By creating a miniscule device that translates brain activity into radiowaves, University of Wisconsin-Madison neuroengineers have taken a key step toward enabling injectable sensors for wireless, localized recording in the brain.
The work, detailed in the May 2023 issue of the journal Sensors and Actuators B: Chemical, is essentially a proof-of-concept for using minimally invasive sensors that wirelessly harvest power and transmit data to external imaging hardware operating on radio frequency, such as magnetic resonance imaging (MRI) scanners.
“Right now, in order to get brain recordings of any description, you’ve got to have either a wired probe or a wireless probe with bulky hardware on top of your head,” says Suyash Bhatt, a PhD student in biomedical engineering and co-first author on the paper along with undergraduate Emily Masterson. “In our case, you can actually inject this into the brain, look at what’s going on in MRI. The MRI provides the power, and you don’t even need anything else in terms of circuitry. So that’s a pretty big step forward.”
While the sensor is broadly applicable, it would be particularly useful for diagnosing and monitoring neurological conditions, including epilepsy, Parkinson’s disease and traumatic brain injury.
The research is part of Biotechnology Training Program (BTP) mentor and biomedical engineering assistant professor Aviad Hai’s quest to create dramatically less invasive technologies that yield more detailed, granular and comprehensive data from across the brain.
The Hai lab is creating milliscale sensors that consist of an inductor and capacitor—which form a resonator, essentially acting as an antenna that can absorb electromagnetic energy from an outside transmitter—along with an ion-sensitive field effect transistor. That transistor, powered by the resonator, detects the rapid flow of ions in the brain, which corresponds to neural activity.
Original article written by Tom Ziemer.