BioMediTech Research Infrastructure

Electrical Impedance Spectroscopy (EIS)

The facility offers equipment and support for electrical impedance measurements of various sample types ranging from cell culture measurements to whole body measurements. Impedance measurements are suitable for both biological and material research.

Introduction

The facility is situated in Computational Biophysics and Imaging Group (CBIG) in Tampere University of Technology in ARVO building. We have two devices for impedance measurements and expertise on processing and analysis of impedance data.

EIS is a method of measuring the electrical impedance of a sample as a function of the frequency of an applied electrical current or voltage. Impedance is a measure of the resistance to the flow of an alternating current or voltage. Biological tissue exhibits electrical impedance, which varies with the frequency in a way that is related to the properties of the tissue. Tissue contains both resistive and capacitive properties resulting in a complex electrical impedance. EIS measurements will generate a spectrum that is characteristic of the biological tissue. Changes in the impedance spectrum can therefore be directly related to changes in the tissue.

EIS is powerful technique with many advantages over other techniques:

  • Non-invasive
  • Non-destructive
  • Repeatable

Our devices can be used to measure biological objects such as humans or cell cultures, but also to measure materials, for example, their porosity.

Equipment

Solartron impedance measurement device

We have the system containing the Solartron 1260A Frequency Response Analyzer and 1294A Impedance Interface (Solartron Analytical, Hampshire, UK).

  • True differential 4-terminal connections
  • Frequency range: from 10 μHz to 32 MHz
  • Impedance range: from 10 Ω to 1 GΩ
  • 1 μV, 1 pA sensitivity

IEC 601 connections – for in vivo investigations including a wide range of applications, e.g. skin measurements.

HF2IS Impedance Spectroscope (Zurich Instruments)

The system consists of the HF2IS impedance spectroscope and the HF2TA current amplifier (Zurich Instruments AG, Switzerland). HF2TA converts two input currents into voltage output and ensures stability and a smooth operation over the entire frequency range.

  • 2 measurement units with single-ended and differential operation
  • 1 µHz – 50 MHz analog frequency range
  • 210 MSample/s, 14 bit A/D conversion
  • 4 frequencies simultaneously (8 with HF2IS-MF option)
  • 2/3/4-terminal measurement configurations
  • Large range of demodulation filter settings
  • 4x 1 MSample/s, 16 bit, ±10 V auxiliary analog output
  • 2x 400 kSample/s, 16 bit, ±10 V auxiliary analog input

Prices

Prices will be defined based on customer needs. Please inquire!

Contacts

Facility Director:
Professor Jari Hyttinen
jari.hyttinen(at)tut.fi
Tel: +358 40 849 0020

Publications

Solartron

Alarautalahti V, Hiltunen M, Onnela N, Nymark S, Kellomäki M, Hyttinen J. Polypyrrole-coated electrodes show thickness-dependent stability in different conditions during 42-day follow-up in vitro. J Biomed Mater Res B Appl Biomater, 23 OCT 2017, DOI: 10.1002/jbm.b.34024.

Böttrich M, Tanskanen JMA, Hyttinen J. Lead field theory provides a powerful tool for designing microelectrode array impedance measurements for biological cell detection and observation. BioMedical Engineering OnLine, Vol. 16, No. 85, 2017. DOI: 10.1186/s12938-017-0372-5.

Kekonen A, Bergelin M, Eriksson JE, Vaalasti A, Ylänen H, Viik J. Bioimpedance measurement based evaluation of wound healing. Physiological Measurement, Vol. 38, No. 7, 2017.

Kekonen A, Bergelin M, Eriksson JE, Ylänen H, Kielosto S, Viik J. Bioimpedance measurement system for evaluation of the status of wound healing. 2016 15th Biennial Baltic Electronics Conference (BEC), Tallinn, 2016, pp. 175-178. DOI: 10.1109/BEC.2016.7743757.

Kekonen A, Bergelin M, Eriksson JE, Ylänen H, Viik J. A Quantitative Method for Monitoring Wound Healing. International Journal of Bioelectromagnetism, Vol. 17, No. 1, pp. 36 – 41, 2015. http://www.ijbem.org/volume17/number1/ijbem_vol17_no1_pp36-41.pdf

Onnela N, Savolainen V, Hiltunen M, Kellomäki M, Hyttinen J. Impedance spectra of polypyrrole coated platinum electrodes. 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Osaka, 2013, pp. 539-542. DOI: 10.1109/EMBC.2013.6609556.

Onnela N, Savolainen V, Juuti-Uusitalo K, Vaajasaari H, Skottman H, Hyttinen J. Electric impedance of human embryonic stem cell derived retinal pigment epithelium. Medical & Biological Engineering & Computing, Vol. 50, No. 2, pp. 107-116, 2012. DOI: 10.1007/s11517-011-0850-z.

Savolainen V, Juuti-Uusitalo K, Onnela N, Vaajasaari H, Narkilahti S, Suuronen R, Skottman H, Hyttinen J. Impedance spectroscopy in monitoring the maturation of stem cell-derived retinal pigment epithelium. Annals of Biomedical Engineering, Vol. 39, No. 12, pp. 3055-3069, 2011. DOI: 10.1007/s10439-011-0387-1.

Ryynänen T, Kujala V, Ylä-Outinen L, Korhonen I, Tanskanen JMA, Kauppinen P, Aalto-Setälä K, Hyttinen J, Kerkelä E, Narkilahti S, Lekkala J. All titanium microelectrode array for field potential measurements from neurons and cardiomyocytes-A feasibility study. Micromachines, Vol. 2 No. 4, pp. 394-409, 2011. DOI: http://dx.doi.org/10.3390/mi2040394.

HF2IS Impedance Spectroscope (Zurich Instruments)

Kaappa ES, Joutsen A, Cömert A, Vanhala J. The electrical impedance measurements of dry electrode materials for the ECG measuring after repeated washing. Research Journal of Textile and Apparel, Vol. 21, No. 1, pp. 59-71, 2017. DOI: 10.1108/RJTA-04-2016-0007.

Cömert A. The Assessment and Reduction of Motion Artifact in Dry Contact Biopotential Electrodes. Tampere University of Technology, 76 pages, 2015. http://urn.fi/URN:ISBN:978-952-15-3575-8

Gracia J, Seppä VP, Viik J. Regional impedance pneumography heterogeneity during airway opening pressure chirp oscillations. International Journal of Bioelectromagnetism, Vol. 17, No. 1, pp. 42–51, 2015. http://www.ijbem.org/volume17/number1/ijbem_vol17_no1_pp42-51.pdf

Lehti-Polojärvi M. Electrical impedance tomography applied to stem cells in hydrogel scaffold. Tampere University of Technology, 72 pages, 2014. http://urn.fi/URN:NBN:fi:tty-201412051588

Cömert A, Hyttinen J. Impedance spectroscopy of changes in skin-electrode impedance induced by motion. Biomedical engineering online, Vol. 13, No. 1, 2014. DOI: https://doi.org/10.1186/1475-925X-13-149.

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