Which device is used to measure a patient's blood pressure?

The sphygmomanometer is the device specifically designed to measure blood pressure. It typically consists of an inflatable cuff that is wrapped around the patient's arm, a measuring unit (which may be analog or digital), and sometimes a stethoscope to listen to the arterial sounds. The device measures the pressure exerted by the blood against the walls of the arteries as it is pumped by the heart.

When using a sphygmomanometer, the cuff is inflated to restrict blood flow, and then it is slowly deflated. As the pressure in the cuff falls, the practitioner listens for specific sounds (Korotkoff sounds) that indicate the systolic and diastolic blood pressure readings. These measurements are critical in assessing a patient's cardiovascular health.

Other devices listed serve different purposes: a stethoscope is used for auscultation, allowing healthcare professionals to hear heartbeats and other internal sounds; a thermometer measures body temperature; and a pulse oximeter provides readings of blood oxygen saturation. Each tool has its unique function in patient assessment, but when it comes to measuring blood pressure, the sphygmomanometer is the appropriate choice.