What device is primarily used to measure oxygen saturation in the blood?

• A. Stethoscope
• B. Sphygmomanometer
• C. Pulse oximeter
• D. Thermometer

Answer: (C)

The pulse oximeter is the primary device used to measure oxygen saturation in the blood. This non-invasive instrument works by emitting light wavelengths that pass through the skin, typically on a fingertip or earlobe, to detect the level of oxygen in the hemoglobin of red blood cells. By measuring the absorption of light in the blood, the pulse oximeter provides a readout of the percentage of hemoglobin that is saturated with oxygen, known as SpO2. This is crucial in monitoring a patient’s respiratory function and ensuring adequate oxygen delivery throughout the body.

In contrast, a stethoscope is used to listen to heartbeats and respiratory sounds, a sphygmomanometer measures blood pressure, and a thermometer is utilized to assess body temperature. These devices serve different functions and do not provide information on blood oxygen levels, making the pulse oximeter uniquely suited for this specific measurement.