Brain researchers have relied on devices called microelectrode arrays for decades, but the technology behind these tools is becoming increasingly outdated. Precision Neuroscience is building a modern alternative that is not only an order of magnitude better, but also much less invasive to implement. newly raised $41 million at the bank, they are all set to begin the complex path to the market.
To understand what’s happening in the brain, sometimes an EEG or MRI from the outside isn’t enough – you really have to go inside. Implanted electrodes have long been used for this purpose, and arrays of them in formation are used to simultaneously collect information from multiple points in the cortex.
But while an electrode array of a few dozen is greatly invaluable in a research environment, it simply isn’t enough for something like a functional brain-computer interface. The information density is too low for the patient to, for example, control a prosthetic limb or move a cursor on the screen. And you can’t just add more electrodes: Because each electrode pierces the brain tissue and necessarily causes a small amount of damage, going from an array with 100 to one with 1000 causes 10 times the damage.
Precision Neuroscience aims to solve both problems with one major innovation: an ultra-thin electrode array that doesn’t need to pierce the brain at all, yet can collect hundreds of times more data than traditional arrays.
It is, so to speak, the brainchild of Dr. Ben Rapoport, a neurosurgeon by trade who spent decades working on the idea and co-founded the company in 2021. (He was previously a member of Neuralink’s founding team.)
“This has been his life’s work,” said Precision CEO Michael Mager. “His view has always been that you need high electrode density even for basic functionality, and that the technology should be minimally invasive, without damage to the brain. Our hope is to scale up to tens of thousands of electrodes – and you can’t just keep penetrating more and more tissue.”
The array they developed is called Layer 7, a reference to the fact that the cortex itself has six layers, with the interface sitting on top. A single Layer 7 array is slightly larger than a thumbnail, but it contains 1024 microelectrodes, producing a density hundreds of times better than what is commonly used today. And they’re designed to be used in arrays themselves, essentially like tiles over part of the brain. Each array would provide a fast, accurate picture of the activity of the cortical areas it covers.
These capabilities and specifications are impressive, but perhaps more importantly, the interface can be implanted without a craniotomy – open brain surgery. Instead, the super-thin film-based Layer 7 can be inserted through a small incision in the skull – still brain surgery for sure, but a much less invasive technique that may not even require general anesthesia. It would be attached to an external control unit, but the dimensions and specifications of that device would vary depending on several factors.
Two cool employees of Precision Neuroscience. You can see the implant on the microscope slide. Image Credits: Precision Neuroscience
Avoiding the risk and complications of major surgery is important because the populations that benefit most from a technology like this are people with pre-existing neural problems.
“In the US alone, there are tens of millions of people suffering from stroke, TBI [traumatic brain injury]degenerative diseases … but for those patients, there are really no medical solutions that we can offer at this point outside of physical therapy,” Mager said.
“There are two broad use cases,” explains chief product officer Craig Mermel. Stimulation of the brain and a two-way interface is one of them, he said, but still very experimental. “What we’re doing that’s supported by research is more on the ‘record and decode’ side, using it to read information from people with epilepsy or stroke and translate the intent into motor or speech output.”
This ability has been studied for years and successfully demonstrated in other contexts, but the problem is that the implants themselves “are still research-grade,” Mermel said. “No one has put this into a clinical rating system that could potentially benefit patients. That this [i.e. Layer 7] does not damage the brain becomes an incredibly important aspect of our system. Every device has a lifespan and you will have to replace it; the fact that our interface is reversible and the brain can remain intact reduces the risk to the patient.”
By now, most readers will be wondering how this compares to Neuralink, the brain-computer interface company funded by Elon Musk. One key difference is that Neuralink’s approach still involves a craniotomy and brain-piercing electrodes – albeit finer and more sensitive than the ones currently used and implanted via robot. But Precision Neuroscience sees the company as a colleague rather than a competitor.
“Honestly, what we’re saying internally is that it’s different approaches that are optimal for different situations,” Mager said. “This is not going to be a winner-takes-all market. There is room for more than one company.”
One of the biggest challenges in building a medical device, not to mention a brain implant, is the daunting task of proving both its uses and safety before bringing it to market. And you can’t just build the gadget – it has to be distributed, supported, documented, etc.
“It’s not just the array, it’s the software: machine learning sophistication is a must to drive really powerful BCI. It is a full-stack product that requires an interdisciplinary team to develop,” says Mager. “And then you have to put it through the FDA regulatory process.
On that side, the company opts for a two-pronged approach. They focus first on short-term and emergency use, such as during a hospital stay — when understanding what’s happening in the brain can be a life-saving technique. They hope to submit their 510K application along these lines to the FDA within a year and be ready to go when the agency gives the green light. Longer term, the plan proves the safety of semi-permanent implantation: the kind where someone could use the implant every day away from home or while traveling for a year. That is a different risk profile and a stricter approval process.
Stephanie Rider from Precision examines the Layer 7 implant. Image Credits: Precision Neuroscience
Such relatively long time horizons are common in medicine, but less so in venture-backed startups. Why ask VCs when so many are interested in businesses that are faster and easier to scale, such as software and services?
“It was a big mistake, we should have started a software company. I talk to Craig about this all the time! joked Mager. “But really, despite the challenges and the times, there is a group of venture capital firms that are not insignificant, that are eager to invest in companies that want to make a huge impact on human health and also build a great company — not in two -three years, but 10 years.”
Here, Mager credited Musk for popularizing the idea that venture capital can support big long-term endeavors like SpaceX and Tesla, not just high-growth software companies that sell out in a year or two. A rocket company might not have seemed like a likely venture-backed venture 10 or 15 years ago, he said, but now no one questions it. The same can be true for neural interfaces – “and we can create a meaningful clinical asset in the meantime.”
The $41 million B round will enable Precision to continue working toward FDA approval and further develop and support the Layer 7 stack from hardware to training and customer service. The round was led by Forepont Capital Partners. Mubadala Capital, Draper Associates, Alumni Ventures, re.Mind Capital, Steadview Capital and B Capital Group.
