MediWave-2: measuring of pulse wave velocity

With the help of the pulse wave velocity direct statements about the vessel elasticity can be made. A simultaneous blood pressure measuring can lead to first hints about the reason of a blood pressure disease.

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Pulse wave velocity

Pulse wave velocity (PWV) means the velocity of pulse pressure waves in arterias. It is different from the blood flow velocity and because of the direct impulse transfer between blood particles much higher than this. The average flow velocity in human blood circulation is c. 0.7 m/s, but the pulse wave velocity is c. 7.5 m/s. It is a function of elasticity and pressure in the arterias. The PWV is increasing the higher the pressure and the stiffer and thicker the vessel walls are. By healthy people it varies between 4-6 m/s in the aorta and 8-12 m/s in the less elastic muscular arm arteria (Arteria radialis). In high age, by vessel diseases and under abnormal pressure conditions (like on high mountains) the values of PWV can be very different.

Measuring of pulse wave velocity

The measuring principle bases on a mechanical scan of the human tissue motions which are proportional to the pulse pressure fluctuations in the arterias. Two piezoelectric sensors are positioned above the examined part of an arteria and are registrating the relative pressure curves. The time a pulse wave needs to pass both sensors in addition with the sensor distance, makes it possible for the digital evaluation unit to compute the PWV. Fig. 1 shows the principle of pulse wave velocity measuring at the forearm.



Fig. 1: Scheme of measuring the pulse wave velocity at the forearm

(c) Mirow - 2003 | disclaimer