Finite-Difference Time-Domain Electromagnetic and Thermal Modeling of Skeletal Muscle Exposed to Millimeter Waves.
详细信息
文摘
This thesis describes a systematic process to develop and characterize a geometric computer model of the mouse foot flexor digitorum brevis (FDB) skeletal muscle,which was then used to compute detailed electric fields (E-fields) within the muscle when exposed to 94 GHz millimeter wave (MMW) fields. The purpose of this research was to investigate the possibility that MMW fields can affect the contractile performance of skeletal muscle through non-thermal mechanisms. Experiments performed in our laboratory documented some possible non-thermal effects on the FDB muscle. When electrically stimulated to contract in the presence of 94 GHz MMW fields,the muscle,which was maintained at a constant temperature,exhibited a decrease in contractile force that was not reversible when the fields were removed. It was not known if high E-fields or temperature changes were occurring within the muscle that could potentially cause such performance deviations. Since it was not possible to measure E-field and temperature distributions within the muscle due to its very small size,computer simulations of these experiments were needed to predict these distributions. To accomplish this,a highly detailed geometric computer model of the FDB muscle was developed and assigned appropriate dielectric properties,which are necessary for EM simulation. Then detailed numerical calculations of the E-fields and temperature changes within the muscle were performed using commercially available Finite-Difference Time-Domain (FDTD) software. Analysis of the results showed little evidence of E-field or temperature "hot spots" within the muscle,which would indicate that the effects observed in the laboratory were non-thermal in nature.