The potential of a brain-computer interface (BCI) is at once exciting and amazing, if seemingly out of reach. The technology to hook up specific areas of the brain to control the motion of an external device promises freedom for many people with injured or missing limbs. What is really needed is a round trip, so that the device sends information back to the brain where it can be experienced in sensory terms.
That’s exactly what researchers are doing at the University of Pittsburgh Medical College (UPMC). With multiple microelectrode arrays implanted in the brain of a man with quadriplegia, the research team has given the man sensation from his robotic fingers and arms. The microelectrode array and control system were developed by Blackrock Microsystems and the robotic arm was built by Johns Hopkins University’s Applied Physics Lab,
The UPMC team has had success with previous BCI efforts. Earlier the team had success with a man who had been paralyzed in a motorcycle accident. With a thought-controlled robotic arm he was able to reach out to touch hands with his girlfriend. In another case, the team was successful in helping a woman with quadraplegia from a degenerative disease feed herself chocolate with mind control and a prosthetic. The neural round trip — the ability to send signals back from the robotic arm and hand — was the next step. Nathan Copeland was in a car accident that snapped his neck and damaged his spinal cord, resulting in quadraplegia\; he is unable to move his lower arms and his legs. After using imagery to determine the precise areas of Copeland’s brain that corresponded to feelings in his fingers and palm, the team implanted the microelectrode arrays and fit him with the robotic arm.
Work with brain-computer interfaces may be in its infancy, but for Nathan Copeland it has returned something he thought he had lost forever, a sense of touch. “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.” That was a month after surgery. Now he can feel pressure and sense intensity to some degree, though he cannot detect heat or cold. But they’re still working on it.
“Slowly but surely, we have been moving this research forward. Four years ago we demonstrated control of movement. Now Dr. Gaunt and his team took what we learned in our tests with Tim and Jan—for whom we have deep gratitude—and showed us how to make the robotic arm allow its user to feel through Nathan’s dedicated work,” said Dr. Micheal Boninger, a co-author on the research paper.