基于改进最小方差波束成形的心磁信号的源重建-《中国医学物理学杂志》

文章信息/Info

Title:: Source reconstruction from magnetocardiography signals based on improved minimum variance beamforming

作者:: 徐俊1; 2; 朱俊杰1; 2; 1.河南理工大学电气工程与自动化学院，河南焦作454003； 2.河南省煤矿装备智能检测与控制重点实验室，河南焦作454003

Author(s):: XU Jun1; 2; ZHU Junjie1; 2; 1. School of Electrical Engineering and Automation, Henan Polytechnic University, Jiaozuo 454003, China 2. Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment, Jiaozuo 454003, China

Keywords:: Keywords: magnetocardiogram improved minimum variance beamforming inverse problem spatial filter source reconstruction

摘要:: 由于冠心病患者的心磁图在信噪比较低时，最小方差波束成形（MV）方法的源重建效果不理想，提出一种基于改进最小方差波束成形（IMV）方法，在MV方法的基础上，使用导联矩阵和磁场信号二阶特征矩阵组成约束矩阵，构造新的空间滤波器的权矩阵，从而降低输出噪声功率增益。利用点扩散函数理论比较IMV方法和MV方法的空间谱估计的单源分辨率；利用3个电流偶极子产生36通道磁场仿真数据，采用IMV方法和MV方法在低信噪比下对仿真数据进行源重建；最后对3名冠心病患者的36通道心磁图的R波峰和T波峰时刻数据进行源重建。结果表明，IMV方法的单源分辨率更高，对仿真数据及冠心病患者心磁数据的重建精度更好。

Abstract:: Abstract: Given the poor source reconstruction results of minimum variance beamforming (MV) for magnetocardiogram (MCG) at low signal-to-noise ratio in coronary heart disease patients, a novel method using the improved minimum variance beamforming (IMV) is proposed. Based on MV, the proposed method uses the lead matrix and the magnetic field signal second-order characteristic matrix to form a constraint matrix, and constructs the weight matrix of a new spatial filter, thus reducing the output noise power gain. The single-source resolution of IMV and MV spatial spectrum estimations is compared using the point spread function. IMV and MV are used to perform source reconstruction from the 36-channel magnetic field simulation data generated by 3 current dipoles at low signal-to-noise ratio and the source reconstruction is also carried out on the R-wave peak and T-wave peak time data of 36-channel MCG of 3 coronary heart disease patients. The results show that IMV has higher single-source resolution and reconstruction accuracy for simulation data and MCG data from coronary heart disease patients.