A man with ALS who lost the ability to speak has used a brain-computer interface at home for 19 months, accumulating more than 3,800 hours of independent use and achieving 99.2% word accuracy across a 125,000-word vocabulary.
The system, described in Nature Medicine, uses four microelectrode arrays implanted in the speech motor cortex of a 45-year-old man with severe paralysis and dysarthria. It decodes neural activity during attempted speech into text and also enables cursor control for browsing the internet.
Unlike previous brain-computer interfaces that required frequent recalibration or researcher oversight, this system needed little daily adjustment. Care partner assistance was limited to putting on and taking off the hardware and starting the software.
The study is part of the BrainGate2 clinical trial. Researchers said the results demonstrate that intracortical brain-computer interfaces can now support practical, independent communication in real-world home settings rather than just controlled laboratory environments.