Story perspectives

ALS Patient Generates 183k Sentences via Home Brain-Computer

6/16/2026

Summary

Story summary

Casey Harrell, an ALS participant, used a home brain-computer interface for over 3,800 hours, generating more than 183,000 sentences at 56 words per minute.
Four 64-electrode arrays implanted in July 2023 in his left precentral gyrus delivered 99 % word accuracy, a 125,000-word vocabulary, and 92 % sentence correctness.
The 3,800 hours constitute the largest dataset, with a team led by David Brandman, Sergey Stavisky and Nicholas Card showing the system can run independently at home.

1 of 1

Story summary

Casey Harrell, an ALS participant, used a home brain-computer interface for over 3,800 hours, generating more than 183,000 sentences at 56 words per minute.
Four 64-electrode arrays implanted in July 2023 in his left precentral gyrus delivered 99 % word accuracy, a 125,000-word vocabulary, and 92 % sentence correctness.
The 3,800 hours constitute the largest dataset, with a team led by David Brandman, Sergey Stavisky and Nicholas Card showing the system can run independently at home.