IMPEDANCE METHOD COMPUTATION OF INDUCED CURRENTS IN A SIMPLE-MODEL OFA CHILD EXPOSED TO ELECTROMAGNETIC-FIELDS OF AN ELECTRIC BLANKET

The three dimensional impedance method has been used to calculate the distribution of induced current densities in a simple model of an 8-y- old child exposed to the electric and magnetic fields of an electric b lanket. Two types of electric blankets have been modeled in the calcul ations, the pre-1989 conventional type and the presently available low magnetic field PTC (positive temperature coefficient) electric blanke t, The purpose of this study was to calculate and compare the induced current densities in the model of the child due to the two types of bl ankets and also to compare the contributions to the induced currents b y the electric and magnetic fields produced by the two types of blanke ts, The computations have shown that as expected and claimed, the indu ced current density in the model of the child due to the magnetic fiel d of the low magnetic field PTC electric blanket is much lower than th e induced current density due to the magnetic field of the conventiona l electric blanket, However, the computations have also shown that the contribution to the total current density by the electric field of th e low magnetic field electric blanket is slightly higher than that due to the electric field of the conventional electric blanket. Hence, th e total average induced current density due to both the electric and m agnetic fields in the case of the low magnetic field PTC electric blan ket is about one-third that in the case of the conventional electric b lanket.