The study of ultrasound field of self-focusing transducer by FDTD method

Because of the high intensity focused ultrasound(HIFU) treating the local tumor is a noninvasive and untouched technique, and has a wonderful prospect, so it has practical worthiness to study the ultrasonic field in focal region The study of ultrasonic field is helpful not only for the design of transducer and enhancing of the treat effect, but also for the project design of ultrasonic field measurement and more safety in ultrasonic dose. In this paper the finite difference time-domain (FDTD) method was used to study the ultrasonic field of self-focusing transducer, both in simple harmonic wave and in pulse wave. It is clear view that the acoustic field in focus can be regard as the plane wave, and this is very useful for fiber-tip method [1] of ultrasonic field measurement.