University of Arizona

How do Pulse Oximeters work? Pulse . oximeters. measure the absorption of red and infrared light by pulsatile blood. They are inexpensive, continuous and portable. Accuracy declines below a . SpO. 2. of 90%. Oxygenated blood absorbs light at 660nm (red light), whereas deoxygenated blood absorbs light preferentially at 940nm (infra-red). ................
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