from the open-your-shirt-and-say-aaaaah dept.
An anonymous reader writes "Researchers at Northeastern University have modified an iPhone to take readings from a special fluorescing nanoparticle tattoo ink, which can then measure sodium and glucose levels in the blood."
I've never been canoeing before, but I imagine there must be just a few
simple heuristics you have to remember...
Yes, don't fall out, and don't hit rocks.