Numerical Realization of Realistic Head and Hand Models for Mobile Telephone Safety Verification

Abstract

A realistic head model for use in numerical electromagnetic dosimetry was realized from a Magnetic Resonance Image (MRI) scan of a human head. Before a useful segmented image was obtained, the original image had to be purged of rogue data points and the effects of image fading had to be compensated. A tissue-classification software package was created with which each voxel of the image could be coloured according to tissue type. Several tissues in the head were found to be suitable for semi-automatic classification. Discontinuities present in the head image after the initial classification were reduced by means of an algorithm based on minimum surface energy.An attempt was also made to develop an articulated and more realistic model of the human hand than is currently used numerical studies of mobile telephone dosimetry. The proposed structure of the hand consists only of the essential details necessary to obtain an acceptable degree of realism for the manner in which the mobile telephone is gripped. With this in mind, the hand was modelled with a block palm with circular cylindrical digits. Interior to the hand, 18 bones (metacarpals and phalanges) were also included, at the joints of which various rotations could be specified. The orientation of the hand and the posture of the digits are determined by specification of 23 angles.