Which instrument is used to measure blood pressure?

The sphygmomanometer is specifically designed to measure blood pressure. It consists of an inflatable cuff that is placed around the arm and a mechanism to read the internal pressure of the cuff, which corresponds to the blood pressure in the arteries. When blood pressure is measured, the cuff inflates to restrict blood flow, and as it deflates, it allows for the measurement of two key pressures: systolic and diastolic. The systolic pressure is the highest pressure in the arteries during heartbeats, while the diastolic pressure is the lowest pressure when the heart is at rest between beats.

Other instruments listed serve different purposes. A stethoscope is used to listen to internal body sounds, such as the heartbeat or breath sounds, and is often used in conjunction with the sphygmomanometer when measuring blood pressure but does not measure it itself. An oximeter measures oxygen saturation levels in the blood, specifically determining how much oxygen is being carried by the hemoglobin in red blood cells, and it does not provide information regarding blood pressure. A thermometer measures body temperature and is used to assess fever but is unrelated to blood pressure measurement. Therefore, the sphygmomanometer is the correct instrument for measuring blood pressure.