Abstract
In electrical impedance tomography (EIT) currents are applied to a body, for example to the human thorax, and resulting voltages are measured to estimate the intra-thoracic impedance distribution. For this purpose 16 or 32 individual electrodes need to be placed onto the patient. The electrical contact with skin is one of the most important performance factors for EIT measurements. In this study, the electrical skin contact of a novel, textile-based electrode assembly comprising 32 active electrodes integrated in a vest-like structure was assessed in 10 volunteers and in 40 patients. Skin contact impedance was measured with dry and wetted electrodes; mid-term stability was measured over a period of 4 h. Results showed that the skin contact impedance of the dry electrodes was higher than 2 kΩ at a frequency of 144 kHz, after applying contact agent, the skin contact impedance dropped below 500 Ω and remained there for the next 4 h. We conclude that the new patient interface in combination with the special contact agent provides a stable electrical contact between electrodes and skin for at least 4 h.
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Costa, E. L., Lima, R. G., & Amato, M. B. (2009). Electrical impedance tomography. Current Opinion in Critical Care, 15(1), 18–24.
Victorino, J. A., Borges, J. B., Okamoto, V. N., Matos, G. F. J., Tucci, M. R., Caramez, M. P. R., et al. (2004). Imbalances in regional lung ventilation: a validation study on electrical impedance tomography. American Journal of Respiratory and Critical Care Medicine, 169(7), 791–800.
Vogt, B., Pulletz, S., Elke, G., Zhao, Z., Zabel, P., Weiler, N., et al. (2012). Spatial and temporal heterogeneity of regional lung ventilation determined by electrical impedance tomography during pulmonary function testing. Journal of Applied Physiology, 113(7), 1154–1161.
Frerichs, I., Dargaville, P. A., van Genderingen, H., Morel, D. R., & Rimensberger, P. C. (2006). Lung volume recruitment after surfactant administration modifies spatial distribution of ventilation. American Journal of Respiratory and Critical Care Medicine, 174(7), 772–779.
Wolf, G. K., Gómez-Laberge, C., Rettig, J. S., Vargas, S. O., Smallwood, C. D., Prabhu, S. P., et al. (2013). Mechanical ventilation guided by electrical impedance tomography in experimental acute lung injury. Critical Care Medicine, 41(5), 1296–1304.
Frerichs, I., Hinz, J., Herrmann, P., Weisser, G., Hahn, G., Quintel, M., et al. (2002). Regional lung perfusion as determined by electrical impedance tomography in comparison with electron beam CT imaging. IEEE Transactions on Medical Imaging, 21(6), 646–652.
Frerichs, I., Pulletz, S., Elke, G., Gawelczyk, B., Frerichs, A., & Weiler, N. (2011). Patient examinations using electrical impedance tomography—Sources of interference in the intensive care unit. Physiological Measurement, 32(12), L1–L10.
Mamatjan, Y., Grychtol, B., Gaggero, P., Justiz, J., Koch, V. M., & Adler, A. (2013). Evaluation and real-time monitoring of data quality in electrical impedance tomography. IEEE Transactions on Medical Imaging, 32(11), 1997–2005.
Meeson, S., Blott, B. H., & Killingback, A. L. (1996). EIT data noise evaluation in the clinical environment. Physiological Measurement, 17(Suppl 4), A33–A38.
Oh, T. I., Kim, T. E., Yoon, S., Kim, K. J., Woo, E. J., & Sadleir, R. J. (2012). Flexible electrode belt for EIT using nanofiber web dry electrodes. Physiological Measurement, 33(10), 1603–1616.
Rahal, M., Khor, J. M., Demosthenous, A., Tizzard, A., & Bayford, R. (2009). A comparison study of electrodes for neonate electrical impedance tomography. Physiological Measurement, 30(6), S73–S84.
Adler, A., Amato, M. B., Arnold, J. H., Bayford, R., Bodenstein, M., Böhm, S. H., et al. (2012). Whither lung EIT: Where are we, where do we want to go and what do we need to get there? Physiological Measurement, 33(5), 679–694.
Puurtinen, M. M., Komulainen, S. M., Kauppinen, P. K., Malmivuo, J. A. V., & Hyttinen, J. A. K. (2006) Measurement of noise and impedance of dry and wet textile electrodes, and textile electrodes with hydrogel. In Conference on Proceedings of the IEEE Engineering in Medicine and Biology Society, vol. 1 (pp. 6012–6015).
Bikker, I. G., Preis, C., Egal, M., Bakker, J., & Gommers, D. (2011). Electrical impedance tomography measured at two thoracic levels can visualize the ventilation distribution changes at the bedside during a decremental positive end-expiratory lung pressure trial. Critical Care, 15(4), R193.
Blankman, P., Hasan, D., van Mourik, M. S., & Gommers, D. (2013). Ventilation distribution measured with EIT at varying levels of pressure support and neurally adjusted ventilatory assist in patients with ALI. Intensive Care Medicine, 39(6), 1057–1062.
Luepschen, H., Meier, T., Grossherr, M., Leibecke, T., Karsten, J., & Leonhardt, S. (2007). Protective ventilation using electrical impedance tomography. Physiological Measurement, 28(7), S247–S260.
Muders, T., Luepschen, H., Zinserling, J., Greschus, S., Fimmers, R., Guenther, U., et al. (2012). Tidal recruitment assessed by electrical impedance tomography and computed tomography in a porcine model of lung injury. Critical Care Medicine, 40(3), 903–911.
Meier, T., Luepschen, H., Karsten, J., Leibecke, T., Grossherr, M., Gehring, H., et al. (2008). Assessment of regional lung recruitment and derecruitment during a PEEP trial based on electrical impedance tomography. Intensive Care Medicine, 34(3), 543–550.
Gaggero, P. O., Adler, A., Brunner, J., & Seitz, P. (2012). Electrical impedance tomography system based on active electrodes. Physiological Measurement, 33(5), 831–847.
Gaggero, P. O. (2011) Miniaturization and distinguishability limits of electrical impedance tomography for biomedical application, Ph.D. dissertation, University of Neuchâtel, Switzerland.
Karsten, J., Stueber, T., Voigt, N., Teschner, E., & Heinze, H. (2016). Influence of different electrode belt positions on electrical impedance tomography imaging of regional ventilation: A prospective observational study. Critical Care, 20(1), 3.
Merletti, R. (2010). The electrode–skin interface and optimal detection of bioelectric signals. Physiological Measurement, 31, 10.
Tronstad, C., Johnsen, G. K., Grimnes, S., & Martinsen, Ø. G. (2010). A study on electrode gels for skin conductance measurements. Physiological Measurement, 31(10), 1395–1410.
Alexe-Ionescu, A. L., Barbero, G., Freire, F. C. M., & Merletti, R. (2010). Effect of composition on the dielectric properties of hydrogels for biomedical applications. Physiological Measurement, 31(10), S169–S182.
Batt, M. D., Davis, W. B., Fairhurst, E., Gerrard, W. A., & Ridge, B. D. (1988). Changes in the physical properties of the stratum corneum following treatment with glycerol. Journal of the Society of Cosmetic Chemists, 39(December), 367–381.
Beckmann, L., Neuhaus, C., Medrano, G., Jungbecker, N., Walter, M., Gries, T., et al. (2010). Characterization of textile electrodes and conductors using standardized measurement setups. Physiological Measurement, 31(2), 233–247.
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This work was partially funded by the Else Kröner-Fresenius-Stiftung.
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Waldmann, A.D., Wodack, K.H., März, A. et al. Performance of Novel Patient Interface for Electrical Impedance Tomography Applications. J. Med. Biol. Eng. 37, 561–566 (2017). https://doi.org/10.1007/s40846-017-0264-y
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DOI: https://doi.org/10.1007/s40846-017-0264-y