“Hello, world!” read one inconspicuous tweet posted on the Twitter account of Tom Oxley, founder and CEO of Synchron, a startup that develops brain-computer interfaces (BCIs), in December 2021. The tweet wasn’t written by Oxley but one of Synchron’s patients, Philip O’Keefe. O’Keefe suffers from ALS, a neurodegenerative disease that is causing him to gradually lose control of his muscles. His BCI, implanted almost two years prior, allowed him to type out the message with his mind, partially restoring his ability to communicate and interact with the world.
hello, world! Short tweet. Monumental progress.
— Thomas Oxley (@tomoxl) December 23, 2021
When BCIs pop up in the popular media, it’s often in connection to Elon Musk’s Neuralink. But Synchron may be ahead of the game in some respects. The company was founded four years earlier than its chief competitor, in 2012, has received investments from Bill Gates and Jeff Bezos, and has already launched two trials – one in Australia, another in the US. The company’s key advantage over Neuralink, which took on its first human patient earlier this year, is that its BCIs do not require brain surgery. Where Neuralink implants its interfaces directly into the cerebral cortex, Synchron implants its devices through the patient’s bloodstream, circumventing the cost and risks of physically penetrating the human skull.
In August 2020, the FDA designated Synchron’s BCI as a Breakthrough Device, acknowledging its potential to improve treatment for debilitating or life-altering conditions, and paving the way for clinical trials. So far, the results are promising. “There are 8 million people in the US living with various forms of paralysis,” Synchron’s CTO, Riki Banerjee, explained in a recent talk at EmTech 2024, a yearly conference on emerging technologies hosted by MIT. “You lose the ability to control not just your interactions with others, but also your environment – whether it’s adjusting the thermostat or ensuring home security. We see BCI as a way to restore this lost connection.”
In an interview with Freethink, Banerjee explains how Synchron’s BCI works, the tech that informed its design, and what it has been able to do for those who agreed to let the company put its invention inside their bodies.
How Synchron’s BCI works
Before joining Synchron, Banerjee spent 15 years in neuromodulation research, which involves stimulating nerve activity through electrical and chemical stimuli. Neuromodulation and – by extension – BCIs evolved from pacemaker technology that dates back to the 1950s, a time when brain implants were still the stuff of science fiction.
“The field has seen significant growth over the last 5 to 10 years,” she tells Freethink over Zoom, with initial research focusing on mental disorders like OCD, depression, and insomnia before moving on to other conditions like paralysis. “Neurotech is not just about the brain,” she explains. “It involves the entire nervous system, including peripheral nerves.”
“The cranium attenuates brainwaves. This is fortunate insofar as we don’t want others to hear our thoughts, but it also complicates treatment.”
Riki Banerjee
Synchron’s decision to develop a BCI that could be delivered through a vein started from the complications of brain surgery. “Accessing the brain is a complex and often highly specialized procedure,” Banerjee says. “There are only around 1,000 to 2,000 neurosurgeons who can perform these types of surgeries, which – while they have long been approved for conditions like Parkinson’s or epilepsy – remain a barrier for many.”
Still, the company understood that for their BCI’s to work properly, they needed to find a way to get them into the brain: “It’s the skull that gets in the way. From a signal processing perspective, the cranium attenuates brainwaves. This is fortunate insofar as we don’t want others to hear our thoughts, but it also complicates treatment.”
Synchron’s BCI is inserted via the jugular vein, which runs up the neck into the brain, using a catheter. Once in the brain, the catheter releases a self-expanding device made from Nitinol, a biocompatible, erosion-resistant nickel-titanium alloy, which is commonly used to widen arteries in surgical procedures. As Banerjee explained in her talk at EmTech, the implanted BCI can detect certain brain waves and send them to a separate receiver, implanted in the chest. In patients suffering from paralysis, the system can transmit their intended but unperformed physical actions to an external device, like a phone, TV remote, or Amazon Alexa, allowing them to use these devices without their voice or hands.
“Our devices are designed for chronic implantation,” Banerjee tells Freethink, “meaning they stay in the body for years. In Australia, we have a patient whose implant has been in place for over four years at this point.” Banerjee says that malfunctioning implants can be repaired by updating their software from the outside. While the brain implant cannot be removed, because tissue grows around the device, the chest component can be taken out and replaced.
Challenges and promises
The advantages of Synchron’s BCI are twofold. First and foremost, the non-invasive implantation procedure makes the operation not only more accessible, but also easier to recover from, though some patients may heal more slowly due to preexisting conditions. More importantly, perhaps, Synchron’s unique implantation technique may also make it easier for the device to access different sections of the brain.
“If your goal is recreating speech, most people think you should target the speech center,” Banerjee explains. “But research shows that speech also generates motor functioning. So, instead of targeting the speech center, you could target the motor region, which is a lot more accessible. By understanding how the mouth and tongue move during speech, you can recreate speech through motor signals. The brain is highly interconnected, so there are multiple ways to approach challenges.”
Synchron’s early trials yielded positive results. The first, conducted by the Royal Melbourne Hospital and University of Melbourne in Australia, involved four human patients with severe paralysis and its main conclusion was that it is possible for the implant to transmit neural signals from the brain’s blood vessels over the long-term without “serious adverse events.” A 12-month follow-up confirmed that the patients did not suffer from persistent neurological deficits, blood clots, or migrations of the device. Among other things, they were able to use their implants to send text messages, write emails, manage their online banking, and – most importantly – communicate their needs to caregivers.
The second trial, carried out through New York City’s Mount Sinai Health System, the Gates Vascular Institute at the University of Buffalo, and the University of Pittsburgh Medical Center, alongside Carnegie Mellon University of Engineering, involved six patients with severe chronic bilateral upper-limb paralysis who had been unresponsive to conventional therapy. Again, the study saw no adverse events related to the device over the course of a year-long evaluation period. What’s more, 100% of the implants were “accurately deployed,” according to the company’s press release, “achieving target motor cortex coverage in the brain for all six patients.”
“The privacy concerns about reading thoughts are far from reality.”
Riki Banerjee
Elad Levy, principal investigator of the study and L. Nelson Hopkins Endowed Chair of Neurosurgery at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, referred to the trial as a “major medical milestone,” adding that “this minimally-invasive approach has the potential to unlock BCI technology at scale for the millions of patients with paralysis and other mobility challenges.”
News coverage of the trials has largely focused on how the BCIs have improved the lives of individual patients. An article from Wired followed Mark, a 64-year-old with ALS, who received his BCI in August 2023. As the trials progressed, Synchron worked to make its implant compatible with various popular electronic devices, including Alexa, which Mark can now command without using his voice. According to the article, Synchron was also able to connect Mark’s BCI to the Apple Vision Pro, a mixed reality headset which – after updates – allowed Mark to play video games like Solitaire by moving the cursor with his thoughts.
Looking ahead
As promising as these trials have been, it’s important to note that the time frame is too short, and the number of participants too few, to draw “firm conclusions,” as Banerjee herself said at EmTech. That said, each new test allows Synchron to better understand the long-term challenges of brain implants and improve their devices accordingly.
In 2025, the company plans to launch its third trial – this time with a commercially available system. In addition to increasing the processing speeds of their BCIs, Synchron is hoping to use the implants to treat other conditions related to the brain and nervous system.
“The current system requires a device on the chest for power and communication,” Banerjee says of the future, “but our next system will have a rechargeable battery, improving usability. Patients will be able to use it anytime, even if they wake up in the middle of the night.”
Along the way, she hopes her work will be able to change the negative, mistrustful attitudes that many people have of brain implants. “The biggest misconception is that we’re directly reading people’s thoughts,” she says. “Actually, we’re looking at small signals – like tapping a finger to click a mouse –simple on/off actions. We’re translating that to activity on a screen or computer. From a privacy standpoint, we’re not extrapolating thoughts. That’s a long way off. In truth, we give away more information using our phones, credit cards, and apps than we do with these implants. The privacy concerns about reading thoughts are far from reality. For now, it’s more like computer code than thought-reading.”
We’d love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at tips@freethink.com.
