Fully Textile, PEDOT:PSS Based Electrodes for Wearable ECG Monitoring Systems.

GOAL: To evaluate a novel kind of textile electrodes based on woven fabrics treated with PEDOT: PSS, through an easy fabrication process, testing these electrodes for biopotential recordings. METHODS: Fabrication is based on raw fabric soaking in PEDOT: PSS using a second dopant, squeezing and annealing. The electrodes have been tested on human volunteers, in terms of both skin contact impedance and quality of the ECG signals recorded at rest and during physical activity (power spectral density, baseline wandering, QRS detectability, and broadband noise). RESULTS: The electrodes are able to operate in both wet and dry conditions. Dry electrodes are more prone to noise artifacts, especially during physical exercise and mainly due to the unstable contact between the electrode and the skin. Wet (saline) electrodes present a stable and reproducible behavior, which is comparable or better than that of traditional disposable gelled Ag/AgCl electrodes. CONCLUSION: The achieved results reveal the capability of this kind of electrodes to work without the electrolyte, providing a valuable interface with the skin, due to mixed electronic and ionic conductivity of PEDOT: PSS. These electrodes can be effectively used for acquiring ECG signals. SIGNIFICANCE: Textile electrodes based on PEDOT: PSS represent an important milestone in wearable monitoring, as they present an easy and reproducible fabrication process, very good performance in wet and dry (at rest) conditions and a superior level of comfort with respect to textile electrodes proposed so far. This paves the way to their integration into smart garments.

Evaluation of novel textile electrodes for ECG signals monitoring based on PEDOT:PSS-treated woven fabrics.

Despite surface electrodes technology for biopotential recording is well established, different researches are aimed at overcoming the limitations exhibited by the available solutions. In this paper, a proposal for the low-cost development of textile electrodes based on woven fabrics treated with polymer poly-3,4-ethylenedioxythiophene doped with poly(styrene sulfonate) ( PEDOT: PSS), is presented. Compared to other approaches, the proposed one can be exploited on any finished fabric. An accurate analysis of the electrodes performance, based on impedance measurements and signal processing techniques, both in wet and dry conditions, reveals the virtues and vices of the proposed solution, when used for electrocardiogram recording. In particular, the potentialities of these electrodes clearly emerge, in terms of ability to work without any electrolyte, providing a valuable interface between the skin and the electrode, in some cases achieving better performance than commercial disposable electrodes.

A new integrated system combining atomic force microscopy and micro-electrode array for measuring the mechanical properties of living cardiac myocytes.

In this paper we present a new experimental set-up which combines the surface characterization capabilities of atomic force microscopy at the sub-micrometer scale with non-invasive electrophysiological measurements obtained by using planar micro-electrode arrays. In order to show the potential of the combined measurements we studied the changes in cell topography and elastic properties of cardiac muscle cells as during the contraction-relaxation cycle. The onset of each beating cycle was precisely identified by the use of the extracellular potential signal, allowing us to combine nanomechanical measurements from multiple cardiomyocyte contractions in order to analyze the time-dependent variation of cell morphology and elasticity. Moreover, by estimating the elastic modulus at different indentation depths in a single location on the cell membrane, we observed a dynamic mechanical behavior that could be related to the underlying myofibrillar structure dynamics.