Known as GlucoSense, the system was developed by Prof. Gin Jose and his team at the University of Leeds.
To use it, patients simply place the pad of their finger against a small glass window on the device. A low-powered laser beam is then projected through that window, and into their finger. Some of that light is absorbed by glucose in the bloodstream, and some is reflected back down onto the window.
Ions on the window glass surface subsequently fluorescence in infrared when exposed to that reflected light – the more light that hits them, the longer they glow. By measuring the duration of that fluorescence, a processor in the device is able to determine how much of the original laser light was absorbed by glucose, and can thus deduce the amount of glucose in the bloodstream. The whole process takes less than 30 seconds.