United States Department of Veterans Affairs
VA Center of Excellence for Limb Loss Prevention and Prosthetic Engineering

Prosthetic Engineering - Overview

VA official seal

Our aim is to improve prosthetic prescription by investigating the efficacy of prosthetic components used in current clinical practice and by developing novel approaches to improve the current standard of care. Our amputee-centric research encompasses improving patient mobility and comfort and preventing injury. Support for this research (2000 to present) includes funding from the Department of Veterans Affairs Rehabilitation Research and Development Service and the National Institutes of Health.

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Mobility Research

Disturbance Response in Amputee Gait

Eversion and Inversion movement

Eversion and inversion movement model.

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.

Foot-Ankle Stiffness

Gait models

Models of foot stiffness

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 Gait

House with bird's eye view of turning corners in house.

Maneuvering required in a typical house.

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.

Energy Storage & Release models

Three different propulsion test devices.

Stochastic Resonance

Stochastic resonance test

Transtibial amputee wearing a stochastic resonance capable socket.

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.

Research in Robotics and Biomechanics

Biologically Informed Robotics

Biologically Informed Robotics

Dr. Aubin’s research spans robotics and biomechanics with applications in health and mobility. He motivates his research by engaging with patients and stakeholders to understand shortcomings in the areas of rehabilitation, prosthetics, orthotics, and physical therapy. Dr. Aubin strives to address these unmet patient and caregiver needs by establishing multidisciplinary research teams that leverage state of the art technologies in robotics, neuroscience, and computational intelligence. Dr. Aubin’s research goal is to develop and utilizes novel sensors, algorithms, assistive powered devices, and robotic tools that can augment human performance and/or improve mobility and function for those affected by disease, age or trauma.

Sensory Feedback For Prosthetic Limbs

It has long been recognized that restoring movement function after amputation is a priority. We are now entering an era in which restoration of sensation may be possible as well through the use of smart sensorized prosthetic devices and haptic feedback. We are working on understanding how feedback of forces and events on the foot - for example the placement of the prosthetic foot as the user is walking down stairs - can lead to improved function.

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.

Energy Storage & Release models

Vacuum suspension system modelling

Socket Systems & Tissue O2

Fiber-optic video-oximetry imaging system

Fiber-optic video-oximetry imaging system

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.

Distributed Sensing

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.

Distributed sensing images

Distributed sensing images

Torsional Prosthesis

prosthetic limb with torsional characteristics

Prosthetic limb with torsional characteristics

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

Thermal Comfort

Embedded sensors monitor skin temperatures

Sensors monitor skin temperatures

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

evaporative cooling system

Evaporative cooling system

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.

Research Areas & Future Directions

Current Project Summaries


Logo of the VA CoE for Limb Loss Prevention & Prosthetic Engineering

Glenn Klute, Ph.D.
Seattle VA Medical Center, University of Washington

Program contact information:
Wesley Edmundson

VA Puget Sound Health Care System, ms 151
1660 S. Columbian Way
Seattle, WA 98108