Fayette County robotic arm recipient highlighted in White House Frontiers Conference
After two years of using a mind-controlled robotic arm, Nathan Copeland still struggles to describe some of the strange sensations that travel through the device to his brain.
The 30-year-old quadriplegic recognizes pressure, which usually is spread across distinct pads on his right palm. There's tingling. There's a kind of warmth, Copeland said, like “a shot of vodka, that warm but not like holding-a-cup-of-coffee warm.”
Then there's something he calls a “spidey sense,” a familiar sensation that is unlike any other he has felt and that he still can't describe.
The sensations come from four pads, half the size of shirt buttons, that a surgeon implanted in his brain above his left ear, the area responsible for movement and sensation in his right hand. The robotic hand sends electrical signals to the pads, each of which contains 60 to 100 pins connected to nerve cells, and the brain interprets the stimulation as touch.
“When we make them become active, the person experiences it as if his own hand has been touched,” said Robert Gaunt, an assistant professor of physical medicine and rehabilitation at the University of Pittsburgh who led a team of experts that developed the hand. The team, a partnership between Pitt and UPMC, published a study Thursday in Science Translational Medicine.
Although other robotic hands have transmitted the sense of touch by connecting the devices to peripheral nerves, Pitt's hand is different because it connects directly to the brain, said Elizabeth Tyler-Kabara, a study co-author who is a UPMC neurosurgeon and an assistant professor in the Department of Neurological Surgery at Pitt School of Medicine.
Copeland, of Dunbar in Fayette County, showed off the device Thursday during a meeting with President Obama in Pittsburgh during a White House Frontiers Conference celebrating technology.
The addition of touch comes about two years after Pitt researchers published a study in the Journal of Neural Engineering on their development of a mind-controlled arm. In that study, electrode panels implanted in quadriplegic Whitehall woman Jan Scheuermann's brain allowed her to move the arm but not feel what it touched.
Copeland lost sensation in his limbs at 18 when he broke his neck in a car accident while driving in the rain. He was a freshman at Penn State Fayette studying nanofabrication.
He's able to raise his right wrist, in the way someone accelerating on a motorcycle would, but is incapable of any other motion in the hand. He said he has sensation around his thumb, the side of his index finger and on a couple of fingertips. He agreed shortly after hospital admission to be contacted about clinical trials and started using the robotic arm in November 2014.
Researchers pinpointed brain areas associated with feeling in Copeland's hand by asking him to imagine certain feelings in his hand while his brain was being scanned, Gaunt said.
There were several things they didn't know going into the trial, including whether Copeland would be able to feel anything after 10 years without sensation, he said.
“We really didn't know what was going to happen or what it was going to feel like,” he said. “We were very happy that many of these electrodes felt like pressure, felt like touch.”
The study found the sensations of pressure in Copeland's hand could be graded for intensity and were stable for months. He cannot distinguish among textures. Gaunt hopes that could come in the future. For now, any feeling beyond basic tingling is an accomplishment, he said.
The study was funded by the Defense Advanced Research Projects Agency's Revolutionizing Prosthetics program and by a National Science Foundation Graduate Research Fellowship grant, according to a Pitt-UPMC news release.
Copeland makes an hour-and-twenty-minute drive three days each week for three- to four-hour sessions moving objects, identifying sensations and performing other tests with the hand. At the end of the study, which he expects to last four more years, he won't get to keep the hand.
That doesn't bother him, he said, because he believes he might be helping others like him in the future.
“This will probably be my biggest contribution to society,” he said. “So I get to feel like I'm doing something.”
Wes Venteicher is a Tribune-Review staff writer. Reach him at 412-380-5676 or firstname.lastname@example.org.