Correlation between the characteristics of acceleration and visco elasticity of artery wall under pulsatile flow conditions (physical meaning of I* as a parameter of progressive behaviors of atherosclerosis and arteriosclerosis).

Previously, I* parameter has been proposed to diagnose noninvasively the progressive degree of atherosclerosis which is considered to concern the discrimination of the progressive degree of visco elasticity of blood vessel wall. However, the detailed physical meaning of this parameter has not yet been clarified. In this paper, the theoretical analysis and experiments were conducted and the detailed physical meaning of I* parameter was clarified.

The analysis and diagnosis of unstable behavior of the blood vessel wall with an aneurysm based on noise science.

Previously, one of the authors developed a noninvasive measurement method of acceleration and deceleration during the expansion process of the blood vessel wall under pulsatile pressure flow by measuring the strain rate of the blood vessel wall using a supersonic Doppler effect sensor aided by computer analysis (DPC method). In this paper, on the basis of the analysis of chaos theory, that is, the complexity of science, the unstable behavior of the blood vessel wall with an aneurysm was investigated by identifying the characteristic DPC wave forms induced by the onset and progression of aneurysm. These results showed that unstable dynamic behavior of the blood vessel wall occurs due to the progression of the aneurysm.