Simultaneous viscoelastic characterization of soft tissues based on shear wave ultrasound dispersion and multi-scale wavelet cross-correlation analysis

Ultrasound shear waves offer a non-destructive testing approach to assess the biomechanical properties of biological soft tissues. This paper presents a method based on the dispersion relations of ultrasound shear waves to inversely derive the viscoelastic properties of soft tissues. In the proposed method, dispersion relations are extracted from shear wave signals based on the multi-scale wavelet correlation analysis. Here, the continuous wavelet transform is employed to convert shear wave signals into various frequencies. The cross-correlation method is utilized to obtain the phase velocity of the shear waves. This approach offers advantages, including multiscale analysis capability, high-resolution time–frequency representation, flexible parameter selection, and continuous time–frequency scaling. Subsequently, an inversion process utilizing the simulated annealing algorithm is designed to characterize the properties of soft tissues. The effectiveness and accuracy of the proposed approach have been verified numerically and experimentally.