An analysis of systematic errors in the electrical impedance measurement of tissue characteristics during an in-vitro study in the frequency range 1 kHz to 4 MHz

This paper describes some of the important systematic errors associated with an in-vitro study, using a four electrode impedance system, into the characteristics that allow for differentiation between normal and abnormal tissues. The impact of system parameters were investigated though the use of saline-filled phantoms and tissue samples. The latter being provided as part of a 100 patient in-vitro study carried out in collaboration with the Glenfield General Hospital, Leicester, UK. It has been found necessary to provide an environment with a known, and calibrated, post sample excision period. However, the orientation of the tissue during the measurement was also found to have a large and important impact upon the measured impedance.