What does a pulse oximeter measure?

A pulse oximeter is a non-invasive medical device that primarily measures the oxygen saturation level in the blood, which reflects how well oxygen is being transported throughout the body. It works by shining two wavelengths of light through a translucent part of the body, usually a fingertip, and detects the amount of oxygenated hemoglobin versus deoxygenated hemoglobin in the blood.

This measurement is crucial in various medical settings as it helps monitor respiratory and cardiovascular conditions, ensuring that patients receive adequate oxygenation. Monitoring oxygen saturation is especially important in critical care, during anesthetic procedures, and in managing conditions like chronic obstructive pulmonary disease (COPD) or during recovery from anesthesia.

Other choices relate to different types of measurements; blood glucose levels are monitored through different kinds of devices, heart rate variability assesses the interval fluctuations between heartbeats and is not specific to oxygen levels, while body temperature is measured with thermometers.