach to design a novel porous fusion cage to minimize the risk associated with cage subsidence and stress shielding. Two innovative porous cervical fusion implants, RPF-G and RPF-D, were proposed through Boolean operations based on optimal topological structures and Triply Periodic Minimal Surfaces (TPMS). After optimizing fusion cages, finite element simulations of ACDF surgeries were performed at C5-C6 segment to evaluate their biomechanical performance. The results showed the range of motion (ROM) in the porous fusion cage model exceeded that of the solid fusion cage model, with maximum intradiscal pressure occurring at the C4-C5 segment in all models. Moreover, stress distribution across the cortical bone surface was more uniform in the porous fusion cages, with the RPF-G and RPF-D cage models exhibiting increased stress at the vertebra C6 cortical bone. Notably, the surface stress on porous cages surpasses solid fusion cages, particularly in flexion loading conditions. The RPF-G model demonstrates superior mechanical stability. In conclusion, the optimized porous fusion cage demonstrates promising mechanical performance and emerges as a potential candidate for fusion surgery. These preliminary investigations guide the design of the fusion cage, potentially offering novel solutions to address the issue of cage subsidence.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"347-359"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147575091","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":"Cross-modal fusion of external magnetic sensing and simulated 2D imaging for 3D guidewire pose estimation.","authors":"Wei Wei, Zhengqian Li, Nan Xiao, Zihan Gao, Dong Yang, Jianming Guo, Qian Zheng, Jiaqian Li","doi":"10.1177/09544119261426514","DOIUrl":"10.1177/09544119261426514","url":null,"abstract":"<p><p>During percutaneous coronary intervention, conventional 2D X-ray imaging lacks depth information, making it difficult for clinicians to determine the 3D position of the guidewire. While some recent approaches incorporate micro-sensors to assist with pose estimation, many rely on implanted electromagnetic sensors, which can introduce additional clinical risks. In the paper, we present a non-invasive alternative by using an external 3-axis electronic magnetometer array. We further propose a <b>L</b>ocal-<b>G</b>lobal <b>Mag</b>neto-Visual <b>Net</b>work framework (LG-MagNet) that fuses magnetic field information with image data to enable precise 3D pose estimation of the guidewire. Specifically, we first perform a shared encoder for cross-modal feature fusion. Then we employ convolutional operations that integrate local and global features. Finally, we utilize a lightweight prediction head for end-to-end depth regression. We constructed experimental equipment and collected a clinical simulation datasets. Results show a root mean square error (RMSE) of (0.797 ± 0.095 mm) for depth prediction along the Z-axis and an overall RMSE of (1.216 ± 0.072) mm for 3D guidewire shape reconstruction. Quantitative analysis indicates that fusing external magnetometer data with 2D imaging improves pose estimation stability, particularly in regions with curvature.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"386-399"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147593996","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":"Utilization of a nonlinear autoregressive neural network with exogenous inputs for foot trajectory generation for upslope terrain.","authors":"Hamza Al Kouzbary, Mouaz Al Kouzbary, Jingjing Liu, Taha Khamis, Nooranida Arifin, Hamam Mokayed, Noor Azuan Abu Osman","doi":"10.1177/09544119261427508","DOIUrl":"10.1177/09544119261427508","url":null,"abstract":"<p><p>The rhythm in which robotic prostheses have evolved over the past two decades indicates that they have a promising potential to replace passive prostheses in the foreseeable future. Powered lower limb prostheses, unlike the passive ones, can provide net positive work during the late stance, thus reducing the metabolic cost. Moreover, robotic prostheses can provide different characteristics in compliance with the walking terrains. The conventional three-level controllers of robotic lower limb prostheses are known for their intermittent and nondynamic properties, which limit prosthesis functioning to certain predefined tasks and require intense calibration for the controller's parameters for each user. In this study, we report the capability of a nonlinear autoregressive recurrent neural network with exogenous inputs of generating the foot patterns for upslope terrain, that is, 10° incline, which is unknown for the neural network (not included in the training dataset). A new set of evaluation data from six able-bodied subjects (average age 31 and average weight 70.2 kg) was used to assess the network performance. The results show that the NARX was able to estimate foot trajectory for the new terrain without any further training, with an average RMSE of 2.953° for all six subjects.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"427-436"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147434946","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":"Bio-fabrication and 3D printing of keratin-enriched sodium alginate-gelatin scaffolds for the application of skin scar regeneration.","authors":"Rajkumar Velu, Anand Sankar Manipuzha, Bobby Tyagi, Harman Sandhu, Nidhi Bannait, Aysha Farzana, Rahul Gorka, Anand Kumar Subramaniyan, Lakshmipriya Ravindran","doi":"10.1177/09544119261427641","DOIUrl":"10.1177/09544119261427641","url":null,"abstract":"<p><p>The advancement of 3D printing technology offers transformative potential in developing functional skin substitutes for scar prevention and tissue regeneration. This research investigates optimized bio-ink formulations comprising sodium alginate, gelatin, and keratin protein, evaluating their structural, mechanical, and biological properties through comprehensive characterization techniques. Scanning Electron Microscopy (SEM) revealed the structural morphology of raw materials and printed constructs, with sodium alginate exhibiting irregular shapes (100-200 µm diameter), gelatin displaying elongated particles (900-1000 µm diameter), and keratin featuring fibrous structures (300-500 µm diameter), all contributing to scaffold integration. Fourier Transform Infrared (FTIR) spectroscopy confirmed the retention of functional groups and formation of new molecular bonds during crosslinking. Rheological analysis highlighted an 81.8% increase in maximum shear stress, from 550 Pa in sodium alginate to 1000 Pa in sodium alginate-gelatin composites, demonstrating enhanced mechanical robustness and optimal shear-thinning behavior critical for printing. Tensile testing analysis revealed composition-dependent mechanical reinforcement, with the incorporation of 20% keratin leading to a maximum tensile strength improvement of approximately 64% relative to the alginate-gelatin matrix. Swelling and degradation studies indicated controlled hydration and improved structural stability of keratin-reinforced scaffolds over 48 h. In vitro biocompatibility was validated through brine shrimp toxicity tests, with keratin-enriched bio-inks achieving a 98% survival rate in seawater, a 5.55% improvement over sodium alginate-gelatin-only solutions. These findings underscore the synergistic role of gelatin in reducing toxicity and keratin in enhancing cellular attachment and tissue regenerative capabilities. This study concludes that the sodium alginate-gelatin-keratin bio-ink formulation offers superior platform for skin tissue engineering, combining enhanced printability, structural integrity, and biocompatibility.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"323-346"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147491474","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":"Inclusion of pelvic ligamentous boundary conditions using 3D continuum volume bodies in finite element modeling of the pelvis.","authors":"Anantha Narayanan Ramakrishnan, Immanuel Ries, Christopher Ludtka, Thomas Mendel, Friederike Klauke, Christoph Muhl, Stefan Schwan","doi":"10.1177/09544119261426439","DOIUrl":"10.1177/09544119261426439","url":null,"abstract":"<p><p>Numerical techniques in the context of osteoporosis and osteoporotic pelvic fracture could potentially contribute toward the development of patient-specific diagnosis. In most finite element simulations of the pelvis the associated ligaments are often neglected due to the modeling complexities involved. This study aims to develop a 3D volume-based continuum approach for these ligaments. The pelvic ligaments were generated based on segmentation of magnetic resonance imaging data from specific patients. Closed volume models were generated based on segmentation and assembled with the 3D models of the corresponding pelvic bones, which themselves were generated from computed tomography data. The resulting pelvic assembly with the ligamentous boundary conditions was numerically simulated under two specific loading conditions: the double-leg stance and double-leg stance with an additional lateral bending moment. The stress state under the force of simulated upper body weight showed a maximum deformation of 0.16 mm at the center of the sacral promontory; this shifted toward the periphery of the sacral promontory and closer to the sacroiliac joint with the addition of the bending moment as well as the contact space between the sacrum and the ilium. The results demonstrated that some of the critical deformation zones are seen in the ligaments and also near their contact regions with the pelvic bones. The approach used for modeling these ligaments, when limited to using 1D springs or force-based boundary conditions, cannot fully factor-in these critical stress concentration zones. As such, this study highlights the necessity of incorporating accompanying ligaments into pelvic bone numerical models.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":"240 4","pages":"360-372"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147779400","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 performance of modified surgical drill margins during bone drilling: An experimental, numerical, and optimization case study.","authors":"Mohd Faizal Ali Akhbar, Shahrizan Jamaludin, Suriani Mat Jusoh, Fatin Alias, Mohd Azlan Musa, Rodianah Alias","doi":"10.1177/09544119261426440","DOIUrl":"10.1177/09544119261426440","url":null,"abstract":"<p><p>Excessive heat generation during bone drilling causes thermal osteonecrosis, posing a significant risk in orthopedic and dental procedures. While various aspects of drill design have been studied, the specific influence of margin geometry remains underexplored in the context of thermal engineering. This study integrates drilling simulation, experimental validation, and statistical optimization to evaluate the thermal impact of drill margin width (<i>M</i>_<i>w</i>) and height (<i>M</i>_<i>h</i>) during cortical bone drilling. A validated thermo-mechanical model was developed using commercial software DEFORM-3D. The simulation results were validated with experimental bone drilling with small temperature prediction errors (2.4% and 8.0%). Key thermal metrics (maximum temperature (<i>T</i>_max), osteonecrosis diameter (OD), and osteonecrosis depth (OH)) were optimized using a central composite design (CCD) of response surface methodology (RSM) and desirability-based multi-objective optimization. Results revealed that <i>M</i>_<i>w</i> had the most significant second-order influence on <i>T</i>_max (47.2%), while <i>M</i>_<i>h</i> dominated OD (41.1%) and OH (47.8%). The optimal drill margins (<i>M</i>_<i>h</i> = 0.05 mm and <i>M</i>_<i>w</i> = 0.22 mm), which achieved a desirability score of 0.985, could reduce <i>T</i>_max by up to 44.8°C, which is below the osteonecrosis threshold. This work highlights drill margins as a critical yet previously underutilized design variable, offering an alternative pathway for the thermally optimized development of surgical tools and next-generation robotic-assisted drilling systems.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"411-426"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147370087","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":"Analysis of nitinol coils expanded using an angioplasty balloon catheter.","authors":"Zakiyyah Auchoybur, Aiden O'Loughlin, Sharath Sriram, Gary Rosengarten","doi":"10.1177/09544119261424552","DOIUrl":"10.1177/09544119261424552","url":null,"abstract":"<p><p>The rupture of vulnerable plaques is associated with life-threatening cardiovascular events such as heart attacks and strokes. While promising medicine therapies could regress the plaque burden and prevent their rupture, no drug delivery device is currently available to deliver medicine directly, efficiently, and effectively into the arterial wall. In this study, a novel device is proposed and analysed. It comprises of a hollow nitinol coil element coupled to a catheter balloon. Finite element analyses were used to determine key geometric constraints of the coil element, including the wire diameter and number of revolution of coils. A catheter balloon inflation model was developed and validated against inflation experiments using corresponding balloons. Different coil geometries were affixed to the balloon model and inflated. It was observed that the balloon sustained an increasing deformation as the wire diameter and number of revolutions increased. Foreshortening of the coil, similar to stent expansion, was also observed. The device will need to be designed to accommodate for the foreshortening of the coil. It was concluded that any number of coil revolution between 0.5 and 3 could be used with a wire diameter of 0.18 mm or smaller. If the wire diameter is larger than 0.18 mm, then only a half revolution coil could be used without obstructing the balloon inflation. From a clinical perspective, smaller wires are more advantageous as they allow for easier navigation to the target lesion due to their smaller diameter and increased flexibility.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"400-410"},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147434861","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":"Maximal isometric force in patients with abdominal wall hernia: Associations with sociodemographic factors and normative reference values.","authors":"José Luis Gil Delgado, Carlos Galiano, Alejandro Sánchez Arteaga, Gonzalo Reverte Pagola, Luis Tallón Aguilar, Borja Sañudo Corrales","doi":"10.1177/09544119261436918","DOIUrl":"10.1177/09544119261436918","url":null,"abstract":"<p><p>This cross-sectional study examined associations between sociodemographic variables and maximal isometric force (MIF) in patients with abdominal wall hernia and established preliminary reference values. A total of 107 patients (62 men, 45 women; median age: 58 years (IQR: 47-67)) underwent standardized assessment of MIF during a seated isometric trunk flexion task. Median MIF was 164.9 N (IQR: 125.8-227.3), with higher values in men than women (207.7 (154.8-263.3) N vs 126.3 (100.0-173.4) N; <i>p</i> < 0.001). MIF was negatively correlated with age (ρ = -0.388, <i>p</i>< 0.001) and positively correlated with body mass (ρ = 0.540, <i>p</i> < 0.001) and height (ρ = 0.656, <i>p</i> < 0.001), while BMI showed no association (ρ = 0.145, <i>p</i> = 0.112). In a multivariable model (adjusted <i>R</i>² = 0.499), age (β = -0.007; <i>p</i>< 0.001) and sex (female vs male: β = -0.249; <i>p</i> = 0.001) were independently associated with MIF. These findings indicate that maximal isometric force is primarily influenced by age and sex, supporting direct force assessment and the interpretation of sex-specific percentile values in this population.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261436918"},"PeriodicalIF":1.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147594081","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}