Magnetocardiogram interference in magnetoencephalographic data: its importance in cases of interictal epileptic data

In this paper, the importance of heart interference to models of magnetic brain activity as measured by magnetoencephalograms (MEG) of epileptic patients is explored. Cases where this is crucial to examine are used as triggers of this discussion. A distributed source modelling technique of brain activity, namely, magnetic field tomography (MFT) provides the context of the methodology used to certify that results obtained are free from cardiac interferences. Different visualisation strategies are employed to further confirm that. These are time depthplots of source activity and global field power measures in association with ECG traces. Finally, possible ECG artifact rejection methods are discussed.