MIセンサアレィにょる心臓磁場計測

摘要

Magnetocardiogram (MCG) measurement is useful for clinical applications because it can reconstruct the magnetic field distribution of the heart activity from the measurement data at a high spatial resolution. However, the SQUID magnetometer used in MCG measurement has problems such as the high cost of equipment, a high running cost due to the use of liquid helium, and the necessity of a magnetically shielded room. Thus, there is desire for a liquid-helium-less, low-cost system that operates without shielding. We tried MCG measurement by using the magneto-impedance sensor (MI sensor) that is cheaper than the SQUID magnetometer and that can be used at room temperature. We developed an MCG measurement system by using an 8 × 8 MI sensor array with an active magnetic canceller. This system can measure MCGs without a magnetically shielded room by applying the active magnetic canceller and a method that reduces magnetic noise by using the space and time information of the sensor array. As a result, we successfully measured MCGs outside a magnetically shielded room. In this paper, we outline the above content.