Figure 8.

Comparison of the self-developed gel electrode and commercial 3M electrode in the performance of ECG acquisition and wearing comfort; (a₁) ECG signal obtained from the self-developed gel electrode and (a₂) the ECG signal from the 3M electrode, the scale bar means 1 s across four units for recording the heart rate; (b₁) two electrodes attached on a human skin at the same time, and (b₂) the skin reaction after six hours of wearing for the self-developed hydrogel (left) and the commercial hydrogel (right).