Temperature Field FDTD Simulation of HIFU in Human Body Tissues

High intensity focused ultrasound (HIFU) therapy has become a new way in the treatment of tumors due to its noninvasive advantage. However, as for the HIFU nonlinear propagation and temperature field in human body in relation to practice HIFU therapy, there are few studies on numerical simulation based on models conforming to practical situation. In this study, we report a numerical method of finite difference time domain (FDTD) for analyzing HIFU temperature field in human body tissues and demonstrate it through a model of 3D breast tissues. The calculation of HIFU propagation in human body tissues is done using Euler´s equation of motion and continuity, which combines nonlinear ultrasound propagation with a bulk modulus and an attenuation parameter. The Pennes Bio-heat transfer equation is used to calculate temperature distribution. The simulation results of the temperature field of HIFU in human body tissues in case of different excitation function frequency and excitation function average ultrasound power densities (USPD) are reported.