Simulation of induced current densities in the human body at industrial induction heating frequencies

At industrial workplaces in the vicinity of induction heating and melting d evices workers are exposed to strong magnetic fields. Up until now, only li ttle knowledge about the coupling of external fields into the human body at low frequencies existed. This paper provides numerical investigations to c larify the ratio between external homogeneous' magnetic fields and induced current densities inside the human body in the frequency range from 250 Hz up to 10 kHz. The finite-difference time-domain (FDTD) method is used to ca lculate the induced current density in a realistic inhomogeneous 1-cm-resol ution human body model with appropriate tissue parameters. The magnitude of the external magnetic held equals the reference value for occupational exp osure in the current guideline of the International Commission on Nonionizi ng Radiation Protection (ICNIRP). It was found that the calculated maximum current densities inside the body may exceed the basic restrictions of the ICNIRP guideline at least up to a factor of two. Finally, the suitablility of the human body model-for dosimetric investigations is discussed in view of fine-resolution models presented in the literature.