Estimation of complex arterial elastic modulus from ring resonance excited by ultrasound radiation force

Abstract

Pulse wave velocity (PWV) is widely used for estimating the stiffness of an artery. PWV is an average measurement of artery stiffness between two measuring sites. From measured PWV, the diameter and thickness are needed to calculate the elastic modulus of the artery. In this paper a new method of using ring resonant mode for estimation of arterial elastic modulus is proposed. To generate the ring resonance, a localized radiation force of ultrasound is remotely and non-invasively applied at the artery. The vibration response of the artery is measured by optical techniques. Three ring resonant modes are identified for estimation of the elastic modulus. The viscoelasticity and the complex modulus of the artery can be obtained. Experiments were carried out on a porcine artery embedded in gelatin. The estimation only requires the diameter of the artery, but does not need the thickness of the artery which is difficult to measure with accuracy and precision.