Simple Analysis of the Pulse Wave for Blood Vessel Evaluation

A pulse wave is considered to be a good indicator to evaluate the viscoelastic properties of blood vessels. The wave is composed of an incident wave and a reflected wave. The evaluation of blood vessels may be possible from the analysis of this reflected wave, because the reflected wave propagates to the peripheral artery. We propose a simple method of estimating the reflected wave from the pulse wave observed at common carotid artery, making use of a commercial piezoelectric transducer. First, we estimate the incident wave from the observed blood flow velocity. Then, the reflected wave is estimated by subtracting the incident wave from the observed pulse wave. The amplitudes of the reflected wave obtained in senior subjects were larger than those of junior subjects. This result is in good agreement with the common point of view about the vessel wall, that the attenuation during pulse wave propagation is usually small in elderly people.