Development Of Bioelectromagnetic Simulation Framework And Electromagnetic Radiation Simulation Application Based On Children Deformable Phantom

Radio frequency electromagnetic radiation has been widely used in the daily life.According to the results of existing research,the absorption of electromagnetic radiation dose of children and adolescents was higher than adults in the daily usage like mobile phone.The International Agency for Research on Cancer has included radio frequency electromagnetic radiation in Category 2B carcinogens.Accurately assess the dose of electromagnetic radiation absorbed by children and adolescents were important.Numerical simulation technology was the primary method for estimating the electromagnetic radiation dose of organisms.This requires the study of the computational electromagnetic calculation platform and the human phantom database that can represent the target population.Commercial computational electromagnetic software has comprehensive features;however,the details regarding the computations are not available to the public.The open-source software was unable to perform EM parallel computing,or to assess the bioelectromagnetic doses,or to implement dispersive media or an effective absorbing boundary.Gender,age,height,weight,size and shape of internal organs will affect the dose of electromagnetic radiation,and the age will affect conductivity and relative permittivity of biological tissues.In order to accurately assess the dose of electromagnetic radiation received by children and adolescents of different physiques in the daily usage,a Chinese children and adolescents phantom database need to be constructed.This work presents a cross-platform open source parallel simulation framework MedFDTD that can meet the research requirements of bioelectromagnetic radiation dose assessment.Based on the Chinese Reference Man?CRM?adult male polygon mesh surface phantom,a Chinese male child phantom database with multiple physiques were constructed.Based on the simulation framework and the Chinese male child phantom database,a research of electromagnetic radiation dose assessment was presented.The MedFDTD was a parallel and open-source cross-platform framework for bioelectromagnetics research.MedFDTD has been developed by solving Maxwell's equations using the finite-difference time-domain?FDTD?method.This framework implements the complex-frequency-shifted perfectly matched layer?CPML?,supports the import of antenna and bioelectromagnetic models through media with non-dispersive/dispersive properties,and can calculate the antenna output power and specific absorption rate?SAR?of biological tissues,thereby making it favorable for bioelectromagnetics studies.In addition,MedFDTD can be implemented on multiple CPUs or a variety of chip-based GPU to accelerate all parallel FDTD computing tasks.According to the distribution and percentile statistical data of Chinese male children's height,weight and physiques,the reference mass of main internal organs,a Chinese male children phantom database were constructed from CRM.The children phantom was constructed with 50^th percentile height and 10^th,50^th and 90^th percentile weight and body circumferences physiques of 11¹2 years old children,to represent the underweight,normal and overweight physique children.The organ adjustment algorithm and arm adjustment algorithm were used to fix the underweight and overweight physique phantom.Based on MedFDTD and the children physique phantom database,this work presents a study to analysis the effect of age and physique to electromagnetic radiation absorbed dose and distribution in children.The results indicate that changes in tissue parameters caused by age will lead to an increase in the whole-body mass average SAR of children,and great changes in the distribution of the electromagnetic radiation absorbed dose.Compared with adults,skin absorb electromagnetic radiation energy capacity of 11¹2 years old children were reduced by 22.21%⁴8.11%.The whole-body mass average SAR of all physique phantom were within the public protection limits of RF electromagnetic waves established by IEEE and ICNIRP.Children phantom with thinner physique will have a higher whole-body mass average SAR.With increases of the electromagnetic wave frequency,the penetration ability of the electromagnetic wave decreases,lead the proportion of the electromagnetic radiation energy absorbed by the skin to increases rapidly,and the proportion of the electromagnetic radiation energy absorbed by the muscle decreases rapidly.Since the standing-wave effects may occur in subcutaneous fat,fat will become the tissue that absorbs most energy from electromagnetic radiation when overweight physique phantom exposed to high-frequency electromagnetic waves.In summary,the present work investigated the bioelectromagnetic simulation framework,Chinese male children deformable phantom database and children absorbed electromagnetic radiation assessment.The bioelectromagnetic simulation framework and Chinese male children deformable phantom database developed in this work have application prospects in the fields of bioelectromagnetism and radiation dose assessment.