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New method for separation of electrode polarization impedance from measured tissue impedance.

Kalvøy H, Johnsen GK, Martinsen OG, Grimnes S - Open Biomed Eng J (2011)

Bottom Line: In 2-electrode measurements the EPI and sample are physically connected in series, and commonly modelled by equivalent components in series.We have calculated the parallel equivalent elements and converted the series connected EPI and sample to a parallel admittance model.By curve fitting on the converted model we have shown that this provides a new method for estimating the EPI with enhanced accuracy compared to similar techniques used on the impedance model.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Clinical and Biomedical Eng, Rikshospitalet, Oslo Univ. Hospital, Norway.

ABSTRACT
In this paper we have shown that electrode polarization impedance (EPI) can be separated from measured tissue impedance as long as the characteristic frequencies of EPI and tissue are not too close, so that the EPI is largely displayed as a separate dispersion. In 2-electrode measurements the EPI and sample are physically connected in series, and commonly modelled by equivalent components in series. We have calculated the parallel equivalent elements and converted the series connected EPI and sample to a parallel admittance model. By curve fitting on the converted model we have shown that this provides a new method for estimating the EPI with enhanced accuracy compared to similar techniques used on the impedance model.

No MeSH data available.


Impedance model Wessel-plot of in vitro measurement data. Segment A: EPI, Segment B: Sample. Details from the HF tail inserted.
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Figure 7: Impedance model Wessel-plot of in vitro measurement data. Segment A: EPI, Segment B: Sample. Details from the HF tail inserted.

Mentions: The results from the in vitro model measurements are plotted in Figs. (7 and 8). The LF segment (A) corresponding to the EPI was not possible to estimate by curve fitting to a Cole element with high accuracy in the impedance model Wessel-plot. In the admittance model Wessel-plot nearly complete arcs of circular segments were found for the A segment.


New method for separation of electrode polarization impedance from measured tissue impedance.

Kalvøy H, Johnsen GK, Martinsen OG, Grimnes S - Open Biomed Eng J (2011)

Impedance model Wessel-plot of in vitro measurement data. Segment A: EPI, Segment B: Sample. Details from the HF tail inserted.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3102312&req=5

Figure 7: Impedance model Wessel-plot of in vitro measurement data. Segment A: EPI, Segment B: Sample. Details from the HF tail inserted.
Mentions: The results from the in vitro model measurements are plotted in Figs. (7 and 8). The LF segment (A) corresponding to the EPI was not possible to estimate by curve fitting to a Cole element with high accuracy in the impedance model Wessel-plot. In the admittance model Wessel-plot nearly complete arcs of circular segments were found for the A segment.

Bottom Line: In 2-electrode measurements the EPI and sample are physically connected in series, and commonly modelled by equivalent components in series.We have calculated the parallel equivalent elements and converted the series connected EPI and sample to a parallel admittance model.By curve fitting on the converted model we have shown that this provides a new method for estimating the EPI with enhanced accuracy compared to similar techniques used on the impedance model.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Clinical and Biomedical Eng, Rikshospitalet, Oslo Univ. Hospital, Norway.

ABSTRACT
In this paper we have shown that electrode polarization impedance (EPI) can be separated from measured tissue impedance as long as the characteristic frequencies of EPI and tissue are not too close, so that the EPI is largely displayed as a separate dispersion. In 2-electrode measurements the EPI and sample are physically connected in series, and commonly modelled by equivalent components in series. We have calculated the parallel equivalent elements and converted the series connected EPI and sample to a parallel admittance model. By curve fitting on the converted model we have shown that this provides a new method for estimating the EPI with enhanced accuracy compared to similar techniques used on the impedance model.

No MeSH data available.