What instrument is used to measure the oxygen saturation of hemoglobin?

The pulse oximeter is the appropriate instrument for measuring the oxygen saturation of hemoglobin in a patient's bloodstream. This non-invasive device uses light sensors to detect changes in the volume of blood and the absorbance of light by oxygenated and deoxygenated hemoglobin. By analyzing these changes, the pulse oximeter can calculate the percentage of hemoglobin that is saturated with oxygen, providing an important indicator of a patient's respiratory and circulatory health.

In contrast, a sphygmomanometer measures blood pressure, a stethoscope is used for auscultation of heart and lung sounds, and a thermometer measures body temperature. Each of these tools serves a different purpose in assessing a patient’s health, but none can specifically evaluate oxygen saturation like a pulse oximeter can. This makes the pulse oximeter essential in contexts where monitoring oxygen levels is critical, such as in respiratory distress or during surgical procedures.