Title :
Biomagnetic measurements with HTS SQUID magnetometers in moderate shielded environments
Author :
Horng, Herng-Er ; Hung, Shou-Yen ; Jeng, Jen-Tzong ; Liao, Shu-Hsien ; Hsu, S.-C. ; Hwang, Ji-Chuu ; Yang, Hong-Chang
Author_Institution :
Dept. of Phys., Nat. Taiwan Normal Univ., Taipei, Taiwan
fDate :
6/1/2003 12:00:00 AM
Abstract :
An HTS SQUID magnetometer for biomagnetic measurements was implemented in a moderate noise shielded environment. The intrinsic noises of the SQUID magnetometer shielded with a tri-layer magnetic shielding cylinder were 50 fT/Hz12/ above 10 Hz and 100 fT/Hz12/ at 0.1 Hz. The moderate shielded environments are constructed of mu-metal layers. With the moderate shielding the magnitude of the QRS complex of a rat specimen was found to be around 10 pT and the signal-to-noise ratio was larger than 10. The requirements for improving biomagnetic measurements in the moderate magnetic shielding are discussed.
Keywords :
SQUID magnetometers; high-temperature superconductors; magnetic shielding; magnetocardiography; superconducting device noise; HTS SQUID magnetometer; QRS complex; biomagnetic measurement; intrinsic noise; magnetocardiography; moderate shielded environment; mu-metal layer; rat; signal-to-noise ratio; trilayer magnetic shielding cylinder; Biomagnetics; Magnetic noise; Magnetic shielding; Noise level; Noise measurement; Physics; SQUID magnetometers; Signal to noise ratio; Superconducting device noise; Working environment noise;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.813859
