抄録
Bioelectrical signals such as electrooculograms (EOGs) and electroencephalograms (EEGs) have many medical applications. Wet electrodes are used widely to acquire these signals; however, their use has several limitations. Other researchers have proposed dry contact electrodes, but they do not solve all of the problems associated with wet electrodes; on the other hand noncontact capacitive coupling electrodes have poor noise performance and are large and complex. In this paper, we present a hybrid electrode that is capable of both capacitive and resistive recordings at lower noise levels, with a smaller hardware footprint. The sensor was designed by optimizing the sensor input impedance value using a new electrode equivalent circuit that contained noise sources. Experiments were performed to investigate the frequency response, noise spectrum, motion artifacts, standard alpha and beta EEG signals, and eyelid and eyeball EOG measurements. We verified that our electrodes are capable of bioelectrical measurements at noise levels comparable to wet electrodes.
