Here is another study that shows passive measurement and detection of a medical condition using a smartwatch (an Apple watch in this case), in conjunction with a neural network (AI/ machine learning):
The detection rate was an outstanding 97%. This diagnosis tool is not available commercially (yet). This comes only a few days after another study showed a way to passively measure potassium blood levels using another smartwatch sensor:
For us, of course, the holy grail would be remote sensing of blood glucose without a skin-embedded sensor. It may not be so far after all. Another 10, 15 years?
It is possible today, just currently very expensive in terms of the processing power required to make the measurement. Over the years a few companies have made a finger sensor (like an O2 sensor) that would give an accurate glucose measurement. They have been successfully made, they just aren’t priced low enough to be commercially viable. As processing power increases, this will be routine.
If you are a science-person, the reason is that the glucose absorption in the water window that our bodies give, is very small (second overtone I believe) as opposed to oxygen which is a primary absorbance in the water window.