Not long after finally scoring an investigational device exemption from the FDA to begin a clinical trial of its brain-computer interface technology, Elon Musk’s Neuralink has followed up that green light with two more from an independent institutional review board and the trial’s first hospital site—allowing participant recruitment to officially begin.
Neuralink is looking for volunteers who have quadriplegia caused by a cervical spinal cord injury or amyotrophic lateral sclerosis (ALS), according to a company blog post Tuesday. It didn’t specify how many patients it’s hoping to recruit for the study, though Reuters reports that the company’s initial aim of 10 participants had been previously nixed by the FDA as too many.
According to a brochure (PDF) for the study, Neuralink is looking for people at least 22 years old with at least one year since they were diagnosed with quadriplegia, and no improvements in limb function since. They’ll also need to have a “consistent and reliable caregiver.”
Those ineligible for the study include individuals already implanted with another medical device—such as a pacemaker or neurostimulator—as well as those undergoing transcranial magnetic stimulation treatment and anyone with a history of seizures or who must undergo regular MRI scans to monitor a medical condition. Those who meet the criteria can join Neuralink’s patient registry.
The trial—which has been dubbed the PRIME study, for its focus on a precise robotically implanted brain-computer interface—is designed to assess both the safety and initial functionality of Neuralink’s N1 brain implant. It’ll also evaluate the safety of the R1 surgical robot, which was built for the sole purpose of putting the implant in place and connecting its electrode threads to specific areas of the brain.
Those 64 threads are equipped with a total of 1,024 electrodes, and each thread is thinner than a human hair, according to Neuralink. They record the brain’s activity, then transmit those data to the connected N1 User App.
From there, once trained to recognize an individual’s neural patterns, the app’s algorithms will ideally be able to translate that brain activity into the user’s intended actions, allowing them to control a computer cursor or keyboard using only their thoughts.
In total, the trial will span about six years: After an 18-month primary study, including nine at-home and in-clinic check-ins, plus at least two one-hour-long BCI research sessions per week, the participants will continue to be followed for a five-year follow-up period that’ll include a total of 20 check-ins.
During a show-and-tell presentation last fall, Musk said that the N1 implant’s first two applications would be to help paralyzed people control external devices—the focus of the PRIME study—and to restore vision by tapping into areas of the brain associated with sight.
Even further in the future, he suggested that the BCI technology could not only “restore full-body functionality to someone who has a severed spinal cord,” but also connect the average consumer even more closely to their smartphone, allowing them to send text messages and emails and complete other tasks with only a thought.