Sweat sensors analyse state of health24 Mar 2016 | Amy Norcross
Share this page with your friends
Engineers at the University of California, Berkeley, have developed a device that is able to measure sodium, potassium, glucose, and lactate levels in sweat to help analyse the state of a person's health and well-being.
The new device is able to calibrate the data based on skin temperature and transmit the information wirelessly in real time to a smartphone. The results of a new study of the wearable technology have been published in the journal Nature.
"Human sweat contains physiologically rich information, thus making it an attractive body fluid for non-invasive wearable sensors," said Ali Javey, a UC Berkeley professor of electrical engineering and computer sciences, and senior author of the study. "However, sweat is complex and it is necessary to measure multiple targets to extract meaningful information about your state of health. In this regard, we have developed a fully integrated system that simultaneously and selectively measures multiple sweat analytes."
Javey and his research team developed a prototype that comprises a flexible printed circuit board holding five sensors. The device was attached to "smart" wristbands and headbands and used on 26 volunteers who performed various exercises of differing levels of intensity, and for varying lengths of time, both indoors and outdoors. The data collected was then processed and wirelessly transmitted using Bluetooth to a smartphone.
Only a tiny amount of sweat–one-fifth of a drop–is required to obtain the data, which can provide insight on, for example, an individual's hydration or blood sugar level, muscle fatigue, and potential for overheating.
The researchers are not alone in their quest to squeeze every drop of data possible out of human perspiration. A "sweat test," which measures the amount of chloride in an individual's sweat, is considered the "gold standard" for diagnosing cystic fibrosis, a genetic disease that causes chronic lung infections and respiratory issues. In addition, a team at the University of Cincinnati's Novel Devices Lab, working with scientists from the U.S. Air Force Research Laboratory, has developed a patch that stimulates skin and gathers data from sweat. The research began five years ago with the intent to find a convenient way to monitor an airman's response to disease, medication, diet, injury, stress, and other physical changes during military training and missions.
Javey concedes that sweat sensors will never be as accurate as blood tests. "Our bodies closely control the molecular composition of our blood, but the content of our sweat is more variable and is sometimes influenced by microbes on our skin—so the medical relevance of the information that sweat provides will need to be rigorously tested," he explained. "However, sweat does have an advantage: taking blood samples with a needle is not a practical means of assessing health on a minute-by-minute basis."
The researchers hope to one day develop medical applications for the technology. Javey points to research suggesting that certain biomarkers in sweat may correlate with symptoms in people with depression. "By looking at those other chemicals we may be able to get information about the mental health of an individual," he says. According to Live Science, another potential use for the technology is to measure additional molecules: "Such molecules could include heavy metals such as lead, which recently made news for appearing in dangerously high levels in the water of Flint, Michigan."
Want to more of this to be delivered to you for FREE?
Subscribe to EDN Asia alerts and receive the latest design ideas and product news in your inbox.
Got to make sure you're not a robot. Please enter the code displayed on the right.Please enter the valid code. Sorry, you have reached the maximum number of requests allowed. You may wish to try again after a few hours.
Time to activate your subscription - it's easy!
We have sent an activate request to your registerd e-email. Simply click on the link to activate your subscription.
We're doing this to protect your privacy and ensure you successfully receive your e-mail alerts.