This monitors the babys blood oxygen level. A tiny infrared light is attached to the babys foot, or hand that is able to detect the amount of oxygen traveling in the blood. Normal values are from 92% to 100%. 
A small device that uses a light sensor to help monitor oxygen saturation in the blood.
a device that measures the amount of oxygen in the blood. Normal oxygen saturation in the arteries is 95 to 100 percent.