Brain implant allows ALS patient to speak and work independently
A brain-computer interface implanted in a UC Davis patient with ALS has enabled him to communicate independently for over two years, achieving 99% word accuracy and returning to full-time work. The system translates neural activity into speech, demonstrating a practical, long-term communication tool outside laboratory settings.
Key points
- A 47-year-old ALS patient, Casey Harrell, has used a UC Davis-developed brain implant for over 3,800 hours during two years.
- The implant uses microelectrode arrays and machine learning to translate neural activity into speech with over 99% word accuracy in tests.
- The system allows Harrell to speak at an average speed of 56 words per minute, producing over 183,000 sentences and returning to full-time work.
- Published in Nature Medicine, the study highlights the longest sustained use of a BCI as a practical daily communication tool outside a lab.
A participant with Amyotrophic Lateral Sclerosis (ALS) has successfully used a brain-computer interface (BCI) for over two years, enabling independent communication and a return to full-time employment. The breakthrough, detailed in a UC Davis study published in Nature Medicine, marks a significant advancement in assistive technology.
Casey Harrell, 47, has utilized a BCI system for more than 3,800 hours, generating over 183,000 sentences. The implant, featuring four microelectrode arrays in the speech-coordinating region of his brain, records neural activity. This data is processed by a machine learning platform called BRAND, developed at UC Davis, which translates the signals into phonemes and then into words, ultimately producing synthesized speech in Harrell's pre-illness voice. In controlled tests with a 125,000-word vocabulary, the system achieved over 99% word accuracy. During daily use, Harrell reported 92% of sentences as accurate or mostly correct.
The system's sustained performance outside a laboratory environment is highlighted as a key achievement. Harrell has been able to resume his career as an environmental advocate, demonstrating the practical applicability of the technology for individuals with severe communication impairments. The average speaking rate achieved was 56 words per minute, allowing for fluid daily interaction.
Sources
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