Because it penetrates the tissue, the Utah matrix may cause inflammation and scarring across the implant site, resulting in poor signal quality over time. And signal quality is significant since it affects how well the BCI works. No one really knows how long Utah plates can survive within the brain; the record to date is held by Nathan Copeland, whose device has been in operation for eight years.
Utah Array placement also requires surgeons to perform a craniotomy, which involves making a small hole within the skull. This is a serious procedure that may cause infection and bleeding, and it takes a month or more to get better from one. Understandably, many patients could also be hesitant to undergo surgery, even when it means regaining a level of communication or mobility.
Precision tries to unravel each problems with a tool that has 1,024 electrodes, but is ultra-thin – about one-fifth the thickness of a human hair – and doesn’t pierce brain tissue. Instead of a craniotomy, the implant can be placed using a minimally invasive procedure that involves making a small incision within the skin and skull, then inserting the implant into the outermost layer of the brain, called the cerebral cortex. “The very idea of doing more damage to a brain or nervous system that is already damaged is pretty tense,” says Rapoport, who was also a co-founder of Neuralink. He believes streamlining the procedure would make these systems way more attractive to patients.
Craig Mermel, company president and chief product officer, says the Precision array is just as easy to remove. As BCI technology improves, patients who receive early brain chips may eventually need to upgrade to latest ones. With the Utah array, latest devices normally can’t be placed in the identical area on account of scar tissue.
With greater than 1,000 electrodes, Mermel says, the Precision device will have the ability to supply the next resolution of brain activity than current arrays. Precision arrays are also designed to be modular. Several may be linked together to gather brain signals from a bigger area. For more precise or complex actions beyond stimulating basic body movements or triggering easy computer functions, “you are going to need more brain coverage,” says Mermel.
Peter Brunner, associate professor of neurosurgery and biomedical engineering at Washington University in St. Louis, says the Precision implant seems impressive, however it’s still unclear how long it can last once implanted. Any device implanted within the body tends to degrade over time. “There’s a tension between making things smaller and still being resilient to the environment these devices face within the human body,” he says.
The brain slides within the skull, very similar to an implant, Brunner says. The surface system has the potential to run on a couple of that penetrates the brain. He says even a micrometric shift can change the group of neurons the device is recording from, which could affect how the BCI works.
Rapoport says all electrodes move a bit over time, but Precision software, which decodes neural signals, can account for these small shifts.
