It's a significant development because glucose tracking traditionally relies on invasive measures, such as pricking a finger to draw blood or sensors under the skin, which then require additional kit to provide a reading. There are some devices that can monitor glucose non-invasively through sweat, but a recurring problem for these has been too much sweat rendering the kit unusable. Preventing hypoglycaemia during exercise, then, has been a big challenge, but the new patch could represent an effective and inexpensive means of overall diabetes management which, according to the researchers, "holds considerable promise."