Development of Non-contact Capacitive Coupled Electrodes for Bio-potential Signal Acquisition

Patient monitoring is one of the challenging and significant tasks in healthcare sector. Generally bio-potential electrodes are used to extract low amplitude physiological signals from the human body and for continuous healthcare monitoring of patients in hospital. The conventional wet electrodes provide an optimal signal, but it needs skin preparation and the application of electrolytic gel before attaching electrodes to the skin surface. The gel becomes dry after some time and is uncomfortable for wearable applications. The limitations faced in wet electrodes can be set aside by a new class of electrodes which can be coupled to the skin without any contact using capacitive coupling effect. The proposed type of electrodes can be easily mounted on to a patient clothing to create a nonintrusive wearable bio-potential recording apparatus. An impedance matching circuit with bootstrap technique is used for developing non-contact electrodes based data acquisition system. Hence the aim of the project is to design a non-contact capacitive coupled electrode with suitable amplifying circuit and signal conditioning for wearable or ambulatory based bio-potential acquisition system. KeywordsBootstrap, Bio-potential electrodes, Impedance matching non-contact capacitive coupled electrodes.