<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The objective of this work is to develop a technique for filtering parasitic effects from the impedance spectra (IS) measured in biological material phantoms. IS data are contaminated with unexpected capacitive and inductive effects from cable, input/output amplifiers capacitances, electrode polarization, temperature and contact pressure when collecting data. It is proposed a model which contains an RLC-network in series with the Cole model (RSC), then called RLC-Cole. It was built four circuits composed by resistors, capacitors and inductors. An impedance analyzer (HF2IS) was used to perform the measurements in the frequency range of 1 to 3000 kHz. Data were fitted into the model and comparisons to the nominal values were made. In order to validate the proposed model, a gelatin phantom and a chicken breast muscle impedance spectra were also collected and analyzed. After filtering, Cole fitting was performed. Results showed a maximum root-mean-square error of 1% for the circuits, 2.63% for the gelatin phantom, whereas 2.01% for the chicken breast. The RLC-Cole model could significantly remove parasitic effects out of a tissue impedance spectrum measured by a 4-point electrode probe. This may be highly important in EIS systems whose objective is to discriminate a normal tissue from a cancerous one.</p></abstract>

The objective of this work is to develop a technique for filtering parasitic effects from the impedance spectra (IS) measured in biological material phantoms. IS data are contaminated with unexpected capacitive and inductive effects from cable, input/output amplifiers capacitances, electrode polarization, temperature and contact pressure when collecting data. It is proposed a model which contains an RLC-network in series with the Cole model (RSC), then called RLC-Cole. It was built four circuits composed by resistors, capacitors and inductors. An impedance analyzer (HF2IS) was used to perform the measurements in the frequency range of 1 to 3000 kHz. Data were fitted into the model and comparisons to the nominal values were made. In order to validate the proposed model, a gelatin phantom and a chicken breast muscle impedance spectra were also collected and analyzed. After filtering, Cole fitting was performed. Results showed a maximum root-mean-square error of 1% for the circuits, 2.63% for the gelatin phantom, whereas 2.01% for the chicken breast. The RLC-Cole model could significantly remove parasitic effects out of a tissue impedance spectrum measured by a 4-point electrode probe. This may be highly important in EIS systems whose objective is to discriminate a normal tissue from a cancerous one.

Extracting parasite effects of electrical bioimpedance measurements

Journal of Electrical Bioimpedance

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Extracting parasite effects of electrical bioimpedance measurements"}

The objective of this work is to develop a technique for filtering parasitic effects from the impedance spectra (IS) measured in biological material phantoms....

	Circuit 1		Circuit 2		Circuit 3		Circuit 4
C₁[nF]	1.00	1.01	1.00	1.15	4.70	4.81	0.82	0.87
R₂ [Ω]	56.8	55.8	50.5	50.4	73.3	80.5	65.2	67.5
R₃ [Ω]	1.2	1.9	1.2	1.5	1.2	2.0	1.2	1.3
R₁ [Ω]	1.1	1.5	1.1	0.7	242.0	294.0	61.9	61.0
L [μF]	100.0	101.0	2.7	2.5	80.0	109.0	15.0	17.3
C₂ [pF]	0.0	0.001	15.0	18.0	271.0	221.0	271.0	350.0
R_∞ [Ω]	1.2	1.3	1.2	1.1	1.2	2.0	1.2	1.3
f_C[Hz]	2.74	2.25	3.08	2.58	0.45	0.40	2.87	2.66
f_R[Hz]	NA	9.60	25.00	22.80	0.34	1.03	2.50	2.02
RMSRE	0.80		0.15		0.15		0.18

Extracting parasite effects of electrical bioimpedance measurements

Pubblicato online: 31 dic 2018

Pagine: 115 - 122

Ricevuto: 09 nov 2018

DOI: https://doi.org/10.2478/joeb-2018-0016

Parole chiave
Bioimpedance, Cole model, parasitic impedance, filtering algorithm

© 2018 D. Dutra, P. Bertemes-Filho published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig.1

Fig.2

Measured and fitted values for circuits 1 to 4, where NA means that the resonance frequency was not measured.

Extracting parasite effects of electrical bioimpedance measurements

Pubblicato online: 31 dic 2018

Pagine: 115 - 122

Ricevuto: 09 nov 2018

DOI: https://doi.org/10.2478/joeb-2018-0016

Parole chiaveBioimpedance, Cole model, parasitic impedance, filtering algorithm

© 2018 D. Dutra, P. Bertemes-Filho published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig.1

Fig.2

Measured and fitted values for circuits 1 to 4, where NA means that the resonance frequency was not measured.

Parole chiave
Bioimpedance, Cole model, parasitic impedance, filtering algorithm