The pulse oximeter is an assessment tool used to evaluate the:

Pulse oximeter is an assessment tool used to evaluate the effectiveness of oxygenation. The assessment process is called the pulse oximetry. It involves indirectly monitoring oxygen saturation in the blood of a patient and changes in the blood volume in the skin. Its aim is to determine how well oxygen is being sent to the parts of the body furthest from the heart such as the legs and the arms.