Yao Sun , Xin Zhu , Wenxi Chen , Weihao Weng , Keijiro Nakamura
{"title":"Computer simulation of low-power and long-duration bipolar radiofrequency ablation under various baseline impedances","authors":"Yao Sun , Xin Zhu , Wenxi Chen , Weihao Weng , Keijiro Nakamura","doi":"10.1016/j.medengphy.2024.104226","DOIUrl":"10.1016/j.medengphy.2024.104226","url":null,"abstract":"<div><p>Compared to traditional unipolar radiofrequency ablation (RFA), bipolar RFA offers advantages such as more precise heat transfer and higher ablation efficiency. Clinically, myocardial baseline impedance (BI) is one of the important factors affecting the effectiveness of ablation. We aim at finding suitable ablation protocols and coping strategies by analyzing the ablation effects and myocardial impedance changes of bipolar RFA under different BIs. In this research, a three-dimensional local myocardial computer model was constructed for bipolar RFA simulation, and <em>in vitro</em> experimental data were used to validate accuracy. Four fixed low-power levels (20 W, 25 W, 30 W, and 35 W) and six myocardial BIs (91.02 Ω, 99.83 Ω, 111.03 Ω, 119.77 Ω, 130.03 Ω, and 135.45 Ω) were set as initial conditions, with an ablation duration of 120-s. In the context of low-power and long-duration (LPLD) ablation, the maximum TID (TID<sub>M</sub>) decreased by 21–32 Ω, depending on the BI. In cases where steam pop did not occur, TID<sub>M</sub> increased with the increase in power. For the same power, there was no significant difference in TID<sub>M</sub> for the range of BIs. In cases where steam pop occurred, for every 1 Ω increase in BI, TID<sub>M</sub> increased by 0.34–0.41 Ω. The simulation results also showed that using a higher power resulted in a smaller decrease in TID<sub>M</sub>. This study provided appropriate ablation times and impedance decrease ranges for bipolar LPLD RFA. The combination of 25 W for 120-s offered optimal performance when considering effectiveness and safety simultaneously.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104226"},"PeriodicalIF":1.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142096555","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":"Real-time identification of noise type contaminated in surface electromyogram signals using efficient statistical features","authors":"Pornchai Phukpattaranont , Nantarika Thiamchoo , Paramin Neranon","doi":"10.1016/j.medengphy.2024.104232","DOIUrl":"10.1016/j.medengphy.2024.104232","url":null,"abstract":"<div><p>Different types of noise contaminating the surface electromyogram (EMG) signal may degrade the recognition performance. For noise removal, the type of noise has to first be identified. In this paper, we propose a real-time efficient system for identifying a clean EMG signal and noisy EMG signals contaminated with any one of the following three types of noise: electrocardiogram interference, spike noise, and power line interference. Two statistical descriptors, kurtosis and skewness, are used as input features for the cascading quadratic discriminant analysis classifier. An efficient simplification of kurtosis and skewness calculations that can reduce computation time and memory storage is proposed. The experimental results from the real-time system based on an ATmega 2560 microcontroller demonstrate that the kurtosis and skewness values show root mean square errors between the traditional and proposed efficient techniques of 0.08 and 0.09, respectively. The identification accuracy with five-fold cross-validation resulting from the quadratic discriminant analysis classifier is 96.00%.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104232"},"PeriodicalIF":1.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142096556","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 the milling response of an artificial temporal bone developed for otologic surgery in comparison with human cadaveric samples","authors":"Martin Boillat , Anne-Sophie Bonnet , Frédérique Groubatch , Aude Falanga , Romain Gillet , Cécile Parietti-Winkler","doi":"10.1016/j.medengphy.2024.104220","DOIUrl":"10.1016/j.medengphy.2024.104220","url":null,"abstract":"<div><p>Temporal-bone milling is a delicate process commonly performed during otologic surgery to gain access to the middle and inner ear structures. Because of the numerous at-risk structures of this anatomic area, extensive surgeon training is required. Artificial temporal bones offer an interesting alternative to cadaveric training. However, the evaluation of such simulators has not been systematic, with an absence of objective validation of their milling response, especially in a surgical context.</p><p>By measuring the milling forces obtained during the classical steps of otologic surgery on six 3D-printed and three cadaveric temporal bones, this work aims at evaluating the ability of the OTOtwin® synthetic temporal bone to reproduce human bone behavior.</p><p>A better repeatability was obtained for artificial bones than for cadaveric ones. However, the level of forces recorded during artificial bone milling was close to the one measured with cadaveric samples. The effects of both surgical phase and irrigation on milling force levels were also quantified. The experiments conducted in this study confirmed the suitability of OTOtwin® temporal bone model for both otologic surgery training and research purposes. Valuable insights were also gained from this study regarding the understanding of the otologic milling process.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104220"},"PeriodicalIF":1.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1350453324001218/pdfft?md5=2deb85e5c06eb5586c9156c86dde09ac&pid=1-s2.0-S1350453324001218-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142096838","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":"An optimal fast fractal method for breast masses diagnosis using machine learning","authors":"S.M.A. Beheshti","doi":"10.1016/j.medengphy.2024.104234","DOIUrl":"10.1016/j.medengphy.2024.104234","url":null,"abstract":"<div><p>This article introduces a fast fractal method for classifying breast cancerous lesions in mammography. While fractal methods are valuable for extracting information, they often come with a high computational load and time consumption. This paper demonstrates that extracting optimal fractal information and focusing only on valuable information for classification not only improves computation speed and reduces process load but also enhances classification accuracy. To achieve this, we define an objective function based on accurate classification of benign and malignant masses to identify the best scale. Instead of extracting information from all nine scales, we extract and employ information solely from the best scale for classification. We validate the obtained scales using three classifiers: Support Vector Machine (SVM), Genetic Algorithm (GA), and Deep Learning (DL), which confirm the effectiveness of the proposed method. Comparative analysis with other studies reveals improved classification performance with the presented method.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"132 ","pages":"Article 104234"},"PeriodicalIF":1.7,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169292","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}
Hossein Ansaripour , Stephen J. Ferguson , Markus Flohr
{"title":"The effects of setup parameters on the measured kinetic output of cervical disc prostheses","authors":"Hossein Ansaripour , Stephen J. Ferguson , Markus Flohr","doi":"10.1016/j.medengphy.2024.104227","DOIUrl":"10.1016/j.medengphy.2024.104227","url":null,"abstract":"<div><p>Mechanical testing machines are used to evaluate kinematics, kinetics, wear, and efficacy of spinal implants. The simulation of \"physiological\" spinal loading conditions necessitates the simultaneous use of multiple actuators. The challenge in achieving a desired loading profile lies in achieving close synchronization of these actuators. Errors in load application can be attributed to both the control system and the intrinsic sample response. Moreover, the presence of friction in the setup can have an impact on the measured outcome. The optimization of setup parameters can substantially improve the ability to simulate spinal loading conditions and obtain reliable data on implant performance. In this study, a reproducible kinematic test protocol was developed to evaluate the sensitivity of the kinetic response (i.e., measured loads, moments, and stiffnesses) of a cervical disc prosthesis to several testing parameters. In this context, five ceramic ball and socket sample implants were mounted in a 6 DOF material testing machine and tested with a constant axial compressive force of 100 N in two motion modes: 1) flexion-extension (±7.5°) and 2) lateral bending (±6°). Parameters including rotation rate, slider friction, friction between the samples' articulating surfaces, and moment arm were considered to determine their effects on measured kinetic parameters. The sensitivity analysis indicated that all setup parameters except friction between the samples' articulating surfaces had a substantial effect on the results. The findings were then compared to predictions from a free body diagram to determine the optimal setup parameters. Consequently, the setup with the lowest rotation rate and employing passive sliders yielded results that were consistent with the free body diagram. This study demonstrated the significance of a comprehensive setup evaluation for reliable and reproducible testing of spinal implants, also for comparison between labs.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104227"},"PeriodicalIF":1.7,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142041059","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}
G. Plet , J. Raviol , H. Magoariec , C. Pailler-Mattei
{"title":"Development of a mechanical characterisation device for intracranial aneurysms: Calibration on polymeric phantom arteries","authors":"G. Plet , J. Raviol , H. Magoariec , C. Pailler-Mattei","doi":"10.1016/j.medengphy.2024.104225","DOIUrl":"10.1016/j.medengphy.2024.104225","url":null,"abstract":"<div><p>Intracranial aneurysm is a major health issue related to biomechanical arterial wall degradation. Currently, no method allows predicting rupture risk based on <em>in vivo</em> quantitative mechanical data. This work is part of a large-scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool, based on the <em>in vivo</em> mechanical characterisation of the aneurysm wall. Thus, the primary objective of the project was to develop a deformation device prototype (DDP) of the artery wall and to calibrate it on polymeric phantom arteries. The deformations induced on the phantom arteries were quantified experimentally using a Digital Image Correlation (DIC) system. The results indicated that the DIC system was able to measure the small displacements generated by the DDP. We also observed that the flow mimicking the blood flow did not significantly disturb the measurements of the artery wall displacement caused by the DDP. Finally, a limit displacement value generated by the DDP was evaluated. This value corresponds to the lowest displacement value detectable by the clinical imaging system that will be tested on animals in the future (Spectral Photon Counting CT).</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104225"},"PeriodicalIF":1.7,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050435","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":"Towards a reduced order model for EVAR planning and intra-operative navigation","authors":"Monica Emendi , Eirini Kardampiki , Karen-Helene Støverud , Antonio Martinez Pascual , Leonardo Geronzi , Sigrid Kaarstad Dahl , Victorien Prot , Paal Skjetne , Marco Evangelos Biancolini","doi":"10.1016/j.medengphy.2024.104229","DOIUrl":"10.1016/j.medengphy.2024.104229","url":null,"abstract":"<div><h3>Introduction</h3><p>The pre-operative planning and intra-operative navigation of the endovascular aneurysm repair (EVAR) procedure are currently challenged by the aortic deformations that occur due to the insertion of a stiff guidewire. Hence, a fast and accurate predictive tool may help clinicians in the decision-making process and during surgical navigation, potentially reducing the radiations and contrast dose. To this aim, we generated a reduced order model (ROM) trained on parametric finite element simulations of the aortic wall-guidewire interaction.</p></div><div><h3>Method</h3><p>A Design of Experiments (DOE) consisting of 300 scenarios was created spanning over seven parameters. Radial basis functions were used to achieve a morphological parametrization of the aortic geometry. The ROM was built using 200 scenarios for training and the remaining 100 for validation.</p></div><div><h3>Results</h3><p>The developed ROM estimated the displacement of aortic nodes with a relative error below 5.5% for all the considered validation cases. From a preliminary analysis, the aortic elasticity, the stiffness of the guidewire and the tortuosity of the cannulated iliac artery proved to be the most influential parameters.</p></div><div><h3>Conclusions</h3><p>Once built, the ROM provided almost real-time and accurate estimations of the guidewire-induced aortic displacement field, thus potentially being a promising pre- and intra-operative tool for clinicians.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104229"},"PeriodicalIF":1.7,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1350453324001309/pdfft?md5=e31c28cf4d82238e7951b8a62951ea41&pid=1-s2.0-S1350453324001309-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142084093","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":"Impact of fractured tibia implant fixation devices on bone stiffness during bending test","authors":"Hajer Ketata , Naila Hfaiedh , Michèle Kanhonou , Houssem Badreddine","doi":"10.1016/j.medengphy.2024.104228","DOIUrl":"10.1016/j.medengphy.2024.104228","url":null,"abstract":"<div><p>This study focuses on evaluating the failure resistance of a previously reduced tibia with internal fixation implants as PLate (PL) or InterMedullary Nail (IMN), subjected later to a tibial lateral trauma. To replicate this type of trauma, which can be caused by a road accident, a three-point bending test is considered using experimental tests and numerical simulations.</p><p>The withstand evaluation of the tibia-PL and tibia-IMN structures was conducted by following the load transfer through, the bone and the used implants. The analysis, up to tibia failure, required the use of an elasto-plastic behavior law coupled to damage. The model parameters were identified using experimental tests.</p><p>Il was shown that the tibia-IMN structure provided a bending resistant load up to three-times higher than the tibia-PL. In fact, the used screws for plate fixation induced a high level of stress in the vicinity of threaded region, leading to a crack initiation and a damage propagation. However, in tibia-IMN structure the highest stress was generated in the trapped zone between the loader and the nail, promoting crack formation.</p><p>From a biomechanical point of view, the structure with IMN is safer than the structure with PL, whose fixation induces earlier damage in bone.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104228"},"PeriodicalIF":1.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142089207","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":"Reliability and validity of a method to measure trunk rotation angle from images using a camera and posture mirror","authors":"Dai Nakaizumi , Takaaki Nishimura , Pleiades Tiharu Inaoka , Hitoshi Asai","doi":"10.1016/j.medengphy.2024.104224","DOIUrl":"10.1016/j.medengphy.2024.104224","url":null,"abstract":"<div><p>This study aimed to measure trunk rotation angle representations from images using a single camera combined with a posture mirror and to examine its reliability and validity. We applied a trunk rotation angle model using a tripod and markers simulating trunk rotation. We compared two methods of trunk rotation angle measurement: the conventional method from the superior aspect using a manual goniometer and a novel measurement method using images from a digital camera and a posture mirror. Measurement error was calculated as the average absolute error between the angle measured by the goniometer and that calculated from the camera and mirror image. The intraclass correlation coefficient (ICC 1, 1) and ICC (2, 1) were calculated as the intra-rater reliability and agreement between the measurement angles of the two methods, respectively. Systematic errors of the angles measured by the two methods were examined by a Bland‒Altman analysis. The mean (SD) of the mean absolute error was 1.17° (0.71°). ICC (1, 1) was 0.978, and ICC (2, 1) was 0.991. The Bland‒Altman analysis showed no systematic errors. The results suggest the validity and accuracy of our novel method to measure the angle of trunk rotation, which does not require high-cost equipment or a special environment.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104224"},"PeriodicalIF":1.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142058422","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":"Long vs short intramedullary nails for reverse pertrochanteric fractures: A biomechanical study","authors":"Gilles Udin , Lore Hoffmann , Fabio Becce , Olivier Borens , Alexandre Terrier","doi":"10.1016/j.medengphy.2024.104230","DOIUrl":"10.1016/j.medengphy.2024.104230","url":null,"abstract":"<div><p>There is currently no definitive evidence for the implant of choice for the treatment of reverse pertrochanteric fractures. Here, we aimed to compare the stability provided by two implant options: long and short intramedullary nails.</p><p>We performed finite element simulations of different patterns of reverse pertrochanteric fractures with varying bone quality, and compared the short vs long nail stabilization under physiological loads. For each variable combination, the micromotions at the fracture site, bone strain, and implant stress were computed.</p><p>Mean micromotions at the fracture surface and absolute and relative fracture surface with micromotions >150 µm were slightly lower with the short nail (8%, 3%, and 3%, respectively). The distal fracture extension negatively affected the stability, with increasing micromotions on the medial side. Bone strain above 1 % was not affected by the nail length. Fatigue stresses were similar for both implants, and no volume was found above the yield and ultimate stress in the tested conditions.</p><p>This simulation study shows no benefit of long nails for the investigated patterns of reverse pertrochanteric fractures, with similar micromotions at the fracture site, bone strain, and implant stress.</p></div>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":"131 ","pages":"Article 104230"},"PeriodicalIF":1.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1350453324001310/pdfft?md5=1fe9fee30f4491794c3f79c37c757e0b&pid=1-s2.0-S1350453324001310-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142075791","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}