This Stamp-Size Silicone Patch Provides Continuous 3D Monitoring of Brain Blood Flow in Comfort

Researchers from the University of California San Diego, working with the Seattle Neuroscience Institute, have demonstrated a tiny wearable patch that allows for comfortable and non-invasive monitoring of blood flow in the brain — through ultrasound imaging.

"The continuous monitoring capability of the patch addresses a critical gap in current clinical practices," claims co-first author Sai Zhou of the team's work. "Typically, cerebral blood flow is monitored at specific times each day, and those measurements do not necessarily reflect what may happen during the rest of the day. There can be undetected fluctuations between measurements. If a patient is about to experience an onset of stroke in the middle of the night, this device could offer information that is crucial for timely intervention."

The stamp-sized patch is made from soft, flexible silicone with stretchable electronics layered within — including piezoelectric transducers, which when connected to a power source produce ultrasonic waves that are reflected from within the brain to provide an image of what's going on beyond the skull. A layer of copper mesh springs reduces interference, boosting the quality of the captured data — allowing the sensor as a whole to develop a 3D image of arteries and blood flow in the brain at a rate of thousands of images per second.

"The cerebral vasculature is a complex structure with multiple branching vessels," explains co-first author Xinyi Yang of the need for high-speed data capture from the device, and the algorithms which process the data into a three-dimensional picture of the brain's health. "You need a device capable of capturing this three-dimensional information to get the whole picture and obtain more accurate measurement."

The team claims that the patch removes the need to have a trained ultrasound technician present during readings, removes human error from the equation, and could be used to provide continuous monitoring of patients as they recover from brain surgery during their whole hospital stay.

The team's work has been published in the journal Natureunder closed-access terms; project lead Shen Xu, a professor at the UC San Diego Jacobs School of Engineering, has founded a startup to commercialize the patch.

Main article image courtesy of David Baillot/UC San Diego Jacobs School of Engineering.