Power density, field intensity, and carrier frequency determinants of RF-energy-induced calcium-ion efflux from brain tissue.


Journal Article

To explain a carrier frequency dependence reported for radiofrequency (RF)-induced calcium-ion efflux from brain tissue, a chick-brain hemisphere bathed in buffer solution is modeled as a sphere within the uniform field of the incident electromagnetic wave. Calculations on a spherical model show that the average electric-field intensity within the sample remains the same at different carrier frequencies if the incident power density (Pi) is adjusted by an amount that compensates for the change in complex permittivity (epsilon *r) and the change of wavelength, as a function of carrier frequency. The resulting formula for transforming Pi is seen to follow the pattern of both positive and negative demonstrations of calcium-ion efflux that have been observed at carrier frequencies of 50, 147, and 450 MHz. Indeed, all results obtained at these three frequencies, when related by Pi's that produce the same average electric-field intensity within the sample, are seen to be in agreement; no prediction is contradicted by an experiment.

Full Text

Duke Authors

Cited Authors

  • Joines, WT; Blackman, CF

Published Date

  • 1980

Published In

Volume / Issue

  • 1 / 3

Start / End Page

  • 271 - 275

PubMed ID

  • 7284025

Pubmed Central ID

  • 7284025

International Standard Serial Number (ISSN)

  • 0197-8462

Digital Object Identifier (DOI)

  • 10.1002/bem.2250010303


  • eng

Conference Location

  • United States