一种消除浅表组织病灶的微型线聚焦换能器声场的数值计算与仿真方法

A Numerical Calculation and Simulation Method of the Acoustic Field of Micro Linear Focused Ultrasound Transducer Used to Eliminate Superficial Tissue Lesions

目的:本文涉及一种消除浅表组织病灶的微型线聚焦超声声场的数值计算与仿真,通过计算得出声场的三维分布,同时研究柱面自聚焦换能器各个参数对声场的影响,以指导微型自聚焦换能器的设计。方法:本文通过建立三维直角坐标系,应用Rayleigh积分得出微型线聚焦超声换能器聚焦区域内每一点的声强表达式,运用C语言和matlab采用直接数值积分的方法对柱面聚焦超声换能器的声场进行了数值计算和仿真,得出声场的三维分布。结果:从声场的三维分布可以看出:按照本文给定的条件设计,微型线聚焦超声换能器展现出良好的聚焦性能,形成明显的焦域。和普通的柱面超声换能器相比,小型的柱面超声换能器形成的声场在z轴上的声场分布更均匀,x,y方向上衰减更快。结论:通过不同的参数对声场三维分布影响可以看出:微型线聚焦超声换能器的厚度,半径,张角和长度对聚焦的效果有明显影响。与给定的条件相比,选择较厚、半径和张角较大的换能器,能提高聚焦性能,而换能器的长度对聚焦效果影响不大。

Objective：This article proposes a numerical calculation and simulation method of the acoustic field of micro linear focused ultrasound transducer used to eliminate superficial tissue lesions.This method obtains the three-dimensional distribution of the sound field by calculating,and studies the each parameter＇s effect on the sound field of the cylindrical self-focusing transducer to guide the design of micro-self-focusing transducer.Methods：This article established the three-dimensional Cartesian coordinates,obtained sound intensity expression of each point in the focal region by using Rayleigh integral method.Then we carried out numerical calculation and simulation of the sound field of the cylinder focused ultrasound transducer using C language and matlab numerical integration,thus obtained the three-dimension distribution of the sound field.Results：The three-dimensional sound field distribution shows：in accordance with the given condition,micro-line focused ultrasound transducer shows good focus performance and forms distinct focal region.Compared to ordinary cylindrical ultrasonic transducer,the small ones show a more uniform distribution in the z axis of the sound,and decay faster in x,y direction.Conclusions：We can see from the effects on the distribution of the three-dimensional sound field of different parameters：the thickness,radius,opening angle and length of the micro line-focused ultrasound transducer have a significant effect on the focusing effect.Compared with the given conditions,Thicker and larger radius and opening angle can improve the focus performance,while the length of the transducer shows little effect on the focus perfoemance.