Elon Musk company Neuralink has a second person a Brain-Computer interface (BCI) and could implant eight more of these devices this year, said Musk.

published in a August 2 8- hours Podcast said Musk that the second implant works well and that around 400 of his 1,042 electrodes provide signals from the recipient's brain. Musk did not reveal any details of the implant surgery or the recipient, except that the person has a spinal cord injury, as well as Noland Arbaugh, the first recipient of a Neuralink BCI.

Now scientists are waiting to see whether this in the Fremont, California, resident companies can avoid the mechanical difficulties that were plagued by the implantation of his first device in January.

"This is a necessary progress," says Sameer Sheth, a neurosurgeon and neurotechnology coward at the Baylor College of Medicine in Houston, Texas. "I really hope that you can continue to do so. You can contribute a lot to human health and illness."

anchored in the skull

The BCI, called Telepathy, developed by Neuralink, is the third commercial BCI implantation, which is tested in tests in tests in the long term. The others use electrode arrays that are either attached to the inside of a cerebral blood vessel or sit directly on the brain. Instead, Telepathy has a roughly coin-sized electronics hub that is placed in a hole that is made in the recipient's skull. From this stroke, 64 flexible threads run through the liquids and membranes around the brain and in the recipient's cortex.

A surgical robot developed by Neuralink uses these threads into the motor cortex, the brain area that controls the movement. This process lasts 20 to 40 minutes, said Dongjin SEO, co -founder and president of Neuralink, in the podcast. Each thread has 16 recording points, a total of 1,024 electrodes that potentially record neuronal activities and send signals to an external device via Bluetooth.

The first person who received a neuralink-bci was Noland Arbaugh from Yuma, Arizona, which was paralyzed from the neck after a diving accident in 2016. , for example to play games.

But one month after the implantation of Arbaugh’s BCI, 85% of its flexible threads that record neuronal activities have withdrawn from his brain. This impaired the performance of the device, which was "really, really difficult" for ARBAUGH. "It would have been a cruel turn of fate if I could have seen the view from the summit of this mountain and then everything would have collapsed after a month," said Arbaugh in the podcast.

The engineers from Neuralink reacted by changing the recording algorithm that convert neural data into commands that are transferred to the computer. The original algorithm recorded the activity of individual neurons, but the revised version records the average activity of neurons near every electrode. Although the average signals have less resolution, the effects were immediate.

"Why do we take this risk and implant so many threads when it works quite well and gets better with fewer threads?" Asks Sheth.

On July 10, Matthew MacDougall, head of neurosurgery at Neuralink, said that the first surgical intervention caused an air pocket that could later have postponed the electrodes. He said that the surgical team would try to avoid such air pockets when the second implant was placed and to make the hole differently in order to put the stroke deeper in the skull and deeper the flexible electrodes into the cortex to threading.

"It is not common" to make so many changes in the BCI implantation process between recipients, "says Sheth." But I think it's good that you learn from the first and then make the second really better. "

questions about stability

Nevertheless, Vikash Gilja, Chief Scientific Officer at Paradromics, a competitive company for BCI based in Austin, says Texas that questions about the stability and durability of the device must be answered.

The brain, according to Gilja, "is not simply static relative to the skull": it moves when a person breathes and moves. It is not clear whether this minor but continuous movement will negatively influence the electrode threads that run from the skull through the brain to the brain, says Gilja.

The long -term stability of the materials from which Neuralink’s electrodes consist of is another unknown. Other BCI implants use different metallic electrodes types with established longevity recordings. "You only understand the time constants when you are in the human body," says Gilja. Devices, he says, have to be studied for years and not months.

long -term plans

During the live stream on July 10,

Musk said that Neuralink plans to regularly offer improved devices, each of which would be implanted in further neurosurgery. In contrast, Paradromic's "demands as much time as possible between successive neurosurgeries," says Gilja.

Musk said in the podcast that the ultimate goal of Neuralink a BCI that enables people to make a symbiosis Artificial intelligence to enter. He predicted that future BCIs will help people with psychoses, seizures and memory loss.

Sheth says that the treatment of such conditions is a much greater challenge than moving computer cursorn and adds that a human augmentation requires a careful discussion.

More immediately, says Anna Wexler, a neuroethics at the University of Pennsylvania in Philadelphia that these predictions could mislead potential study participants. "It certainly raises questions about what these people are drawing to the studies and what they understand about what they are involved".