The Research of Nonlinear Characteristics of High Intensity Focused Ultrasound in Biological Tissue

The Nonlinear propagation of high intensity focused ultrasound(HIFU) at high power can easily lead to waveform distortion and generate high order harmonic. This paper is based on the finite element method to establish the propagation model of high intensity focused ultrasound in biological tissues. Firstly, analyzing the nonlinear characteristic of HIFU propagation in biological tissue. Then, making quantitative comparisons with the nonlinear model in water to obtain the nonlinear characteristics of the focal area. At last, explaining the propagation characteristics of nonlinear ultrasound in biological tissue, and establishing a simulation basis for HIFU in the field treatment for future use.