Low-cost wearable device to monitor diabetes through sweat

Scientists, including one of Indian origin, have developed a new wearable device that can help manage diabetes by monitoring the patient's sweat, an advance that may spell the end for painful needle jabs.

The wearable diagnostic biosensor can detect three interconnected compounds - cortisol, glucose and interleukin-6 - in sweat for up to a week without loss of signal integrity. "Type 2 diabetes affects so many people. If you have to manage and regulate this chronic problem, these markers are the levers that will help you do that," said Shalini Prasad, professor at The University of Texas at Dallas in the US.

"We believe we've created the first diagnostic wearable that can monitor these compounds for up to a week, which goes beyond the type of single use monitors that are on the market today," said Prasad.

"If a person has chronic stress, their cortisol levels increase, and their resulting insulin resistance will gradually drive their glucose levels out of the normal range," said Prasad. "At that point, one could become pre-diabetic, which can progress to type 2 diabetes, and so on. If that happens, your body is under a state of inflammation, and this inflammatory marker, interleukin-6, will indicate that your organs are starting to be affected," she said.

The team showed that the biomarker measurements are reliable even with a tiny amount of sweat - just one to three microlitres, much less than the 25 to 50 previously believed necessary.

"We wanted to make a product more useful than something disposable after a single use," Prasad said. "It also has to require only your ambient sweat, not a huge amount," she said.

"And it's not enough to detect just one thing. Measuring multiple molecules in a combinatorial manner and tracking them over time allows us to tell a story about your health," she added. Prasad envisions that the wearable devices will contain a small transceiver to send data to an application installed on a cellphone.  "With the app we're creating, you'll simply push a button to request information from the device," Prasad said.

"If you measure levels every hour on the hour for a full week, that provides 168 hours' worth of data on your health as it changes," she said. Prasad has emphasised "frugal innovation" throughout the development process, making sure the end product is accessible for as many people as possible. "We made sure we used processes that will allow for mass production without adding cost," Prasad said.

"Our cost of manufacturing will be comparable to what it currently takes to make single-use glucose test strips - as little as 10 to 15 cents," she said. The study was published in the journal Scientific Reports.