Analysis Of Nonlinear Focused Ultrasound Field With Finite Element Method

High intensity focused ultrasound (HIFU) is widely accepted as a treatment modality enabling noninvasive tissue heating and ablation for numerous applications. Nonlinear phenomena such as wave distortion and amplitude difference between peak positive and negative acoustic pressure are observed. The nonlinear field of HIFU is numerical calculated based on the Westervelt equation. The equation is performed with finite element method (FEM). The result agrees very well with the results carried with finite difference time domain (FDTD) method. The nonlinear ultrasound field of HIFU are obtained. And nonlinear phenomena are analyzed.