Jonathan Ra | Noor Photos | Getty Images
Neuralink disclosed last week that tiny wires in its first patient’s brain had become dislocated, according to five people familiar with the matter, a problem that Elon Musk’s company has known about for years.
Three sources said the company knew from animal testing last year ahead of U.S. approval that the wires could retract, removing sensitive electrodes that decode brain signals. Neuralink believes the risk is low enough to not warrant a redesign, the source added.
Neuralink is testing its implants to allow paralyzed patients to use digital devices by thinking alone, a prospect that could help people with spinal cord injuries.
The company said last week that in the first human trial, the implant’s thin wires – thinner than a human hair – retracted from the patient’s brain, leaving fewer electrodes to measure brain signals.
These signals are converted into actions, such as moving a mouse cursor on a computer screen. The company said it successfully restored the implant’s ability to monitor the patient’s brain signals by modifying the algorithm to make it more sensitive.
The sources declined to be named, citing confidentiality agreements they signed with the company. Neuralink and its executives did not respond to calls and emails seeking comment.
The FDA became aware of potential problems with the wires because the company shared animal testing results as part of its application to begin human trials, one of the people said.
The FDA declined to comment on whether it was aware of the issue or its possible significance. The agency told Reuters it would continue to monitor the safety of patients participating in the Neuralink study.
If Neuralink continues its trials without a redesign, it could face challenges if more wires are pulled and its tweaks to the algorithm prove insufficient, one source said.
But redesigning threads has its own risks. If they are fixed in the brain, for example, it could cause damage to brain tissue if the wires come off or the company needs to remove the device, two sources said.
Current and former employees said the company tried to design the threads in a way that they can be removed seamlessly so that the implants can be updated over time as technology advances.
In January, Neuralink implanted the device into the brain of its first patient, Noland Arbaugh, who was paralyzed from the shoulders down after a diving accident in 2016.
Neuralink said in a blog update last week that “many threads retracted from the brain” in the weeks following the surgery. The post made no mention of adverse effects on Abo’s health, nor did it reveal how many of the device’s 64 threads quit or stopped collecting brain data.
So far, the device has allowed Apple to play video games, browse the Internet and think alone using the cursor on the laptop, according to company blog posts and videos. Shortly after the surgery, Abo surpassed the world record for controlling the speed of a cursor using only his thoughts, Neuralink said.
It’s common for medical device companies to troubleshoot different designs during animal testing and problems that arise during animal and clinical testing, according to outside researchers and sources who have worked at Neuralink and other medical device companies.
Experts who study brain implants say the problem of thread movement can be difficult to solve, in part because of the mechanisms by which the brain moves within the skull.
Robert Gaunt, a neuroengineer at the University of Pittsburgh, said the movement of the wires soon after surgery was disappointing, but he said it was not unforeseen. “In the days, weeks, months after an implant like this, that’s probably the most vulnerable period,” he said.
Pig weightlifting
Neuralink conducted additional animal testing to address these concerns, and the FDA last year gave the company permission to begin human testing.
The company found that a type of inflammation called granuloma developed in the brains of some of the pigs implanted with its device, causing concern among Neuralink researchers, according to three sources familiar with the matter and records seen by Reuters , thought these lines might be the cause.
Granuloma is an inflammatory tissue reaction that can form around a foreign body or infection.
In at least one case, a pig became seriously ill. Company records reviewed by Reuters showed the pig developed a fever and vomited after the surgery. Neuralink researchers didn’t realize the extent of the problem until they examined the pigs’ postmortem brains.
Researchers within Neuralink discussed how to correct the problem and began a months-long investigation, people familiar with the matter said.
Ultimately, the company was unable to determine the cause of the granulomas but concluded that the device and the threads of the connection were not to blame, one source said.
About The Author
