Download or read book Computer Modelling of the Residual Limb for the Development of Prosthetic Sockets and Liners with the Cellular Structure written by Vasja Plesec and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of lower limb prostheses continues to rely primarily on manual methods, which are outdated and characterized by labour-intensive processes, lengthy time requirements, high costs, and a heavy reliance on the expertise of prosthetists. Achieving a satisfactory fit between the residual limb and socket remains a challenge, often leading to discomfort, pain, and potential wearer tissue damage. However, advancements in computer technology and numerical simulation offer an opportunity to predict stresses and strains experienced by the residual limb during prosthesis usage. This, in turn, aids in the development process by enhancing the design of the prosthetic socket and liner through virtual environments. In this dissertation we developed a generic numerical transtibial model to bridge the gap between clinical practice and numerical simulations. Biomechanically validated, this model generates outcomes applicable to a broader amputee population, facilitating comparative analysis of socket and liner designs and materials under different loading conditions. Furthermore, the dissertation explores the utilization of a 3D-printed socket manufactured through the cost-effective fused filament fabrication process, using polylactic acid filament, aiming to reduce the costs and establish a streamlined production process. The 3D-printed socket was evaluated within the virtual environment using the developed transtibial model. The numerical findings indicate that the 3D-printed socket can effectively withstand the loads encountered during the stages of prosthesis donning, single-leg stance, heel strike, and push-off, thereby presenting a viable alternative to the prevalent composite socket. Additionally, a cellular structure composed of a flexible thermoplastic elastomeric material is proposed as a prosthetic liner to enhance comfort by reducing contact pressure while maintaining the required stability. Numerical results indicate that by manipulating cellular parameters such as unit cell type and relative density of the structure, a customized response can be achieved. This customized response effectively reduces contact pressure for a given scenario without increasing displacement, thereby improving comfort while maintaining stability.

Download or read book Development of a Biomechancial Model of the Interface Between the Residual Limb and Prosthesis for Trans femoral Amputees written by V.S.P Lee and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Synergistic Approach to Transtibial Socket Interface Mechanics written by Amy Lorraine Lenz and published by . This book was released on 2017 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prosthetic Designs for Restoring Human Limb Function written by William Craelius and published by Springer Nature. This book was released on 2021-07-30 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a thorough introduction and overview of the design and engineering of state-of-the-art prosthetics and assistive technologies. Innovations in prosthetics are increasingly made by cross-disciplinary thinking, and the author introduces the application of biomedical, mechanical, electrical, computer, and materials engineering principles to the design of artificial limbs. Coverage includes the fundamentals of biomechanics, biomechanical modeling and measurements, the basics of anatomy and physiology of limb defects, and the historical development of prosthetic design. This book stimulates the innovative thinking necessary for advancing limb restoration, and will be essential reading for students, as well as researchers, professional engineers, and prosthetists involved in the design and manufacture of artificial limbs. Learning enhanced by the exercises, including physical modeling with MATLAB and Simulink; Includes appendices with relevant equations and parameters for reference; Introduction to the design and engineering of prosthetics and assistive technologies.

Download or read book Modeling and Design of Perforated Prosthetic Sockets ARCHM to Increase Heat Transfer of Residual Limbs written by Luis Carbajal and published by . This book was released on 2015 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat build-up in prosthetic sockets is a significant problem experienced by many amputees in America, with no central solution in sight. Heat and discomfort accounts for over 70% of problems experienced by lower limb amputees in America. Although there have been advances in prosthetics in the active-power knees and ankles, not even cybernetics can improve the comfort of the prosthesis if there is still a socket. The materials in prosthetic sockets are not conductive enough to relieve the heat inside of the socket. The purpose of this study is to model the temperature variance and heat transfer of an amputee's residual limb and design ways to improve current prosthetic socket technologies. With the addition of small holes, or perforations, in the socket, there will be an increase in the heat transfer by convection, while still maintaining the strength of a carbon fiber prosthesis. Through the use of discrete approximation modeling, the transient temperature inside of the socket layers can be identified and improved through design patterns cut into the socket. Increased heat transfer can be observed as the perforations in the socket become larger, although the larger the holes, the larger the stresses are in the prosthesis. Non-intrusive designs were developed for sockets before and after they are made to increase convection surface area. More modeling needs to be done in 3-dimensional polar coordinates.

Download or read book Generation and Development of a Biomechanical Finite Element Model of the Residual Limb and Prosthetic Socket written by Laura Finney and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Computational Tool to Enhance Clinical Selection of Prosthetic Liners for People with Lower Limb Amputation written by John C. Cagle and published by . This book was released on 2016 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: People with transtibial amputation experience a loss of mobility that results from the removal of propulsive and load bearing anatomy. The more delicate soft tissues of the residual limb are coupled to a hard prosthetic socket, and this results in regular instances of skin breakdown. Soft and flexible prosthetic liners worn between the limb and socket are a common method of reducing these interface stresses. Advances in materials and manufacturing technics over the previous two decades has led to the development of over 70 liner products on the clinical market. The aims of this dissertation were to (1) design a set of benchtop protocols to accurately measure clinical relevant liner characteristics, (2) use the design characteristics to measure a selection of liner products and evaluate assumptions on their use in clinical practice, (3) develop a finite element model (FEM) that simulates a modern prosthetic design, and (4) use the developed FEM to assess the effect of liner product and socket size. Six protocols were used to assess 24 liner products available on the clinical market. Results showed that liner products demonstrated significant variability, even when products were formulated from a common base polymer (e.g., polyurethane or silicone). This emphasized the need for a tool to facilitate liner selection in a clinical setting. The developed FEM produced results that were reasonable with the context of literature reported interface mechanics, and showed focused stresses in locations that corresponded with incidences of skin breakdown experienced by participants in their as-prescribed prosthesis. Further evaluations showed that a change in liner product could result in 15-25% change in interface stresses, while a 1-2% change in limb volume could correspond to a 15-30% increase in interface stresses.

Download or read book Characterising Patient Specific Soft Tissue Deformation in the Residual Limb Under Compressive Loads written by Mahamandige Kaushini Mendis and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A prosthetic socket can be considered as the primary link between the prosthesis and the residual limb in a lower limb amputated patient. Within the first two years post-amputation, the residual limb soft tissues tend to change in the aspects of shape, volume, composition, and sensitivity due to environmental, mechanical, and surgical factors. As these changes could occur within a single day, or within several months, a single mechanical design is not capable of interpreting the high rate of change of the stump. Thus, patients tend to wear temporary sockets within this time period. Patients wear a permanent socket at a later stage following amputation when the stump reaches its maturity. Even though the matured residual limb continues to change due to fluid movements and temperature variations, a single mechanical design can cope up with the low rate of change of the stump. The project considered the patient-specific soft tissue deformations at the matured stage of the residual limb under compressive loads. -- The elevated stresses and strains caused by imperfect permanent socket fittings contribute to a range of short- and long-term complications and affect patient satisfaction in physical, mental, and financial aspects. The project intends to improve the current socket designing and manufacturing process, which depends on prosthetists' experience and unreliable feedback from patients towards an engineering-driven framework to benefit the patient's health, healthcare system and the economy. -- Biomechanical modelling has been used over the past two decades to model the residual limb soft tissue mechanics in order to eliminate the ill-fitting sockets. The efficacy and fidelity of biomechanical models require accurate information on the geometry and material properties of soft tissues. The main limitation of the previous work was the consideration of literature reported material properties; most of the researchers were leaned towards assuming linear, elastic, isotropic and homogenous material properties for the residual limb soft tissues. Hence, the project's aim was to estimate patient specific soft tissue deformations of the residual limb employing medical image data acquired while performing quasi-static loading experiments, which could assist in estimating patient specific material properties in the future. -- The project considered the magnetic resonance imaging (MRI) scans related to three patients where each patient had to undergo a series of uniaxial quasi-static compression tests. The MRI scans were obtained using an MRI compatible sphygmomanometer (Cone Instruments, USA) which covered the patient's residual limb at 0 , 30 , 60 and 100 pressures, respectively. The MRI scans were segmented through Simpleware ScanIP (Synopsys, California, USA) to obtain surface and solid geometries of the uncompressed and the compressed states of the residual limb. -- Rigid iterative closest point (ICP) algorithms were performed to register the uncompressed to each of the compressed surface geometries of the residual limb. Non-rigid ICP was then used to calculate soft tissue deformation at the entire residual limb surface for each of the compressed states. The area in contact with the sphygmomanometer was extracted to derive the force applied at each compressed state. Finally, the patient specific soft tissue deformations of the residual limb were characterized by fitting piecewise linear models to force-deformation data acquired for each patient. All data processing were performed using MATLAB (MathWorks, Massachusetts, USA). The force-deflection plots indicated unique shapes for each patient confirming the discrepancies between the soft tissue deformations between patients. The obtained soft tissue deformations could aid substantially in biomechanical modelling of residual limb soft tissues. The study anticipates developing accurate computational models of the mechanical contact between the residual limb and encasing socket. Such models can aid current socket design and customization process in an effort to reduce the risk of tissue injury, to lessen the time, materials and workforce required for design and fabrication of a best-fit prosthetic socket, and to improve patient satisfaction rates. The study anticipates employing more patients in the future to understand the variability within the patient population.

Download or read book The Use of a Novel Residuum Model to Design a Variable impedance Transtibial Prosthetic Socket written by David Moinina Sengeh and published by . This book was released on 2016 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: For people living with limb amputation, the prosthetic socket - the interface between the residuum and prosthesis - is the most critical component. When a socket is uncomfortable, especially due to poor fit, the quality of life for a patient is greatly hindered. However, conventional design of sockets is largely artisan, with limited input of quantitative data. Current computer-aided and manufacturing (CAD/CAM) designs are still not clinically applicable solutions. Due to model identification procedures that employ non patient-specific and incomplete data sets, today's finite element (FE) models of the residuum are not predictive, leading to suboptimal socket designs. As such, there exists a need for a comprehensive biomechanical model of the residuum for the quantitative design and computational evaluation of patient-specific prosthetic sockets. This thesis presents a combined experimental-numerical approach to evaluate and validate a transtibial residuum biomechanical model. The central hypothesis of the work is that a single biomechanical model can predict the large non-linear response at various sites on a residuum under load. To evaluate this hypothesis, a non-linear, two-tissue model was formulated where tissue geometries were defined using MRI data of the residuum. The non-linear viscoelastic material parameters of the model were identified through inverse FEA-based optimization using in-vivo indentation experimental data at four locations. Using optimized model tissue parameters, the mean percentage error (mean absolute error/ maximum experimental force) between the experimental and simulation force-time curves at 14 other locations across the evaluated transtibial residuum was 7 ± 3%. Using this same modeling methodology and a single set of material constants to describe the bulk soft tissue biomechanical response of seven distinct transtibial residual limb models, the average percentage error for indentations at multiple locations across all seven limbs was 7 ± 1%. From these predictive models of residuum limbs, one rigid novel socket and two multimaterial transtibial sockets were designed, fabricated and evaluated through an entirely quantitative, automated and repeatable methodology. In a preliminary clinical investigation, the novel sockets were shown to reduce peak contact pressures at the tibia and fibular head regions on the residuum by significant amounts during standing compared to a conventional socket interface designed and fabricated by a trained prosthetist.

Download or read book Design and Manufacturing Process Optimization for Prosthesis of the Lower Limb written by Abbass Ballit and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prosthetic socket, an essential interface element between the patient's stump and prosthetic device, is most often the place where the degree of prosthetic success is defined. It is the most critical part of the prosthesis, customized to fit with the unique residual limb of the amputee. Without a proper socket shape and fit, the prosthesis becomes uncomfortable, or even unusable, and causes pain and skin issues. The state-of-the-art prosthetic production is still missing universal numerical standards to design a socket. The current practice is expensive and relies on the manual refinements of the orthopedic technician, and the fit quality strictly correlates with his skills as well as the subjective feedback of the patient. The thesis aims to conduct a deep analysis of an optimal design of the prosthetic socket by studying and developing an alternative computer-aided design process. This process is fully based on the virtual model of the patient's residual limb and relies on the calculation of the socket-stump interaction. A fast calculation is favorable in this case, that's why we propose to use the Mass-Spring System (MSS) instead of the widely used FE method to model the soft tissues of the residual limb. A new configuration of the MSS model is proposed to respect the non-compressibility property of the soft tissues by adding non-linear “Corrective Springs”. The numeric model is to be generated from the scanned model of the stump. For this purpose, we propose a fusion scheme of four RGB-Depth sensors for a rapid and low-cost scan with error reduction techniques. Finally, the virtual residual limb is used in the socket designing phase. A parametric design method is proposed and investigated. The design problem is transformed into a constraint-satisfaction-problem whose constraints are derived from the inverse calculation of the stump-socket interaction. The inverse approach has been chosen to eliminate the need for expensive contact formulation. This fact leads to rapid calculations, and consequently, allows to provide real-time numerical feedback during the designing process. The validation was done by comparing the results of our system with the output of FE simulations. The system has been implemented with a user-friendly graphical interface and virtually tested and numerically validated. This system reduces the limitations of the current practices. However, a lot of works is still ahead to refine and develop the system and validate it with clinical experiments.

Download or read book Biomechanical Model of Transhumeral Prostheses written by Rebekah Freilich and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: It has been shown that the interface between the prosthetic socket and residual limb (S-RL) interface is an important factor in determining acceptance and outcomes of upper limb prostheses. [1] Among the most common complaint from amputees is that the prosthesis is uncomfortable due to developing skin irritation which is usually attributed to poor fit (Nielson 1990). In order to understand why skin irritations can and do occur it is imperative to examine the biomechanical properties of the S-RL interface. A primary reason behind the development of skin irritation is instability of the socket upon the residuum. Alley (2009) asserts that excess slip, axial rotation, and translation are the facets of instability that cause skin irritations due to friction and shear. Measuring the motion at the S-RL interface is not commonly done and therefore there is still no valid and reliable method to quantify the motion clinically. A licensed prosthesis fabricated a transhumeral residual limb model to fit within a typical, harness suspended transhumeral prosthesis. A custom testing apparatus was built to hold the residual limb model and prosthesis for testing. Eight infrared markers were placed on the prosthesis and residual limb model: Two each respectively on the "wrist", elbow axis, socket, and on the residual limb model. The model consists of 3 rigid segments, the forearm, socket, and residual limb. Pearson r correlations were done to see how strongly correlated the motion analysis calculated values were to the accepted values. All results were significant with a r

Download or read book Lower limb Prosthetics written by Norman Berger and published by . This book was released on 1997 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biomechanics of Lower Limb Prosthetics written by Mark R. Pitkin and published by Springer. This book was released on 2009-10-14 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foreword from a Clinical Biomechanist, Applied Physiologist and Prosthetist teaching graduate students in Prosthetics & Orthotics. While there are many books on Biomechanics, arguably the quintessential science of limb prosthetics, none addresses the fundamental principles in sufficient detail and depth to be practically useful to the prosthetist, rehabilitation specialist or researcher. Dr. Pitkin’s monograph is an exemplary collection of theoretical principles from his research and o- ers, presented in its clinical and applied biomechanics form. The textbook provides an excellent overview of the many facets of lower limb prosthetic design and engineering for the ardent clinician researcher and student. The book delves into many of the basic concepts that are required knowledge for the clinician and the scientist to have as the foundation for their work. Dr. Pitkin has an e- quent manner in which he reflects on the history and literature to tell the storied evolution of prosthetic design . He takes the reader on a journey to consider his theories, which have substantive foundations to contemplate. By the end of chapter one, we have the basic h- tory and an appreciation for the rationale behind the “rolling joint ankle” with evidence to support his theoretical views.

Download or read book The Glossary of Prosthodontic Terms written by and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Postgraduate Orthopaedics written by Paul A. Banaszkiewicz and published by Cambridge University Press. This book was released on 2012-08-16 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The must-have book for candidates preparing for the oral component of the FRCS (Tr and Orth).

Download or read book Pressure Ulcer Research written by Dan L. Bader and published by Springer Science & Business Media. This book was released on 2005-12-14 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents both current and future aspects of diagnosis and treatment. Presents evidence-based knowledge of pressure ulcer aetiology. Contains over 90 illustrations. Explores the possiblities of tissue repair using new tissue engineering strategies.

Download or read book 3D Printing in Biomedical Engineering written by Sunpreet Singh and published by Springer Nature. This book was released on 2020-07-16 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive overview of the rapidly evolving field of three-dimensional (3D) printing, and its increasing applications in the biomedical domain. 3D printing has distinct advantages like improved quality, cost-effectiveness, and higher efficiency compared to traditional manufacturing processes. Besides these advantages, current challenges and opportunities regarding choice of material, design, and efficiency are addressed in the book. Individual chapters also focus on select areas of applications such as surgical guides, tissue regeneration, artificial scaffolds and implants, and drug delivery and release. This book will be a valuable source of information for researchers and professionals interested in the expanding biomedical applications of 3D printing.