A man paralyzed from a diving accident has used a brain implant to control and sense another person's hand as if it were his own. The technology, developed by researchers in New York, allowed him to distinguish between objects by touch and assist another paralyzed individual. This breakthrough could aid rehabilitation and raise ethical questions about remote body control.
Keith Thomas, a man in his 40s, became paralyzed from the chest down following a diving accident in July 2020, resulting in complete loss of sensation and movement in his hands. In a 2023 study, researchers at the Feinstein Institutes for Medical Research in New York implanted five sets of tiny electrodes in the brain regions responsible for moving and feeling his right hand. These electrodes, connected to a skull-fixed device, captured neural activity, which an AI model decoded to stimulate forearm muscles and provide tactile feedback through force sensors on his hand. This enabled Thomas to grasp and feel objects mentally for the first time in years.
Building on this, the team extended the system to allow Thomas to control a non-disabled woman's hand. She wore forearm electrodes and force sensors on her thumb and index finger but did not move voluntarily. By imagining his own hand movements, Thomas opened and closed hers. Blindfolded, he sensed her fingers gripping a baseball, a soft foam ball, and a firmer ball, distinguishing their hardness with 64 percent accuracy. "It definitely feels strange," Thomas said. "Eventually, you get used to it."
Chad Bouton, the lead researcher, noted that optimizing sensor placement could improve accuracy and enable shape detection. In another test, Thomas assisted Kathy Denapoli, a woman with partial paralysis, in picking up and drinking from a can—tasks she struggled with alone. "It actually was pretty amazing, you're helping somebody by just thinking about it," Thomas remarked. After months of collaboration, Denapoli's grip strength nearly doubled, and both found the interaction more engaging than solo therapies.
Bouton plans trials with more participants next year and aims for broader medical approval within a decade. Rob Tylor, a paralyzed advocate with the Inspire Foundation, praised the approach for enhancing quality of life through shared experiences but stressed the need for compatible pairings. Ethically, Bouton envisions non-medical uses like remote connections, though experts like Harith Akram warn of risks, such as unintended harm or criminal misuse. The study appears in medRxiv (DOI: 10.1101/2025.09.21.25336267).