APL to Lead Team Developing Revolutionary Prosthesis

The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., has been awarded a $30.4 million contract to start the first phase of Revolutionizing Prosthetics 2009, a 4-year program that aims to develop a next-generation mechanical arm that mimics the properties and sensory perception of the real thing.

The contract was awarded under the Defense Advanced Research Projects Agency (DARPA) Revolutionizing Prosthetics program, an ambitious effort to provide the most advanced medical and rehabilitative technologies for military personnel injured in the line of duty. APL's Stuart Harshbarger, along with a core group of engineers, scientists, and medical professionals from APL, the Johns Hopkins School of Medicine, the Whiting School of Engineering, and the Bloomberg School of Public Health, will lead an interdisciplinary team of government agencies, universities and private firms to implement DARPA's vision.

Rising to the Challenge

According to Harshbarger, there have been significant improvements in upper extremity prosthetics in recent years. The state-of-the-art myoelectric arm, for example, allows users to control hand and arm movements by deliberately flexing a muscle or through mechanical movement.  Still, he says, "these devices have relatively limited degrees of motion and can generally allow control of only one motion at a time."

The APL-led team's research will focus mainly on advanced neural control strategies that will allow the user to operate the arm in a near-biological manner; that is, to feel and manipulate objects as that person would with a real hand. They also aim to develop new power, actuation, and control technologies, as well as advanced sensors. "The resulting prosthetic system will provide a significantly improved quality of life over a range of daily living and job functions, including the dexterous manipulation of objects," Harshbarger says.

"Our challenge is to advance the base of scientific understanding related to neural control mechanisms and physiological function of the human limb, while at the same time developing innovative engineering solutions that can be successfully implemented," he adds. "DARPA wants this technology ready for clinical trials in only 4 years, so there is no time for us to recreate the wheel. We have handpicked a team that has decades of experience in prosthetics, but more importantly has made recent advances that are ready to be realized."

Patient Outreach

A critical aspect of the program will be patient outreach, making sure that the APL-led team creates a limb that patients will accept and use. Dr. Ross E. Andersen, an associate professor of medicine at the Johns Hopkins School of Medicine and co-investigator on this project, will coordinate this aspect of the effort.

"We will be working with the patient care community, including the amputee program at the U.S. Army Walter Reed Medical Center and with investigators at the [Hopkins] School of Public Health and the National Rehabilitation Hospital, to determine patient needs and develop measures of effectiveness in terms of cognitive loading during prosthetic use, functional performance, and patient acceptance at each step as we move forward," says Dr. Andersen. "This is a critical aspect of the program and ultimately demonstrates the importance of collaboration between the medical and scientific communities."

Restoring Choices

Ultimately, the main goal of DARPA's Revolutionizing Prosthetics program is to restore to the wounded warfighter the range of choices that would have been available to them prior to the injury, says DARPA's Col. Geoffrey Ling, the program manager for the Revolutionizing Prosthetics programs. "Although our warfighters suffer fewer fatalities, they still endure horrible injuries, and today one of the most devastating battlefield injuries is loss of a limb," he says. "DARPA's vision is a future where a soldier who has lost an extremity in battle will regain full use of that limb. We will do whatever is necessary to restore these people who have given up so much for the idea of freedom and in service to their country."

The diverse APL team brings together some of the most respected scientific researchers in their fields and commercial leaders from the prosthetics industry, including investigators from Arizona State University, the BioSTAR Group, California Institute of Technology, The Johns Hopkins University, National Rehabilitation Hospital, New World Associates, Northwestern University and the Northwestern University Prosthetics Research Laboratory, Oak Ridge National Laboratories, Otto Bock Health Care (Austria), Rehabilitation Institute of Chicago, Umea University (Sweden), University of Michigan, University of Rochester, University of California, Irvine, University of Southern California, University of Utah and Vanderbilt University. Second-tier subcontractors and other collaborators include Chicago P/T, the Fraunhoffer Institutes for Biomedical Technology and Reliability & Microintegration (Germany), FLEXSYS, Harvey Mudd College, Martin Bionics, Punch Communications, Ripple, Scott Sabolich Prosthetics and Research, the Scuola Superiore Sant' Anna (Italy), Sigenics of Lincolnwood, and the University of New Brunswick (Canada).

"Developing this broad consortium and providing both the technical and managerial leadership for the design and systems integration of this advanced limb is an example of what APL does best," says Dr. Dexter G. Smith, APL's Business Area Executive for Biomedicine. "We focus on programs where we can make critical contributions to our nation's critical challenges. I can think of no better example of a critical contribution than having a positive impact on the quality of life and future opportunities for our injured soldiers."