This man with ALS is “the first power user” of a brain implant that lets him speak

Casey Harrell, a 45-year-old ALS patient paralyzed by the disease, has become the first long-term independent user of a brain-computer interface that lets him speak. Brain electrodes decode his neural activity into words with 99% accuracy across a 125,000-word vocabulary, and he now uses the device to work, browse the internet, and bond with his daughter — largely without researcher assistance.