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Sanders JE, Vamos AC, Mertens JC, Allyn KJ, Larsen BG, Ballesteros D, Wang H, DeGrasse NS, Garbini JL, Hafner BJ, Friedly JL. An adaptive prosthetic socket for people with transtibial amputation. Sci Rep 2024; 14:11168. [PMID: 38750086 PMCID: PMC11096356 DOI: 10.1038/s41598-024-61234-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 05/01/2024] [Indexed: 05/18/2024] Open
Abstract
It is essential that people with limb amputation maintain proper prosthetic socket fit to prevent injury. Monitoring and adjusting socket fit, for example by removing the prosthesis to add prosthetic socks, is burdensome and can adversely affect users' function and quality-of-life. This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking. A socket fit metric was calculated from inductive sensor measurements of the distance between the elastomeric liner surrounding the residual limb and the socket's inner surface. A proportional-integral controller was implemented to adjust socket size. When tested on 12 participants with transtibial amputation, the controller was active a mean of 68% of the walking time. In general, participants who walked more than 20 min/day demonstrated greater activity, less doff time, and fewer manual socket size adjustments for the adaptive socket compared with a locked non-adjustable socket and a motor-driven socket that participants adjusted with a smartphone application. Nine of 12 participants reported that they would use a motor-driven adjustable socket if it were available as it would limit their socket fit issues. The size and weight of the adaptive socket were considered the most important variables to improve.
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Affiliation(s)
- Joan E Sanders
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA.
| | - Andrew C Vamos
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Joseph C Mertens
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Katheryn J Allyn
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Brian G Larsen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Daniel Ballesteros
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Horace Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Nicholas S DeGrasse
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Joseph L Garbini
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Box 352600, Seattle, WA, 98195, USA
| | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific St, Box 356490, Seattle, WA, 98195, USA
| | - Janna L Friedly
- Department of Rehabilitation Medicine, University of Washington, 325 Ninth Ave, Box 359612, Seattle, WA, 98104, USA
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Devin KM, Tang J, Hamilton AR, Moser D, Jiang L. Assessment of 3D printed mechanical metamaterials for prosthetic liners. Proc Inst Mech Eng H 2024; 238:348-357. [PMID: 38279687 PMCID: PMC10941651 DOI: 10.1177/09544119231225529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/21/2023] [Indexed: 01/28/2024]
Abstract
This study focuses on novel design and evaluation of Elastic 50A (EL50) mechanical metamaterials with open-cell patterns for its potential application to lower limb residuum/socket interfaces, specifically that of a transtibial (TT) amputee. Mechanical characteristics, that is, effective Young's modulus (E), was tuned by altering metamaterial porosity, which was experimentally verified. Specifically, pore radius of the unit cell was varied to achieve a range of E-values (0.05-1.71 MPa) for these 3D printed metamaterials. Finite Element Analysis (FEA) was conducted to evaluate pressure distribution across key load-bearing anatomical sites of a TT residuum. Using designed metamaterials for homogeneous liners, pressure profiles were studied and compared with a silicone liner case. Additionally, a custom metamaterial liner was designed by assigning appropriate metamaterials to four load-sensitive and tolerant anatomical sites of the TT residuum. The results suggest that lowest pressure variation (PV), as a measure of pressure distribution levels and potential comfort for amputees, was achieved by the custom metamaterial liner compared to any of the homogeneous liners included in this study. It is envisaged that this work may aid future design and development of custom liners using now commonly available 3D printing technologies and available elastomer materials to maximise comfort, tissue safety and overall rehabilitation outcomes for lower limb amputees.
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Affiliation(s)
- Kirstie M Devin
- School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Jinghua Tang
- School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Andrew R Hamilton
- School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - David Moser
- School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Liudi Jiang
- School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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3
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Karthik Rajashekar K, Regalla SP, Suresh K, Shrivastava PN. Numerical simulation and experimental testing for static failure prediction in additively manufactured below-knee prosthetic sockets. Proc Inst Mech Eng H 2024; 238:257-268. [PMID: 38214296 DOI: 10.1177/09544119231221179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
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.
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Affiliation(s)
| | | | - Kurra Suresh
- Department of Mechanical Engineering, BITS Pilani, Hyderabad Campus, Hyderabad, Telangana, India
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4
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Armitage L, Cho K, Sariyildiz E, Buller A, O’Brien S, Kark L. Validation of a Custom Interface Pressure Measurement System to Improve Fitting of Transtibial Prosthetic Check Sockets. SENSORS (BASEL, SWITZERLAND) 2023; 23:3778. [PMID: 37050838 PMCID: PMC10099032 DOI: 10.3390/s23073778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/31/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
Achievement of fit between the residual limb and prosthetic socket during socket manufacture is a priority for clinicians and is essential for safety. Clinicians have recognised the potential benefits of having a sensor system that can provide objective socket-limb interface pressure measurements during socket fitting, but the cost of existing systems makes current technology prohibitive. This study will report on the characterisation, validation and preliminary clinical implementation of a low cost, portable, wireless sensor system designed for use during socket manufacture. Characterisation and benchtop testing demonstrated acceptable accuracy, behaviour at variable temperature, and dynamic response for use in prosthetic socket applications. Our sensor system was validated with simultaneous measurement by a commercial sensor system in the sockets of three transtibial prosthesis users during a fitting session in the clinic. There were no statistically significant differences between the sensor system and the commercial sensor for a variety of functional activities. The sensor system was found to be valid in this clinical context. Future work should explore how pressure data relates to ratings of fit and comfort, and how objective pressure data might be used to assist in clinical decision making.
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Affiliation(s)
- Lucy Armitage
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Kenny Cho
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Emre Sariyildiz
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Angela Buller
- Orthopaedic Appliances, Pty, Ltd. (OAPL), Alexandria, NSW 2015, Australia
| | - Stephen O’Brien
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Lauren Kark
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Tyree Foundation Institute of Health Engineering, University of New South, Sydney, NSW 2052, Australia
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5
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Oddes Z, Solav D. Identifiability of soft tissue constitutive parameters from in-vivo macro-indentation. J Mech Behav Biomed Mater 2023; 140:105708. [PMID: 36801779 DOI: 10.1016/j.jmbbm.2023.105708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/27/2023] [Accepted: 02/02/2023] [Indexed: 02/05/2023]
Abstract
Reliable identification of soft tissue material parameters is frequently required in a variety of applications, particularly for biomechanical simulations using finite element analysis (FEA). However, determining representative constitutive laws and material parameters is challenging and often comprises a bottleneck that hinders the successful implementation of FEA. Soft tissues exhibit a nonlinear response and are commonly modeled using hyperelastic constitutive laws. In-vivo material parameter identification, for which standard mechanical tests (e.g., uniaxial tension and compression) are inapplicable, is commonly achieved using finite macro-indentation test. Due to the lack of analytical solutions, the parameters are commonly identified using inverse FEA (iFEA), in which simulated results and experimental data are iteratively compared. However, determining what data must be collected to accurately identify a unique parameter set remains unclear. This work investigates the sensitivities of two types of measurements: indentation force-depth data (e.g., measured using an instrumented indenter) and full-field surface displacements (e.g., using digital image correlation). To eliminate model fidelity and measurement-related errors, we employed an axisymmetric indentation FE model to produce synthetic data for four 2-parameter hyperelastic constitutive laws: compressible Neo-Hookean, and nearly incompressible Mooney-Rivlin, Ogden, and Ogden-Moerman models. For each constitutive law, we computed the objective functions representing the discrepancies in the reaction force, the surface displacement, and their combination, and visualized them for hundreds of parameter sets, spanning a representative range as found in the literature for the bulk soft tissue complex in human lower limbs. Moreover, we quantified three identifiability metrics, which provided insights into the uniqueness (or lack thereof) and the sensitivities. This approach provides a clear and systematic evaluation of the parameter identifiability, which is independent of the selection of the optimization algorithm and initial guesses required in iFEA. Our analysis indicated that the indenter's force-depth data, despite being commonly used for parameter identification, was insufficient for reliably and accurately identifying both parameters for all the investigated material models and that the surface displacement data improved the parameter identifiability in all cases, although the Mooney-Rivlin parameters remained poorly identifiable. Informed by the results, we then discuss several identification strategies for each constitutive model. Finally, we openly provide the codes used in this study, to allow others to further investigate the indentation problem according to their specifications (e.g., by modifying the geometries, dimensions, mesh, material models, boundary conditions, contact parameters, or objective functions).
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Affiliation(s)
- Zohar Oddes
- Faculty of Mechanical Engineering, Technion Institute of Technology, Haifa, Israel
| | - Dana Solav
- Faculty of Mechanical Engineering, Technion Institute of Technology, Haifa, Israel.
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6
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Plesec V, Humar J, Dobnik-Dubrovski P, Harih G. Numerical Analysis of a Transtibial Prosthesis Socket Using 3D-Printed Bio-Based PLA. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1985. [PMID: 36903100 PMCID: PMC10004398 DOI: 10.3390/ma16051985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Lower-limb prosthesis design and manufacturing still rely mostly on the workshop process of trial-and-error using expensive unrecyclable composite materials, resulting in time-consuming, material-wasting, and, ultimately, expensive prostheses. Therefore, we investigated the possibility of utilizing Fused Deposition Modeling 3D-printing technology with inexpensive bio-based and bio-degradable Polylactic Acid (PLA) material for prosthesis socket development and manufacturing. The safety and stability of the proposed 3D-printed PLA socket were analyzed using a recently developed generic transtibial numeric model, with boundary conditions of donning and newly developed realistic gait cycle phases of a heel strike and forefoot loading according to ISO 10328. The material properties of the 3D-printed PLA were determined using uniaxial tensile and compression tests on transverse and longitudinal samples. Numerical simulations with all boundary conditions were performed for the 3D-printed PLA and traditional polystyrene check and definitive composite socket. The results showed that the 3D-printed PLA socket withstands the occurring von-Mises stresses of 5.4 MPa and 10.8 MPa under heel strike and push-off gait conditions, respectively. Furthermore, the maximum deformations observed in the 3D-printed PLA socket of 0.74 mm and 2.66 mm were similar to the check socket deformations of 0.67 mm and 2.52 mm during heel strike and push-off, respectively, hence providing the same stability for the amputees. We have shown that an inexpensive, bio-based, and bio-degradable PLA material can be considered for manufacturing the lower-limb prosthesis, resulting in an environmentally friendly and inexpensive solution.
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Affiliation(s)
- Vasja Plesec
- Laboratory for Intelligent CAD Systems, Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Jani Humar
- Laboratory for Intelligent CAD Systems, Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Polona Dobnik-Dubrovski
- Mechanical Engineering Research Institute, Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Gregor Harih
- Laboratory for Intelligent CAD Systems, Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
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7
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Optimal design and 3D printing of prosthetic socket based on the interface pressure between the socket and residual limb. Prosthet Orthot Int 2023; 47:87-93. [PMID: 35511448 DOI: 10.1097/pxr.0000000000000147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/16/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND At present, the quantifiable pressure distribution at the interface between the socket and stump is seldom applied in the design and fabrication of the socket. OBJECTIVES This study aimed to optimize the socket based on the interface pressure of residual limb-socket, thereby avoiding excessive local load on the residual limb, reducing the load on the pressure-sensitive (PS) regions and making the limb more evenly loaded. METHODS The residual limb was divided into the main load-bearing regions, the pressure-tolerant regions, and the PS regions according to the carrying capacity at its different regions. Based on these bearing regions, a mathematical function was developed, which applied modifications/adjustments to the socket design in a Computer Aided Design (CAD) environment by using the adjustment function. Besides, three adjusted sockets were produced by using selective laser sintering 3D printing technology. RESULTS The wearing of the 3D-adjusted printed sockets reduced the contact interface pressures in the distal tibial region and the fibular head region by 85.6% and 84.4%, respectively. In addition, the walking distance of the subject was increased by 18.34%, and the overall pressure distribution on the stump became more uniform. CONCLUSIONS The pressures in the original overpressure regions and the PS regions could reduce, whereas the pressure in the low-load regions of main load-bearing or pressure-tolerant regions could increase by modifying the socket with the pressure adjustment function. At the same time, the pressure among different regions was more uniform except for the sensitive regions.
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8
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Yang X, Zhao R, Solav D, Yang X, Lee DR, Sparrman B, Fan Y, Herr H. Material, design, and fabrication of custom prosthetic liners for lower-extremity amputees: A review. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Amudhan K, Vasanthanathan A, Anish Jafrin Thilak J. An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives. Expert Rev Med Devices 2022; 19:123-140. [PMID: 35142577 DOI: 10.1080/17434440.2022.2039624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION A Transfemoral prosthesis restores any limb amputated above the knee. Designing and developing a transfemoral prosthesis that is consistent with human performance is a tough task. While prosthetic components are widely available in the market, ongoing research is being conducted to develop parts that would restore the lost capability, taking into account numerous social, economic and technological considerations. AREAS COVERED The present paper provides a comprehensive review about the mechanical aspects and performance of transfemoral prosthesis in recent years based on the research findings on materials, manufacturing methods and evaluations for suitability of the prostheses. The fundamental terminologies as well as technical advancements are covered in order to impart a better knowledge in the area of Lower Limb prostheses. This review also provides a concise description on the role of computers, advanced software packages, sensors and other hardware components for the design, fabrication and testing of transfemoral prosthetic devices in the current environment. EXPERT OPINION The current state of lower limb prostheses and future research opportunities are summarised to address upcoming challenges. Based on survey of various research works, adapting modern technology may aid in the development of functional and cost-efficient prosthetic components with superior safety, comfort and quality.
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Affiliation(s)
- K Amudhan
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
| | - A Vasanthanathan
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
| | - J Anish Jafrin Thilak
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
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10
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Cabrera IA, Pike TC, McKittrick JM, Meyers MA, Rao RR, Lin AY. Digital healthcare technologies: Modern tools to transform prosthetic care. Expert Rev Med Devices 2021; 18:129-144. [PMID: 34644232 DOI: 10.1080/17434440.2021.1991309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Digital healthcare technologies are transforming the face of prosthetic care. Millions of people with limb loss around the world do not have access to any form of rehabilitative healthcare. However, digital technologies provide a promising solution to augment the range and efficiency of prosthetists. AREAS COVERED The goal of this review is to introduce the digital technologies that have the potential to change clinical methods in prosthetic healthcare. Our target audience are researchers who are unfamiliar with the field of prostheses in general, especially with the newest technological developments. This review addresses technologies for: scanning of amputated limbs, limb-to-socket rectification, additive manufacturing of prosthetic sockets, and quantifying patient response to wearing sockets. This review does not address biomechatronic prostheses or biomechanical design practices. EXPERT OPINION Digital technologies will enable affordable prostheses to be built on a scale larger than with today's clinical practices. Large technological gaps need to be overcome to enable the mass production and distribution of prostheses digitally. However, recent advances in computational methods and CAD/CAM technologies are bridging this gap faster than ever before. We foresee that these technologies will return mobility and economic opportunity to amputees on a global scale in the near future.
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Affiliation(s)
- Isaac A Cabrera
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, United States
| | - Trinity C Pike
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, United States
| | - Joanna M McKittrick
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, United States
| | - Marc A Meyers
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, United States.,Department of Nanoengineering, University of California San Diego, La Jolla, United States
| | - Ramesh R Rao
- California Institute for Telecommunications and Information Technology (Calit2), La Jolla, United States
| | - Albert Y Lin
- California Institute for Telecommunications and Information Technology (Calit2), La Jolla, United States
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Lutfi SNN, Abd Razak NA, Ali S, Gholizadeh H. Compression and tension behavior of the prosthetic foam materials polyurethane, EVA, Pelite™ and a combination of polyurethane and EVA: a preliminary study. ACTA ACUST UNITED AC 2021; 66:317-322. [PMID: 34062632 DOI: 10.1515/bmt-2019-0110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 10/05/2020] [Indexed: 11/15/2022]
Abstract
Materials with low-strength and low-impedance properties, such as elastomers and polymeric foams are major contributors to prosthetic liner design. Polyethylene-Light (Pelite™) is a foam liner that is the most frequently used in prosthetics but it does not cater to all amputees' limb and skin conditions. The study aims to investigate the newly modified Foam Liner, a combination of two different types of foams (EVA + PU + EVA) as the newly modified Foam Liner in terms of compressive and tensile properties in comparison to Pelite™, polyurethane (PU) foam, and ethylene-vinyl acetate (EVA) foam. Universal testing machine (AGS-X, Shimadzu, Kyoto, Japan) has been used to measure the tensile and compressive stress. Pelite™ had the highest compressive stress at 566.63 kPa and tensile stress at 1145 kPa. Foam Liner fell between EVA and Pelite™ with 551.83 kPa at compression and 715.40 kPa at tension. PU foam had the lowest compressive stress at 2.80 kPa and tensile stress at 33.93 kPa. Foam Liner has intermediate compressive elasticity but has high tensile elasticity compared to EVA and Pelite™. Pelite™ remains the highest in compressive and tensile stiffness. Although it is good for amputees with bony prominence, constant pressure might result in skin breakdown or ulcer. Foam Liner would be the best for amputees with soft tissues on the residual limbs to accommodate movement.
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Affiliation(s)
- Siti Nur Nabilah Lutfi
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Nasrul Anuar Abd Razak
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Sadeeq Ali
- Department of Occupational Therapy, Prosthetics and Orthotics, Oslomet University, Oslo, Norway
| | - Hossein Gholizadeh
- Ottawa Hospital Research Institute, 120 University, Ottawa, K1N 6N5, ON, Canada
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12
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Olaya Mira N, Viloria Barragán C, Plata JA. Evaluation of different Jaipur foot-ankle assemblies using infrared thermography. Prosthet Orthot Int 2021; 45:184-188. [PMID: 33028146 DOI: 10.1177/0309364620958510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 08/20/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Mechanical behavior is difficult to monitor in experimental environments, usually because of geometric or technology implementation limitations. Nevertheless, thermography has been shown to overcome these issues. OBJECTIVES The aim of this study was to evaluate four types of assemblies between a Jaipur foot and a polyethylene tube using infrared thermography in order to find the best mechanical configuration in terms of thermal behavior. STUDY DESIGN Mechanical testing. TECHNIQUE An infrared camera captured short videos every 5 min over 10 h in six different positions (three in the back and three in front of the Jaipur foot) around a prosthesis subjected to repetitive stresses (axial force 980 N) simulating kinematic variables like joint angles. We established a region of interest around the foot-ankle assemblies and calculated maximum temperatures and thermographic indices. RESULTS In this study, the best foot-ankle assembly used epoxy adhesive because it presented the lowest temperature in the six positions and the lowest thermal index. CONCLUSIONS Thermographic techniques can be used to study mechanical behaviors in complex experimental situations.
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Affiliation(s)
- Natali Olaya Mira
- Grupo de Investigación e Innovación Biomédica, Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano, Medellín, Colombia.,Laboratorio de Biomecánica y Rehabilitación, Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano, Medellín, Colombia
| | - Carolina Viloria Barragán
- Grupo de Investigación e Innovación Biomédica, Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano, Medellín, Colombia
| | - Jesus Alberto Plata
- Corporación Mahavir Kmina Artificial Limb Center, Medellín, Colombia.,Grupo de investigación Rehabilitación en Salud, Departamento de Medicina Física y Rehabilitación, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
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13
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Steer JW, Worsley PR, Browne M, Dickinson A. Key considerations for finite element modelling of the residuum-prosthetic socket interface. Prosthet Orthot Int 2021; 45:138-146. [PMID: 33176573 DOI: 10.1177/0309364620967781] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 09/22/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Finite element modelling has long been proposed to support prosthetic socket design. However, there is minimal detail in the literature to inform practice in developing and interpreting these complex, highly nonlinear models. OBJECTIVES To identify best practice recommendations for finite element modelling of lower limb prosthetics, considering key modelling approaches and inputs. STUDY DESIGN Computational modelling. METHODS This study developed a parametric finite element model using magnetic resonance imaging data from a person with transtibial amputation. Comparative analyses were performed considering socket loading methods, socket-residuum interface parameters and soft tissue material models from the literature, to quantify their effect on the residuum's biomechanical response to a range of parameterised socket designs. RESULTS These variables had a marked impact on the finite element model's predictions for limb-socket interface pressure and soft tissue shear distribution. CONCLUSIONS All modelling decisions should be justified biomechanically and clinically. In order to represent the prosthetic loading scenario in silico, researchers should (1) consider the effects of donning and interface friction to capture the generated soft tissue shear stresses, (2) use representative stiffness hyperelastic material models for soft tissues when using strain to predict injury and (3) interrogate models comparatively, against a clinically-used control.
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Affiliation(s)
- Joshua W Steer
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Peter R Worsley
- Clinical Academic Facility, School of Health Sciences, Faculty of Environment and Life Sciences, University of Southampton, Southampton, UK
| | - Martin Browne
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Alex Dickinson
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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Analysis of the Relative Motion Between the Socket and Residual Limb in Transtibial Amputees While Wearing a Transverse Rotation Adapter. J Appl Biomech 2020; 37:21-29. [PMID: 33152690 DOI: 10.1123/jab.2019-0362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 07/10/2020] [Accepted: 08/14/2020] [Indexed: 11/18/2022]
Abstract
The coupling between the residual limb and the lower-limb prosthesis is not rigid. As a result, external loading produces movement between the prosthesis and residual limb that can lead to undesirable soft-tissue shear stresses. As these stresses are difficult to measure, limb loading is commonly used as a surrogate. However, the relationship between limb loading and the displacements responsible for those stresses remains unknown. To better understand the limb motion within the socket, an inverse kinematic analysis was performed to estimate the motion between the socket and tibia for 10 individuals with a transtibial amputation performing walking and turning activities at 3 different speeds. The authors estimated the rotational stiffness of the limb-socket body to quantify the limb properties when coupled with the socket and highlight how this approach could help inform prosthetic prescriptions. Results showed that peak transverse displacement had a significant, linear relationship with peak transverse loading. Stiffness of the limb-socket body varied significantly between individuals, activities (walking and turning), and speeds. These results suggest that transverse limb loading can serve as a surrogate for residual-limb shear stress and that the setup of a prosthesis could be individually tailored using standard motion capture and inverse kinematic analyses.
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15
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Hobusch GM, Döring K, Brånemark R, Windhager R. Advanced techniques in amputation surgery and prosthetic technology in the lower extremity. EFORT Open Rev 2020; 5:724-741. [PMID: 33204516 PMCID: PMC7608512 DOI: 10.1302/2058-5241.5.190070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Bone-anchored implants give patients with unmanageable stump problems hope for drastic improvements in function and quality of life and are therefore increasingly considered a viable solution for lower-limb amputees and their orthopaedic surgeons, despite high infection rates.Regarding diversity and increasing numbers of implants worldwide, efforts are to be supported to arrange an international bone-anchored implant register to transparently overview pros and cons.Due to few, but high-quality, articles about the beneficial effects of targeted muscle innervation (TMR) and regenerative peripheral nerve interface (RPNI), these surgical techniques ought to be directly transferred into clinical protocols, observations and routines.Bionics of the lower extremity is an emerging cutting-edge technology. The main goal lies in the reduction of recognition and classification errors in changes of ambulant modes. Agonist-antagonist myoneuronal interfaces may be a most promising start in controlling of actively powered ankle joints.As advanced amputation surgical techniques are becoming part of clinical routine, the development of financing strategies besides medical strategies ought to be boosted, leading to cutting-edge technology at an affordable price.Microprocessor-controlled components are broadly available, and amputees do see benefits. Devices from different manufacturers differ in gait kinematics with huge inter-individual varieties between amputees that cannot be explained by age. Active microprocessor-controlled knees/ankles (A-MPK/As) might succeed in uneven ground-walking. Patients ought to be supported to receive appropriate prosthetic components to reach their everyday goals in a desirable way.Increased funding of research in the field of prosthetic technology could enhance more high-quality research in order to generate a high level of evidence and to identify individuals who can profit most from microprocessor-controlled prosthetic components. Cite this article: EFORT Open Rev 2020;5:724-741. DOI: 10.1302/2058-5241.5.190070.
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Affiliation(s)
- Gerhard M Hobusch
- Medical University of Vienna, Department of Orthopaedics and Trauma Surgery, Vienna, Austria
| | - Kevin Döring
- Medical University of Vienna, Department of Orthopaedics and Trauma Surgery, Vienna, Austria
| | - Rickard Brånemark
- Gothenburg University, Gothenburg, Sweden.,Biomechatronics Group, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Reinhard Windhager
- Medical University of Vienna, Department of Orthopaedics and Trauma Surgery, Vienna, Austria
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16
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Ballit A, Mougharbel I, Ghaziri H, Dao TT. Fast Soft Tissue Deformation and Stump-Socket Interaction Toward a Computer-Aided Design System for Lower Limb Prostheses. Ing Rech Biomed 2020. [DOI: 10.1016/j.irbm.2020.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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17
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Steer JW, Worsley PR, Browne M, Dickinson AS. Predictive prosthetic socket design: part 1-population-based evaluation of transtibial prosthetic sockets by FEA-driven surrogate modelling. Biomech Model Mechanobiol 2020; 19:1331-1346. [PMID: 31256276 PMCID: PMC7423807 DOI: 10.1007/s10237-019-01195-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 06/23/2019] [Indexed: 11/26/2022]
Abstract
It has been proposed that finite element analysis can complement clinical decision making for the appropriate design and manufacture of prosthetic sockets for amputees. However, clinical translation has not been achieved, in part due to lengthy solver times and the complexity involved in model development. In this study, a parametric model was created, informed by variation in (i) population-driven residuum shape morphology, (ii) soft tissue compliance and (iii) prosthetic socket design. A Kriging surrogate model was fitted to the response of the analyses across the design space enabling prediction for new residual limb morphologies and socket designs. It was predicted that morphological variability and prosthetic socket design had a substantial effect on socket-limb interfacial pressure and shear conditions as well as sub-dermal soft tissue strains. These relationships were investigated with a higher resolution of anatomical, surgical and design variability than previously reported, with a reduction in computational expense of six orders of magnitude. This enabled real-time predictions (1.6 ms) with error vs the analytical solutions of < 4 kPa in pressure at residuum tip, and < 3% in soft tissue strain. As such, this framework represents a substantial step towards implementation of finite element analysis in the prosthetics clinic.
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Affiliation(s)
- J. W. Steer
- Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - P. R. Worsley
- Clinical Academic Facility, Faculty of Health Sciences, University of Southampton, Southampton, UK
| | - M. Browne
- Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - A. S. Dickinson
- Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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18
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Armitage L, Buller A, Rajan G, Prusty G, Simmons A, Kark L. Clinical utility of pressure feedback to socket design and fabrication. Prosthet Orthot Int 2020; 44:18-26. [PMID: 31769736 DOI: 10.1177/0309364619868364] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The clinical utility of measuring pressure at the prosthetic socket-residual limb interface is currently unknown. OBJECTIVES This study aimed to identify whether measuring interface pressure during prosthetic design and fabrication results in closer agreement in pressure measurements between sockets made by different clinicians, and a reduction in pressure over areas of concern. It also investigated whether clinicians value knowing the interface pressure during the fabrication process. STUDY DESIGN Mixed methods. METHODS Three prosthetists designed a complete prosthetic system for a transtibial residual limb surrogate. Standardised mechanical testing was performed on each prosthetic system to gain pressure measurements at four key anatomical locations. These measurements were provided to the clinicians, who subsequently modified their sockets as each saw fit. The pressure at each location was re-measured. Each prosthetist completed a survey that evaluated the usefulness of knowing interface pressures during the fabrication process. RESULTS Feedback and subsequent socket modifications saw a reduction in the pressure measurements at three of the four anatomical locations. Furthermore, the pressure measurements between prosthetists converged. All three prosthetists found value in the pressure measurement system and felt they would use it clinically. CONCLUSIONS Results suggest that sensors measuring pressure at the socket-limb interface has clinical utility in the context of informing prosthetic socket design and fabrication. If the technology is used at the check socket stage, iterative designs with repeated measurements can result in increased consistency between clinicians for the same residual limb, and reductions in the magnitudes of pressures over specific anatomical landmarks. CLINICAL RELEVANCE This study provides new information on the value of pressure feedback to the prosthetic socket design process. It shows that with feedback, socket modifications can result in reduced limb pressures, and more consistent pressure distributions between prosthetists. It also justifies the use of pressure feedback in informing clinical decisions.
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Affiliation(s)
- Lucy Armitage
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, NSW, Australia
| | | | - Ginu Rajan
- School of Electrical, Computer and Telecommunications Engineering, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW, Australia
| | - Gangadhara Prusty
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW, Australia
| | - Anne Simmons
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, NSW, Australia
| | - Lauren Kark
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, NSW, Australia
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19
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Use of Dynamic FEA for Design Modification and Energy Analysis of a Variable Stiffness Prosthetic Foot. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10020650] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Different tasks and conditions in gait call for different stiffness of prosthetic foot devices. The following work presents a case study on design modifications of a prosthetic foot, aimed at variable stiffness of the device. The objective is a proof-of-concept, achieved by simulating the modifications using finite element modeling. Design changes include the addition of a controlled damping element, connected both in parallel and series to a system of springs. The aim is to change the stiffness of the device under dynamic loading, by applying a high damping constant, approaching force coupling for the given boundary conditions. The dynamic modelling simulates mechanical test methods used to measure load response in full roll-over of prosthetic feet. Activation of the element during loading of the foot justifies the damped effect. As damping is in contrast to the main design objectives of energy return in prosthetic feet, it is considered important to quantify the dissipated energy in such an element. Our design case shows that the introduction of a damping element, with a high damping constant, can increase the overall rotational stiffness of the device by 50%. Given a large enough damping coefficient, the energy dissipation in the active element is about 20% of maximum strain energy.
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20
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Solav D, Moerman KM, Jaeger AM, Herr HM. A Framework for Measuring the Time-Varying Shape and Full-Field Deformation of Residual Limbs Using 3-D Digital Image Correlation. IEEE Trans Biomed Eng 2019; 66:2740-2752. [PMID: 30676943 DOI: 10.1109/tbme.2019.2895283] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Effective prosthetic socket design following lower limb amputation depends upon the accurate characterization of the shape of the residual limb as well as its volume and shape fluctuations. OBJECTIVE This study proposes a novel framework for the measurement and analysis of residual limb shape and deformation, using a high-resolution and low-cost system. METHODS A multi-camera system was designed to capture sets of simultaneous images of the entire residuum surface. The images were analyzed using a specially developed open-source three-dimensional digital image correlation (3D-DIC) toolbox, to obtain the accurate time-varying shapes as well as the full-field deformation and strain maps on the residuum skin surface. Measurements on a transtibial amputee residuum were obtained during knee flexions, muscle contractions, and swelling upon socket removal. RESULTS It was demonstrated that 3D-DIC can be employed to quantify with high resolution time-varying residuum shapes, deformations, and strains. Additionally, the enclosed volumes and cross-sectional areas were computed and analyzed. CONCLUSION This novel low-cost framework provides a promising solution for the in vivo evaluation of residuum shapes and strains, as well as has the potential for characterizing the mechanical properties of the underlying soft tissues. SIGNIFICANCE These data may be used to inform data-driven computational algorithms for the design of prosthetic sockets, as well as of other wearable technologies mechanically interfacing with the skin.
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21
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Ramasamy E, Avci O, Dorow B, Chong SY, Gizzi L, Steidle G, Schick F, Röhrle O. An Efficient Modelling-Simulation-Analysis Workflow to Investigate Stump-Socket Interaction Using Patient-Specific, Three-Dimensional, Continuum-Mechanical, Finite Element Residual Limb Models. Front Bioeng Biotechnol 2018; 6:126. [PMID: 30283777 PMCID: PMC6156538 DOI: 10.3389/fbioe.2018.00126] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 08/23/2018] [Indexed: 11/30/2022] Open
Abstract
The lack of an efficient modelling-simulation-analysis workflow for creating and utilising detailed subject-specific computational models is one of the key reasons why simulation-based approaches for analysing socket-stump interaction have not yet been successfully established. Herein, we propose a novel and efficient modelling-simulation-analysis workflow that uses commercial software for generating a detailed subject-specific, three-dimensional finite element model of an entire residual limb from Diffusion Tensor MRI images in <20 min. Moreover, to complete the modelling-simulation-analysis workflow, the generated subject-specific residual limb model is used within an implicit dynamic FE simulation of bipedal stance to predict the potential sites of deep tissue injury. For this purpose, a nonlinear hyperelastic, transversely isotropic skeletal muscle constitutive law containing a deep tissue injury model was implemented in LS-DYNA. To demonstrate the feasibility of the entire modelling-simulation-analysis workflow and the fact that detailed, anatomically realistic, multi-muscle models are superior to state-of-the-art, fused-muscle models, an implicit dynamic FE analysis of 2-h bipedal stance is carried out. By analysing the potential volume of damaged muscle tissue after donning an optimally-fitted and a misfitted socket, i.e., a socket whose volume was isotropically shrunk by 10%, we were able to highlight the differences between the detailed individual- and fused-muscle models. The results of the bipedal stance simulation showed that peak stresses in the fused-muscle model were four times lower when compared to the multi-muscle model. The peak interface stress in the individual-muscle model, at the end of bipedal stance analysis, was 2.63 times lower than that in the deep tissues of the stump. At the end of the bipedal stance analysis using the misfitted socket, the fused-muscle model predicted that 7.65% of the residual limb volume was injured, while the detailed-model predicted 16.03%. The proposed approach is not only limited to modelling residual limbs but also has applications in predicting the impact of plastic surgery, for detailed forward-dynamics simulations of normal musculoskeletal systems.
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Affiliation(s)
- Ellankavi Ramasamy
- Department of Biomechatronic Systems, Fraunhofer-Institut für Produktionstechnik und Automatisierung (Fraunhofer IPA), Stuttgart, Germany
| | - Okan Avci
- Department of Biomechatronic Systems, Fraunhofer-Institut für Produktionstechnik und Automatisierung (Fraunhofer IPA), Stuttgart, Germany
| | - Beate Dorow
- Department of Biomechatronic Systems, Fraunhofer-Institut für Produktionstechnik und Automatisierung (Fraunhofer IPA), Stuttgart, Germany
| | - Sook-Yee Chong
- Diagnostische und Interventionelle Radiologie, Sektion für Experimentelle Radiologie, Department für Radiologie, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Leonardo Gizzi
- Institut für Mechanik (Bauwesen), Universität Stuttgart, Stuttgart, Germany
| | - Günter Steidle
- Diagnostische und Interventionelle Radiologie, Sektion für Experimentelle Radiologie, Department für Radiologie, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Fritz Schick
- Diagnostische und Interventionelle Radiologie, Sektion für Experimentelle Radiologie, Department für Radiologie, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Oliver Röhrle
- Department of Biomechatronic Systems, Fraunhofer-Institut für Produktionstechnik und Automatisierung (Fraunhofer IPA), Stuttgart, Germany.,Diagnostische und Interventionelle Radiologie, Sektion für Experimentelle Radiologie, Department für Radiologie, Universitätsklinikum Tübingen, Tübingen, Germany.,Stuttgart Centre for Simulation Sciences, Universität Stuttgart, Stuttgart, Germany
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