By Sandra Basu
WASHINGTON — Last fall, Tim Hemmes, a 30-year-old quadriplegic at the University of Pittsburgh Medical Center (UPMC) was able to control an advanced mechanical arm using nothing but his brain signals.
Hemmes, paralyzed seven years earlier after a motorcycle accident damaged his spinal cord, was the first to participate in a trial to determine whether a spinal-cord injury patient could control an advanced prosthetic arm by thoughts.
With a grid of electrodes placed on the surface of the brain to control the prosthetic arm, Hemmes was able to reach up to touch hands with his girlfriend for the first time since the accident.
“Seeing Tim reach out with a mechanical arm to touch his girlfriend was an unexpected and poignant bonus for all of us who are involved with this exciting project,” co-principal investigator Michael Boninger, MD, director of the UPMC Rehabilitation Institute, said in a statement.
The advanced prosthetic arm used in the project, known as the Modular Prosthetic Limb (MPL), was built at Baltimore’s Johns Hopkins University Applied Physics Laboratory (APL) and was funded by Defense Advanced Research Projects Agency (DARPA) and dubbed Revolutionizing Prosthetics.
Revolutionizing Prosthetics was begun by DARPA in 2006 to expand prosthetic arm options for troops, a need that has been driven by the reality of war. In 2011 alone, statistics from the Armed Forces Health Surveillance Center indicate that 240 deployed servicemembers suffered at least one arm or leg amputation.
The Modular Prosthetic Limb was used by wounded troops at the Walter Reed National Military Medical Center for the first time on Jan. 24, 2012. – U.S. Navy Photo
While lower-limb prostheses have enabled some troops to return to duty, DARPA program manager Army Col. Geoff Ling said that “by providing increased upper-prosthetic capability that option may someday be available to servicemembers with upper-limb loss.
“When the Revolutionizing Prosthetics program was launched, the state of upper-limb prosthetic technology was far behind lower-limb technology. Advancing upper-limb technology was judged to be harder, and it wouldn’t have happened without a significant research-and development-investment, such as the $153 million budgeted by DARPA,” he told U.S. Medicine in a written statement.