Researchers at the University of Tokyo have developed what they call "Life Beans". These are fluorescent beads that are implanted inside the human body. They glow with varying intensity subject to the glucose level of the patient:
Researchers tested it in the ears of a mouse, and watched as the ear fluoresced at different intensities depending on the mouse's blood sugar.
The researchers think it would be possible to develop devices that manage diabetics' blood sugar without them noticing it.
One difficulty with the current design is that the patient's immune system attacks the beads and dims the lights.
http://www.popsci.com/science/article/2010-08/life-beans-could-be-made-implantable-glucose-monitor | Video | Image: DigInfo
Previously:
Contact Lenses That Change Color to Alert Diabetics of Glucose Levels
Diabetes-Monitoring Nanoparticle Tattoos