| 摘要 |
PURPOSE:To improve the estimation accuracy by estimating tentatively a living body action current source from magnetic field data in a direction vertical to the surface of a living body and subsequently estimating only the vicinity of the position of the living body action current source by using magnetic field data in three directions to a precise model for which electric conductivity of the inside of the living body is set. CONSTITUTION:From measuring data Bra, Brb and Brc in three directions of a magnetic field by a living body action current which appears in a brain, magnetic field data Brd in a direction vertical to the surface of the head part is derived. A current source Mojik of arbitrary position, size and direction is assumed. Magnetic data in the vertical direction is calculated by the number of channels by the current source Mojik and a square error to the magnetic field data Brd is derived and a current source M1(obj) in which the square error becomes minimum is estimated. Subsequently, with respect to the precise model of plural requests for which electric conductivity of a head part shape is set, respectively, a magnetic field generated in three directions by the current source M1(obj) is calculated by the number of channels, a square error to the magnetic field data Bra, Brb and Brc measured already is derived, a position, size and a direction of the current source are varied successively, and the current source in which the square error is minimum is obtained. |
