Evaluation of low cost capacitive ECG prototypes: A hardware/software approach

Demographic change is greatly affecting more and more industrial nations. Therefore, healthcare solutions become increasingly interesting for end-users. However, existing solutions like fitness trackers are mostly worn for a short period of time, i.e. during exercising. Therefore, the implementation of unobtrusive biological sensors via capacitive Electrocardiography (ECG), for application within the user home environment, becomes interesting in the Ambient Assisted Living (AAL) research areas. A capacitive ECG has been developed using an Arduino/Wattuino Uno microcontroller board in order to enable the realization of a low cost capacitive ECG System, using existing of-the-shelf components. The developed system comprises an improved version of an earlier prototype of the authors, differing in both hardware and software components used. Furthermore, wireless data transmission quality has been here investigated, in order to enable an unobtrusive implementation of the proposed system when it is used in home environments. In this paper the authors investigate and compare the quality of the measured ECG signal under different hardware and software configurations. The results in the paper show that using XBee modules as a secure wireless data transfer solution has a significant deterioration of the measured signal quality. Therefore, solutions are proposed and discussed in the paper to overcome the aforementioned limitations.