Differential impedance testing of EC2© and Ten-20© adhesive paste for tripolar concentric electrodes

Electroencephalogram (EEG) recordings have been shown to be an alternative method of communication for paralyzed or disabled persons. Recording EEGs and defining parameters for optimal spatial resolution and classification methods have been the focus of many research papers. This study seeks to analyze how the impedance changes over time with two commonly used impedance matching gels. It is a continuation of ongoing research into tripolar concentric ring electrodes as an alternative to conventional disc electrodes. By acquiring this information, the parameters of the electrodes in relation to the pastes can be determined and proper testing procedures can be evaluated to allow for optimal recording parameters. The best paste will provide low impedance and low noise while still maintaining a good connection between the electrode and the scalp. Two commercially available pastes, Ten-20^copy and EC2^copy, were tested. The Ten-20^copy paste had a higher impedance but remained at a fairly consistent impedance throughout the test. The EC2^copy paste had a lower impedance but showed a decrease in impedance over time.