SAINT JOHN, N.B. -- An expert trained at the University of New Brunswick says prosthetics powered by artificial intelligence are no longer the stuff of science fiction -- thought-controlled bionic limbs have already arrived and are getting more sophisticated by the day.
Levi Hargrove, a UNB graduate and director of neural engineering for the prosthetic and orthotics laboratory at the Rehabilitation Institute of Chicago, will return to his alma matter next week to deliver a lecture on "rewiring humans" who have lost limbs using state-of-the-art artificial prosthetics controlled by the power of the mind.
"We've made a lot of improvements in their control and functionality partly by actually doing innovative surgeries ... (and) using artificial intelligence to figure out how to put that information to work so that people can move arms and legs just by thinking about it," Hargrove said in an interview.
Nerves are like your body's "communication highway," says Hargrove, sending messages to your muscles in the form of electrical signals and relaying information from the environment back to your brain. After an amputation, he says, nerves in the residual limb are "scarred" but remain active and continue to transmit signals intended for severed muscles.
Hargrove says he and his colleagues have advanced a surgical technique that involves transferring spaghetti-like bundles of nerves to "target" muscles in or near the residual limb. Once the process is complete, he says, neural signals from the brain are re-routed to make the target muscles contract and send messages to a prosthetic device as if it were the missing limb.
"We want them to be able to move their limbs as if you would move ... even though we have our intact limbs," the Hargrove says. "It's just a natural thing. You just subconsciously just move when you want to move and we're trying to do the same thing."
Hargrove says older prosthetic technologies use electrodes to detect muscle contractions in the residual limb and translate them into prosthetic motions through "Morse code switching." For example, three pulses might trigger the prosthetic hand to make a fist.
"It's not intuitive, because you have to remember this Morse code," he says. "It would be the difference between you and I communicating by speaking versus dots and dashes and having to figure out what each thing meant."
Hargrove co-founded a Chicago-based start-up called Coapt to commercially produce a prosthetic arm that uses artificial intelligence to create more fluid, life-like movements based on a user's anatomy. Hargrove compared the prosthetic technology to a smartphone using machine learning to respond to personalized voice commands, and says much of the "pioneering" work was engineered in collaboration with UNB.
"We really are reaching that point where what seemed to be science fiction in all of these implanted devices will become routine," says Kevin Englehart, director of UNB's biomedical institute. "(Hargrove) really is one of few individuals now who are leading this next generation of medical devices."
Hargrove says Coapt is selling prosthetics across North America and plans to expand internationally next spring. The prosthetic arms are capable of elbow movement, wrist rotation and a variety of hand grasps -- but can't control individual fingers.
The devices are powered by rechargeable batteries with a roughly 14-hour lifespan, and while an artificial limb weighs about as much as a human arm, Hargrove says it feels like "dead weight" because it isn't attached to the skeleton.
The price tag for a prosthetic arm can run anywhere between $2,500 to $100,000, depending on the device's capabilities and the sophistication of the technology.
Hargrove says the next frontier in "rewiring" humans is putting sensors inside the body, which could restore sensations of touch for people with amputated limbs. Researchers are making headway in developing better prosthetic technology for lower limbs, he says, and are "pushing the boundaries" with regard to treating people who have suffered strokes or spinal cord injuries.
The New Brunswick native says Terry Fox's cross-Canada trek in 1980 has been a source of inspiration since he was a child. A marathoner himself, Hargrove marvels at Fox's stamina given how "primitive" the prosthetic technology was at the time of his run for cancer research.
"That's certainly in my mind as we go," Hargrove says. "(Today) it may have been a little bit easier, but running a marathon a day whether you have one leg or two legs is a really difficult thing to do."
Hargrove is scheduled to speak at UNB's Fredericton and Saint John campuses on Nov. 8 and 9.
