HealthDay News — A set of four brain implants—chips half the size of a dress shirt button—have allowed a paralyzed 30-year-old man to not only control a robot arm but also feel sensations from the individual fingers of the arm, researchers with the University of Pittsburgh and the University of Pittsburgh Medical Center report online Oct. 13 in Science Translational Medicine.
The patient, Nathan Copeland, was paralyzed from the upper chest down at age 18 following a car accident that broke his neck and injured his spinal cord in the winter of 2004. In 2014, doctors implanted two chips in Copeland’s motor cortex and two more in his somatosensory cortex, senior researcher Robert Gaunt, PhD, of the University of Pittsburgh School of Medicine, told HealthDay.
Before the surgery, doctors used imaging techniques to identify the exact regions in Copeland’s brain that corresponded to the sense of touch in each of his fingers and his palm. When the chips are electrically stimulated, Copeland can feel people touching his real right hand. He can feel sensations like warmth and pressure along the base of the four fingers, and 9 times out of 10 can perceive things like a cotton swab pressed on the surface of the skin in a way described as “possibly natural.” In addition, connectors extending from Copeland’s head can be attached to a robot arm. When attached, Copeland can both move the arm using his mind and also feel when the robot fingers are being touched, Gaunt said.
“We’ve provided him with at least a component of touch. When the robot hand touches an object, he can feel it,” Gaunt said. “He can reach out and grab objects and pick them up and move them around.” The researchers found that Copeland could correctly identify 84% of the time which individual prosthetic finger was being touched while blindfolded.
Flesher SN, Collinger JL, Foldes ST, et al. Intracortical microstimulation of human somatosensory cortex. Sci Transl Med. 2016. DOI: 10.1126/scitranslmed.aaf8083.