Research On The Hyperthermia Treatment On The Tumor Exposed To The Ultra-wide Band Electromagnetic Pulse

The main objective of this paper is to study the biological response of tissueobtaining tumor exposed in the radiation of1-11GHz broadband pulse signal. Themodeling software used in this paper is a commercial software named XFDTD6.3based on the finite difference time domain (FDTD) algorithm. Firstly we establish the2-D model of the organization with the mesh grid size of1mm×1mm×1mm. The modelcontains three materials: tumor tissue, fat tissue and deionized-water as the couplingmedium between biological tissue and free space. The electrical characteristics oforganizations which change varies frequency can be solved with Debye equation. Theconductivity of tumor tissue is4.82S/m and relative dielectric constant is50.74at6GHz, while the conductivity of fat tissue0.4S/m and relative dielectric constant9.8.Secondly, with the different positions of tumor in fat tissue, we manage to make sure thetime-delay of every antenna unit for maximum electromagnetic energy at the tumor’sposition. Thirdly, SAR and temperature calculation programs based on specific formulaare designed in MATLAB software, then we draw the SAR distribution and temperaturedistribution of the whole biological model. At last we analyze the data of SAR andtemperature at the request of tumor hyperthermia treatment.At the analysis of distribution of SAR and temperature in this paper, we considertwo positions: tumor in the center of the fat tissue and not in the center. With the tumorin the center, the edge temperature between tumor and fat is above41.5oC, while thecenter of the tumor is above48oCand the border of the fat tissue39.4oC. Thesetemperature dada comply with the requirement of clinical tumor heat treatment. Whenthe tumor is not in the center, the tumor edge temperature is41.75oC, the maximumtemperature in tumor is49.43oCand the border temperature of fat tissue is41.46oCwhich is thought in the requirement of tumor hyperthermia treatment.