This new brain-computer interface from Synchron goes through your chest

Thanks to the success of a first safety trial for an implantable device capable of translating electrical impulses from the brain into readable signals, we are one step closer to the possibility of texting or interfacing with our devices using only our thoughts. .

Best of all, this new brain-computer interface (BCI) – “brain modem”, if you will – doesn’t require a hole in the head. However, this requires a hole in your chest. And that’s just one factor that could slow the development of the technology, not to mention complicate any future public deployment.

Brain modems are coming, whether delivered by Elon Musk’s Neuralink company or another group. But how quickly they’ll be ready, how well they’ll work, and how many people will want them are all big open questions.

Late last month, New York-based biotech company Synchron announced results from a trial of its two-part brain modem in four people with amyotrophic lateral sclerosis, or ALS, a progressive neurodegenerative disease that affects the brain and spinal cord and can lead to paralysis. This was the first time the United States Food and Drug Administration had approved a BCI for clinical trials.

“This will allow millions of patients to have better abilities to interact with their environment and therefore have a better quality of life,” J Mocco, neurosurgeon and Synchron consultant, told The Daily Beast.

The testers monitored the four volunteers for a year, looking for any negative effects from the implants. There were “no serious adverse events resulting in disability or death,” the company said. The Synchron team published their results in the Journal of Neurointerventional Surgeries.

The implants weren’t just safe, according to Synchron. They also worked, at least at a rudimentary level. The devices “allowed participants to use a computer to communicate via text and perform daily tasks such as online shopping and banking.”

It may sound like science fiction, but the idea is quite simple. Our brain moves information via subtle electrical impulses. Our thoughts, in other words, are electricity. And they flash in recognizable patterns. Put a sensor in the brain, and it can read the patterns. Connect this sensor to a radio transmitter and you can literally transmit your thoughts to a compatible device the same way phones connect to phones or your computer connects to WiFi.

The applications are obvious, especially for paralyzed people. With a safe and effective brain modem, you wouldn’t need to move or even speak to text, browse the internet, or interact with any number of electronic devices.

All you would have to do is think— and let the modem do the work.

There are problems, of course. For starters, the first brain modems were combination sensors and transmitters that researchers implanted directly into people’s skulls. Every time you pierce someone’s skull, there is a significant risk of infection, inflammation and brain damage. “Intracranial surgery will always be a risky part of invasive BCI procedures,” Chris Crawford, head of the Human-Technology Interaction Laboratory at the University of Alabama, told The Daily Beast.

Not to mention, it’s scary. If the goal is to first help millions of people who suffer from some degree of paralysis, and then eventually bring brain modems to the general public, punching holes in the head is an obvious failure. Crawford cited the “public perception of the BCI” as “the next hurdle”.

The solution to the hole in the head problem came from cardiac medicine. It is increasingly common for heart surgeons to treat blockages without operating close to the heart or making large incisions. Instead, they make a small incision in the groin or wrist and insert a collapsed mesh tube, potentially a few centimeters long, into an artery. This “stent” acts as a scaffold. Electrically expanded, a stent lodges in a blood vessel near the heart, where it maintains blood flow past a blockage.

Neurosurgeons have begun adapting stent technology to their latest brain modem designs. As the first company to gain FDA approval for a clinical trial, Synchron is arguably the leader in this field.

Start with a stent. Add a layer of electrical sensors to the mesh, producing an electrode and stent combination the developers call a “stentrode.” Inject it into an artery in your neck and lodge it in one of the blood vessels inside your skull. From there, it detects impulses in your brain, without ever touching this. “It doesn’t directly violate the brain,” Mocco pointed out.

Now here comes the tricky part. The stentrode needs a way to get a signal out of the body. Bones, especially thick bones like the skull, tend to block radio signals, hence the hole-in-the-head approach that was typical of the first generation of experimental BCIs.

But there are parts of the body without bones. The chest between your ribs, for example. Synchron got around the skull problem by implanting its transmitter in the chest and connecting it, via a thin wire under the skin, to the stentrode in the brain.

This combo – a sensor in the brain and a coin-sized transmitter in the chest – is Synchon’s special sauce. It is potentially non-invasive enough that many people are willing to have it implanted. “It has the potential to be an outpatient procedure,” Mocco said.

And even if people still balk at a chest implant, at least they won’t balk as badly as they would attaching a bone drill aimed at their skull. Synchron’s thoracic stentrode-transmitter combo “may be a good middle ground,” Marvin Andujar, director of the University of South Florida’s Neuro-Machine Interaction Laboratory, told The Daily Beast.

Synchron’s technology appeals to some experts in the field, even those who are skeptical of implanted devices. Crawford thinks attitudes will change as stentrodes replace riskier cranial transmitters. “As long as safety is considered first, marketability and effectiveness will eventually improve over time,” he said.

No one is claiming that there is not much more work to be done. The Synchon device might be safe, if a year-long trial with just four people is any indication. But safe is not the same as useful.

This first stentrode from Synchron allows only very limited interaction with the devices. A BCI implanted in the skull can accurately transmit only 90 characters of text per minute. The equivalent of typing a single sentence in 60 seconds. It’s not fast. The Synchron device with its chest transmitter is even slower. The best result in recent trials was 20 characters per minute. One sentence every four minutes or so.

BCIs need to become faster and less invasive. Ultimately, a brain modem should be “trendy, not weird” and also “robust and safe at the same time,” Andujar said. The perfect version is completely non-invasive: a cap that you wear on your head. Sensors in the liner read your thoughts. Transmitters on the same heading are linked to your devices. Your thoughts flow across your screens at the rate you think them.

But this ideal brain modem is just a dream for now. Today’s technology still requires a way to pass small bursts of data through or around our bones. Synchron is the leader in stentrode brain modems and has only just begun testing its device. “Additional leads over longer time periods will be needed to continue progress,” Crawford said.

Yet even a small-scale safety trial of a compromised device with lackluster efficacy results is a big step for a technology that could, with time and refinement, so much improve the lives of so many.

Next up for Synchron is a larger trial, which Mocco says will focus on “maximizing efficiency.” That is, to make more devices work better when all the user can do is think about it. To start, they must be able to produce more than a few words per minute. After all, our thoughts go much faster than that.