In biometric terms, sweat may soon be the new black. Blood testing remains the current gold standard for biometric measurement, but it is invasive, at times awkward or difficult, and sometimes painful. The greatest downside from a single blood draw, however, is the measurement becomes a single point on a chart with no information on duration, consistency, cycles, or other changes over time. Compared to taking a blood sample, gathering sweat is uncomplicated and painless, and it can be carried on over time. We’ve written about sweat measurement to identify diseases, speed healing, monitor pH, track cortisol, and much, much more.
Led by professor Jason Heikenfeld, Engineers and students at the University of Cincinnati’s College of Engineering and Applied Science’s Novel Device Lab developed what the team claims is the world’s first continuous-testing sweat sample device. In an article published in Nature Biotechnology, Heikenfeld states the sweat tester is as effective as testing blood but does so noninvasively for many hours. The UC team investigated tears, saliva, and interstitial fluid as alternative sources for sampling, but stuck with sweat because it can be controlled and measured and produces information similar to blood.
The UC sensor stimulates sweat for up to 24 hours, says Heikenfeld. Placed on a patch the size of a Band-Aid, the device measures specific compounds including drugs and hormones, as well as evaluations hydration levels. In testing for metabolized ethanol, for example, Heikenfeld’s group determined that measuring sweat had the same result as measuring blood.
The UC studies focus primarily on using sweat measurement to monitor medication dosage. The desired end result would be personalized data that tracks how an individual metabolizes a specific drug. Co-author Tongli Shang from the UC School of Medicine points to the challenges of dosing when the amount that works for one patient may not be enough for another patient, and could even be deadly to others.
