Next generation of prosthetics restore capabilities and even a sense of touch

Published July 20, 2015
By Military Health System Communications Office

Washington D.C. -- While athletes at the recently completed Warrior Games were able to run, jump and throw using some of the latest prosthetic arms and legs, the next generation of this technology will allow them to do much more.

“We have developed prosthetics that interact directly with the brain and move much like a real limb. Beyond movement, these advances will restore the sense of touch,” said Michael McLoughlin, chief engineer for Research and Exploratory Development at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “This will give wounded warriors and all who have lost use of their arms by amputation or paralysis much better options in the future.”

McLoughlin’s lab is supported by the Defense Advanced Research Projects Agency (DARPA), the military’s primary research and development office for cutting edge technologies. DARPA, in turn, is one of the agencies that work with the Military Health System to make sure wounded warriors get the prosthetics needed to live as normal a life as possible. Much of what he talks about in how the artificial limbs interact with the body’s own nerves is futuristic, but he says some of technology is available now. “Today we are working in the lab. In a few years, we expect the technology to be much more common.”

But McLoughlin is quick to point out that this is not easy. As an example, he said, “Hold your hand up and wiggle your fingers.” While this is an easy, natural task for the brain to accomplish, imagine translating each little motion of a finger, all independent of each other, into pushing buttons on a video game controller. Even the best gamer would find it impossible to replicate this simple motion.

“If you’re just trying to do something simple, such as operating a hook or rotating the wrist, that’s easy,” he said. “We’re unlocking the power that already exists in your brain to make the prosthetic work more like a natural hand.”

Besides the advantages of more natural motion with a prosthetic arm or hand, McLoughlin said these prosthetic limbs might help diminish phantom limb pain, a condition many amputees experience. Having the more natural artificial limb connected to the nerves helps the wearer develop a sense of embodiment. “When the brain sends a command to move the hand and sees the prosthetic hand opening and closing as expected, it can help end the disconnect that is believed to contribute to phantom pain.”

In addition, the next generation of prosthetics will use sensors to send signals back to the brain so amputees could actually feel through their artificial fingers.

McLoughlin believes this will make a tremendous difference in the lives of injured service members and civilians alike.

“Many are young men and women in their 20s,” he said. “They have a lot of great experiences ahead of them—careers, getting married, having children. This could give them back something personally: a chance to gain back some of what was lost due to the injury.”

USAF. (U.S. Air Force Graphic by Rosario "Charo" Gutierrez)