A STUDY OF DIELECTRIC ANISOTROPY IN DEHYDRATED CORTICAL BONE

The complex permittivity of dehydrated bovine femoral bone has been st udied in vitro, in the three orthogonal directions from 1 kHz to 3 MHz , as part of an analysis of the various factors involved in the dielec tric behavior of fluid-saturated cortical bone. In this study the bone 's physical structure reveals its anisotropic nature by its dependence on both the real and imaginary parts of permittivity on the orientati on of the applied electric field. The real permittivity and the total conductivity are generally higher in the longitudinal direction than i n the other two transverse directions, with the tangential direction p resenting values between those of the longitudinal and radial directio ns and closer to the former. The high frequency limit of the real part of the permittivity was found to be around 10 and its low frequency l imit is of the order of 1000. The dispersion parameters of relaxation time show values of about 0.4 and the corresponding mean relaxation fr equencies are below 100 Hz.