Development of a novel four-channel atomic gradiometric magnetometer for magnetocardiography: Advancing non-invasive cardiac research with enhanced sensitivity and spatial resolution

Abstract

The field of magnetocardiography (MCG) has witnessed significant advancements with the use of atomic magnetometers (AMs) and gradiometers, offering numerous advantages over traditional superconducting quantum interference devices (SQUIDs). This study focuses on the development of a highly sensitive four-channel atomic gradiometer specifically designed for measuring the biomagnetic fields of a rat’s heart. By utilizing gradiometric detection and monitoring deviations in the Larmor frequency of rubidium (Rb) atoms, this gradiometer captures cardiac signals with exceptional sensitivity and spatial resolution. One of the key challenges in utilizing AMs as gradiometers lies in minimizing cross-talk effects among the sensors to ensure accurate measurements. In this study, we successfully address this challenge, leading to precise and reliable data acquisition. Furthermore, our gradiometer demonstrates a linear response across a wide range of frequencies, enhancing its versatility and applicability in various experimental setups. The achieved sensitivity of 350 fT/√Hz by our atomic gradiometer showcases its potential in assessing MCG measurements for studying cardiac electrical activities. The non-invasive nature of the technique, combined with the elimination of cryogenic cooling requirements, opens up new avenues for cardiac research and diagnostics. The enhanced spatial and spatiotemporal resolution offered by optically pumped magnetometers (OPMs) further enhances our ability to understand and analyze complex cardiac phenomena.