Magnetocardiography with a modular spin-exchange relaxation free atomic magnetometer array

TL;DR

This paper introduces a portable, modular atomic magnetometer array designed for biomagnetic measurements like fetal magnetocardiography, demonstrating high sensitivity and flexible configuration in a shielded environment.

Contribution

The paper presents a novel modular, portable atomic magnetometer array optimized for biomagnetic applications, enabling flexible array geometries and high sensitivity.

Findings

Achieved 6-11 fT/Hz^{1/2} sensitivity in measurements.

Successfully recorded adult magnetocardiograms.

Demonstrated modular design flexibility.

Abstract

We present a portable four-channel atomic magnetometer array operating in the spin exchange relaxation-free regime. The magnetometer array has several design features intended to maximize its suitability for biomagnetic measurement, specifically foetal magnetocardiography, such as a compact modular design, and fibre coupled lasers. The modular design allows the independent positioning and orientation of each magnetometer, in principle allowing for non-planar array geometries. Using this array in a magnetically shielded room, we acquire adult magnetocadiograms. These measurements were taken with a 6-11 fT Hz^(-1/2) single-channel baseline sensitivity that is consistent with the independently measured noise level of the magnetically shielded room.