Guided waves in pre-stressed hyperelastic plates and tubes: Application to the ultrasound elastography of thin-walled soft materials

TL;DR

This paper introduces a novel ultrasound elastography method using guided waves in pre-stressed soft tissue models to non-invasively measure their elastic properties, combining theory, simulation, and experiments.

Contribution

It develops a new non-destructive technique for imaging the elastic properties of thin-walled soft tissues and materials based on guided wave analysis in pre-stressed conditions.

Findings

Theoretical analysis of guided waves in pre-stressed structures.

Finite element simulations validating the approach.

Experimental demonstration on soft tissue phantoms.

Abstract

In vivo measurement of the mechanical properties of thin-walled soft tissues (e.g., mitral valve, artery and bladder) and in situ mechanical characterization of thin-walled artificial soft biomaterials in service are of great challenge and difficult to address via commonly used testing methods. Here we investigate the properties of guided waves generated by focused acoustic radiation force in immersed pre-stressed plates and tubes, and show that they can address this challenge. To this end, we carry out both (i) a theoretical analysis based on incremental wave motion in finite deformation theory and (ii) finite element simulations. Our analysis leads to a novel method based on the ultrasound elastography to image the elastic properties of pre-stressed thin-walled soft tissues and artificial soft materials in a non-destructive and non-invasive manner. To validate the theoretical and numerical solutions and demonstrate the usefulness of the corresponding method in practical measurements, we perform (iii) experiments on polyvinyl alcohol cryogel phantoms immersed in water, using the Verasonics V1 System equipped with a L10-5 transducer. Finally, potential clinical applications of the method have been discussed.