APA Dictionary of Psychology

n. a method of measuring, with an oximeter, the amount of oxygen in blood. It is used in the assessment of numerous medical conditions, particularly those affecting cardiac and pulmonary function. The most common type of oximetry, pulse oximetry, involves clipping a noninvasive oximeter onto a thin part of the body—such as a finger, an earlobe, a skin fold, or, in the case of infants, a foot—and using light to measure the saturation of oxygen in the blood. In intercardiac oximetry, a catheter is inserted into the heart to monitor blood oxygen level, blood pressure, and the flow of blood in different vessels of the heart.