A model of several dipoles in free space in the primary processing of magnetocardiographic data

The magnetic field of a dipole in an inhomogeneous conductive medium (the human body) is considered. The magnetic field consists of the primary field and the secondary field produced by induced conduction currents. It is shown that, in many cases, the secondary field can be described as the field of a single secondary dipole in free space. The dipole location in the vicinity of the boundary of an electric conductivity inhomogeneity is confirmed in simulations. It is shown that, when the dipole fields in an inhomogeneous object are analyzed with the use of the model of several dipoles in free space, it is possible to characterize the location of conductivity boundaries inside the body. This data can be used to develop a more adequate model that takes into account the effect of the conductivity jump at the heart boundary. Such an improved model can be used for the further refinement of the positions of primary dipole sources.