Why can't blood oxygen be measured proactively on the Galaxy Ring like heart rate?

[Lidya]

Why can't blood oxygen be measured proactively like heart rate? It's a good idea to add an eligibility option in the next update.

[LongHiker]

@Lidya I'm thinking because you have to stationary to get a good blood oxygen level. That is why it is done while you are sleeping. If it attempts to do it at random times, most will fail and just uselessly use battery. 

Click the Measure button in Samsung Health and you will see the instructions.