Scientists in the US have restored a sense of touch to a paralyzed man using a mind-controlled robotic arm. While the same team of scientists had created a mind-controlled prosthetic arm before, the addition of a sense of touch is an important new breakthrough. The study was published on Thursday in the journal Science Translational Medicine.
According to Robert Gaunt, the lead author of the study and assistant professor of physical medicine and rehabilitation at the University of Pittsburgh, “Really this is the first time this has been done in a person. There was always this question, will it work? Will it work in a person who has had an injury for a long time?”
“We know that without sensation, movement is really challenging,” he continued. “What we’ve added now is the ability to feel something through those fingers… We’re feeding back touch that the artificial hand encounters when it makes contact with an object.”
The arm was surgically wired to the patient’s brain, allowing electrical feedback to and from the brain. Sensory feedback was achieved by having the arm stimulate the precise areas of the brain that are stimulated when a healthy person experiences touch in different areas.
The patient, 28-year-old Nathan Copeland, who lost all feeling below the chest in a car accident when he was 18, described the feeling of the implant:
“I can feel just about every finger, it’s a really weird sensation. Sometimes it feels electrical and sometimes its pressure, but for the most part, I can tell most of the fingers with definite precision. It feels like my fingers are getting touched or pushed.”
For six months, Copeland wore a neural implant to practice controlling the movement of the prosthetic arm.
In the trial, he was able to accurately report which of the prosthetic fingers were being touched 84 percent of the time, and described the different sensations of touch as “possibly natural” 93 percent of the time.
The breakthrough could offer new hope to amputees and those with spinal cord injuries, and also suggests the possibility of human enhancement through such methods in the more distant future.
“The ultimate goal is to create a system which moves and feels just like a natural arm would. We have a long way to go to get there, but this is a great start,” said Gaunt.