Bold statements by Elon Musk about the prospects of creating a ready-made product based on the brain-computer interface (BCI) of the Neuralink startup, it seems, remain distant, reports Engadget, citing Reuters.

Sources indicate that in 2022 Neuralink received a waiver from the FDA to conduct human trials using the same devices that killed pigs.

“The agency’s major safety concerns involved the device’s lithium battery; the potential for the implant’s tiny wires to migrate to other areas of the brain; and questions over whether and how the device can be removed without damaging brain tissue,” current and former Neuralink employees told Reuters.

The FDA’s concerns regarding the battery system and its novel transdermal charging capabilities revolve around the the device’s chances of failure. According to Reuters, the agency is seeking reassurances that the battery is “very unlikely to fail” because should it do so, the discharge of electrical current or heat energy from a ruptured pack could fry the surrounding tissue.

The FDA is also very concerned with potential problems should the device need to be removed wholesale, either for replacement or upgrades, due to the minuscule size of the electrical leads that extend into the patient’s grey matter. Those leads are so small and delicate that they are at risk of breaking off during removal (or even during regular use) and then migrating to other parts of the brain where they might get lodged in something important.

During Neuralink’s open house in November of last year, Musk confidently stated that the company will receive FDA approval “within six months”, that is, by the spring of this year. This estimate turned out to be as accurate as his guesses for when the Cybertruck might finally go into production.

“He can’t appreciate that this is not a car,” one employee told Reuters. “This is a person’s brain. This is not a toy.”