In 2020, Casey Harrel began losing his voice to amyotrophic lateral sclerosis (ALS), a neurodegenerative disease also known as Charcot disease. Aged 42 at the time, he made the bet to entrust his brain to science, agreeing to have experimental devices implanted into his gray matter.
Casey Harrel is known in the scientific literature as “T15”, as a participant in the BrainGate2 clinical trial, a project funded by the US government. Its brain houses four tiny devices that record brain signals, then analyzed by artificial intelligence (AI). The technology translates them into text, then into speech. A pioneer in brain-computer interfaces, this American spent hours with researchers at the University of California to document the progress of his speech, which he can now generate through thought.
In a study published on June 15 in the scientific journal Nature Medicine, researchers took a new step. Their work shows how brain-computer interfaces can provide a form of communication close to natural conversation for people with severe paralysis, by decoding the neural activity associated with attempts to speak and move.
Unlike many medical technologies, the device offered to Casey Harrel can be used without the intervention of medical personnel or scientists. A loved one simply removes the caps from the port attached to their skull and connects it to a computer system placed on a cart. Ultimately, the researchers hope to offer a wireless version, specifies the Washington Post.
Nearly 2 million words spoken in two years
Thanks to this technology, Casey Harrel can make FaceTime calls, participate in work meetings or simply chat with her 7-year-old daughter, without a screen. Over two years, the patient used the device for more than 3,800 hours, speaking 183,060 sentences, or nearly 2 million words, at a rate of 56 words per minute. “This is a significant step forward, a considerable leap forward”underlines Mariska van Steensel, researcher in brain-computer interfaces at the University Medical Center of Utrecht, in the Netherlands.
However, brain-computer interfaces remain at the experimental stage, experts point out. But some biotechnology companies have already invested in the niche: Neuralink, the start-up co-founded by Elon Musk, like Paradromics, is banking on future commercial development of innovations developed in research laboratories. This new study also illustrates the power of technology put to the service of patients. Thanks to the device, Casey Harrel can once again make jokes, imitate the sound of the “sad trombone” and, above all, stay in touch with his family.
“Our technology is truly at a turning pointsays David Brandman, neurosurgeon at the University of California and co-author of the article. Until now, most advances in brain-computer interfaces have been one-off scientific demonstrations (…) The real breakthrough with this technology is that you no longer need a team of scientists and engineers to make it work.”
Casey Harrel, above all, hopes that the device will continue to improve. Because behind his own case lies a broader promise: that of helping the 352,000 people who, like him, live today with Charcot’s disease throughout the world.
