Teamwork Makes Tiny Implantable Brain-connected Interface Sensors a Reality
Brain IC implants might sound fictional, but with joint research from top universities and Qualcomm, a new brain-computer interface called "neurograins" has been born.
Once thought of as pure science fiction, brain-computer interfaces (BCIs) are a new and growing technological field. No longer based in fiction, BCIs are gaining interest from academics and companies alike. Still, the technology is in its infancy and needs a lot of improvements and growth.
A high-level design of a type of BCI. Image used courtesy of REKNEW
This week, joint research from Brown University, Baylor University, the University of California at San Diego, and Qualcomm is hoping to push towards those improvements and growth. In their paper, they propose a new and improved form of BCI, which this article will aim to cover.
Before diving into the new BCI, let's first look at the current state of BCIs.
The Current State of BCIs
BCIs are best defined as computer-based systems that acquire brain signals produced by the central nervous system, analyze them, and translate them into commands to measure and use. Sounding a bit like science-fiction, many BCIs work via an IC being physically implanted into a subject's brain.
Currently, the way BCIs are implemented in industry and academia is usually via arrays of monolithic electrode sensors.
Example of an intracortical microelectrode array. Image from Shih et al
The researchers liken this approach to a bed of needles, where one structure consists of hundreds of individual probes which read hundreds of firing neurons in a confined area. The problem with this approach is that it isn't particularly scalable and can limit the flexibility of electrode placement, especially when trying to cover wide, spaced-out areas of the brain.
Now that the basics of BCIs are slightly more clear, let's go over the recent joint venture in creating a new BCI.
The "Neurograin" Proposal
In a joint paper published in Nature, the researchers from Brown University, Baylor University, the University of California at San Diego, and Qualcomm introduce a new technology that is as small as a grain of salt; hence they are dubbed "neurograins."
The newest BCI called neurograins. Image from Jihun Lee and Brown University
The idea behind neurograins is that, instead of using one monolithic sensor array to measure neuron activity, they use an array of tiny, wirelessly connected sensors that could be distributed across the brain.
When it comes to the hardware aspect of this research, this proposal required developing tiny, complex electronics capable of detecting, amplifying, and wirelessly transmitting neural signals.
For neurograins to achieve those goals, they needed a central hub to communicate with. To create that central hub, the researchers developed a thin patch, about the size of a thumbprint, that gets placed outside the body on the user's scalp. Then, working as a miniature cellular phone tower, the hub utilizes a wireless protocol to coordinate the signals from the neurograins, as well as wirelessly supplying power to them.
In theory, this seems like an interesting concept and approach to BICs; it's essential to look at the final results.
Big Challenges = Big Results
Despite this research facing multiple challenges in electromagnetics, RF, circuit design, fabrication, and neuroscience, the research proved ultimately successful.
In their experiment, the researchers were able to implement 48 neurograins onto a rat's cortical surface. As proof of concept, the system successfully stimulated the rat's brain and recorded characteristic neural signals from it, all while individually addressing each neurograin wirelessly.
By using theoretical calculations and experimental measurements, the results show that the system could have the potential to scale to 770 neurograins in the future.
Moving Beyond Sci-fi
Even though this experiment on a high level sounds very much like something from science-fiction, it aimed to show that their system could record neural signals from a living brain, and for all intents and purposes, it was a success.
Moving forward, the researchers hope to develop a system at full scale which could provide new insights into the brain, and ultimately new therapies that can help people affected by injuries, including paralysis. By threading together different disciplines, like electrical engineering and biology, it is fascinating what new and groundbreaking technologies can be developed with the same goals in mind. It will be interesting to see what happens next with this research.
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