Prosthetic Engineering - Overview
Disturbance Response in Amputee Gait
Errors in foot placement while avoiding obstacles and maneuvering in the household and community environments may lead to falls and injuries. This research aims to develop an ankle that can invert and evert and thereby control the center of pressure under the prosthetic foot; enhancing balance and stability of lower limb amputees.
Many ambulatory lower limb amputees exhibit fatigue, asymmetrical gait, and the inability to walk at varying speeds. We are using a rapid prototyping approach to fabricate feet of varying stiffness for exploring the effects of foot stiffness on amputee gait.
Turning corners and maneuvering around obstacles are essential abilities for successful community and household ambulation. The aim of this research is to test the efficacy of a compliant torque adapter in the pylons of transtibial amputees.
Energy Storage & Release
Many ambulatory lower limb amputees exhibit fatigue, asymmetrical gait, and the inability to walk at varying speeds. We are developing and testing several approaches aimed at providing the propulsive forces necessary to alleviate these problems.
Stochastic resonance (sub-threshold vibration) may enhance peripheral sensation sufficiently to result in improved postural stability and locomotor function. This research explores application of this phenomenon to the residual limb and intact plantar surface of diabetic lower limb amputees.
Injury Prevention Research
Vacuum Suspension Systems
Many amputees live with an ill-fitting socket and can experience limb pistoning within the socket, which in turn may result in skin irritation, tissue breakdown, discomfort, and a reduction in activity. The aims of this research are to characterize the response of the lower residual limb to a vacuum suspension system and to measure changes in limb volume with a structured light scanning system.
Socket Systems & Tissue O2
Limb health and wound healing capacity is closely related to the amount of oxygen present in limb tissues. Using our fiber-optic video-oximetry imaging system, we aim to discover if prosthetic prescription can influence residual limb tissue oxygenation during both rest and gait.
The goal of the proposed project is to develop enabling sensing technology based on a flexible array and to build a prototype of a prosthetic liner with distributed, unimodal field sensing capability. The specific aims include: (1) the design of the flexible sensing array for measurement of moisture, temperature, pressure, and shear stress; (2) integration of this array into a prosthetic liner/socket; and (3) testing of device performance.
This research seeks to develop a prosthetic limb whose torsional characteristics can adapted depending activity. Our goal is to reduce torsional stresses and the incidence of residual limb injuries.
Patient Comfort Research
Lower limb amputations often experience discomfort related in part to higher skin temperatures within their prosthetic socket. Our research has found prosthetic liners and sockets are excellent insulators that can retain heat. Activity can cause a dramatic increase in skin temperature within the prosthesis requiring substantially long periods of inactivity to restore resting state temperatures. Our current work involves developing active cooling systems and embedded sensor networks to monitor skin temperature.
Evaporative Cooling and Perspiration Removal
Amputees often complain about uncomfortably warm residual limb skin temperatures and the accumulation of perspiration within their prosthesis. This research will discover if a novel evaporative cooling system can provide ameliorate these problems.
Current Project Summaries