Measurement of two-dimensional impedance magnetocardiogram. Model experiment

The purpose of this paper is to clarify the relationship between impedance magnetocardiogram (I-MCG) signal and its source position. We measured I-MCG signals that could be obtained above a heart two-dimensionally by inducing a current with high frequency. To record the signals, we used a superconducting interference device (SQUID) that was connected to a pickup coil of first-order-gradiometer type. To ensure the source of I-MCG signals, we measured magnetic field changing to the movement of rubber balloon in water tab. The magnetic field of the balloon model could be obtained around the balloon shape. In comparison between the I-MCG signals and the result of balloon model, the I-MCG signals have the information due to changes of electrical conductivity in a heart. Furthermore, it can be thought that the peak position of I-MCG signals might slightly be different from that of electrical conductivity change.