Synthetic gradiometer systems for MEG

Author

Fife, A.A. ; Vrba, J. ; Robinson, S.E. ; Anderson, G. ; Betts, K. ; Burbank, M.B. ; Cheyne, D. ; Cheung, T. ; Govorkov, S. ; Haid, G. ; Haid, V. ; Hunter, C. ; Kubik, P.R. ; Lee, S. ; McKay, J. ; Reichl, E. ; Schroyen, C. ; Sekachev, I. ; Spear, P. ; Tayl

Author_Institution

CTF Syst. Inc., Port Coquitlam, BC, Canada

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

4063

Lastpage

4068

Abstract

This paper will describe features and performance of low-T/sub c/ whole-cortex MEG systems which utilise synthetic gradiometers to achieve a high level of environmental noise cancellation. The near field MEG sensitivities achieved through use of synthetic gradiometers typically range from 3 to 7 fT//spl radic/Hz above 1 Hz in moderately shielded rooms and less than 10 fT//spl radic/Hz above a few Hz in open environments. This performance has been observed for fixed vertical and also adjustable MEG systems which can tilt between vertical and horizontal orientations.

Keywords

SQUID magnetometers; biomedical equipment; magnetoencephalography; superconducting device noise; SQUID; adjustable systems; baseline optimisation; environmental noise cancellation; fixed vertical systems; horizontal orientation; low-T/sub c/ whole-cortex MEG systems; near field MEG sensitivities; reference forward solutions; synthetic gradiometer systems; vertical orientation; Brain mapping; Councils; Epilepsy; Instruments; Magnetic sensors; Magnetometers; Noise cancellation; SQUIDs; Sensor systems; Working environment noise;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783919

Filename

783919