电磁致热超声系统设计及基于小波阈值去噪方法的信号处理  

The Design of Electromagnetically Induced Thermo-Acoustic System and the Signal Processing Using Wavelet Analysis with a Soft Thresholding Method

作　　者：陈国平[1] 于万宝[1] 赵志钦[1] 聂在平[1] 柳清伙[1,2] 

机构地区：[1]电子科技大学电子工程学院,四川成都610054 [2]电子与计算机工程系,Duke University,Durham,NC27708

出　　处：《电子学报》2008年第6期1130-1134,共5页Acta Electronica Sinica

基　　金：长江学者讲座教授项目;新世纪优秀人才支持计划项目;高等学校学科创新引智计划

摘　　要：本文给出了一个电磁致热超声(EMITA)实验系统,针对实验信号的提取问题,首先研究了实验平台的改进方法,通过置入波导内容器截面的设计,增加微波透过率;对耦合液的选择研究,减小微波脉冲对超声波接收传感器的电磁冲击,从而提高系统在强电磁脉冲下的电磁兼容(EMC)能力;其次为了从低信噪比数据中有效提取EMITA超声信号,研究了应用小波分析方法和阈值去噪重构方法处理实验采集的EMITA信号.This paper presents an experimental system of ElectroMagnetically Induced Thermo-Acoustic （EMITA）. Focusing on the signal extraction of EMITA, several treatments are adopted to improve the compatibility of the system under high power electromagnetic pulses. To improve the transition of the microwave energy to the biologic tissue, the cross section of the vessel front to the microwave is designed as bevel;to decrease the electromagnetic impose of ultrasound transducer due to the microwave pulse, the coupling liquid is used after careful study. In order to extract the EMITA signals from low signal-to-noise ratio （SNR） background, wavelet analysis with soft thresholding is used to filter the strong noise. Experimental results indicate the effectiveness of the wavelet analysis in the extraction of EMITA signals.

关 键 词：电磁致热超声 小波分析 阈值去噪重构 

分 类 号：Q684[生物学—生物物理学]