凹球面HIFU换能器声焦域的位置和形状  

Site and Shape of Sound Focal Region of a Concave Spherical HIFU Transducer

作　　者：毛彦欣[1] 程建政[1] 张德俊[1] 

机构地区：[1]中国科学院武汉物理与数学研究所,武汉市430071

出　　处：《中国超声医学杂志》2004年第7期558-560,共3页Chinese Journal of Ultrasound in Medicine

基　　金：国家自然科学基金资助项目 (No.1 0 1 340 2 0 )

摘　　要：目的　研究凹球面超声换能器的声焦域在高声强和媒质有较大衰减情况下 ,其形状和几何位置的变化。方法　从物理声学的角度 ,分析高声强引起的非线性和媒质衰减对声焦域的影响 ,并采用瑞利积分的线性叠加算法 ,进行数值模拟计算。结果　理论分析和数值计算均表明 ,随着声强和媒质衰减的增加 ,声焦域的几何位置沿着声轴向换能器方向有一个毫米量级的前移量 ;同时 ,声焦域的形状逐渐由对称的长椭球形变为“头胖尾细”的短椭球形。结论　高声强和媒质衰减对凹球面换能器的声焦域的位置和形状均有重要影响。在 HIFU设备的精确定位与剂量控制、检验标准制定、乃至临床应用中 。Objective The variations of the site and shape of focal region for a concave spherical ultrasound transducer in the case of high sound intensity and stronger attenuation were studied.Methods From the view point of physical acoustics,the influence of non-linearity induced by high intensity and stronger medium attenuation on focal region was analyzed,and the numerical simulation was completed by adopting Rayleigh integral superposition method.Results Both theoretical analysis and numerical computation indicated that the displacement value of focal region towards the transducer had the order of one millimeter with the increase of attenuation and intensity under the condition in this paper.At the same time,the shape of focal region was gradually changed from a long ellipsoid to a short ellipsoid with a'fatty head and thin tail'form.Conclusions Both high intensity and stronger attenuation have important influence on the site and shape of focal region.It should be taken into full account in the accurate locating and dosage controlling,test standard constituting,and the clinical application of HIFU equipment.

关 键 词：凹球面HIFU换能器 声焦域 物理声学 声轴 

分 类 号：O429[理学—声学]