Analysis of Temperature Distribution within the Human Body in Electromagnetic Hyperthermia

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In this research project, an algorithm has been completed for calculating electromagnetic fields and power loss distributions within the human body for very practical models which are almost the same as the real models consisting of inhomogeneous human body regions, water bolus regions and waveguide multi-applicator systems. In this algorithm, the following important techniques are accomplished :1. Excitation mechanism by a post situated inside the wavequide applicator is pertinently taken into account to accommodate itself to FD-TD analyzing.2. New absorbing boundary conditions are derived which are useful for the absorbing boundaries located in lossy media such as the human body regions.Also completed in the project is the algorithm for calculating the temperature distributions within the human body changing time-dependently under the influence of the power loss induced by electromagnetic wave irradiation as well as the influence of various cooling effects inherent in the human body and coming from outside the body. An Implicit Alternating Direction method is employed in this algorithm.Moreover, several new findings have been obtained from careful examinations of various numerical results. Typical ones are1. For the hyperthermia multi-applicator system, the TE(Transverse Electric)wave type applicator system is superior over the TM(Transverse Magnetic)wave type system, because better concentration of the power loss distribution in the longitudinal direction of the body is attained by the former system than the latter.2. The water bolus should be used in the limited region near around the heated regions of interest because the water region tends to expand the hot regions unnecessarily.