Patients with long-term conditions, such as diabetes, could one day benefit from new types of sensor technology that are being developed by UK researchers.
A wearable sensor that monitors the chemical composition of sweat could help patients with long-term conditions avoid the discomfort of regular pin-prick blood tests, according to the researchers who hope the technology will be ready to market in the next couple of years.
“Human sweat contains much of the same physiological information that blood does”
Scientists at University of Glasgow’s school of engineering have built a stretchable, wireless system that they say is capable of measuring the pH level of users’ sweat.
Writing in the journal Biosensors and Bioelectronics, they noted that sweat, like blood, contained chemicals generated in the human body, including glucose and urea.
They suggest that monitoring their levels in sweat could help clinicians diagnose and monitor conditions like diabetes, kidney disease and some types of cancers without invasive tests that require blood to be drawn.
However, the researchers highlighted that non-invasive, wearable systems require consistent contact with skin to offer the highest-quality monitoring.
They also noted that current systems were made from rigid materials, making it more difficult to ensure consistent contact, and other potential solutions such as adhesives can irritate skin.
“Ultimately we’d like to see a system ready for market in the next few years”
In addition, wireless systems that use Bluetooth to transmit their information were often bulky and power-hungry, requiring frequent recharging, they said.
The Glasgow University team’s new system is built around an inexpensively-produced sensor, which can stretch and flex to better fit the contours of users’ bodies.
Made from a graphite-polyurethane composite and measuring around a single square centimetre, it can stretch up to 53% in length without compromising performance, they said.
It will also continue to work after being subjected to flexes of 30% up to 500 times, which they said would allow it to be used comfortably on skin with minimal impact on the sensor’s performance.
The sensor can transmit its data wirelessly, and without external power, to an accompanying smartphone application, called SenseAble, which has also been developed by the same team.
Stretchable sensor could improve chronic condition monitoring
The app allows users to track pH levels in real time and was demonstrated in the lab using a chemical solution created by the researchers, which mimics the composition of human sweat.
Lead researcher Professor Ravinder Dahiya said: “Human sweat contains much of the same physiological information that blood does, and its use in diagnostic systems has the significant advantage of not needing to break the skin in order to administer tests.
“Now that we’ve demonstrated that our stretchable system can be used to monitor pH levels, we’ve already begun additional research to expand the capabilities of the sensor and make it a more complete diagnostic system,” he said.
He added: “We’re planning to add sensors capable of measuring glucose, ammonia and urea, for example, and ultimately we’d like to see a system ready for market in the next few years.”
The research was supported by funding from the European Commission and the Engineering and Physical Sciences Research Council.