I'm actually part of a research team working on using a wrist mounted spectrometer to actually measure glucose continuously and non-invasively. Turns out it's a really really hard problem.
If you crack it is there anything preventing using the same tech to get a whole host of measurements like vitamin levels or other blood components? I'm imagining you are going down the same path as oxygen saturation meters except it's way easier measuring elemental content than complex molecules. What's the hardest problem, if I may ask?
All I keep hearing is that Apple is pouring a fortune into cracking this problem. They've certainly been snapping up every prominent person in the industry in the last decade.
