A man who was paralyzed from the chest downwards is the first person to regain a ‘natural’ sense of touch by use of a mind-controlled robotic arm.
In 2004, Nathan Copeland had been driving in wet weather. He skidded off the road and snapped his neck and injured his spine. He was just 18 at the time. a freshman in college studying for a degree in nanofabrication, following a high school spent in advanced science courses.
Due to his injury and health problems, Copeland had to put his degree on hold. “For the last year and a half, I have been part of a research study through the University of Pittsburgh.” He said.
When asked if he would do it he replied “Why would I not do it? This will help tons of people.”
A team of researchers led by Robert Gaunt who is an assistant professor of physical medicine at the university 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?”
Scientists at the university operated on Copeland implanting 4 microelectrodes into his brain, it’s called BCI, the Brain Computer Interface.
The BCI is connected to the area where the neurons that control hand movement and touch are located, the Somatosensory Cortex.
The scientists then blind-folded Copeland to test the robotic arm. “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.”
While blindfolded he could correctly identify which robotic finger they touched with 84% accuracy, and described 93% of the touch sensations he was given, such as pressing a cotton swab on the surface of the skin, as feeling “possible natural.”
And when a researcher touched two fingers at the same time? ‘I just laughed and I said, “Are you trying to be tricky or something?”
“The most important result in this study is that microstimulation of sensory cortex can elicit natural sensation instead of tingling,” said Andrew Schwartz, professor of neurobiology at University of Pittsburgh School of Medicine, and a co-author.
The system is the work of nearly 20 years of research by Sliman Bensmaia, a neuroscientist at the university of Chicago. His research focuses on how the nervous system receives and deciphers sensory feedback when people touch or grasp objects, touch textured surfaces and move their limbs.
He announced for the first time on October 13th that a paralyzed man was able to experience the sense of touch with an electronic arm, controlled by his brain.
Bensmaia said that reproducing natural-feeling sensations is crucial to building neuroprosthetics that has the dexterity of native hands. With time, patients like Copeland will be able to view these robotic arms as an extension of themselves.
“As he uses this prosthesis and has this visual experience of seeing the robot touch things, and any time it touches something, feeling something in response, I think eventually he’s going to start to embody the robot,” Bensmaia said “The robot is going to feel like part of the body, maybe even actually supplanting his own arm because it’s going to be taking over what the arm used to do.”
The findings of the study were recently published in the journal, Science Translational Medicine.