Casey Harrell, a man with ALS, has spent nearly three years using a brain‑computer interface (BCI) implanted in July 2023. The device lets him speak, browse the web and continue climate activism, earning an income despite paralysis. UC Davis researchers refined its accuracy, adding a privacy mode and profanity filter so he can converse with his daughter safely and personal independence.

The field has expanded rapidly. China approved its first medical BCI this year, and trial volunteers have surged, and regulatory support. A 2024 review counted 21 research groups and 67 participants since 1998; Mariska Vansteensel now estimates roughly 150 implanted individuals. Companies such as Neuralink, Synchron and Shanghai’s Neuracle are running trials across North America, Australia and China.

Academic teams continue to diversify device architectures, from fully implanted wireless arrays to surface caps. UC Davis’s BrainGate project shifted from cursor‑click control to speech decoding, now using a voice clone based on Harrell’s recordings. While BCIs remain experimental and long‑term durability unclear, the growing volunteer pool provides essential data to determine which patient groups, beyond spinal injury, can benefit for future clinical deployment.