But then youre still dealing with measuring it penetrating the skin and all the variables that have to with it - sensor position, changes in temperature and blo

But then youre still dealing with measuring it penetrating the skin and all the variables that have to with it - sensor position, changes in temperature and blood flow, etc. We do it with pulse ox pretty well, but +\- 2-3% O2 sat and repositioning isnt a big deal. Having the watch move and misreadibg blood sugar can have serious consequences.