Publication Date


Document Type


Committee Members

James Christensen (Committee Member), Ping He (Advisor), Julie Skipper (Committee Member)

Degree Name

Master of Science in Engineering (MSEgr)


Current physiologically-driven operator cognitive state assessment technology relies primarily on electroencephalographic (EEG) signals. Traditionally, gel-based electrodes have been used; however, the application of gel-based electrodes on the scalp requires expertise and a considerable amount of preparation time. Additionally, discomfort can occur from the abrasion of the scalp during preparation, and the electrolyte will also begin to dry out over extended periods of time. These drawbacks have hindered the transition of operator state assessment technology into an operational environment. QUASAR, Inc., (San Diego, CA) has developed a prototype dry electrode system for electroencephalography that requires minimal preparation. A comparison of the dry electrode system to traditional wet electrodes was conducted and is presented here. The results show that initially the EEG recorded by the dry electrode system was quite similar to that recorded by the wet electrodes, but the similarity decreased over a testing period of six months. For cognitive state assessment, the dry electrodes were able to achieve classification accuracies within one to two percent of those achieved by the wet electrodes, with no decrease in accuracy over time. The results suggest that the dry electrode system is capable of recording electroencephalographic signals to be used in cognitive state assessment, and aiding in the transition of that technology into an operational environment. Further work should be conducted to improve the reliability of this novel system.

Page Count


Department or Program

Department of Biomedical, Industrial & Human Factors Engineering

Year Degree Awarded