Capacitive electrocardiography measurement with indirect skin contact

This article describes measurement of ECG by active, capacitive-coupled electrodes with no direct galvanic contact with the human skin. The measurement is more preferable compared to conventional ECG systems since there is no need of using conductive gel and avoids possible irritating problems of metal electrodes abutting epidermis. Method is more sophisticated and less demanding for long term stability where conductive gel signifies desiccation and therefore exasperates or loss of contact what results in reduction of movement artifacts caused by poor preparation of measurement. Situating of electrodes on patient´s clothes, we are able to record ECG without any background preparation. The article also describes hardware unit and problems related to electrocardiogram recording. Application is demonstrated by communication circuit connected to personal computer for on-line reading or Micro SD card module for long-term monitoring. Capacitive electrode system was configured as prototype following next generation of standalone 24-hrs Holter ECG monitoring in future.