Researchers from the University of Pittsburgh and the University of Pittsburgh Medical Center (UPMC) demonstrated in a human a technology that allows an individual to experience the sensation of touch directly in the brain through a neural interface system connected to a robotic arm.

By enabling two-way communication between brain and machine—outgoing signals for movement and inbound signals for sensation—the technology could support new ways for people to engage with each other and with the world.

Pitt Assistant Professor Robert Gaunt prepares Nathan Copeland for BCI sensory tests.Pitt Assistant Professor Robert Gaunt prepares Nathan Copeland for BCI sensory tests.This is not the team’s first attempt at a brain computer interface (BCI): four years ago a BCI enabled a patient with quadriplegia caused by a degenerative disease to feed herself chocolate using the mind-controlled robotic arm.

The next step for the researchers is to achieve near-natural and more-nuanced tactile feedback with a system that not only provides direct neural control of a robotic arm but also sends information from the robotic arm to the brain.

The first recipient of this system, 28-year-old Nathan Copeland, has lived with quadriplegia from the upper chest down since a 2004 car accident. Copeland underwent surgery to have four microelectrode arrays—each about half the size of a shirt button—placed in in the sensory cortex regions of his brain that correspond to feeling in his fingers and palm. Wires connect the arrays to a robotic arm developed by the Applied Physics Laboratory (APL) at Johns Hopkins University. Torque sensors in the APL arm detect when pressure is applied to any of its fingers, and convert those physical “sensations” into electrical signals that the wires transmit back to the arrays in Copeland’s brain to provide precise patterns of stimulation to his sensory neurons.

Video documents initial tests, in which researchers touched each of the robotic fingers while Copeland was blindfolded. “I can feel just about every finger—it’s a really weird sensation,” he said about a month after surgery. “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.”

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