The FDA has approved Neuralink's plan to put its brain implant in a second human patient—with adjustments for issues that arose with the first. Some 85% of the implant's electrode-containing threads became dislodged from Noland Arbaugh's motor cortex, severely limiting the data that could be gained from neurons and translated into action through a computer cursor, per the Wall Street Journal. Though the human brain pulsates, Neuralink found Arbaugh's brain moved up to three times what it had expected, per the Journal. Neuralink has since proposed fixes, viewing the issue as not severe enough to require an entire product redesign, Quartz reports.
Its solution is to embed some of the threads deeper into the brain tissue—up to eight millimeters instead of the three to five millimeters in Arbaugh's case, per the WSJ. Neuralink hopes to implant the device in a second quadriplegic participant next month. More than 1,000 people have joined the patient registry, though fewer than 100 meet the qualifications for the study, the Journal reports, noting Neuralink continues to accept new applications. It hopes to implant its device in 10 diverse candidates before the year is up. Applicants in Canada and Britain, where Neuralink soon hopes to launch trials, are also invited to sign up. (Arbaugh continues to have high hopes for his brain-computer interface.)