Caracterização da taxa de absorção específica e do aumento de temperatura no olho humano devido a campos eletromagnéticos emitidos por dispositivos de comunicação sem fio

• Ano de defesa: 2015
• Autor(a) principal: Dalmy Freitas de Carvalho Júnior
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Campos eletromagnéticos; Distribuição de temperatura; Olho humano; Taxa de absorção específica; Absorção; Campos eletromagneticos; Olhos; Engenharia elétrica; Temperatura; Microondas
• Link de acesso: http://hdl.handle.net/1843/BUBD-A8GNEE

The objective of this thesis is to calculate the specic absorption rate (SAR) and the temperature increase induced in the human eye when exposed to wireless radiation (1.9 GHz, 2.4 GHz, 5.1 GHz and Multi RF) at distances of 30, 15 and 2 cm. For this work, only wireless communication devices with power density up to 183 mW/m2 were considered. In this work, it was developed a detailed and precise three-dimensional computer model of the human eye, including the cornea, aqueous humor, iris, lens, the muscles, the vitreous, retina, choroid and sclera.The nite-dierence time-domain method (FDTD) was used for the numerical solution of the dierential equations that describe the physical problem concerning the temperature increase in the human eye. From Maxwell's equations, the FDTD was employed to calculate the electromagnetic elds and SAR, and from the bioheat equation, the FDTD was used to compute the temperature increase, taking the SAR to couple the equations. The resolution used was 0.05 mm. The results obtained from the SAR in the human eye show that for the distance of 2cm the limit of 2 W/kg, recommended by international standard, was exceeded in all tissues. Regarding the Multi RF source, it was found exceeding threshold values of 2 W/kg for distances of 15 cm in the vitreous humor and 2 cm in all tissues of the human eye. It was observed that the temperature in the lens above values described in the literature was only found when the source was situated 2 cm away from the eye, which indicates possibility of causing damage in the lens tissue. It was also veried that the frequency of 5.1 GHz is the most favorable tothe crystalline heating.