Elon Musk says Neuralink brain implant will test on second patient in ‘next week or so’

The wires connecting the brain of the first Neuralink patient to the implant in his skull have become “more or less very stable” after becoming disconnected months ago, the company said Wednesday.

“Once you do brain surgery, it takes a while for the tissue to develop and the wires to anchor in place. Once that happens, everything is stable,” Neuralink CEO Dongjin “DJ” Seo said during a livestream on Twitter/X on Wednesday night.

That same day, CEO Elon Musk said the company would soon test its pound-sized implant and brain-computer interface, collectively called Telepathy, on a second patient. The unnamed patient’s surgery is scheduled for “the next week or so,” Musk said.

Neuralink, founded by Musk, said in May that some wires in the head of Noland Arbaugh, who is paralyzed from the shoulders down, had become dislocated. The company did not specify why the disconnection occurred. Neuralink’s implant uses 64 wires to connect to the brain; only 15 percent of them worked after the connection was severed.

After the surgery, air was trapped in Arbaugh’s head, Neuralink executives said. In light of that and the disconnection, the company would implement new risk mitigation measures, such as skull sculpting and reducing blood carbon dioxide levels to normal levels in future patients, company executives said during the livestream.

“With future implants, our intention is to very deliberately sculpt the surface of the skull to minimize the gap under the implant … bringing it closer to the brain and taking some of the tension off the wires,” said Matthew MacDougall, chief of neurosurgery at Neuralink.

So far, Arbaugh, who lost the use of much of his body after a diving accident in 2016, is the only patient to receive the implant. But Musk hopes this year will see more participants in the high single digits.

Neuralink is testing its implant to give paralyzed patients the ability to use digital devices using only their thoughts. The device works by using tiny wires, thinner than a human hair, to pick up signals from the brain and translate them into actions. The company released a video of Arbaugh using his implant to play online chess and move a computer mouse. After the disconnection, he could no longer use the mouse, but functionality has returned, executives said in the livestream.

Musk said during the livestream that the device does not harm the brain. The U.S. Food and Drug Administration raised safety concerns when it first considered the device years ago, but eventually gave the company the green light to begin human trials last year.

Neuralink is also working on a new device that the company believes will implant half the number of electrodes in the brain to make it more efficient and powerful, executives said. Musk said the company was working on another product called Blindsight that would allow blind people to see.