Localization of current dipole by minimizing entropy of dipole distribution for magnetoencephalography

Issue title: Proceedings from the 17th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2015)

Guest editors: Fumio Kojima, Futoshi Kobayashi and Hiroyuki Nakamoto

Article type: Research Article

Authors: Okawa, Shinpei^{a; *} | Nara, Takaaki^b

Affiliations: [a] Department of Medical Engineering, National Defense Medical College, Tokorozawa, Saitama, Japan | [b] Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan

Correspondence: [*] Corresponding author: Shinpei Okawa, Department of Medical Engineering, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan. E-mail:okawa@ndmc.ac.jp

Abstract: A method to reconstruct the current dipoles in human brain for magnetoencephalography was examined. In the method, a spatial filter provided the initial guess of the current dipole distribution. Then the current dipoles were localized by minimized the entropy calculated with the current dipole distribution. The reconstructed dipole moments were corrected in a post processing. In the numerical simulations the proposed method was compared with the focal underdetermined system solver (FOCUSS) which reconstructed a sparse distribution of the current dipoles. The proposed method was able to reconstruct the current dipoles more robustly than FOCUSS from the measured magnetic fluxes with low signal-to-noise ratio.

Keywords: Inverse problem, magnetoencephalography, biomedical engineering

DOI: 10.3233/JAE-162192

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 1-2, pp. 73-78, 2016