Biomag 96 pp 892-895 | Cite as

Separation of Overlapping Sources Induced by Mixed Stimulations Using 3-Dimensional MEG Mappings

  • Y. Uchikawa
  • K. Kobayashi
  • K. Sakawa
  • M. Kotani
Conference paper

Abstract

There is a problem of separating multi-sources overlapping in time when many distinct areas of the cortex are active. Several methods for evaluating source localization from spatio-temporal MEG data have been reported[1],[2],[3],[4]. Almost all SQUID magnetometers for MEG study are for measuring magnetic field perpendicular to the scalp. There is a limitation in spatial resolution, using flux-detection coils with finite radius in regular devices, to separate multi-sources [5]. To get more accurate information about source configuration, we have proposed a new 3-D measurement of MEG, namely vector magnetoencephalogram [6].

Keywords

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References

  1. [1]
    Smith, W. E., Estimation of the Spatio-Temporal Correlations of Biological Electrical Sources from Their Magnetic Fields, IEEE Trans. Biomed. Engng., 1992, 39: 997–1004.CrossRefGoogle Scholar
  2. [2]
    Baumgartner, C., Sutherling, W. W., Shi Di and Barth, D.S., Spatiotemporal modeling of cerebral evoked magnetic fields to median nerve stimulation, Electroencephalography and clinical Neurophysiology, 1991, 79: 27–35.CrossRefGoogle Scholar
  3. [3]
    Achim, A., Richer, F. and Saint-Hilaire, J.M., Methodological considerations for the evaluation of spatio-temporal source models, Electroencephalography and clinical Neurophysiology, 1991, 79: 227–240.CrossRefGoogle Scholar
  4. [4]
    Achim, A., and Richer, F., Methods for Separating Temporally Overlapping Sources of Neuroelectric Data, Brain Topography, 1988, 1: 22–28.CrossRefGoogle Scholar
  5. [5]
    Okada, Y., Discrimination of localized and distributed current dipole sources and localized single and multiple sources, Biomagnetism:Applications and Theory, ed. by H. Weinberg, G. Strolnk, T. Katila, 1985: 266–272.Google Scholar
  6. [6]
    Uchikawa, Y., Matsumura, F., Kobayashi, K. and Kotani, M., Application to Discrimination of Multi-Sources to Somatosensory Evoked field using 3-Dimensional second-order gradiometer, In: Deecke, L., Baumgartner, C., Stroink, G. and Williamson, S.J. (eds.), Biomagnetism: Fundamental research and clinical application, 1993: 219–220.Google Scholar
  7. [7]
    Ahonen, A., Hamalainen, M., Kajola, M., Knuutila, J., Lounasmaa, O., Simola, J., Tesche, C., and Vilkman, V., Multichannel SQUID systems for brain research, IEEE Trans. Magn., 1991, 27: 2786–2792.ADSCrossRefGoogle Scholar
  8. [8]
    Cohen, D., Proc. 12th Intern. Conf. on Med. and Bio. Eng., Jerusalem, Israel, 1979.Google Scholar

Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • Y. Uchikawa
    • 1
  • K. Kobayashi
    • 1
  • K. Sakawa
    • 1
  • M. Kotani
    • 2
  1. 1.Faculty of Science and EngineeringTokyo Denki UniversitySaitamaJapan
  2. 2.Faculty of EngineeringTokyo Denki UniversityChiyodaku, TokyoJapan

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