Abstract
To design practical planar high-Tc SQUID gradiometers for magnetocardiographs, a signal-to-noise (S/N) chart that will enable the gradiometers to detect P-waves was developed. The signal was estimated as the gradient field generated by the mean current dipole of P-waves of 20 healthy volunteers. The current dipoles were obtained by using a conventional magnetocardiograph comprising low-Tc SQUID gradiometers. On the other hand, the noise was estimated from studies on previously reported gradiometers based on the limit of intrinsic gradient field noise. The obtained S/N chart indicates that a gradiometer with a baseline longer than 12 mm is necessary for detecting P-waves without averaging. The reliability of the S/N chart was confirmed by detecting actual P-waves with 100-beat averaging by using a fabricated planar high-Tc SQUID gradiometer with a baseline of 6.75 mm.
Original language | English |
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Pages (from-to) | 136-140 |
Number of pages | 5 |
Journal | Superconductor Science and Technology |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 1 2002 |
Externally published | Yes |
ASJC Scopus subject areas
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry