What does a pulse oximeter measure through vascularized tissue?

A pulse oximeter measures the oxygen saturation level in the blood, which is the correct answer. This device uses light absorption principles; it emits light wavelengths that pass through vascularized tissue, such as a fingertip or earlobe, and assesses how much light is absorbed by oxygenated and deoxygenated hemoglobin in the blood.

The capability of the pulse oximeter to provide accurate readings of oxygen saturation is crucial in clinical settings, especially for monitoring patients with respiratory issues or during anesthesia. By indicating the percentage of hemoglobin saturated with oxygen, it helps healthcare providers determine how well oxygen is being transported throughout the body.

In contrast, heart rate is often measured using an electrocardiogram or other monitoring devices, and while a pulse oximeter may provide a heart rate reading derived from the pulse signal, this is not its primary function. Blood pressure is measured using sphygmomanometers or other specific blood pressure monitoring devices, as it requires different types of assessments and devices for accurate readings. Carboxyhemoglobin levels, which indicate carbon monoxide binding to hemoglobin, require specific blood tests for measurement and are not provided by standard pulse oximeters.