SUMMARY
In recent years, institution has increased imposition of electromagnetic radiation in many applications. This radiation react with the human tissue and may lead to harmful and injurious effects on human health. However a finite difference thermal model of lossy medium as (spinal cord of human body) has been developed to calculate temperature rises generated in the spinal cord by radiation from cellular telephones with different frequencies. The natural metabolic heat production and the power density absorbed from the electromagnetic field have been evaluated. The specific absorption rate (SAR) was derived from a finite difference time domain model (FDTD) of the spinal cord. This is a numerical analysis is technique used for modeling computational electrodynamics. Aside from the specific absorption rate, through the exposure of radiation is an extremely important parameter while assessing the effects on spinal cord tissue. The heat distribution was calculated using the bioheat equation coupled with Maxwell's equation. A one dimensional finite difference time domain method has been used, some simulations for electromagnetic wave through the spinal cord tissue is made using software program. Also for the simulation, the dielectric properties supposed medium are directly taken by numerical program. Results show that electromagnetic fields penetrate the life tissues and attenuate fast to reach zero at large time steps. Specific absorption rate show maximum at the first boundary of tissue and becomes less value by using high frequency. The absorbent power and specific absorption rate show maximum at the interface of tissue, and the technique developed may be used to estimate temperature rises associated with specific absorption rate (SARs) for different types of radiation. Also, the results note that low-frequency waves have significantly affected the biological tissue.