THE EXPERIMENTAL-THEORETICAL METHOD FOR FINDING ELASTIC MODULES OF RUBBER-LIKE MATERIALS BASED ON THE VERASONICS ACOUSTIC SYSTEM
The experimental-theoretical method for determining the elastic characteristics of rubber-like materials is presented. This method is founded on the technology SWEI (Shear Wave Elasticity Imaging) with using the open architecture Verasonics speaker system that implements a method for generating and measuring shear wave velocity in rubbery media. The SWEI method makes it possible to measure the shear wave velocity (and, accordingly, elastic characteristics: Young's and shear modules) in soft biological tissues and finds application in medical diagnostics – shear wave elastography. The results of measuring the elastic characteristics of rubber-like media are presented. For physical modeling, polymer CIRS phantoms (Model 049 Elasticity QA Phantom Spherical) were used as measurement media. Young's modules of different types of polymer calibrated phantom measured on the Verasonics acoustic system are comparable with the tabular values. Numerical modeling of the evolution of shear waves in rubber-like media is carried out. Numerical analysis was performed using the k-Wave programming package. This programming package is based on k-space transition, where spatial gradients are computed using a Fast Fourier Transform scheme and temporal gradients are computed using a corrected k-space difference scheme. The k-Wave programming package combines the optimization of the MATLAB programming environment for working with matrix operations and a set of tools that allows you to simulate an ideal (non-dissipation) propagation environment using parameters such as density and sound velocity for a given rubber-like material. The combination of these factors allows you to model 2D and 3D spaces while maintaining high computational speed. For polymer CIRS phantoms, the results of physical and numerical modeling are compared to determine the elastic characteristics of rubber-like media.