Channel Capacity of Multichannel Magnetometers

  • P. K. Kemppainen
  • R. J. Ilmoniemi


We have applied Shannon’s theory of communication to develop a figure of merit for the comparison and optimization of multichannel magnetometers. This new measure is the channel capacity of the equipment in conveying information about cerebral currents. Like other figures of merit (Abraham-Fuchs et al., 1988; Carelli and Leoni, 1986; Erné 1985; Knuutila and Hämäläinen, 1989), it is a function of the SQUID noise level, the coil configuration, and the distance of the sensor array from the brain. Channel capacity as a cost function enables us to compare the marginal utility of different parameters, for example, of additional channels or a reduced brain-sensor distance, without specific source models.


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Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • P. K. Kemppainen
    • 1
  • R. J. Ilmoniemi
    • 1
  1. 1.Low Temperature LaboratoryHelsinki University of TechnologyEspooFinland

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