Numerical Simulation Method for Prediction of HIFU Induced Lesions in Human Tissue: FDTD-LBM

High-intensity focused ultrasound (HIFU) is a therapy method to treat the tumors in prostate, liver, kidney, pancreas, bone, breast, and uterine fibroids. In the HIFU therapy process, the ultrasound generated in an ultrasonic transducer concentrates on a focal zone. At the zone, the temperature rises locally up to 56 degrees C to provoke the necrosis of human tissue. Therefore, to control the therapy process, it is essential to perceive the main principle of heat generation in human tissue. We study FDTD-LBM (finite difference time domain-lattice Boltzmann method) as a method of predicting the temperature distribution in human tissue during HIFU therapy. The nonlinear Westervelt wave equation is employed for computing the pressure distribution in human tissue during ultrasound propagation, while the Pennes bio-heat transfer equation is used for calculating the temperature distribution in the tissue. Finite difference time domain (FDTD) is applied to solving the nonlinear Westervelt wave equation, and the lattice Boltzmann method can solve the Pennes bio-heat transfer equation. Simulation results have shown that the numerical simulation method proposed has improved the accuracy in analyzing the temperature field in human tissue.