Pulse oximetry is a noninvasive, painless test that measures your oxygen saturation or the level of oxygen in your blood. It can quickly detect how efficiently oxygen is delivered to the extremities farthest from the heart, including the legs and arms.
A pulse oximeter is a small, clamp-like device that can be attached to a body part, such as a toe or earlobe. It is usually used on the fingers and is often used in intensive care units such as emergency rooms or hospitals.Some doctors, such as pulmonologists, may use it in the office.