{"title":"Numerical simulation and experimental testing for static failure prediction in additively manufactured below-knee prosthetic sockets.","authors":"Kavuri Karthik Rajashekar, Srinivasa Prakash Regalla, Kurra Suresh, Prakash Narayan Shrivastava","doi":"10.1177/09544119231221179","DOIUrl":"10.1177/09544119231221179","url":null,"abstract":"<p><p>The socket of a transtibial prosthesis is a structural part customized to a patient's amputated residual lower limb. The free-form geometry of the socket can be suitable for additive manufacturing (AM) to save time and cost. However, the mechanical fracture of additively manufactured lower limb prostheses is not yet fully understood. A novel experimental method and numerical approach by finite element method (FEM) to test the strength and fracture behavior of a lower limb prosthetic socket of acrylonitrile butadiene styrene (ABS), reverse-engineered using computer-aided design (CAD) from the actual amputee's residual limb and manufactured using fused filament fabrication (FFF) are proposed in the present work. The mechanical behavior, von Mises stress distribution, and the damage status of layered AM sockets of different thicknesses were simulated by FEM using Hashin's transversely isotropic mechanical damage model, initially developed for composite materials. The experimental work showed that the fracture failure initiated at the corner of the lobe in the 4 mm thickness socket at a failure load of 918.5 N. The FEM results predicted this failure load to be 896.6 N, with only a 2.45% error as compared to the experiment. The failure loads predicted by FEM in the sockets with thicknesses of 3, 5, and 6 mm were 618.1, 1008.6, and 1105.2 N, respectively. The present work provides a dependable method for testing a below-knee prosthetic socket against static failure and arriving at a factor-of-safety (FoS) based socket thickness selection for any amputee.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139425397","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":"Deep learning-based tooth segmentation methods in medical imaging: A review.","authors":"Xiaokang Chen, Nan Ma, Tongkai Xu, Cheng Xu","doi":"10.1177/09544119231217603","DOIUrl":"10.1177/09544119231217603","url":null,"abstract":"<p><p>Deep learning approaches for tooth segmentation employ convolutional neural networks (CNNs) or Transformers to derive tooth feature maps from extensive training datasets. Tooth segmentation serves as a critical prerequisite for clinical dental analysis and surgical procedures, enabling dentists to comprehensively assess oral conditions and subsequently diagnose pathologies. Over the past decade, deep learning has experienced significant advancements, with researchers introducing efficient models such as U-Net, Mask R-CNN, and Segmentation Transformer (SETR). Building upon these frameworks, scholars have proposed numerous enhancement and optimization modules to attain superior tooth segmentation performance. This paper discusses the deep learning methods of tooth segmentation on dental panoramic radiographs (DPRs), cone-beam computed tomography (CBCT) images, intro oral scan (IOS) models, and others. Finally, we outline performance-enhancing techniques and suggest potential avenues for ongoing research. Numerous challenges remain, including data annotation and model generalization limitations. This paper offers insights for future tooth segmentation studies, potentially facilitating broader clinical adoption.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139692789","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 model with realistic bone geometries for the optimal design of internal fixation during the fibula healing process.","authors":"Yafeng Li, Peng Yi, Zichun Zou, Fengyuan Lu, Xi Zhang, Jing Zhang","doi":"10.1177/09544119231221193","DOIUrl":"10.1177/09544119231221193","url":null,"abstract":"<p><p>A finite element model with realistic bone geometries is developed to design optimal internal fixation during the fibula healing process in this study. The effect of bone plate parameters on fibula fracture healing is studied. The relationship between differences in plate length, thickness and working length, and bone healing performance is focused. The optimal combination form of the bone plate parameters was selected by the orthogonal experimental design and fracture block strain to achieve bone healing maximize the performance. The model results show that the maximum equivalent force of the bone plate was below the material yield limit; the higher mean contact stresses in the bone fragments indicate that the bone plate is prone to higher contact stresses when they are long. The working length of the bone plate has a greater effect on callus healing than the thickness and length of the bone plate. The optimal internal fixation option for distal fibula fractures is achieved when it provides the stability required for internal fixation during bone healing. It ensures lower contact stresses in the fibula as well as maximum Young's modulus during callus healing process.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139486161","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}
Alberto Maria Albiero, Lorenzo Bevilacqua, Federica Pegoraro, Gianluca Turco, Stefano Momic, Roberto Di Lenarda, Michele Maglione
{"title":"Mechanical and fatigue resistance of restorations supported by welded-framework and realized using computer-aided designed prosthetic shells: In vitro pilot study.","authors":"Alberto Maria Albiero, Lorenzo Bevilacqua, Federica Pegoraro, Gianluca Turco, Stefano Momic, Roberto Di Lenarda, Michele Maglione","doi":"10.1177/09544119231221189","DOIUrl":"10.1177/09544119231221189","url":null,"abstract":"<p><p>Resin coating in implants rehabilitation cannot always be aesthetic, durable and comfortable for the patient mainly due to the limited dimensions of the final structure. Intraoral welding technique and computer-aided designed prosthetic shells may be a solution. This in vitro study evaluates the capacity of load and the weakest point of implant-supported provisional prosthesis using welded titanium framework. Twelve samples were produced to simulate an implant supported fixed prosthetic bridge. Two implants (Ankylos; Dentsply Sirona Implants; Germany) were inserted inside blocks of nanoceramic material produced with a stereolithographic 3D printer. A polymethylmethacrylate (PMMA) resin shell was performed with CAD/CAM and relined on welded framework. Six samples were produced with the same procedure reducing resin thickness. The samples were subjected to fatigue test (6,500,000 cycles) using ElectroForce 3310 fatigue machine (<i>t</i><sub>1</sub>); subsequently a mechanical compression test using a universal Shimadzu AGS-X 10 machine (<i>t</i><sub>2</sub>). The samples were analyzed with a photographic and radiographic documentation at <i>t</i><sub>0</sub>, <i>t</i><sub>1</sub> and <i>t</i><sub>2</sub>. The samples survived mechanical fatigue test without evidence of failure. The radiographic and photographic evaluation revealed the fracture of resin coating after the mechanical compression test. The samples with minimal resin thickness fractured first. Adequate assessment of the resin thickness is mandatory to improve the longevity of these rehabilitations. CAD-CAM digital prosthetic design allows us to optimize the thicknesses and the prosthetic shapes, allowing us to obtain good degrees of resistance even in the presence of reduced prosthetic spaces.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139378205","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":"Regional differences in electroactive response of the sclera.","authors":"Hamed Hatami-Marbini, Jafar Arash Mehr","doi":"10.1177/09544119231217240","DOIUrl":"10.1177/09544119231217240","url":null,"abstract":"<p><p>The sclera exhibits mechanical response when subjected to an external electric stimulation. The scleral electroactive response is a function of its charge density, mechanical properties, thickness, and strength of the applied electric voltage. The primary objective of the present work was to investigate the regional differences in the electroactive response of porcine sclera. To this end, we cut scleral strips in meridional directions from superior-temporal, superior-nasal, inferior-temporal, and inferior-nasal quadrants. In addition, we excised samples circumferentially from the posterior, equatorial, and anterior regions. The electroactive bending response of these samples was measured under 10 and 15 V in 0.15 M NaCl solution. The meridional samples were tested under two different configurations by clamping them either from their anterior or posterior end. It was observed that the scleral electroactive deformation increased with increasing the the electric voltage. Furthermore, regardless of the region from which meridional strips were excised, their electroactive response was considerably larger when they were clamped from their anterior end. Unlike meridional strips, the electroactive response of circumferential samples was significantly dependent on the location, that is, the average maximum bending angle of posterior samples was significantly larger than that of equatorial and anterior strips. The regionally different electroactive bending response of the sclera was discussed in terms of the variation in its biochemical and biomechanical properties throughout the eyeball.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139642781","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}
Dominic Jl Rivas, Holly D Aitken, Kevin N Dibbern, Michael C Willey, Robert W Westermann, Jessica E Goetz
{"title":"Incorporating patient-specific hip orientation from weightbearing computed tomography affects discrete element analysis-computed regional joint contact mechanics in individuals treated with periacetabular osteotomy for hip dysplasia.","authors":"Dominic Jl Rivas, Holly D Aitken, Kevin N Dibbern, Michael C Willey, Robert W Westermann, Jessica E Goetz","doi":"10.1177/09544119231221023","DOIUrl":"10.1177/09544119231221023","url":null,"abstract":"<p><p>Computational models of the hip often omit patient-specific functional orientation when placing imaging-derived bony geometry into anatomic landmark-based coordinate systems for application of joint loading schemes. The purpose of this study was to determine if this omission meaningfully alters computed contact mechanics. Discrete element analysis models were created from non-weightbearing (NWB) clinical CT scans of 10 hip dysplasia patients (11 hips) and oriented in the International Society of Biomechanics (ISB) coordinate system (NWB-ISB). Three additional models were generated for each hip by adding patient-specific stance information obtained via weightbearing CT (WBCT) to each ISB-oriented model: (1) patient-specific sagittal tilt added (WBCT-sagittal), (2) coronal and axial rotation from optical motion capture added to (1; WBCT-combo), and (3) WBCT-derived axial, sagittal, and coronal rotation added to (1; WBCT-original). Identical gait cycle loading was applied to all models for a given hip, and computed contact stress and contact area were compared between model initialization techniques. Addition of sagittal tilt did not significantly change whole-joint peak (<i>p</i> = 0.922) or mean (<i>p</i> = 0.871) contact stress or contact area (<i>p</i> = 0.638). Inclusion of motion-captured coronal and axial rotation (WBCT-combo) decreased peak contact stress (<i>p</i> = 0.014) and slightly increased average contact area (<i>p</i> = 0.071) from WBCT-sagittal models. Including all WBCT-derived rotations (WBCT-original) further reduced computed peak contact stress (<i>p</i> = 0.001) and significantly increased contact area (<i>p</i> = 0.001). Variably significant differences (<i>p</i> = 0.001-1.0) in patient-specific acetabular subregion mechanics indicate the importance of functional orientation incorporation for modeling applications in which local contact mechanics are of interest.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10985972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139478813","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}
Peter Jan Ogrodnik, Peter Brian MacFarlane Thomas, Alexander Collingwood
{"title":"Tibial fractures treated with mono-lateral fixation: Principles of design and application.","authors":"Peter Jan Ogrodnik, Peter Brian MacFarlane Thomas, Alexander Collingwood","doi":"10.1177/09544119231215998","DOIUrl":"10.1177/09544119231215998","url":null,"abstract":"<p><p>This paper presents the outcome of a data review of patients treated with the IOS external fixation system at the Royal Stoke University Hospital: a fixation designed to meet four requirements for external fixation proposed in this paper. Demographic data and outcome were collected and assessed. From 69 initial patients, 64 patients (55 males and 9 females) had an average age of 35.9 years. The mean time to union was 127 days. There were no incidences of malunion, or refracture post fixation removal attributable to the treatment method. In addition, in this cohort, there was no incidence of pin tract infection resulting in osteomyelitis. Of all the factors assessed the only factor to have any significant effect on healing was smoking: an average delay of 31 days. An examination of RUST (radiographic union score tibia) and modified RUST scores illustrated a potential false negative of up to 80%. Hence, this study cannot support the use of either scoring system to diagnose fracture healing. IOS external fixation was shown to be an effective method for the treatment of unstable tibial fractures. The reduction at fixation removal was shown to be very good. There was no incidence of osteomyelitis. It is, therefore, suggested that appropriately used external fixation is a viable alternative to intramedullary nailing if designed and surgically applied using four design principles outlined in this paper. Furthermore, it is proposed that external fixation be designed and applied to meet these four principles.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139692790","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":"Machine learning (ML) techniques as effective methods for evaluating hair and skin assessments: A systematic review.","authors":"Choudhary Sobhan Shakeel, Saad Jawaid Khan","doi":"10.1177/09544119231216290","DOIUrl":"10.1177/09544119231216290","url":null,"abstract":"<p><p>Machine Learning (ML) techniques provide the ability to effectively evaluate and analyze human skin and hair assessments. The aim of this study is to systematically review the effectiveness of applying Machine Learning (ML) methods and Artificial Intelligence (AI) techniques in order to evaluate hair and skin assessments. PubMed, Web of Science, IEEE Xplore, and Science Direct were searched in order to retrieve research publications between 1 January 2010 and 31 March 2020 using appropriate keywords such as \"hair and skin analysis.\" Following accurate screening, 20 peer-reviewed publications were selected for inclusion in this systematic review. The analysis demonstrated that prevalent Machine Learning (ML) methods comprised of Support Vector Machine (SVM), <i>k</i>-nearest Neighbor, and Artificial Neural Networks (ANN). ANN's were observed to yield the highest accuracy of 95% followed by SVM generating 90%. These techniques were most commonly applied for drafting framework assessments such as that of Melanoma. Values of parameters such as Sensitivity, Specificity, and Area under the Curve (AUC) were extracted from the studies and with the help of comparisons, relevant inferences were also made. ANN's were observed to yield the highest sensitivity of 82.30% as well as a 96.90% specificity. Hence, with this systematic review, a summarization of the studies was drafted that encapsulated how Machine Learning (ML) techniques have been employed for the analysis and evaluation of hair and skin assessments.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139058614","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}
Johari Yap Abdullah, Abdul Manaf Abdullah, Syafawati Zaim, Helmi Hadi, Adam Husein, Zainul Ahmad Rajion, Jafri Malin Abdullah
{"title":"Three-dimensional analysis of reconstructed skulls using three different open-source software versus commercial software.","authors":"Johari Yap Abdullah, Abdul Manaf Abdullah, Syafawati Zaim, Helmi Hadi, Adam Husein, Zainul Ahmad Rajion, Jafri Malin Abdullah","doi":"10.1177/09544119231212034","DOIUrl":"10.1177/09544119231212034","url":null,"abstract":"<p><p>This study aimed to compare the 3D skull models reconstructed from computed tomography (CT) images using three different open-source software with a commercial software as a reference. The commercial Mimics v17.0 software was used to reconstruct the 3D skull models from 58 subjects. Next, two open-source software, MITK Workbench 2016.11, 3D Slicer 4.8.1 and InVesalius 3.1 were used to reconstruct the 3D skull models from the same subjects. All four software went through similar steps in 3D reconstruction process. The 3D skull models from the commercial and open-source software were exported in standard tessellation language (STL) format into CloudCompare v2.8 software and superimposed for geometric analyses. Hausdorff distance (HD) analysis demonstrated the average points distance of Mimics versus MITK was 0.25 mm. Meanwhile, for Mimics versus 3D Slicer and Mimics versus InVesalius, there was almost no differences between the two superimposed 3D skull models with average points distance of 0.01 mm. Based on Dice similarity coefficient (DSC) analysis, the similarity between Mimics versus MITK, Mimics versus 3D Slicer and Mimics versus InVesalius were 94.1, 98.8 and 98.3%, respectively. In conclusion, this study confirmed that the alternative open-source software, MITK, 3D Slicer and InVesalius gave comparable results in 3D reconstruction of skull models compared to the commercial gold standard Mimics software. This open-source software could possibly be used for pre-operative planning in cranio-maxillofacial cases and for patient management in the hospitals or institutions with limited budget.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138291671","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}
Min Jae Kim, Soo Hong Kim, Sung Uk Yun, Gun Ho Kim, Kyoung Won Nam
{"title":"In vitro comparative study of wall portbased high-frequency chest wall oscillation device and internal air-pulse generator device.","authors":"Min Jae Kim, Soo Hong Kim, Sung Uk Yun, Gun Ho Kim, Kyoung Won Nam","doi":"10.1177/09544119231214620","DOIUrl":"10.1177/09544119231214620","url":null,"abstract":"<p><p>Owing to environmental and disease issues, the use of high-frequency chest wall oscillation (HFCWO) devices in hospitals is consistently increasing. This study proposes a cost-effective actuator-less HFCWO device that utilizes an external wall port utility in hospitals to generate the positive and negative pneumatic pressures required for HFCWO treatment instead of an embedded mechanical actuator. The manufactured prototype with the no-amplification (NO-AMP) setting contained an electric pressure regulator to enable intensity level adjustment and two solenoid valves to enable vibration frequency adjustment, whereas the prototype with the pre-amplification (PRE-AMP) setting contained an additional air reservoir and an air-pressure booster. The prototype device was tuned to output average local maximum values in the pressure waveform similar to a commercial VEST-205 device at an 8-12 Hz frequency and 2-4 pressure intensity levels. In vitro comparative experiments demonstrated that the prototype device showed similar local maximum pressures to those of the VEST-205 (mean absolute pressure difference, <3 mmH<sub>2</sub>O); in contrast, the proposed device showed significantly higher local minimum pressures than those of the VEST-205 (mean absolute pressure difference, >8 mmH<sub>2</sub>O). Additionally, the driving sound of the proposed device was 17.0-17.8 dB higher than that of VEST-205. We conclude that the proposed device has the potential to substitute for conventional HFCWO devices under the limited but most frequently used operating conditions, although more detailed modifications are necessary in future studies to improve its performance and clinical usability.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138478405","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}