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Electrocardiography (ECG) is the most essential physiological signal in diagnosing and managing heart diseases. The quality of the ECG signal is essential to receive accurate information and electrodes are the main components that affect the acquired signal quality. In this work, we have developed silver printed and embroidered textile electrodes to measure ECG signals from a dog and compare the results with signals collected using AG/AgCl electrodes. ECG signals were collected while the dog was in a sitting position and walking on a smooth surface and collected signals were analysed on visibility and amplitude of major peaks, HR, and R-R intervals. The ECG signals collected from the developed textile electrodes have identifiable P, QRS, and T waveforms and were comparable with signals from standard Ag/AgCl electrodes. The heart rate (HR) was 127 bpm77 for signals acquired using embroidered and Ag/AgCl electrodes and 113 bpm for the signal from silver printed electrodes. The results revealed that these textile electrodes can be used for the proposed application to avoid associated problems with crocodile clamps electrodes, especially for long-monitoring. While the dog is walking, collected signals show some distortion that would be due to unstable skin-electrode contact, showing this aspect requires further improvement. KEYWORDS: ECG; ECG electrodes; embroidered electrodes; silver-printed electrodes

Electrodes are the main components in monitoring and recording electrocardiogram (ECG) signals. Selecting the right type of electrode is required during ECG monitoring which is the main factor that affects the quality of the acquired signals. Electrode-skin impedance is a key indicator of electrode performance. Skin-electrode impedance test is very important to evaluate whether the electrodes can be able to use for recording bioelectric because if the skin-electrode impedance is too high it means the electrodes cannot be used for ECG recording. The performance of electrodes in detecting biopotential signals is highly dependent on electrode-skin impedance. In this work, we have developed silver-based textile ECG electrodes by embroidering a 29-tex silver-plated polyamide yarn having a 136 Ω/m resistance on cotton fabric at 1.5 mm stitch length and screen printing of silver ink (Metalon HPS-FG32) having a solid content of 75% and particle size 1.5 Micron on cotton fabric. The electrode-skin impedance and ECG detection performance of the electrodes were studied and the results were compared with standard Ag/AgCl electrodes. Skin-electrode impedance was measured using IVIUM potentiostat with a three-electrode configuration by wrapping the same type of electrodes on the subject's forearm using an elastic strap. To investigate the effect of strap tightness on stability and skin-electrode impedance, testing was carried out at 12 mmHg, 18 mmHg, and 24 mmHg contact pressure. The standard Ag/AgCl electrodes show lower impedance than dry textile electrodes due to the presence of conductive gel in such electrodes. Comparatively, embroidered textile electrodes show lower impedance than silver printed electrodes. It was observed that the skin impedance decreased with an increase in contact pressure, which would reveal that the performance of the electrodes becomes improved with an increase in strap tightness. The ECG detection performance of the electrodes was studied by placing the measuring electrodes on the right and left armpits, and the reference electrode around the chest on a lead I configuration where the electrodes were embedded on a shoulder strap with Velcro. Measurement was carried out at static and dynamic conditions and results show that the ECG signals collected from the embroidered and silver printed textile electrodes have identifiable P, QRS, and T waveforms and have comparable signal quality with signals acquired using standard Ag/AgCl electrodes.