Brain-computer interface helps man with paralysis feed himself and regain touch after two years

After revolutionary brain-computer implant, man with paralysis can feed himself

In 2023, neurologists at the Feinstein Institutes for Medical Research in New York achieved a medical breakthrough that many experts believed was once impossible. After 15-hours of open-brain surgery, a team of specialists successfully completed the first "double neural bypass" procedure, and installed and virtually mapped a brain-computer interface (BCI) for a man named Keith Thomas living with quadriplegia. As Thomas slowly regained feeling and strength in his arm and wrist, the monumental advancement made international headlines and was inducted into TIME Magazine's Best Inventions Hall of Fame. "There was a time that I didn't know if I was even going to live, or if I wanted to, frankly. And now, I can feel the touch of someone holding my hand. It's overwhelming," Thomas said four months after the initial surgery. Nearly three years later, the pioneers behind the double neural bypass have offered updates on their findings and Thomas' progress. As they detail in a study published today in the journal Nature Medicine, the combination of BCI and artificial intelligence technologies continues to provide their patient with lasting, life-changing recovery in their limb. By rerouting the nervous system's neural pathways, Thomas can now feed himself and drink from a cup using restored feeling in his hand, and has gained increased both his arm strength and wrist sensation. "This approach is a new way to treat severe paralysis -- we're not just bypassing the injury, we're actually rewiring the nervous system," Chad Bouton, a bioelectronic medical specialist and study co-author, said in a statement. The system relies on five microelectrode arrays surgically installed in Thomas' brain, which machine learning algorithms then interpret brain signals denoting movement with nearly 85 percent accuracy. Those neural messages are then translated into electrical stimulation patterns given to the forearm muscles, which move as intended. Meanwhile, sensors inside a 3D-printed limb brace that measures grasping pressure. This then creates electrical stimulation in the sensory cortex to generate the perception of touch. The results are so effective that Thomas is now able to grab and lift hollow eggshells without breaking them nearly 90 percent of the time. He can also perform this and similarly calculated tasks while talking -- a vast improvement compared to existing BCI systems when handling cognitive burdens. "Being able to feel my sister's hand, to pet my dog and feel her fur -- these experiences that the injury took away have been restored. "But beyond the study sessions, I can now scratch my face, wipe my eyes independently," Thomas said. "The technology has given me back both connection and sense of self." "This research holds promise for millions of patients, opening up potential for future research and practical clinical applications that could help hundreds of thousands of people living with paralysis," said Bouton. Moving forward, the team is working to improve their system while expanding clinical trials to include other patients with differing levels of spinal injuries and neurological conditions. Recently, they tested the first interhuman neural bypass, which allowed Thomas to feel sensations from another patient as they touched multiple objects. "We're not just bypassing the injury, we're actually rewiring the nervous system," Bouton added.

AI brain implant restores a paralysed man's movement

An AI brain implant called the "double neural bypass" has restored movement and touch to a man with complete paralysis, and the gains lasted for years, researchers report in Nature Medicine. Researchers have restored hand movement and the sense of touch to a man paralysed from the chest down. The results, published in Nature Medicine, suggest the technology partly rewired his nervous system. The system, called a "double neural bypass," comes from the Feinstein Institutes for Medical Research, the research arm of Northwell Health, the team said. It combines a brain-computer interface, AI, and electrical stimulation of the spinal cord and brain. What the participant regained The participant, Keith Thomas, broke his neck in a 2020 diving accident. He had complete tetraplegia and could not lift his hands to his face. He enrolled in the three-year trial 13 months later. After training, Thomas could feed himself and drink from a cup with his own hand. Over 35 weeks, his right arm grew 86% stronger and his left 62% stronger, the researchers reported. He could also scratch his nose and wipe his mouth unaided. A separate technique, called cortical mirroring, targeted touch. After about 25 weeks, Thomas regained feeling in a wrist that had been numb since his injury. Why the lasting effect matters Many gains held after the stimulation stopped. On a recent follow-up, they were still present more than two years later. The team says this points to real rewiring, or neuroplasticity, rather than a temporary assist. "We're not just bypassing the injury; we're actually rewiring the nervous system," said Chad Bouton, the study's corresponding author, in a statement. "For me this is an incredible moment," he told the Guardian. "Being able to feel my sister's hand, to pet my dog and feel her fur, these experiences that the injury took away have been restored," Thomas said. How it works Surgeons implanted five microelectrode arrays in Thomas's brain during a 15-hour operation. AI decodes his movement intentions and stimulates his forearm muscles to move his own hand. Sensors in a 3D-printed brace then trigger stimulation of the sensory cortex to create the feeling of touch. The decoder held up to 84.6% accuracy over five months without retraining. Thomas could lift empty eggshells without breaking them 87% of the time, even while holding a conversation. The wider field The work joins a fast-moving field of brain-computer interfaces. Rivals have used implants to restore speech, while others chase wearable or non-invasive approaches, and China has cleared its first commercial brain implant. About 15 million people live with spinal cord injury worldwide, and most with tetraplegia rank hand function as their top priority. The team plans larger trials and is testing the system for other conditions, including stroke.