Fig. 2
From: Inexpensive and flexible nanographene-based electrodes for ubiquitous electrocardiogram monitoring
Electrocardiography recording and processing methods. a Comparison of the skin–electrode contact resistance as a function of the frequency for two commercial electrodes (Ambu® BlueSensor VL and Biopac EL503, respectively) and the LINA electrode. b ECG recordings carried out simultaneously with the LINA electrodes (in red) and the Ag/AgCl commercial electrodes (in blue). c One step wavelet-preprocessing method for the baseline wandering and noise correction. d Clustering-based method for the heart rate monitoring based on the max–min amplitude
