Pulse oximetry may be useful in both inpatient and outpatient settings. In some cases, your doctor may recommend that you have a pulse oximeter for home use.
To take a reading with a pulse oximeter, you will:
Remove any jewelry or fingernail polish on your finger if measuring from this location.
Make sure your hand is warm, relaxed, and below heart level if attaching the device here.
Place the device on your finger, earlobe, or toe.
Keep the device on for as long as needed to monitor your pulse and oxygen saturation.
Remove the device once the test is over.
In pulse oximetry, small beams of light pass through the blood in your finger, measuring the amount of oxygen. According to the British Lung Foundation, pulse oximeters do this by measuring changes in light absorption in oxygenated or deoxygenated blood. This is a painless process.
The pulse oximeter will be able to tell you your oxygen saturation levels along with your heart rate.