Pulse oximetry
![A wrist mounted remote sensor pulse oximeter with plethysmogram.](/Images/godic/202502/05/Wrist-oximeter5718.jpg")
![Absorption spectra of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb) for red and infrared wavelengths](/Images/godic/202502/05/Oxy_and_Deoxy_Hemoglobin_Near-Infrared_absorption_spectra5718.png")
![A pulse oximeter probe applied to a person's finger](/Images/godic/202502/05/Saturometre_25718.jpg")
Pulse oximetry is a noninvasive method for monitoring a person's oxygen saturation (SO2). Its reading of SpO2 (peripheral oxygen saturation) is not always identical to the reading of SaO2 (arterial oxygen saturation) from arterial blood gas analysis, but the two are reliably enough correlated that the safe, convenient, noninvasive, inexpensive pulse oximetry method is valuable for measuring oxygen saturation in clinical use.