Signals which are used to compute the Oxygen Saturation Percentage are generally very weak. These signals can very easily get distorted under any of the following condition.
- When wrist-band is not tight.
- When there is slight hand movement during the recording session.
- And when there is ambient light.
If you make sure that your wristband is tight, you don’t move your hand during recording and that there is no (or very minimal) ambient light falling on the wristband, your chances of getting Oxygen Saturation Percentage will increase.
One way to make sure that the ambient light is not interfering with the recording is to cover your wristband with a towel or some other piece of cloth.