Our research is focused on development and implementation of novel measurement techniques for external prosthetics. We create instruments to help practitioners better understand patient prosthetic fit problems and select treatments to improve function and quality of life.
A main area of on-going research is in residual limb fluid volume assessment. We developed a custom instrument to monitor residual limb fluid volume while an amputee subject wears their prosthesis. We use the instrument to assess how design variables of the prosthesis and subject affect fluid volume. For example, adding/removing prosthetic socks, applying elevated vacuum, and adjusting fluid within a bladder-liner have all been studied. This information is relevant to fit of the prosthesis since volume changes as small as 1.0% can affect clinical fit. A next step is to use the instrument towards the design of automated control strategies to adjust the prosthesis to accommodate limb volume fluctuations so as to maintain a proper fit.
Another area of focus is in the characterization of elastomeric materials used as a cushioning interface between the residual limb and prosthetic socket. We developed a testing suite of instrument to test commercially-available liner materials commonly used in the industry. Collected information is disseminated to the prosthetics community via an interactive website. Currently, we are developing training materials for enhancing use of the collected data for clinical care. We are also pursuing computational models to predict and compare interface mechanical action of different liners.
Applied research on skin adaptation to mechanical stress and skin breakdown is a third area of focus. This research has strong application in Rehabilitation Medicine where it is of interest to encourage adaptation so as to avoid skin breakdown or ulceration (wheelchair users, prosthesis users, bedridden patients). We developed an imaging system to quantify adaptation and to predict imminent skin breakdown. In pilot studies the instrument was shown to effectively predict imminent injury 1 to 2 months before it was visually apparent.
Sanders JE, Severance MR, Allyn KJ. Computer-socket manufacturing error: How much before it is clinically apparent? Journal of Rehabilitation Research and Development 2012; 49(4):567-582.
Sanders JE, Cagle JC, Allyn KJ, Harrison DS, Ciol MA. How do the activities walking, standing, and resting influence trans-tibial amputee residual limb fluid volume? Journal of Rehabilitation Research and Development 2014; 51(2):201-212.
Sanders JE, Harrison DS, Allyn KJ, Myers TR, Ciol MA, Tsai EC. How do sock ply changes affect residual limb fluid volume in people with trans-tibial amputation? Journal of Rehabilitation Research and Development 2012; 49(2):241-256.
Sanders JE, Rogers EL, Sorenson EA, Lee GS, Abrahamson DC. CAD/CAM transtibial prosthetic sockets from central fabrication facilities: How accurate are they? Journal of Rehabilitation Research and Development 2007; 44(3):395-406.
D’Silva K, Hafner BJ, Allyn KJ, Sanders JE. Self-reported prosthetic sock use among persons with trans-tibial amputation. Prosthetics and Orthotics International 2014; 38(4):321-331.
Hafner BJ and Sanders JE. Considerations for development of sensing and monitoring tools to facilitate treatment and care of persons with lower limb loss. Journal of Rehabilitation Research and Development 2014;51(1):1-14.