An array of microelectrodes implanted into a paralyzed man’s brain has restored sensation to his hands, according to a study published today in Science Translational Medicine by a team of researchers at the University of Pittsburgh.
The team touts that this is the 1st time a brain computer interface has helped a user experience the sensation of touch.
“The most important result in this study is that microstimulation of sensory cortex can elicit natural sensation instead of tingling,” study co-author Andrew Schwartz said.”This stimulation is safe, and the evoked sensations are stable over months. There is still a lot of research that needs to be carried out to better understand the stimulation patterns needed to help patients make better movements.”
Nathan Copeland, 28, suffered a spinal cord injury in 2004, leaving him with quadriplegia from the upper chest down, completely unable to feel or more his lower arms or legs.
“I can feel just about every finger – it’s a really weird sensation,” Copeland said about a month after surgery, according to the university. “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.”
Brain computer chips can electrically stimulate neurons to recreate the feeling of touch. Intracortical microstimulation has shown promise in animal studies, but until now researchers haven’t known how the sensation feels to a person.
The University of Pittsburgh researchers designed a system that transmitted inputs from the robotic arm through an array of microelectrodes implanted in the part of the brain responsible for hand movement and touch.
Copeland described 93% of stimuli, such as pressing a cotton swab to his skin, as feeling “possibly natural”. He experienced sensation when connected to a prosthetic limb and correctly identified, while blindfolded, which prosthetic finger was being touched 84% of the time.
“The ultimate goal is to create a system which moves and feels just like a natural arm would,” lead researcher Robert Gaunt said. “We have a long way to go to get there, but this is a great start.”