I have a weird question here. I'm doing research on using a smartwatch to monitor people's sleep quality. One of my goals is to monitor blood oxygen.
I know that most smartwatches today can monitor heart rate by emitting green light and inferred on the back. I also know that pulse oximeters people use to monitor blood oxygen today emit red light and inferred. My idea is to let smartwatch emits red light to detect blood oxygen.
However, I cannot find any way to change the color of LED lights. I searched Android Wear API and it looks like there is no such API.
Any help would be appreciated. Thank you!