How the oximeter works

author: Sky Wang
How the oximeter works?

The oximeter does not need to take blood to measure blood oxygen, you can know your blood oxygen level and pulse by gently clipping your finger, and you can check your health status anytime and anywhere at home. What is the principle of oximeter? Let's understand how the oximeter works.

The role of hemoglobin is to carry oxygen to all parts of the body. We call the oxygen content of hemoglobin at any time as blood oxygen saturation.
fingertip oximeter
The finger oximeter measures this blood oxygen saturation. Hemoglobin has a state of carrying oxygen, and of course also has an empty state. We call the hemoglobin carrying oxygen as oxyhemoglobin, and the hemoglobin in the empty state is called reduced hemoglobin.

Oxyhemoglobin and reduced hemoglobin have different absorption properties in the visible and near-infrared spectral ranges. Reduced hemoglobin absorbs more red frequency light and less infrared frequency light; while oxyhemoglobin absorbs less red frequency light and more infrared frequency light. This distinction is the most basic basis for finger oximeters.