Reading A Pulse Oximeter

A pulse oximeter functions by emitting a beam of infrared light through the capillaries towards a sensor on the other side. Before the blood is oxygenated at the lungs, it is a bit darker red in color. The oximeter measures the intensity of both shades of the oxygenated and deoxygenated blood, rates the heart beat, and then subtracts the amount of the darker oxygenated blood through some mathematical equations. The difference is the percentage of the saturation of oxygen in the blood. The results of the reading, along with the heartbeat rate, appear on the display monitor attached to the device.