Electrode Comparison for Textile-Integrated Electrocardiogram and Impedance Pneumography Measurement

Wearable electronics is a quickly broadening category in sports, wellbeing and entertainment products. Also, fully textile-integrated electronics is used increasingly to improve user experience. Medical industry is interested in exploiting, especially the latter sub-category of wearable electronics in long-term home care. In this study, we report a textile-integrated electrocardiography (ECG) and impedance pneumography (IP) measurement system. The performance of the system is evaluated by comparing the measurement accuracy for heart rate and respiration rate obtained with different electrode types and different measurement methods. Three electrode types: disposable, textile, and printed electrodes, are investigated and both, bipolar and tetrapolar measurement methods are compared by using a modified commercial evaluation board. Disposable electrodes provide the least noisy signal and the most stable results. However, the skin irritation caused by these electrodes prevents their use in long-term monitoring. The textile and printed electrodes did not seem to cause similar skin irritation. From the two measuring techniques, tetrapolar measuring method had higher noise levels, but heart rate and breathing were estimated with better accuracy compared to bipolar measuring method.