Impedance spectroscopy of conductive commercial hydrogels for electromyography and electroencephalography
| Autor: | S. Ponti, F.C.M. Freire, Elio Miraldi, M. Becchi, Alfredo Strigazzi |
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| Rok vydání: | 2010 |
| Předmět: |
Materials science
Physiology electromyogram Biomedical Engineering Biophysics Noise (electronics) Signal interface impedance Physiology (medical) Electronic engineering Electrodes Electrical impedance Electrical conductor Electromyography business.industry Constant phase element Electric Conductivity Electroencephalography Hydrogels Dielectric spectroscopy bulk impedance hydrogel conductivity Dielectric Spectroscopy Self-healing hydrogels Electrode Optoelectronics business Algorithms |
| Zdroj: | Physiological Measurement. 31:S157-S167 |
| ISSN: | 1361-6579 0967-3334 |
| DOI: | 10.1088/0967-3334/31/10/s01 |
| Popis: | In biomedical applications such as the electroencephalogram, electrocardiogram and electromyogram, usually conductive hydrogels are applied to the skin providing a skin-electrode layer, with the aim of lowering contact impedance and improving the signal/noise ratio. It is important to know the electrical behavior of these materials, obtaining reliable values of their conductivity. It can be extracted by the whole cell impedance, which is affected not only by the bulk but also by the surface properties. The aim of the present work is to characterize the impedance of some currently available conductive hydrogels in the frequency range 5 Hz-1 MHz. For this purpose we have designed a novel cell, with silver electrodes, optical detection of the gap and guard ring. In this paper the results are compared with those obtained by means of a commercial cell with stainless steel electrodes, without a guard ring. In order to extract the different contributions of the bulk and the interface, we fitted the experimental data with a very simple model: the bulk properties are described by a single RC-parallel, whereas the interface is represented by a constant phase element. |
| Databáze: | OpenAIRE |
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