What happened
A UC Davis-led research team reported that one participant with amyotrophic lateral sclerosis used an implanted brain–computer interface in his home on a near-daily basis for nearly two years. The system translated neural activity connected to attempted speech into text and also provided cursor control.
The participant, Casey Harrell, used it for more than 3,800 hours without researchers present. The paper reports more than 183,000 communicated sentences, close to 2 million words and an average communication rate of 56 words per minute. He also used the system for messages, email, web browsing and work.
Why this is meaningful
High accuracy in a controlled demonstration is different from a tool that keeps working during ordinary life. This study adds evidence on two practical questions: whether a participant and trained care partners can operate the system at home, and whether it can remain useful over a long period.
The accuracy numbers also need their labels. In prompted tests, the decoder exceeded 99% word accuracy. For sentences the participant chose to say in daily use, he labeled 92% as at least mostly correct. Those measurements are encouraging, but they answer different questions and should not be collapsed into one headline number.
Why we are publishing now
The published study and the participant’s documented experience are enough to report this feasibility milestone now. Open questions about broader safety, access, portability and performance across more people belong in follow-up coverage; they do not erase what this participant and research team have already demonstrated.
Good News IRL will publish a separate update when the trial produces material new evidence instead of waiting to make one article carry every future answer.
The receipts
What the evidence supports
The participant used the implanted system at home for more than 3,800 hours over nearly two years without researchers present.
Source 1, Source 2He communicated 183,060 sentences totaling 1,960,163 words at an average rate of 56 words per minute.
Source 1He rated 92% of sentences at least mostly correct, while structured prompted testing exceeded 99% word accuracy.
Source 1, Source 2The implanted device remains investigational, and FDA guidance treats this class of technology as requiring staged feasibility and pivotal clinical evidence.
Source 2, Source 3
No blinders
What this does not prove
- This report describes one participant in an ongoing clinical trial; it cannot establish how well the system would work across people with different conditions, speech patterns or care environments.
- The system is invasive: four microelectrode arrays were implanted and connected through percutaneous hardware. It is an investigational device, not an approved consumer or clinical product.
- The study was not designed to establish comparative safety, long-term durability across participants, affordability or equitable access.
- Structured word-accuracy tests and participant-rated everyday sentences measure different kinds of performance and should not be treated as interchangeable.
The return date
What we’re watching next
- Follow results from additional BrainGate2 participants and any reported adverse events or hardware failures.
- Track whether future versions reduce setup burden, external equipment and invasive hardware.
- Ask prospective users and care partners which tradeoffs matter most for communication, privacy and daily independence.
- Report any regulatory milestones or larger clinical studies as separate updates.
Primary sources
Check our work
- Long-term independent use of an intracortical brain–computer interface for speech and cursor controlNature Medicine · Academic journal · June 15, 2026
- Brain-computer interface enables independent, accurate communication for man living with ALSUC Davis Health · University · June 15, 2026
- Implanted Brain-Computer Interface Devices for Patients with Paralysis or AmputationU.S. Food and Drug Administration · Government · May 20, 2021