Purpose: Automatic non-invasive measurement of the force exerted by circulating blood on the walls of arteries. Adequate blood pressure is essential to maintain the blood supply and function of vital organs. Measurement of blood pressure is therefore a key part of the monitoring of patients during anaesthesia and critical care.
How Works: A single cuff is applied to the patients leg, and the machine inflates it to a level assumed to be greater than systolic pressure (i.e. peak arterial pressure when the ventricles contract). The cuff is deflated gradually. A sensor then measures the tiny oscillations in the pressure of the cuff caused by the pulse.; Systolic is taken to be when the pulsations start, mean pressure (i.e. average arterial pressure throughout cardiac cycle) is when they are maximal, and diastolic (i.e. lowest arterial pressure during resting phase) is when they disappear.