Frequency characteristic of tissue response by dual acoustic radiation pressure for estimating viscoelastic properties of biological tissue

Abstract

When the lesion progresses in living tissue, the hardness of the tissue changes. Therefore, quantitative measurement of tissue hardness is required. In this study, the object is vibrated by dual acoustic radiation pressure. We aim to estimate viscoelastic properties by examining the frequency response of the tissue. In this report, we observed the change in the displacement amplitude of the object by changing the oscillating frequency. As a result, it was found that the displacement amplitude becomes smaller as the frequency is set higher. It was confirmed that it decreases with a slope of -40dB/decade between 10 Hz and 200 Hz. This phenomenon is thought to be due to stress relaxation. We will clarify frequency characteristics from stress relaxation function.