A Worcester Polytechnic Institute (WPI) professor, a Massachusetts-based prosthetics company, and an occupational therapist with limb absence have teamed up to develop wireless sensors to improve the performance of prosthetic devices for individuals with upper-limb amputations.
WPI Professor Ted Clancy, PhD; Liberating Technologies (LTI); and Debra Latour, OTD, MEd, OTR/L, aim to create wireless sensors to communicate with a prosthesis.
“This wireless sensor technology will have a major impact for individuals with limb absence and allow them to control their hand and wrist prostheses,” said Clancy, a professor of electrical and computer engineering at WPI.
Clancy is working with Todd Farrell, director of research at LTI, and Latour, an assistant professor in the Division of Occupational Therapy program at Western New England University. Latour, a consultant on the project, was born without a right hand.
Existing wired sensors detect the electrical activity of remnant muscle tissue in the arm—similar to how a cardiologist detects the electrocardiogram activity of a patient’s heart—and use this signal to control the movement of a hand-wrist prosthesis. This technique can be successful for many people with limb absence since most of the muscles that control the hand reside within the forearm. In making the transition from wired to wireless sensors, researchers had to consider the structure of the overall prosthetic device including the emerging use of osseointegration, a prosthesis that would be attached to a metal rod that has been surgically implanted into the bone.
“You no longer need a socket and have a much more rigid attachment, which is tremendously important,” Clancy said. “But now all of these wired sensors you would use to control the device have nowhere to go.”
In effect, wires would be hanging loose and could potentially become caught on objects and pose other problems, Clancy said. To address the challenge, Clancy and his colleagues plan to place silver-dollar-size wireless sensors on remnant arm muscle locations. The team plans to start with two sensors, which could expand to up to eight or more sensors primarily for better control, he said. “The idea is to create a standardized system that is more space efficient that could be readily adapted onto various products.”
Clancy received a two-year, $400,000 subaward from LTI, which received funding from the U.S. Department of Defense.
Editor’s note: This story was adapted from materials provided by WPI.