The next frontier of continuous health monitoring could be skin deep.
Biomedical engineers at the University of Cincinnati say interstitial fluid, the watery fluid found between and around cells, tissues or organs in the body, could provide an excellent medium for early disease diagnosis or long-term health monitoring.
In a paper published in the journal Nature Biomedical Engineering, they outlined the potential advantages and technological challenges of using interstitial fluid.
"Why we see it as a valuable diagnostic fluid is continuous access. With blood, you can't easily take continuous readings," said UC doctoral graduate Mark Friedel, co-lead author of the study.
"Can you imagine going about your day with a needle stuck in your vein all day? So we need other tools."
In UC College of Engineering and Applied Science professor Jason Heikenfeld's Novel Devices Lab, students are developing sensors to measure hormones and other chemicals in interstitial fluid. They use microneedles less than 1 millimeter in length that pierce the skin through a tiny patch.
"If you had a splinter, it probably went deeper into your skin than our microneedles," Friedel said. "They're generally painless. I don't feel it most of the time. The most uncomfortable part is removing the tape that holds the device down."
