Title :
The development of a high-T/sub c/ magnetocardiography system for unshielded environment
Author :
David, B. ; Dossel, O. ; Doormann, V. ; Eckart, R. ; Hoppe, W. ; Kruger, J. ; Laudan, H. ; Rabe, G.
Author_Institution :
Dept. of Tech. Syst., Philips Res. Lab., Hamburg, Germany
fDate :
6/1/1997 12:00:00 AM
Abstract :
A modular, 9-channel high-T/sub c/ SQUID system for magnetocardiography (MCG) was developed and tested in an unshielded environment. Galvanically-coupled magnetometers made from Y-Ba-Cu-O films, with intrinsic white noise levels as low as 70 fT//spl radic/Hz, are used as SQUID sensors. In an unshielded environment, a noise level of about 1 pT//spl radic/Hz for each channel was achieved using an active noise compensation system. A new digital planar gradiometer is proposed. First magnetocardiograms recorded in an unshielded environment are presented.
Keywords :
SQUID magnetometers; active noise control; barium compounds; high-temperature superconductors; magnetocardiography; superconducting device noise; superconducting device testing; white noise; yttrium compounds; SQUID sensors; Y-Ba-Cu-O films; YBaCuO; active noise compensation system; digital planar gradiometer; galvanically-coupled magnetometers; intrinsic white noise levels; magnetocardiography; modular 9-channel high-T/sub c/ SQUID system; unshielded environment; Biomagnetics; Frequency; Galvanizing; Magnetic shielding; Noise level; Performance evaluation; Pollution measurement; SQUID magnetometers; White noise; Working environment noise;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
