Comparison of electrode impedances of Pt, PtIr (10% Ir) and Ir-AIROF electrodes used in electrophysiological experiments
- 142 Downloads
In tissue impedance measurements with the 4-electrode assembly, unexpected difficulties may occur because a combination of electrode impedance and stray capacitance in the array of four electrodes, can lead to serious measuring failures in the low-frequency range. An optimal solution to this problem can be obtained if the electrode impedances are frequency independent. A comparative study of the electrode impedances of Pt and PtIr electrodes and of a new electrode material (Ir-AIROF) is reported. It is shown that the impedance of Ir-AIROF electrodes is relatively low and almost frequency independent. Therefore the use of Ir-AIROF electrodes provides a solution to the problem mentioned above.
KeywordsElectrode impedance Four-electrode assembly Iridium electrodes Tissue impedance
Unable to display preview. Download preview PDF.
- Block, M. T. (1968) The electrical and biological properties of tungsten microelectrodes.Med. & Biol. Eng.,6, 517–525.Google Scholar
- Boer, R. W. de andOosterom, A. van (1978) Electrical properties of platinum electrodes.Med. & Biol. Eng. & Comput.,16, 1–10.Google Scholar
- Gottesfeld, S. andMcIntyre, J. D. E. (1979) Electrochromism in anodic iridium oxide films. II. pH effects on corrosion stability and the mechanism of coloration and bleaching.J. Electrochem. Soc.: Electrochemical science and technology,126, 742–750.Google Scholar
- Oosterom, A. van, Boer, R. W. de andDam, R. Th. van (1979) Intramural resistivity of cardiac tissue.Med. & Biol. Eng. & Comput.,17, 337–343.Google Scholar
- Rooij, N. F. de andBergveld, P. (1980) The Iridium/anodic iridium oxide film (Ir/AIROF) electrode as a pH-sensor. Proceedings of International Conference on monitoring of blood gasses, blood ion concentrations and respiratory gas exchange,Kimmich, H. P. (Ed.), Nijmegen, The Netherlands.Google Scholar
- Schwan, H. P. (1968) Electrode polarization impedance and measurements in biological materials.Ann. N.Y. Acad. Sciences,148, 191–209.Google Scholar