Abstract
Recently, much research has been done to evaluate mental stress based on heartbeat fluctuation and lower restraint, and a non-invasive ECG measurement method is been expected to be able to record the heartbeat during daily life. In this study, a new ECG measuring method that uses capacity coupled electrodes without any reference electrode is proposed. In this paper, five different settings of signal electrodes and ground connections were compared: One capacity coupled signal electrode with no ground electrode, two capacity coupled signal electrodes with no ground electrode, two capacity coupled signal electrodes with a common ground electrode on the skin, one capacity coupled signal electrode with one capacity coupled ground electrode, and two capacity coupled signal electrodes with the amplifier grounded. We also examined our new ECG measurement method under different electrical environments: in a noise-filled laboratory, outdoors with no commercial electrical power nearby, and inside a car with the engine and air conditioner operating. As a result, our new measurement method proved to be effective for obtaining ECG signals during daily life.
