A pulse oximeter is a clever tool used to measure a person’s blood oxygen saturation (SpO2) and pulse rate.
Within your body, inside each red blood cell exists around 270 million hemoglobin proteins that transport oxygen molecules from your lungs to the rest of your body. Oxygen saturation is the percentage of hemoglobin that is carrying oxygen. The typical range is 95–99% saturation.
This meter uses 2 lights, one red and one infrared, that alternate blinking through your fingertip about 30 times per second.
Saturated and desaturated blood each absorb these light frequencies at different rates. So a sensor on the opposite side of your finger measures how much of each light makes it all the way through your finger and calculates the ratio.
