June 28, 2023 – A smartwatch can tell you a lot about your health, but for guarding against big threats like diabetes and heart disease, blood tests remain the gold standard – for now.
If you’ve ever seen or used a continuous glucose monitor, then you’ve already glimpsed this future. These skin patches, typically worn on the back of the upper arm, use interstitial fluid to track blood sugar levels in real time.“The vision is eventually to develop a lab under the skin,” said Joseph Wang, PhD, a professor of nanoengineering at the University of California San Diego.
The microneedles or wires are made from a polymer that sucks up the fluid, which flows to a biochemical sensor targeting the marker you want to measure. “There's a lot you can do over telemedicine, over the phone,” said Justin T. Baca, MD, PhD, an associate professor at the University of New Mexico. “But we still haven’t figured out how to collect reliable biosamples and analyze them remotely.”
Scientists in the U.K. and Norway developed a waist-worn device that collects interstitial fluid samples continuously for up to 3 days. In their study, samples were sent out for analysis, but someday the device could be equipped with a sensor to monitor a single hormone in real time, said study author Thomas Upton, PhD, a clinical research fellow at the University of Bristol in England. “There is a lot of interest in real-time cortisol monitoring,” he said.