| Project/Area Number |
01550265
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子通信系統工学
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| Research Institution | Chiba Institute of Technology (1991)
Osaka University (1989-1990) |
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Principal Investigator |
MORITA Nagayoshi Chiba Institute of Technology Dept. of Electrical Eng., Professor, 工学部, 教授 (40029137)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1990: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1989: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Hyperthermia / Electromagnetic Heating / Waveguide Applicator / Power Loss Distribution / Temperature Distribution / FD-TD Analysis / Deep Seated Tumor Heating / 電磁加温 / 導波器アプリケ-タ / ハイパ-サ-ミア・アプリケ-タ |
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| Research Abstract |
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 are
1. 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.
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