Explanation:

• Pulse oximetry is a test used to measure the oxygen level (oxygen saturation) of the blood.
• It is an easy, painless measure of how well oxygen is being sent to parts of your body furthest from your heart, such as the arms and legs. 
• The device is generally used to check the health of patients who have known conditions that affect blood oxygen levels, such as heart and lung conditions, and for those who show symptoms such as shortness of breath. 
• The device measures the saturation of oxygen in red blood cells, and can be attached to a person’s fingers, toes, nose, feet, ears, or forehead.
• It can be reused or disposed of after use. The device is now being recommended for the early detection of ‘Covid pneumonia’, a potentially deadly condition seen among the most severe coronavirus cases.