Development of high-temperature superconducting SQUID system for magnetocardiography

As a new clinical examination apparatus for cardiac diseases, attention is focused on the magnetocardiograph, which can represent electrophysiological phenomena of the heart noninvasively as graphical information. We have been developing a compact and portable high-temperature superconducting magnetocardiograph based on our technology for magnetocardiographs using low-temperature superconductors. Since a high-temperature superconducting magnetocardiograph can work with liquid nitrogen cooling, it allows miniaturization and lower running costs. Hence, it is expected to help popularize magnetocardiographs by its use in smaller hospitals and in group medical examinations in the field. In this paper, we introduce the prototype high-temperature superconducting magnetocardiographs we have made, and report the fabrication technology for a highly sensitive high-temperature SQUID and the technology for external noise shielding and compensation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 46– 55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20273