Precise estimation of elastic modulus of radial artery using blood pressure and vessel wall strain measured by ultrasound and photoplethysmography

In an earlier study, we investigated methods for estimating the elastic modulus of blood vessel walls for early diagnosis of atherosclerosis. Because the pulse pressure varies from beat to beat, in the present study, we proposed a method for estimating the elastic modulus of the vessel walls that simultaneously measures the pulse pressure and vessel wall strain due to the pulse pressure; this method estimates the systolic and diastolic blood pressures from the vessel diameter and pulse wave velocity. Consequently, changes in vessel wall strain in response to beat-by-beat pulse pressure variation were measured. In the elastic modulus estimation, the maximum deviation among consecutive beats was reduced, and the reproducibility of elastic modulus estimation was improved. Hence, we conclude that simultaneous measurement of vessel wall strain and pulse pressure is effective in improving the reliability of elastic modulus estimation.