Conference,
Validation of numerical dosimetry for contact current exposure with the actual measurement of induced electric field inside phantom in intermediate frequency band
(2013)
Abstract
Currently, new technologies using intermediate frequency electromagnetic field
(EMF) has spread to our daily life, for example induction heating (IH) hob, wireless power
transmission system, and so on. These equipments may induce voltage on the surface of
peripheral objects. Contact current is caused by different potentials between those objects and
the human body, and that is indirect coupling human body with EMFs. Numerical simulations
are the general trend for the dosimetry to estimate contact current. However, there is no
experimental investigation to evaluate estimated contact current. It is warrant to perform the
validation of numerical dosimetries by using experimental measurement.
In this study, an experimental system is constructed to measure induced electric fields due to
contact current. Two phantom models that are made from blood and skin of pig are developed
for this system. To suppress electrochemical reactions as small as possible on the surface of
electrode, effective value of voltage set to 1 OOm V between two electrodes. Lock-in amplifier
is used to detect small signal from the electric field prove. Induced electric field distributions
are measured by sweeping the electric field probe inside the phantoms at lkHz, 1 OkHz, and
1 OOkHz. 2 dimensional (2D) distributions of induced electric field vectors are obtained at
intervals of 1 Omm grid. Measured 2D electric field distributions are appropriate for quasistatic
theory of EMF. Measurement results are compared with results obtained by the quasistatic
FDTD method. We found that, numerical results have good agreement with
experimental results. Typical deviation between the two results is approximately from 30% to 40%.
