基于分布式时延矢量联合估计的血流检测算法  

A blood flow movement measurement method based on joint time-delay vector estimation of distributed echo array

作　　者：肖杨[1] 余建国[1] 

机构地区：[1]复旦大学电子工程系,上海200433

出　　处：《声学技术》2011年第3期227-231,共5页Technical Acoustics

基　　金：上海市重点学科建设资助项目(B112)

摘　　要：依据超声血流散射回波信号的产生机理,引入更精确的分布式回波阵列模型来代替传统的点目标模型。基于散射子的运动效应对序列脉冲串激励信号的检测回波之间产生的附加时延效应,定义函数形式已知的分布式时延矢量,该矢量含有两个未知参数:中心速度和分布参数,利用其与回波阵列协方差矩阵的噪声子空间的正交特性,进行二维参数的联合搜索。搜索得到的中心速度值即为流速的估计值,分布参数则表征了测量速度的扩展程度,衡量了估计值的置信度,剔除对应分布参数过大的估计值,计算出最终的流速剖面。仿真实验结果表明该算法能利用小样本数据获得较高的测量精度,具有较强的抗干扰性。According to the ultrasonic echo signal mechanism from the human blood,the distributed model firstly men-tioned in this paper represents the echo array more accurately than the conventional point source model.As a time-delay problem,a vector corresponding to a known distribution function is defined,which has two unknown pa-rameters including a central velocity and a distribution parameter.By the two-dimensional joint search,the two pa-rameters can be estimated using orthogonal property between noise subspace of the correlation matrix of the echo array and the time-delay vector.Then the velocity estimation is obtained from the central velocity and its validity is denoted by the distribution parameter which denotes the velocity extension.After rejecting the invalid data,the final velocity profile can be acquired.Simulation results show the good accuracy,stability and achieving the good purpose by small sampling data.

关 键 词：分布式回波阵列 时延矢量 联合搜索 流速剖面 

分 类 号：TP273.5[自动化与计算机技术—检测技术与自动化装置]