Effect of Applied Force on Baseline Drift in Two- Electrode ECG Measurement

The motion artifact is one of the significant problems in ECG measurements. Motion artifact often deteriorates the ECG signal quality, and in the worst case, ECG signals must be discarded. Local skin deformation by mechanical disturbances causes the variation of electrical properties of electrode-skin interfaces. This may consider being the most contribution to the motion artifact or baseline drift in ECG signals. In this paper, we have studied the change of ECG baseline under externally applied force using a two-electrode ECG measurement system with thin-film force sensors. As a result, an increase of applied force on one electrode shows a large ECG baseline drift. In the case of the simultaneous increase of applied force on both electrodes shows reduced ECG baseline drift. We also confirmed the change of 50 Hz interference is often together with the baseline drift by an external force disturbance. In addition, an electrical model for motion artifact generation is also presented.