Contact Pressure and Flexibility of Multipin Dry EEG Electrodes

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Patrique Fiedler (Author) Other; Richard Mühle (Author) Other; Stefan Griebel (Author) Other; Paulo Pedrosa (Author) Other; Carlos Fonseca (Author) FEUP; Filipe Vaz (Author) Other; Frank Zanow (Author) Other; Jens Haueisen (Author) Other

Journal

Title: IEEE Transactions on Neural Systems and Rehabilitation Engineering

Vol. 26

Pages: 750-757

ISSN: 1534-4320

Publisher: IEEE

Indexing

ISI Web of Knowledge - 46 Citations

Scopus - 56 Citations

INSPEC

Other information

Authenticus ID: P-00N-WKB

DOI: 10.1109/tnsre.2018.2811752

Abstract (EN): In state-of-the-art electroencephalography (EEG) Silver/Silver-Chloride electrodes are applied together with electrolyte gels or pastes. Their application requires extensive preparation, trained medical staff and limits measurement time and mobility. We recently proposed a novel multichannel cap system for dry EEG electrodes for mobile and out-of-the-lab EEG acquisition. During the tests with these novel polymer-based multipin dry electrodes, we observed that the quality of the recording depends on the applied normal force and resulting contact pressure. Consequently, in this paper we systematically investigate the influence of electrode-skin contact pressure and electrode substrate flexibility on interfacial impedance and perceived wearing comfort in a study on 12 volunteers. The normal force applied to the electrode was varied between the minimum required force to achieve impedances < 1.3 M Omega and a maximum of 4 N, using a new force measurement applicator. We found that for a polymer shore hardness A98, with increasing normal force, the impedance decreases from 348 +/- 236 k Omega and 257 +/- 207 k Omega to 29 +/- 14 k Omega and 23 +/- 11 k Omega at frontal hairless and temporal hairy positions, respectively. Similar results were obtained for shore A90, A80, and A70. The best compromise of low and stable impedances as well as a good wearing comfort was determined for applied normal forces between 2 and 3 N using electrodes with shore A98 or A90. Our results provide the basis for improved EEG cap designs with optimal wearing comfort and recording quality for dry multipin electrodes, which will enable new fields of application for EEG.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8