Light Through Your Fingertip
Two colors of light shine through your fingertip. What comes out the other side tells the story.
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How a Pulse Oximeter Reads Your Blood Oxygen
A pulse oximeter shines red and infrared light through your fingertip. Hemoglobin with and without oxygen absorbs these colors differently. By looking only at the part of the signal that pulses with each heartbeat, the device isolates arterial blood and estimates the percentage of hemoglobin carrying oxygen. The result is an estimate, not a diagnosis.
Transcript
Clip it on, and in seconds it knows your oxygen. How? Let's cut it open. One side holds two tiny lights: red and infrared. They shine through your fingertip. Blood full of oxygen soaks up infrared and lets red through. A sensor underneath counts what's left. With every heartbeat, it compares red to infrared. That ratio becomes your oxygen number.
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