Magnetocardiographic Functional Localization.

摘要

The thesis considers the basic principles and mathematical modeling of magnetocardiographic source localization. In the beginning, the genesis of biomagnetic fields is presented briefly for the background. Most localization studies require the solution of the forward problem, i.e. solution of the external potential and magnetic field for a given source configuration and volume conductor. The forward problem is considered both for a current dipole source in realistically shaped boundary element models, and for a propagation model of the bioelectric excitation in normal myocardial tissue. The basic goal in most MCG mapping studies is to solve the inverse problem, i.e. to determine the source currents from measured external fields. The solution of the inverse problem is presented both for equivalent point sources in different volume conductor models, and for a minimum-norm approach dealing with distributed sources. Both simulation results and applications to measured MCG data are considered. In the end, some instrumentational aspects and validation of the localization results are discussed. Some modeling problems and future aspects are also viewed.