Bioelectric Activity Recording based on a Single Electrode for Use on Wearable Devices

Wearable devices are used to unobtrusively record several physiological signals. Bioelectric signals are one of the most important variables monitored. Despite the available techniques, including capacitive coupling, it is still lacking a contactless solution that can be integrated into wearable devices. We propose a new approach where an instrumentation amplifier is directly driven by a bioelectric signal. In this way, the voltage drop on the capacitive electrodes is avoided. In this paper we show the proof of concept, and results are presented to show how to record an Electrocardiogram (ECG) using this new approach. Measurements were made using a high-impedance instrumentation amplifier. Results have shown that our approach is viable for bioelectric signal detection using contactless methods.