Pulse oximetry is a technique for monitoring a person’s oxygenation. It is a simple, non-invasive method which indirectly monitors the percentage of haemoglobin that is loaded with oxygen in the blood.
Oxygen saturation should ideally be above 95%. A pulse oximeter is a device that helps detect oxygen level drop below safe levels allowing prompt mediation. The device, usually placed on fingertip, shines light with two different wavelengths (red and infrared) through the finger. Red light is absorbed by ‘oxygen poor’ blood and infrared light is absorbed by ‘oxygen rich’ blood. A sensor device or photodetector detects how much oxygen is in the blood by measuring the difference in absorbance of each of the wavelengths.
Pulse oximetry is used in people with COPD, asthma, congestive heart failure (CHF), etc. to rapidly detect changes in the blood oxygen level. It is also useful in monitoring blood oxygen levels during operations, emergency and critical care, etc. Battery-operated portable pulse oximeters can be used for home blood-oxygen monitoring.