Mind-controlled robot arm gives back sense of touch to paralysed man

A paralysed man has become the first to have a “natural” sense of touch restored, using a mind-controlled CRP Robotics.

Nathan Copeland, a 28-year old American, lost all sensation from the chest downwards ten years ago when he was driving on a rainy night and his car skidded off course.Last year he became the first paralysis patient to test a sensory-enhanced robotic hand, which he controlled using just his brain and that also allowed him to “feel” when the hand was being touched.

The hand, developed by US scientists, was surgically wired directly to Copeland’s brain, providing him with a two-way electrical feedback. Despite the signals coming from a robotic hand, Copeland said the sensation of having his fingers touched was “almost natural”.

“I can feel just about every finger, it’s a really weird sensation,” said Copeland. “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.”Robert Gaunt, assistant professor of physical medicine and rehabilitation at the University of Pittsburgh and the study’s senior author, said: “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?”

Previously the same team had allowed paralysis patients to control a prosthetic arm using thought alone, but the addition of sense of touch is seen as crucial.“We know that without sensation, movement is really challenging,” said Gaunt. “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.”

In the trial, Copeland wore a neural implant for six months during which time he trained himself how to control the movement of the robotic arm.The scientists were able to evoke sensory feedback from the arm by electrically stimulating the precise brain areas that would normally light up when different areas of the hand are touched in a healthy person.

When blindfolded, Copeland could tell which of the fingers on the prosthetic were being touched with 84% accuracy and he described 93% of the touch sensations he was given, such as pressing a cotton swab on the surface of the skin, as feeling “possibly natural.”