Wearable electrocardiogram (ECG) is attracting much attention in daily healthcare applications, and human body communication (HBC) technology provides an evident advantage in making the sensing electrodes of ECG also working for transmission through the human body. In view of actual usage in daily life, however, non-contact electrodes to the human body are desirable. In this Letter, the authors discussed the ECG circuit structure in the HBC-based wearable ECG for removing the common mode noise when employing non-contact capacitive coupling electrodes. Through the comparison of experimental results, they have shown that the authors' proposed circuit structure with the third electrode directly connected to signal ground can provide an effect on common mode noise reduction similar to the usual drive-right-leg circuit, and a sufficiently good acquisition performance of ECG signals.
Keywords: ECG circuit structure; HBC technology; acquisition performance; biomedical electrodes; body sensor networks; capacitive coupling electrodes; capacitive sensors; circuit noise; common mode noise; daily life; electrocardiography; human body communication-based wearable ECG; noncontact electrodes; signal ground; wearable electrocardiogram.