Alginate-based hydrogels as an alternative to electrolytic gels for rapid EEG monitoring and easy cleaning procedures

We propose a novel alginate-based hydrogel as an alternative to the traditional EEG electrolytic gels. The new product is injected into the electrode cap cavities in the form of a viscous liquid, just like a commercial electrolytic gel, but it forms a solid and homogeneous hydrogel shortly after application. The solid hydrogel substantially reduces the risks of gel leaking from the electrode cavities and it showed first evidence of enabling a faster and easier cleaning of the scalp after the recording procedure, when compared to electrolytic gels. The electrochemical studies prove the proposed hydrogels to be applicable for bioelectric signal acquisition. Moreover, in-vivo EEG tests show no considerable differences between signals acquired with the hydrogel and the commercial electrolytic gel during the same signal acquisition, in terms of amplitude, signal shape, power spectral density and signal-to-noise ratio. In conclusion, the proposed hydrogels enhance the applicability and reliability of EEG by reducing gel running risks and simplifying the cleaning after the exam, as evidenced by the performed cleaning tests.