Second-order, high-temperature superconducting gradiometer for magnetocardiography in unshielded environment

Zhang, Y.; Soltner, H.; Wang, S. G.; Otto, R.; Krause, H.-J.; Zander, W.; Schubert, J.; Bousack, H.; Wolters, N.; Panaitov, G.; Braginski, A. I.

Journal Article

Second-order, high-temperature superconducting gradiometer for magnetocardiography in unshielded environment

Zhang, Y.FZJ* ; Panaitov, G.FZJ* ; Wang, S. G. ; Wolters, N. ; Otto, R.FZJ* ; Schubert, J.FZJ* ; Zander, W.FZJ* ; Krause, H.-J.FZJ* ; Soltner, H.FZJ* ; Bousack, H.FZJ* ; Braginski, A. I.FZJ*

2000
American Institute of Physics Melville, NY

Applied physics letters 76, 906 (2000)

This record in other databases:

Please use a persistent id in citations: http://hdl.handle.net/2128/2343

Abstract: By employing high-temperature superconducting quantum interference device (SQUID) magnetometers, we have assembled a second-order gradiometer for magnetocardiography (MCG) in unshielded environment. With this high-temperature superconductor (HTS) SQUID system, we demonstrated its diagnostic relevance for MCG in terms of signal-to-noise ratio, spatial resolution, frequency bandwidth, rejection of environmental disturbances, and long-term stability. The electronically balanced gradiometer consists of three HTS radio-frequency SQUIDs with superconducting coplanar resonators, mounted in axial gradiometric arrangement with a baseline of 7.5 cm. The system achieves a common mode rejection for axial homogeneous fields of about 10(4) without any mechanical balancing, and a white noise about 130 fT/root Hz at 77 K, with an 8x8 mm(2) flux pickup area. MCG maps above volunteers' chests have been recorded in unshielded environment in a bandwidth of about 130 Hz. We showed the influence of several notch filters (suppressing the power line frequency) on the quality of the MCG signals. (C) 2000 American Institute of Physics. [S0003-6951(00)03307-6].

Keyword(s): J

Classification: