Abstract

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

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

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.