The Simulation And Measurement Of High Intensity Focused Ultrasound Sound Field

High Intensity Focused Ultrasound (HIFU) is a non-invasive tumor treatment technology, has a rapid development in recent years. The accurate measurement and simulation of the sound field is a key part to improve the safety of HIFU treatment.In the apart of Sound field simulation, in this paper, because the shortcomings current method in sound field simulation of HIFU has, is can not simulate on the irregular interface. And we put forward a new approach using a method named point source to improve this question. And under the same conditions through using the point source method and the Rayleigh integral method to calculating the sound field of a circular piston sound source in the degassing water respectively, and through contrast the two results in order to verify the feasibility of the method.In the field of Sound field measurements, in current HIFU ultrasonic distributed sound field measurement system, it used oscilloscope to achieve data processing and transmission, because oscilloscope need to processing a large quantity of high frequency signal data, so can't achieve uniform sampling in the process of uniform movement when measuring the sound field, and because long time and heavy workload of measurement, it can not guarantee the stability of the signal acquired. In this paper, we improved the acoustic field measurement devices of HIFU, in the system control device designed to integrated control stepper motor sports, A / D conversion and signal transmission module in a circuit board, At the same time an increase of signal pre-processing module and the device monitoring module limit. This design not only to resolve a large amount of data processing, but also resolve the problem of real-time and stability of signal transmission, and to simplify the measurement system and reduce costs, with a fast sampling, system stability, and easy to implement.In the mechanical transmission structure, this paper presents the mechanical structure by adjusting the legs to achieve the high absolute level of the mechanical structure, and thereby reaching the purposes of simplify the hydrophone conditioning way. At the same time, based on the actual measurements of sound field, we reduced the Z-axis motor control, reaching the purpose of simplifying the measurement system. The system has been initially applied in the HIFU acoustic field measurement. It has been reached the design requirements.