The long-term goal of the proposed research is to improve the quality of life for injured soldiers and veterans who have experienced loss of a lower limb. We propose to develop an integrated system of prosthetic knee and ankle-foot components that will substantially improve comfort and endurance for lower limb amputees. The proposed devices will take advantage of human motion to greatly reduce energy requirements of active prosthetics, by self-generating electricity from the user, and by taking advantage of and redirecting the person's own energy to improve walking economy without requiring the prostheses to actively perform work. This will allow the prostheses to have essentially unlimited endurance range, so that they can be used even where electricity supply is poor or unavailable to provide charging. The devices will also gather sensory information from the user's own muscles and movement to determine the user's intent and conditions such as the slope of the terrain. This information will then be used to adapt prosthetic behaviors for stair climbing, descent of slopes, and other ambulatory modes. A final component of the project is development of a device to record these data over extended durations, to quantify the mobility of an amputee during activities of daily living. Accurate information about the activities an amputee actually engages in, and how a prosthesis enhances or inhibits this activity, has been lacking. The overall project will not only develop new prosthetic technologies, but also provide new means of assessing the technologies in actual use.

The prosthetic technologies are aimed at lower limb amputees, who may have loss of limb above or below the knee. These technologies may provide clinical benefit in the form of greater endurance, comfort, and mobility. Although actively controlled prostheses are now becoming available in the marketplace, the proposed technologies will greatly advance the efficiency and capabilities of such devices. The new technology is intended to be ready for clinical trials at the end of the performance period, for rapid deployment 1 to 2 years after such trials.

In addition to the clinical benefits, the proposed work will provide information to advance research. Most available data regarding amputee locomotion quantifies their economy when walking on level ground at steady speed. But in daily living, amputees perform turns, step over obstacles, and negotiate uneven terrain. There is little information about how much they perform such activities, nor whether different prosthetic technologies aid them. The data collected from the proposed work will help determine the future needs for the next generation of prosthetic technologies.