A new wearable multichannel magnetocardiogram system with a SERF atomic magnetometer array

Yanfei Yang,Yang Gao,Xin Ma,Xiaolin Ning,Yan Yin,Mingzhu Xu,Aimin Liang

doi:10.1038/s41598-021-84971-7

Abstract

In this study, a wearable multichannel human magnetocardiogram (MCG) system based on a spin exchange relaxation-free regime (SERF) magnetometer array is developed. The MCG system consists of a magnetically shielded device, a wearable SERF magnetometer array, and a computer for data acquisition and processing. Multichannel MCG signals from a healthy human are successfully recorded simultaneously. Independent component analysis (ICA) and empirical mode decomposition (EMD) are used to denoise MCG data. MCG imaging is realized to visualize the magnetic and current distribution around the heart. The validity of the MCG signals detected by the system is verified by electrocardiogram (ECG) signals obtained at the same position, and similar features and intervals of cardiac signal waveform appear on both MCG and ECG. Experiments show that our wearable MCG system is reliable for detecting MCG signals and can provide cardiac electromagnetic activity imaging.

Highlights

In this study, a wearable multichannel human magnetocardiogram (MCG) system based on a spin exchange relaxation-free regime (SERF) magnetometer array is developed
A person-sized magnetically shielded cylinder made of four-layer permalloy and onelayer aluminum is used to reduce the interference of external magnetic fields
Principal component analysis (PCA) decomposition was performed on the original multichannel MCG signals, and 99% of the signal power was taken as the signal subspace, while the remaining 1% was ignored as the noise subspace

Summary

Introduction

A wearable multichannel human magnetocardiogram (MCG) system based on a spin exchange relaxation-free regime (SERF) magnetometer array is developed. BSPM is sensitive in detecting local electrical events, and it provides a high spatial resolution. Due to the different physical characteristics between electric and magnetic fields, cardiac magnetic field signals may provide information on cardiac current that is difficult to obtain by ECG or BSPM. The combined MCG and BSPM can provide comprehensive data for a comparison of electric and magnetic field properties under physiological c onditions[9]. Magnetometers can measure multiple components of the magnetic field and can obtain more complete information about the field and provide much better localization information for the detection of cardiac anomalies[20]

Methods

Results

Conclusion