130 – Blood Pressure Measurement for the BSL PRO

The most common form of indirect blood pressure measurement employs a pressure cuff, pump and pressure transducer. This complete assembly is commonly referred to as a Sphygmomanometer.

Typically, the cuff is wrapped around the upper arm and is inflated to a pressure exceeding that of the brachial artery. This amount of pressure collapses the artery and stops the flow of blood to the arm. The pressure of the cuff is slowly reduced as the pressure in the cuff is monitored by the pressure transducer. As the pressure drops, it will eventually match the systolic (peak) arterial pressure. At this point, the blood is able to “squirt” through the brachial artery. This squirting results in turbulence which creates the Korotkoff sounds. The Korotkoff sounds are detected using an SS17L physiological sounds transducer. As the cuff pressure continues to drop, the pressure will eventually match the diastolic pressure of the artery. At this point the Korotkoff sounds stop completely, because the blood is now flowing unrestricted through the artery.