Pedro Bertemes-Filho et al 2003 Physiol. Meas. 24 517 doi:10.1088/0967-3334/24/2/362
Pedro Bertemes-Filho1, Brian H Brown1, Rod H Smallwood1 and Adrian J Wilson2
Show affiliationsTetrapolar probes have been widely used for measuring the impedance spectra of tissues. However, the non-uniform sensitivity distribution of these probes limits the ability to identify conductivity changes in tissue. This paper presents a novel method for improving the sensitivity distribution beneath a tetrapolar probe. The method consists of placing a hydrogel layer between the probe and the tissue in order to make the sensitivity positive everywhere within the tissue. Theoretical and measured sensitivity distributions are compared. A good agreement between theoretical and measured data from an electrolytic tank was obtained with a maximum error of 1.3%. In vivo forearm measurements showed that the use of a conductive layer does enable tissue conductivity spectra to be determined. A smaller variation between subjects was obtained when using the stand-off. It was not possible to assess the absolute accuracy of the method due to the absence of a 'gold standard' for the measurement of tissue conductivity spectra.
87.80.-y Biophysical techniques (research methods)
87.19.R- Mechanical and electrical properties of tissues and organs
Issue 2 (May 2003)
Received 13 January 2003
Published 30 April 2003
Pedro Bertemes-Filho et al 2003 Physiol. Meas. 24 517
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M R Koblischka et al 2007 Supercond. Sci. Technol. 20 681
Giuseppe Schirripa Spagnolo et al 2004 J. Opt. A: Pure Appl. Opt. 6 869
D C Walker et al 2002 Physiol. Meas. 23 159
Alex J Cadotte and Thomas B DeMarse 2005 J. Neural Eng. 2 114
V Baranauskas et al 2004 Nanotechnology 15 1661
Hequan Sun 2002 Meas. Sci. Technol. 13 1996