Assessment of SAR in human body model with the cochlear implant inside a railway vehicle

Abstract

This article details simulation and analysis of electromagnetic field distribution within a railway vehicle, with special focus on distribution thereof in human body phantom with a cochlear implant. Research was carried out using modelling of electromagnetic fields based on the Finite Integration Method. Simulations were performed and analysed in cases where passengers were exposed to long-term radiofrequency field stemming from the use of mobile phones during railway transport. Results were evaluated based on the specific absorption rate (SAR) – the measure of electromagnetic energy absorption in the body (in watts per kilogram [W/kg]). Dual band (900 and 1800MHz) PIFA antennas were designed and employed as radio frequency sources. The homogeneous passenger model includes a cochlear implant and dielectric properties are set according to the evaluated frequency band. Results have shown that the calculated maximum values of SAR are higher than those established within the European maximum SAR limit and additionally, the obtained values are higher than values obtained in simulation in open space.