Adjustable Liners and Sockets for Prosthetic Devices

Abstract

INTRODUCTION
 Ras Labs’ Synthetic Muscle™ will allow amputees to continue their active lives without needing to adjust the fitting of their prosthetic device(s) throughout the day. This technology promises to resolve major issues facing amputees, most notably the pain of prosthetic slippage and tissue breakdown. Synthetic Muscle™, comprising electroactive polymers (EAPs), actively expand or contract at low voltages, while offering impact resistance and pressure sensing, all in one integrated solution. The main objectives of this project is to determine the feasibility of the EAP pads incorporated into prosthetic liners or sockets and to create prototypes of these EAP based shape-morphing pad systems. In collaboration with UPI, testing of these EAP based pads located in strategic areas of the socket was initiated with customers (BK and AK) for evaluation and feedback. Characterization of Synthetic Muscle™ as dual use pressure sensors was initiated. This is a continuation Ras Labs’ dynamic prosthetic pad project, which demonstrated how the volume of the EAP can be changed from applying a low voltage and operating temperatures for use in adjustable prosthetic liners and sockets 1-8.
 Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32048/24462
 How to cite: Rasmussen L, Rodriguez S, Bowers M, Smith D, Martino G, Rizzo L, Scheiber C, d’Almeida J, Dillis C. Adjustable Liners and Sockets for Prosthetic Devices. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32048 
 Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee. 
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Investigation of Orthopedic Prosthesis Socket Management after Transfemoral Amputation by Expert Survey

“…However, the requirement of easy handling is in opposition to this, as it is necessary to don/doff the prosthesis. In the literature [18,29,[54][55][56][57][58], a trend towards automatic compensation is emerging. Automatic adjustment is also seen as being beneficial by the orthopedic technicians.…”

Lower limb prosthetic interfaces

“…Work is underway developing electroactive polymer (EPA) networks capable of actively expanding or contracting at low voltages, offering impact resistance and pressure sensing. 99 It has been suggested that EPA can be used in liners or sockets for automatic socket volume adjustment. 99 Also, a ferrous polymer can be used as an inductive sensor (0.50 mm thickness) and as a magnetically permeable target to measure socket wall and liner distance, and decrease socket volume by approximately 2.1%.…”

“…99 It has been suggested that EPA can be used in liners or sockets for automatic socket volume adjustment. 99 Also, a ferrous polymer can be used as an inductive sensor (0.50 mm thickness) and as a magnetically permeable target to measure socket wall and liner distance, and decrease socket volume by approximately 2.1%. 100 Overall, VASS with a controller and the active panel socket with an in-socket sensor appear to be viable clinical options for management of diurnal residual limb volume fluctuation; though, further developments are needed to make them commercially available.…”