1. Electrical impulses in the heart originate in the sinus node and travel through the original conduction system to the myocardium. The impulse excites the contraction of myocardial fibers and causes myocardial contraction. The tiny electrical currents generated by the myocardium are transmitted to the surface of the skin.
2. After the electrical signals generated by the human heart muscle are transmitted to the body surface, a potential difference is generated due to the different distribution on the body surface, and this potential difference of only millivolt level is filtered and amplified, and then the human heart electrical signals are obtained. The electrodes are placed on the left and right handles of the motorized treadmill to obtain the ECG signals of the human body, and the heart rate information of the trainer can be obtained by measuring the time intervals between two adjacent R waves in the ECG signals.