探针引导相控阵HIFU原型机的设计与实现

Design and implementation of phased array HIFU prototype guided by probe

基于人体组织是复杂的多层介质,超声在传播要经过多层介质这一事实,怎样实现探针可以在人体靶区精确聚焦目前也是研究的一大难点,本文提出一种以探针引导的测试相控阵超声聚焦HIFU原型机的焦域的声压分布的实现方案。首先从相控阵超声换能器的声场特性的理论角度上出发,用伪逆矩阵法和瑞利积分法结合计算对聚焦超声情况进行了仿真分析,仿真采用的是MATLAB软件对声压的快速算法进行计算的到空间各点的声压值,随后画出声压分布。然后在实验中,采用时间反转法用于高强度超声聚焦,以探针探头为焦点,设计了相控阵HIFU原型机,并用探针测量水中焦域的声场分布。最后简单介绍了原型机测试分析平台。从仿真与实验测试的对比,探针测得聚焦的焦域的长轴半径为5mm,短轴半径为0.8mm,这也正是符合了HIFU治疗系统的要求。实践证明,探针引导的相控阵超声聚焦HIFU原型机的设计与实现的方案的可行,对HIFU治疗肿瘤具有十分重要的意义。

Based on the fact that human tissue is a complex multi-layer medium and ultrasound travels through the multi-layer medium,how to realize the precise focusing of the probe in the target area of human body is also a major difficulty in research. This paper proposes a probe-guided implementation scheme to test the sound pressure distribution in the focal area of phased array ultrasound focusing HIFU prototype. Firstly,from the theoretical point of view of the sound field characteristics of the phased array ultrasonic transducer,the focused ultrasonic situation is simulated and analyzed by combining the calculation of Generalized inverse method and Rayleigh integration method. In the simulation,the sound pressure value to each point in space is calculated by the fast algorithm of sound pressure using MATLAB software,and then the sound pressure distribution is drawn. Then,in the experiment,the time reversal method is used for high-intensity ultrasonic focusing,and a phased array HIFU prototype is designed with the probe as the focus,and the probe is used to measure the sound field distribution in the focal region of water. Finally,the prototype testing and analysis platform is briefly introduced. From the comparison between simulation and experimental tests,the probe measured the radius of the major axis of the focused focal region to be 5mm and the radius of the minor axis to be 0.8mm,which also meets the requirements of HIFU treatment system. Practice has proved that the design and implementation of probeguided phased array HIFU prototype is feasible and of great significance for HIFU treatment of tumors.