One year down, a lifetime to go. New results from Synchron’s first human study of its brain-computer interface system—a permanent, stent-like implant—found that one year after the device’s placement, none of the four participants had experienced any adverse events that led to disability or death.
The Stentrode system reaches the brain via the jugular vein through a minimally invasive, two-hour procedure that stands in stark contrast to most other operations under development, which typically require physicians to drill through the patient’s skull. Once in place, the Stentrode expands to fit flush against the blood vessel’s walls, where its sensors can pick up the brain’s neurological signals.
At the one-year point, researchers found that the implant stayed in place for all four patients and that the surrounding blood vessels had remained open, according to the study results presented this week.
The one-year safety data follows preliminary results in 2020 from the Australia-based study, where the Stentrode’s first two patients demonstrated they could use it to perform daily tasks like sending text messages and emails, as well as shop and bank online.
That list now includes tweeting. One of the study participants last December became the first person to use direct thought to post on social media, by using the account of Synchron’s CEO and co-founder, Thomas Oxley.
Over time, those patients—who, like the other two participants who have since joined the study, are paralyzed due to amyotrophic lateral sclerosis, known as ALS—were able to achieve more than 90% accuracy in controlling cursor clicks with their thoughts and hit typing speeds of at least 14 characters per minute without any help from predictive text.
As the Stentrode gathers brain signals, it immediately transmits them to the battery-free BrainPort receiver unit implanted in the patient’s chest. From there, the unit uses Bluetooth technology to wirelessly send the data to Synchron’s BrainOS platform on a nearby mobile device or computer, where they’re converted into clicks and keystrokes. Meanwhile, a separate eye-tracking reader is used to control the cursor’s movements.
“We’ve shown that our endovascular BCI approach is safe and allows patients to accomplish daily online tasks without invasive brain surgery,” Oxley said in a statement. “Years of research and technological development culminated in this moment, and as we continue to develop our technology, it has the potential to change the lives of millions of patients globally who suffer from paralysis and other debilitating neurological and brain-related diseases.”
Synchron is now expanding the study to the U.S., following an investigational device exemption approval from the FDA last July. The agency had already expressed its confidence in the implant a year prior when it gave the Stentrode system its breakthrough device designation.
The new U.S.-based trial is expected to include six paralysis patients and will be supported in part by the $40 million series B funding the New York City startup roped in last summer. According to Synchron, it’s the first FDA-sanctioned clinical trial of a permanently implanted brain-computer interface.