Definition: Pulse oximetry is a non-invasive diagnostic test used for detecting the percentage of hemoglobin (Hb) that is saturated with oxygen.
A pulse oximeter is the device used for performing the test. It has a probe, which is attached to the patient's finger or ear lobe, that is connected to a computerized unit. The unit displays the percentage of Hb saturated with oxygen. In some pulse oximeter models, the heart rate and blood flow can also be monitored. The oximeter can detect hypoxia before a patient becomes cyanotic.
How Pulse Oximetry is Performed
What the Pulse Oximetry Test Results Mean
Source: World Federation of Societies of Anaesthesiologists