Reconstruction of the human heart functional structure based on a few-channel magnetocardiogram

The new method of magnetocardiography data analysis is proposed. The method is based on the Fourier transform of prolonged time series and on the massive inverse problem solution for all spectral components. Magnetocardiograms (MCG) were registered in the plane above the subject’s chest in the nodes of the “rectangular” (6$\times$6) grid with the step 40 mm at usual laboratory conditions without any additional magnetic shielding. The 9-channel MCG-system “MAG-SCAN-09” with dc-SQUID-based axial second order gradiometers was used. The MCG-recording was performed in four positions of investigated subjects under the instrument to get all 36 MCGs. For each of four positions of the MCG-recording the partial functional tomogram was calculated, which is the spatial distribution of elementary magnetic dipoles, observed in this position. The complete functional tomogram of the thorax was obtained by the summation of four partial functional tomograms, containing the data about the same object, observed from various positions. Filtering and contrasting of the complete functional tomogram made it possible to extract the 3D-object, representing the functional structure of the heart. The method was used for five subjects and provided consistent results. It is possible to use this method in cardiography, because the functional tomogram contains all measured information about individual heart.