聚焦换能器声场特性的快速检验方法  

A Fast Field Testing Method for Focused Transducer

作　　者：马蕊生 李文溢 胡济民 李禹志 郭各朴[1] 马青玉[1] Ma Ruisheng;Li Wenyi;Hu Jimin;Li Yuzhi;Guo Gepu;Ma Qingyu(School of Computer and Electronic Information,Nanjing Normal University,Nanjing 210023,China;Jiangsu Institute of Medical Device Testing,Nanjing 210019,China)

机构地区：[1]南京师范大学计算机与电子信息学院,江苏南京210023 [2]江苏省医疗器械检验所,江苏南京210019

出　　处：《南京师范大学学报（工程技术版）》2024年第2期20-27,49,共9页Journal of Nanjing Normal University(Engineering and Technology Edition)

基　　金：国家自然科学基金项目(11934009、11974187、12174198、12227808);江苏省自然科学基金项目(BE2022814)。

摘　　要：高强度聚焦超声(HIFU)已在无创肿瘤治疗方面展示出巨大的应用潜力,而换能器聚焦性能的优劣对疗效起到至关重要的作用,因此声场的精确测量成为实际应用的重要保障.由于加工工艺和安装精度的限制,聚焦换能器的实际声场和理想声场可能存在一定偏差.针对传统三维扫描测量存在速度慢和精度低的问题,提出了一种基于双平面双精度测量的聚焦换能器声场特性快速检验方法.通过沿理想z轴的高精度一维扫描确定换能器倾斜角范围,在声压极值点所在横截面内利用低精度和高精度变邻域搜索法实现最大声压点的精准定位,进一步通过焦域内双平面最大声压点构建声场的实际轴线,完成实际声场焦点的精确定位,最后基于实际焦平面内轴向与径向的高精度测量结果,计算获得焦域尺寸、旁瓣大小、分布对称性和声功率等性能参数.利用构建的声场扫描实验系统对聚焦换能器声场进行三维扫描和快速测量,结果表明在相同的测量精度(0.1 mm)下可以有效提高测量速度百倍以上,具有测量速度快、测量精度易于调节和性能分析全面等优点.方法为聚焦换能器检验提供一种高精度的快速声场测量新技术,在超声治疗仪器的检验中具有重要的指导意义与应用价值.The high intensity focused ultrasound(HIFU)has shown great applied potential in non-invasive tumor treatment,and the focusing performance of the transducer plays a crucial role in the therapeutic effect.Hence,the accurate measurement of the focused acoustic field shows great significance to guarantee treatment accuracy of practical HIFU therapy.However,due to the limitation of fabrication technology and installation accuracy,some difference between the actual and ideal field of the focused transducer may be produced.In this paper,to solve the low-speed and low-accuracy of the traditional three-dimensional scanning,a rapid inspection method for focused acoustic field is proposed on the basis of the dual-precision measurement in double planes.The inclination angle range of the transducer is first determined by the extreme point in the focal distance based on the high-precision one-dimensional scanning along the ideal axis.And then,the pressure-peak position is accurately located in the cross section by applying the variable neighborhood search algorithm in both low and high precisions.The actual beam axis is further constructed by the pressure-peak points in double planes within the focal region,and the precise location of the focus is achieved.Finally,based on the high-precision axial and radial measurements in the actual focal plane,the performance parameters such as the focal field size,side lobe level,field symmetry and acoustic power are obtained.Compared with the experimental three-dimensional measurements,the measurement efficiency can be greatly enhanced by the proposed fast inspection method by over 100 times,with the advantages of high speed,flexible accuracy and comprehensive performance analysis.This study provides a new high-precision fast measurement technology for focused transducers,and exhibits prosperous perspectives in the inspection of ultrasonic therapeutic instruments.

关 键 词：聚焦换能器声场 双平面双精度测量 变邻域搜索法 性能参数 

分 类 号：TB551[理学—物理]