Optically pumped magnetometers: From quantum origins to multi-channel magnetoencephalography

Tierney, Tim M.; Holmes, Niall; Mellor, Stephanie; López, José David; Roberts, Gillian; Hill, Ryan M.; Boto, Elena; Leggett, James; Shah, Vishal; Brookes, Matthew J.; Bowtell, Richard; Barnes, Gareth R.

Abstract

Optically Pumped Magnetometers (OPMs) have emerged as a viable and wearable alternative to cryogenic, superconducting MEG systems. This new generation of sensors has the advantage of not requiring cryogenic cooling and as a result can be flexibly placed on any part of the body. The purpose of this review is to provide a neuroscience audience with the theoretical background needed to understand the physical basis for the signal observed by OPMs. Those already familiar with the physics of MRI and NMR should note that OPMs share much of the same theory as the operation of OPMs rely on magnetic resonance. This review establishes the physical basis for the signal equation for OPMs. We re-derive the equations defining the bounds on OPM performance and highlight the important trade-offs between quantities such as bandwidth, sensor size and sensitivity. These equations lead to a direct upper bound on the gain change due to cross-talk for a multi-channel OPM system.

Citation

Tierney, T. M., Holmes, N., Mellor, S., López, J. D., Roberts, G., Hill, R. M., …Barnes, G. R. (2019). Optically pumped magnetometers: From quantum origins to multi-channel magnetoencephalography. NeuroImage, 199, 598-608. https://doi.org/10.1016/j.neuroimage.2019.05.063

• Journal Article Type: Article
• Acceptance Date: May 25, 2019
• Online Publication Date: May 26, 2019
• Publication Date: Oct 1, 2019
• Deposit Date: Jul 8, 2019
• Publicly Available Date: Jul 8, 2019
• Journal: NeuroImage
• Print ISSN: 1053-8119
• Electronic ISSN: 1095-9572
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 199
• Pages: 598-608
• DOI: https://doi.org/10.1016/j.neuroimage.2019.05.063
• Public URL: https://nottingham-repository.worktribe.com/output/2285905
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1053811919304550
• Additional Information: This article is maintained by: Elsevier; Article Title: Optically pumped magnetometers: From quantum origins to multi-channel magnetoencephalography; Journal Title: NeuroImage; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.neuroimage.2019.05.063; Content Type: article; Copyright: © 2019 The Authors. Published by Elsevier Inc.