Neuralink's brain-chip implant malfunctioned and the company reportedly considered removing it from its human patient

Neuralink's human patient experienced a thread retraction in his brain-chip implant leaving it less effective, but tweaks later improved performance.

• Some threads pulled away from Neuralink's first brain implant in a human, but it's now been fixed.
• Elon Musk's company considered removing the device from the patient, The Wall Street Journal reported. 
• Neuralink reportedly wants to install 10 more devices in humans this year.

Neuralink's brain-chip implant is working — except that some of the device's threads pulled away from the first human patient's brain.

Elon Musk's company shared a progress update in a blog post on Wednesday and said a number of threads "retracted" from the patient's brain a few weeks after his surgery. That rendered the implant less effective.

The "Link" device lets the patient move a computer cursor using his thoughts. The process involves more than 1,000 electrodes in the device and at least 64 "threads," which are each thinner than a strand of human hair, Neuralink said in an earlier blog post.

Neuralink measures the Link's speed, accuracy, and performance and its cursor control using a metric called bits-per-second (BPS). The Wednesday blog post said a higher BPS score means it has stronger cursor control.

The retraction of some of the threads caused the electrodes in the device to be less effective, Neuralink said. It's since made tweaks which in turn "produced a rapid and sustained improvement in BPS, that has now superseded Noland's initial performance."

Neuralink revealed in a livestream on X in March that 29-year-old Noland Arbaugh, who was paralyzed below the shoulders after a diving accident in 2016, was the first person to receive its implant in January.

Neuralink considered removing the implant from the patient altogether, The Wall Street Journal reported citing unnamed sources.

In February, Musk said on an X Spaces session that "progress is good" and that "the patient seems to have made a full recovery."

On Thursday he posted on X:

Neuralink plans to implant 10 devices in other human patients by the end of this year, according to the Journal.

In a meeting at Neuralink, shared on X in March, Arbaugh said it took five months from applying to be in Neuralink's human trials to having brain surgery, which took less than two hours. Since it was implanted, he's used it to play video games, including "Mario Kart," post on social media, and play chess.

Neuralink didn't immediately respond to a request for comment from Business Insider, made outside normal working hours.