论文信息 - Heating within spheres of different size irradiated by an electromagnetic plane wave

Heating within spheres of different size irradiated by an electromagnetic plane wave

This paper presents the results obtained by multiphysics (electromagnetic and thermal) numerical simulations which show the influence of the size in two different spheres that are irradiated by an electromagnetic plane wave. Each sphere is constituted by a series of concentric layers that emulate the tissues in the head. A 10 mW/cm2 plane wave is used as source, and the frequency is setup to 1.8 GHz. The power absorbed per unit volume by the tissues (W/m3) is calculated by using the 3-D Finite Difference Time Domain (FDTD) method. Then, temperature inside the spheres is calculated by using a Finite Differences (FD) formulation of the heat diffusion equation. Two different ways of calculating the power-loss density are presented, and validated with analytical results. It is observed that the increase of temperature inside a 66 mm sphere is higher than inside a 100 mm sphere. However, the power absorbed per unit volume in the brain zone is six times higher in the 100 mm sphere.

[1] K. Mei,et al. Penetration of a focused electromagnetic pulse into a biological material and its application to hyperthermia , 1989, Digest on Antennas and Propagation Society International Symposium.

[2] K. Yee. Numerical solution of initial boundary value problems involving maxwell's equations in isotropic media , 1966 .

[3] F. Torres,et al. Complete FDTD analysis of microwave heating processes in frequency-dependent and temperature-dependent media , 1997 .

[4] A. Taflove,et al. Computation of the Electromagnetic Fields and Induced Temperatures Within a Model of the Microwave-Irradiated Human Eye , 1975 .

[5] R. Lutomirski,et al. Induced Fields and Heating Within a Cranial Structure Irradiated by an Electromagnetic Plane Wave , 1971 .

[6] G. Mur. Total-field absorbing boundary conditions for the time-domain electromagnetic field equations , 1998 .

[7] Yilong Lu,et al. Electromagnetic and thermal simulations of 3-D human head model under RF radiation by using the FDTD and FD approaches , 1996 .

[8] T M Uusitupa,et al. The effect of finite-difference time-domain resolution and power-loss computation method on SAR values in plane-wave exposure of Zubal phantom. , 2008, Physics in medicine and biology.