“…Recently, the magnetocardiography (MCG) has attracted much attention as a potential application of SQUID, because MCG systems with SQUID provide higher sensitivity than other systems and because cardiac diagnosis plays an important role in the prevention of heart disease. Thus far, we have developed a multi-channel MCG system by using Nb SQUID [27]. Following that effort, we developed a conventional MCG system made of MgB 2 .…”