Dr Niall Holmes NIALL.HOLMES@NOTTINGHAM.AC.UK
MANSFIELD RESEARCH FELLOW
A lightweight magnetically shielded room with active shielding
Holmes, Niall; Rea, Molly; Chalmers, James; Leggett, James; Edwards, Lucy J.; Nell, Paul; Pink, Stephen; Patel, Prashant; Wood, Jack; Murby, Nick; Woolger, David; Dawson, Eliot; Mariani, Christopher; Tierney, Tim M.; Mellor, Stephanie; O’Neill, George C.; Boto, Elena; Hill, Ryan M.; Shah, Vishal; Osborne, James; Pardington, Rosemarie; Fierlinger, Peter; Barnes, Gareth R.; Glover, Paul; Brookes, Matthew J.; Bowtell, Richard
Authors
Molly Rea
James Chalmers
Dr JAMES LEGGETT JAMES.LEGGETT@NOTTINGHAM.AC.UK
RESEARCH FELLOW
Lucy J. Edwards
Paul Nell
Stephen Pink
Prashant Patel
Jack Wood
Nick Murby
David Woolger
Eliot Dawson
Christopher Mariani
Tim M. Tierney
Stephanie Mellor
George C. O’Neill
Miss ELENA BOTO ELENA.BOTO@NOTTINGHAM.AC.UK
SENIOR RESEARCH FELLOW
Ryan M. Hill
Vishal Shah
James Osborne
Rosemarie Pardington
Peter Fierlinger
Gareth R. Barnes
Paul Glover
Professor MATTHEW BROOKES MATTHEW.BROOKES@NOTTINGHAM.AC.UK
PROFESSOR OF PHYSICS
Professor RICHARD BOWTELL RICHARD.BOWTELL@NOTTINGHAM.AC.UK
PROFESSOR OF PHYSICS
Abstract
Magnetically shielded rooms (MSRs) use multiple layers of materials such as MuMetal to screen external magnetic fields that would otherwise interfere with high precision magnetic field measurements such as magnetoencephalography (MEG). Optically pumped magnetometers (OPMs) have enabled the development of wearable MEG systems which have the potential to provide a motion tolerant functional brain imaging system with high spatiotemporal resolution. Despite significant promise, OPMs impose stringent magnetic shielding requirements, operating around a zero magnetic field resonance within a dynamic range of ± 5 nT. MSRs developed for OPM-MEG must therefore effectively shield external sources and provide a low remnant magnetic field inside the enclosure. Existing MSRs optimised for OPM-MEG are expensive, heavy, and difficult to site. Electromagnetic coils are used to further cancel the remnant field inside the MSR enabling participant movements during OPM-MEG, but present coil systems are challenging to engineer and occupy space in the MSR limiting participant movements and negatively impacting patient experience. Here we present a lightweight MSR design (30% reduction in weight and 40–60% reduction in external dimensions compared to a standard OPM-optimised MSR) which takes significant steps towards addressing these barriers. We also designed a ‘window coil’ active shielding system, featuring a series of simple rectangular coils placed directly onto the walls of the MSR. By mapping the remnant magnetic field inside the MSR, and the magnetic field produced by the coils, we can identify optimal coil currents and cancel the remnant magnetic field over the central cubic metre to just |B|= 670 ± 160 pT. These advances reduce the cost, installation time and siting restrictions of MSRs which will be essential for the widespread deployment of OPM-MEG.
Citation
Holmes, N., Rea, M., Chalmers, J., Leggett, J., Edwards, L. J., Nell, P., Pink, S., Patel, P., Wood, J., Murby, N., Woolger, D., Dawson, E., Mariani, C., Tierney, T. M., Mellor, S., O’Neill, G. C., Boto, E., Hill, R. M., Shah, V., Osborne, J., …Bowtell, R. (2022). A lightweight magnetically shielded room with active shielding. Scientific Reports, 12, Article 13561. https://doi.org/10.1038/s41598-022-17346-1
Journal Article Type | Article |
---|---|
Acceptance Date | Jul 25, 2022 |
Online Publication Date | Aug 9, 2022 |
Publication Date | Aug 9, 2022 |
Deposit Date | Oct 12, 2022 |
Publicly Available Date | Oct 13, 2022 |
Journal | Scientific Reports |
Electronic ISSN | 2045-2322 |
Publisher | Nature Publishing Group |
Peer Reviewed | Peer Reviewed |
Volume | 12 |
Article Number | 13561 |
DOI | https://doi.org/10.1038/s41598-022-17346-1 |
Keywords | Multidisciplinary |
Public URL | https://nottingham-repository.worktribe.com/output/10071782 |
Publisher URL | https://www.nature.com/articles/s41598-022-17346-1 |
Files
Holmes Et Al-2022-Scientific Reports (2)
(3.5 Mb)
PDF
Publisher Licence URL
https://creativecommons.org/licenses/by/4.0/
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