What does a pulse oximeter measure?

A pulse oximeter is a non-invasive medical device specifically designed to measure the oxygen saturation level in a patient's blood. It works by employing a light sensor that passes through a segment of tissue—usually a fingertip or an earlobe—and measures the amount of light absorbed by oxygenated and deoxygenated hemoglobin. This information allows the device to calculate the percentage of hemoglobin in the blood that is saturated with oxygen, typically displayed as a number between 0 and 100%.

Understanding this technology is essential for medical professionals, as it provides immediate data regarding a patient's respiratory function and oxygen delivery within the body, which is critical in many clinical scenarios. Monitoring oxygen levels helps in assessing whether a patient is getting enough oxygen, which is vital for proper organ function and overall health. This functionality sets the pulse oximeter apart from other devices that measure heart rate, lung volume, or respiratory rate, as it directly targets the oxygenation of the blood.