摘要
本文系统阐述生物电磁计量学的研究内容、方法与最新研究进展。围绕生物电磁计量学的目标任务,介绍了其所涉及主要内容,即真实三维人体模型与头模型;生物组织介电特性(电导率、介电常数)的频率依赖关系;数值计算方法(阻抗法、时域有限差分法)及电磁辐射安全评估的国内外标准等。作为典型的低频电磁计量学的实例,给出了核磁共振梯度场电磁辐射安全评估的结果;作为典型的高频电磁计量学的实例,给出了手机电磁辐射的安全评估结果与静电放电电磁脉冲辐射在人体中感应电场的分布特点。本文所列的分析方法,可用于解决任意频率电磁辐射的安全评估,也可为非电离电磁辐射安全标准的制定提供支撑。
The major research aspects and the recent developments related with the bioelectromagnetic dosimetry have been presented.Details about the numerical bioelectromagnetic dosimetry have been discussed.This includes the development of realistic human body and head models;the calculation of frequency dependence of tissue properties such as conductivity and permittivity;the introduction of numerical methods such as impedance method and finite difference time domain;and the international standards of safety assessment etc.As an example of typical low-frequency dosimetry,the safety assessment of MRI gradient magnetic fields was presented.As examples of typical high-frequency dosimetry,the safety assessment of mobile phone exposure and the electrostatic discharge(ESD)pulse were presented.The analysis method in this paper can be applied to safety assessment for most situations of electromagnetic exposures with any working frequency.It also provides supports for formulating the safety guidelines for non-ionizing radiation to electromagnetic fields.
引文
[1]IARC.Non-Ionizing Radiation,Part 1:Static and Extremely Low-Frequency(ELF)Electric and Magnetic Fields.IARC Monographs on the Evaluation of Carcinogenic Risks to Humans[R].2002:1-395.
[2]World Health Organization,PRESS RELEASE.N°208.IARC Classified Radiofrequency Electro-magnetic Fields as Possibly Carcinogenic to humans(Group 2B),http://www.iarc.fr/en/media-centre/pr/2011/pdfs/pr208_E.pdf[R],2011.
[3]European Commission 2004 Directive2004/40/EC of the European Parliament and of the Council of 29 April 2004 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents(electromagnetic fields).Official Journal of the European Union L 159 of30 April 2004,and corrigenda L 184 of 24 May2004.[S]
[4]刘文魁,庞东.电磁辐射的污染及防护与治理[M].北京:科学出版社,2003.
[5]姜槐.工频磁场与癌症发生的关系以及对健康影响的研究[J].中华劳动卫生职业病杂志.1999.12(6):322-323.
[6]姜槐,许正平.电磁辐射与人体健康[J].中华劳动卫生职业病杂志.2002,20(1):241-242.
[7]Orcutt N and Gandhi,OP.A 3-D impedance method to calculate power deposition in biological bodies subjected to time varying magnetic fields[J],IEEE Trans.Biomed.Eng.,1988,35(8):577-583.
[8]Sullivan DM,Gandhi OP,Taflove A.Use of the finite-difference time-domain method for calculating EM absorption in man models[J].IEEE Trans.Biomed Eng.,1988,35(3):179-186.
[9]Ackerman MJ.The visible human project[J].Proc.IEEE,1998,86(3):504-511.
[10]Christ A,Kainz W,Hahn EG,Honegger K,Zefferer M,Neufeld E,et al.The Virtual family-development of surface-based anatomical models of two adults and two children for dosimetric simulations[J].Phys.Med.Biol.2010,55(2):N23-N38.
[11]Cole KS and Cole RH,Dispersion and absorption in dielectrics:alternating current characteristics[J].J.Chem.Phys.,1941,9(4):341-351.
[12]Gabriel C,Gabriel S,and Corthout E,The dielectric properties of biological tissues:I.Literature survey[J].Phys Med and Biol,1996,41(11):2231-2249.
[13]Gabriel S,Lau RW and Gabriel C.The dielectric properties of biological tissues:II.Measurements in the frequency range 10 Hz to20 GHz,Phys.Med.Biol.,1996,41(11):2251-2269.
[14]Gabriel S,Lau RW and Gabriel C,The dielectric properties of biological tissues:III.Parametric models for the dielectric spectrum of tissues[J].Phys Med.and Biol.1996,41(11):2271-2293.
[15]Lu M,Ueno S,Thorlin T and Persson M.Calculating the current density and electric field in human head by multichannel transcranial mgnetic stimulation[J].IEEE Trans.Magn.2008,45(3):1662-1665.
[16]Nadeem,M.Hamnerius,Y.Mild,KH.Persson,M.Magnetic field from spot welding equipment-Is the basic restriction exceeded?[J].Bioelectromagnetics,2004,25[4]:278-284.
[17]Yee KS.Numerical solution of initial boundary value problems involving Maxwell’s equations in isotropic media,IEEE Trans.Antenn Prop[J].1966,14(3):302-307.
[18]牛中奇,侯建强,周永军,王海彬,卢智远.生物电磁剂量学及人体吸收电磁剂量的数值分析[J].中国生物医学工程学报,2006,25(5):580-584.
[19]Institute of Electrical and Electronics Engineers(IEEE).C95.1 IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields,3 k Hz to 300GHz.2005[S].(New York:IEEE)
[20]International Commission on Non-Ionizing Radiation Protection(ICNIRP).Guidelines for Limiting Exposure to Time-Varying Electric,Magnetic,and Electromagnetic Fields up to 300GHz.Health Physics[J].1998,74(4):494-522.
[21]杨新村,李毅.WHO国际电磁场计划的评估结论[R].2008.中国电力出版社.
[22]环境保护部,电磁环境控制限值[S].2014.中国环境科学出版社.
[23]Lu M,Ueno S,Dosimetry of Exposure of Patients to Pulsed Gradient Magnetic Fields in MRI[J],IEEE Trans.Magn.2011,47(10):3841-3844.
[24]Lu M,Ueno S,Comparison of specific absorption rate induced in brain tissues of a child and an adult using mobile phone[J],J.Appl.Phys.2012,111(7):07B311.
[25]刘尚合,魏光辉,刘直承,等.静电理论与防护[M].北京:兵器工业出版社,1999.
[26]刘尚合,武占成.静电放电及危害防护[M].北京:北京邮电大学出版社,2004.
[27]刘尚合,周万珍,孙秋红.静电放电电磁脉冲理论建模与作用机理研究进展[J].河北科技大学学报,2005,26(2):87-92.
[28]满梦华,巨政权,原青云,周永学,原亮,刘尚合基于电磁仿生概念的静电放电注入损伤防护模型设计[J].高电压技术,2011,37(2):375-381.
[29]Yuan ZY,Li T,He JL,Chen SM,Zeng R,New mathematical descriptions of ESD current waveform based on the polynomial of pulse function[J].IEEE Transactions on Electromagnetic Compatibility,2006,48(3):589-591.
