Instead of building a device from scratch, Synchron and Paradromics took inspiration from previous medical devices. For example, Paradromics’ design is based on the Utah array but with some important improvements. First, it’s wireless and has 421 electrodes at the tips of tiny wires embedded in brain tissue. Those ropes are all much smaller than the legs of the Utah plate, Angle said.
Meanwhile, Synchron’s device is a hollow mesh tube similar to a cardiac stent. Instead of going straight into the brain, it is inserted into the jugular vein at the nape of the neck and pushed up into the cerebral cortex. To date, Synchron has implanted its device in 10 participants, including one who has been using the device for more than three years. (Arbaugh’s implant still works after 100 days). Banerjee said the company has not yet seen a deterioration in signal quality or performance.
Andrew Schwartz, a professor of neurobiology at the University of Pittsburgh who built the brain-computer interface, also speculated that Neuralink’s design may have caused the implanted fibers to push out of the brain.
The outermost layer of the brain, the dura mater, needs to be opened to place the device. “With multiple wires inserted individually into the cortex, it can be difficult to suture the dura mater closed after wire implantation,” he said. Leaving this hole can cause scar tissue to form around the hole, causing the threads to pull out. Schwartz said the Utah array is designed so that the dura mater can be sutured after implantation.
Despite Neuralink’s failure, the company is still trying Live stream the performance of the device on March 20, showing Arbaugh using the implant to play chess just by thinking about it. Arbaugh also used the device to play video games Mario Kart. “I can’t even describe how great it feels to be able to do this,” he said. said in the video.
In the blog post, Neuralink said it compensated for lost streams by modifying the recording algorithm to be more sensitive to neural signals. It also says it has improved the way those signals are translated into cursor movements and enhanced the user interface, and that these changes can boost device performance.
To move the cursor, Angle said having more electrodes isn’t as important. But for more complex tasks, such as text-to-speech, higher data speeds will be important.
Before the implant, Arbaugh used a mouth-held stylus, called a mouth stick, to operate a tablet that a caregiver had to put in place. The mouthpiece can only be used in an upright position and it interferes with normal speech. When used for long periods of time, it can cause discomfort, muscle fatigue and pressure sores.
To Arbaugh, Neuralink’s device is “luxury overload,” according to the company’s blog post. He is still using the implant, which has allowed him to “reconnect with the world” and do things on his own again without his family at all hours of the day and night.
“It’s good that patients can still use the device and remain satisfied with it. In the end it was a win,” Angle said. “But in our view, companies that are building brain-computer interfaces need to build devices that are robust and reliable over a multi-year time frame.”
There will likely be bumps in the road to commercialization of brain-computer interfaces, and with Neuralink taking a unique approach with its device, the company may face more bumps in the road .
