Elon Musk’s startup Neuralink revealed that it experienced a problem with its brain implant after the device was installed in its initial participant, 29-year-old quadriplegic Noland Arbaugh.
Cofounded by Musk, Neuralink is one of several companies developing a brain-computer interface, a system that provides a direct link from the brain to an external device.
The threads are meant to extend into the brain tissue to collect signals from groups of neurons.
“Suffice to say, that’s not supposed to happen,” says Matt Angle, CEO of Paradromics, an Austin-based company that is also developing a wireless brain implant to help paralyzed people communicate.
However, the brain naturally moves within the skull, and it’s possible that some of the Neuralink threads were pulled out by that movement.
By contrast, Neuralink’s implant is wireless and has a total of 1,024 electrodes.
Prior to getting the implant, Arbaugh used a mouth-held stylus, known as a mouth stick, to operate a tablet that had to be put in place by a caregiver.
For Arbaugh, Neuralink’s device is “luxury overload,” according to the company’s blog post.
After implanting the device in its first patient, 29-year-old quadriplegic Noland Arbaugh, Elon Musk’s startup Neuralink disclosed that it encountered an issue with the brain implant.
Musk swiftly declared on X following the January 28 surgery that Arbaugh was “recovering well” and that “initial results show promising neuron spike detection.”. However, the device began to malfunction only a few weeks later, the company announced on Wednesday.
Among the companies developing brain-computer interfaces—a system that establishes a direct connection between the brain and an external device—is Neuralink, which Musk cofounded. A paralyzed person can move a cursor or type on a keyboard with just their thoughts thanks to Neuralink’s technology, which decodes intended movement signals from the brain.
The mechanical problems with Neuralink’s device might have been caused by its unique design. The company’s implant is a puck the size of a coin that is placed inside the skull. It is equipped with a battery, a CPU chip, and additional electronics required for system power. 64 pliable, human hair-thin “threads” with 16 electrodes each are attached to this puck. The threads are designed to reach into the brain tissue in order to gather neuronal group signals. Neuralink claims that some of those threads, however, were not stable.
A Neuralink blog post states that “in the weeks following the surgery, a number of threads retracted from the brain, resulting in a net decrease in the number of effective electrodes.”. The pace of data transfer, expressed in bits per second, decreased as a result. More bits per second is a sign of improved cursor control.
There is no indication in the blog post about the number of threads that have been removed or that remain in the brain. Matt Angle, CEO of Paradromics, an Austin-based business that is also creating a wireless brain implant to enable paralyzed people to communicate, says, “Suffice to say, that’s not supposed to happen.”.
Neuralink did not immediately reply to a request for comment from WIRED, nor did it provide an explanation for why or how the threads surfaced. Nonetheless, it’s likely that some of the Neuralink threads were separated by the brain’s normal movement within the skull.
The earlier Utah array, a mainstay of brain-computer interface research since the late 1980s, has been compared to Neuralink’s device, which Musk and Neuralink have highlighted as having advantages. The Utah array is a stiff square with 96 tiny shanks on it, each with a recording electrode at the tip. It pierces tissue with its shanks. Being wired and requiring a connection to an external device is one of its main drawbacks.
Neuralink’s implant, in comparison, has 1,024 electrodes overall and is wireless. If every electrode is still in place, then more information can be gathered from the brain.
According to Riki Banerjee, chief technology officer of Synchron, a New York startup that is now testing brain-computer interfaces in paralyzed individuals, “Neuralink designed a very novel neural interface.”. “As part of the process, they are learning. “.
Synchron and Paradromics drew inspiration from pre-existing medical devices rather than creating a new one from scratch. For example, the design of Paradromics is based on the Utah array but incorporates some significant improvements. Among its many features are its wireless nature and the 421 electrodes it has attached to minuscule wires that are inserted into the brain. According to Angle, all of those wires are substantially smaller than the Utah array’s shanks.
In contrast, Synchron’s gadget is a hollow mesh tube that looks like a heart stent. Rather than entering the brain directly, it is pushed up against the cortex after being inserted into the jugular vein at the base of the neck. Ten individuals have received Synchron’s device thus far, and one has had it for more than three years. (Arbaugh’s implant is still functional one hundred days later). According to Banerjee, there hasn’t been a drop in signal performance or quality yet.
Neuralink’s design might have contributed to the implanted threads pushing out of the brain, according to Andrew Schwartz, a professor of neurobiology at the University of Pittsburgh who specializes in brain-computer interface construction.
To place the device, the dura, the brain’s outermost layer, must be opened. The surgeon notes that suturing the dura closed after implanting multiple wires individually into the cortex may pose a challenge. If this incision had been left unchecked, scar tissue might have developed around it and the threads would have withdrew. According to Schwartz, the Utah array is made such that, following implantation, the dura can be sutured shut.
Despite this setback, Neuralink was still able to go live on March 20 with a demonstration of their device, in which Arbaugh used the implant to play chess simply by thinking about it. Arbaugh has additionally played Mario Kart on the device. “The video captures the sheer coolness of being able to do this—I just can’t even express it.”.
According to the blog post, Neuralink changed the recording algorithm to make it more perceptive of neural signals, which made up for the lost threads. Additionally, it claims to have improved the way it converted those signals into cursor movements, improved the device’s user interface, and increased performance as a result of these modifications.
Angle says it doesn’t really matter how many electrodes you have for moving a cursor. However, a greater data rate will be crucial for more complicated tasks like translating text to speech.
Before receiving the implant, Arbaugh operated a tablet that required an attendant to place using a mouth-held stylus called a mouth stick. Normal speech is obstructed by a mouth stick, which can only be used upright. Long-term use of it may result in soreness, muscle exhaustion, and pressure sores.
Neuralink’s gadget is “luxury overload” for Arbaugh, the company writes on their blog. He continues to use the implant, which has given him the ability to “reconnect with the world” and live independently once more, without requiring his family at all times of day or night.
The fact that the patient is still able to use the device and is content with it is positive. That’s a victory in the end, according to Angle. In our view, however, businesses developing brain-computer interfaces should be developing products that will endure for several years. “.
Since Neuralink is taking a novel approach with its device, there may be more challenges ahead for the company as it moves toward commercializing brain-computer interfaces.
