Calculation of Temperature Rise Induced by Cellular Phones in the Human Head

Ana O. Rodrigues, Juliano J. Viana, Luiz O. C. Rodrigues, Jaime A. Ramirez

Abstract


The problem associated with the calculation of temperature rise induced by cellular phones in the human head taking into account the effects of the thermoregulatory system (TS) is discussed in this work. The formulation uses the finite difference time domain method. The inclusion of the TS considered three modifications in the bioheat equation, which was solved dynamically: first, the convective heat transfer coefficient as a function of the gradient between the skin temperature and the environment temperature; second, the skin blood flow rate as a function of the energy absorved by the skin and by the brain; and third, the temperature in the brain constant at 36.8oC. The bioheat equation was solved for a 3D anatomically based model of the human head composed of 15 tissues. The cellular phone was modeled as a half-wavelength dipole irradiating at 1.8GHz with a power of 120mW. The inclusion of the TS resulted in a maximum temperature rise of 0.029oC in the skin, a value considerably smaller than previously reported. These results suggest that modern cellular phones operating at full power would produce temperature rise in the human head within the basal temperature of these tissues.

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References


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