Direct method for reconstruction of multiple equivalent current dipoles

We propose a novel parametric algorithm to reconstruct positions, moments and number of equivalent current dipoles directly from instantaneous MEG data. In our method, the source positions projected on the xy-plane are obtained by solving an eigenvalue problem, whereas the z-coordinates of the positions and moments are reconstructed by solving linear equations. By diagonalizing the Hankel matrix consisting of multipole moments, the number of the ECDs are reasonably estimated. Numerical simulations show that the number and the xy-plane projected positions of centroids of patches are well estimated, which can at least give an initial guess for conventional iterative algorithms.