Investigation of the electrical conductivity in perfused liver using micro electrical probe

Abstract

In this paper, we present the design, fabrication and calibration of new micro machined electrical probe and experimental studies on liver tissues using this probe. The probe was fabricated by photolithography and mounted in a catheter, 1.5mm in diameter, which can be used to measure local impedance of the biological tissues. After the calibration of the impedance at 500k Hz against different concentrations of saline water, the electrical conductivity can be obtained from the measured impedance value. The micro electrical probe was first used to investigate the effect of temperature elevation on the electrical conductivity liver tissues by different heating methods. Also, the electrical conductivity change caused by directional placement and perfusion rate was investigated on a perfused pig liver model. The experimental results show that the local electrical conductivity varies location to location and that the electrical conductivity has a strong directional dependence. Also by varying the perfusion rate, the probe shows that the local electrical conductivity varies linearly with the square root of perfusion rate. These results may be of great value to many biomedical applications. © 2011 SPIE.