A model for frequency dependence of conductivities of the live human skull.
A mathematical model (sigma(omega) approximately equal to A omega alpha, where, sigma is identical with conductivity, omega = 2 pi f is identical with applied frequency (Hz), A (amplitude) and alpha (unit less) is identical with search parameters) was used to fit the frequency dependence of electrical conductivities of compact, spongiosum, and bulk layers of the live and, subsequently, dead human skull samples. The results indicate that the fit of this model to the experimental data is excellent. The ranges of values of A and alpha were, spongiform (12.0-36.5, 0.0083-0.0549), the top compact (5.02-7.76, -0.137-0.0144), the lower compact (2.31-10.6, 0.0267-0.0452), and the bulk (7.46-10.6, 0.0133-0.0239). The respective values A and alpha for the respective layers of the dead skull samples were (40.1-89.7, -0.0017-0.0287), (5.53-14.5, -0.0296 - -0.0061), (4.58-15.9, -0.0226-0.0268), and (12.7-25.3, -0.0158-0.0132).
Department of Physics and Astronomy, The University of New Mexico, Albuquerque, NM, USA.
M
M
Akhtari
H C
HC
Bryant
D
D
Emin
W
W
Merrifield
A N
AN
Mamelak
E R
ER
Flynn
J J
JJ
Shih
M
M
Mandelkern
A
A
Matlachov
D M
DM
Ranken
E D
ED
Best
M A
MA
DiMauro
R R
RR
Lee
W W
WW
Sutherling
D000465:Algorithms; D000704:Analysis of Variance; D003198:Computer Simulation; D004553:Electric Conductivity; D017097:Electric Impedance; D004566:Electrodes; D004569:Electroencephalography / Q000379:methods; D005781:Gelatin Sponge, Absorbable; D006801:Humans; D066298:In Vitro Techniques; D015225:Magnetoencephalography / Q000379:methods; D008954:Models, Biological; D012886:Skull / Q000502:physiology*