Magnetic noise rejection in the MCG using independent component analysis.

In magnetocardiogram (MCG) measurements, the magnetic noise from any magnetic wire, used to suture the sternum after heart surgery, becomes a problem. As one method of noise rejection, independent component analysis is seen here to be effective. In this study, MCG measurements were carried out under conditions where a wire was attached to a normal subject, also where no wire was attached. Signal processing by independent component analysis was carried out in order to reduce the effect of magnetic noise from the wire. From the comparison of the waveforms after this signal processing and the waveforms where the wire was not attached, it was apparent that the magnetic noise from the wire was reduced. Thus, we have shown that independent component analysis is effective for the reduction of magnetic noise from a magnetic wire, in MCG measurements.