EXPERIMENTAL AND CLINICAL EVALUATIONS FOR NONINVASIVE MEASUREMENT OF VASCULAR ELASTIC PROPERTY USING PHOTOPLETHYSMOGRAPHY TECHNIQUE.

The experimental and clinical evaluations for a noninvasive technique previously proposed for measuring vascular elastic properties in human fingers and rabbit forearms were conducted; By this technique the relative pressure (P)-volume (V) relation and volume elastic modulus (E//v) as a function of transmural pressure could be obtained from the photoelectrically detected volume signals and the simultaneously determined indirect arterial pressure. The changes in P-V relationships and E//v values were clearly demonstrated showing the progressive and regressive responses of the atherosclerotic process in the hyperlipedemic rabbits. The differences in E//v values with aging and the changes in E//v values in response to vasodilatation agents were also successfully measured in human fingers.