MEASURED AND EXPECTED COLE PARAMETERS FROM ELECTRICAL-IMPEDANCE TOMOGRAPHIC SPECTROSCOPY IMAGES OF THE HUMAN THORAX

Electrical impedance tomographic spectroscopy (Errs) images have been recorded from a group of 12 normal subjects using frequencies from 9.6 kHz to 1.2 MHz. The impedance changes with frequency have been modell ed on a pixel by pixel basis to produce parametric images as a means o f characterizing tissue. The modelling was based on the Cole equation. The lungs are seen as areas of high characteristic frequency and low time constants SC and RS. The R/S images are much less uniform over th e region of the lungs. Values characterizing the lung and cardiac regi ons are given. The results appear to be consistent with a model for th e lungs whereby the model parameters can be related to alveolar struct ure and composition.