Here is a wearable device that combines with your smartphone to track your blood oxygen saturation level and heart rate as you sleep. The Wellue Checkme O2 Max has a soft silicone sensor, so you can wear it comfortably at night. It is smart enough to activate an alarm if abnormal pulse rate or low blood oxygen level is detected.
The device has built-in memory, so it can operate without its app. It lasts up to 72 hours on battery and creates shareable sleep reports. You can use the companion app to change vibration intensity and other settings.[where to get it]