Non-contact Capacitive ECG Signal Acquisition Using an Electrode Array

This paper provides a non-contact capacitive coupling electrocardiogram (cECG) acquisition system. The shielded electrode structure can effectively reduce the power line interference. By integrating the multi-electrode array on the mattress, we can get cECG signals in different sleeping positions. In order to verify the accuracy of the system, the cECG signal is compared with the ECG signal collected by the wet electrode, the cECG signals can obtain QRS complex, P, and T waves obviously, but its amplitude is only half that of ECG. The correlation degree between cECG and ECG was evaluated by using the template matching method, and the correlation coefficient of the waveform reached 0.9839. Also, the change of RR interval of cECG in different sleeping positions is highly correlated with reference ECG system. The correlation coefficient was 0.9994, and the root mean square error was 0.00153 s. Compared to the wet electrode, the non-contact ECG collection method is more comfortable. So, the proposed cECG acquisition system is feasible for the long-term monitoring of cardiovascular diseases.