Main description:

The objective of this book is to describe techniques to investigate the behaviour of electric fields and induced currents in the human body exposed to different scenarios of extremely low frequency (ELF) high voltage-low current electromagnetic fields by means of numerical modelling with improved Boundary Element Methods (BEM). A novel improved BEM approach is introduced in order to solve this type of problem, leading to more accurate results and more efficient calculations. The mathematical formulation for the case of human exposure to ELF electromagnetic fields departing from Maxwell equations and for the electrical properties of biological tissue is provided. Also, a variety of three dimensional anatomically shaped human body models under different exposure conditions are presented and solved. This developed methodology is applied to three different case studies: (i) overhead power transmission lines, (ii) power substation rooms, and (iii) pregnant woman including foetus and evolving scenarios. In all cases, a sensitivity analysis investigating the influence of varying geometrical and electrical properties of the tissues has been conducted.The results obtained from this research allow us to identify situations of high and low exposure in the different parts of the body and to compare with existing exposure guidelines.

Contents:

Chapter 1: Introduction Extremely low frequency exposure; Computational dosimetry at ELF Chapter 2: ELF Electromagnetic exposure Introduction; EM exposure. Basic concepts; Theoretical model for ELF; Different sources of exposure at ELF; Summary Chapter 3: Dielectric properties of biological tissues Introduction; Modelling biological systems; Available data on dielectric properties; Theoretical aspects. Biological matter in electric field; General dielectric properties of some tissues; Biological tissue at ELF; Summary Chapter 4: Numerical method Introduction; Integral formulation; Boundary discretisation; Internal solution; Continuous and discontinuous boundary element method; Staggered boundary element; Analytical approach for the integrals; Accuracy tests; Summary Chapter 5: Exposure to overhead power lines Introduction; Physical model; Human body modelling; Numerical implementation. Extreme and minimal domain decomposition; Global results; Analysis of the refinement of geometry; Analysis of variations on conductivity; Summary Chapter 6: Exposure in power substations rooms Introduction; Induced currents in the human body inside a power substation room; Induced currents in the human body resulting from the proximity to surfaces at fixed potentials; Summary Chapter 7: Pregnant woman Introduction; Physical model; BEM for vertically incident field in open environments; Numerical implementation; Results and discussion; Summary Chapter 8: Conclusions Concluding remarks