Pre-gelled Electrode Grid for Self-Applied EEG Sleep Monitoring at Home

Abstract

The need for diagnostic capabilities for sleep disorders such as sleep apnea and insomnia far exceeds the capacity of inpatient sleep laboratories. Some home monitoring systems omit electroencephalography (EEG) because trained personnel may be needed to apply EEG sensors. Since EEG is essential for the detailed evaluation of sleep, better systems supporting the convenient and robust recording of sleep EEG at home are desirable. Recent advances in EEG acquisition with flex-printed sensors promise easier application of EEG sensor arrays for chronic recordings, yet these sensor arrays were not designed for sleep EEG. Here we explored the self-applicability of a new sleep EEG sensor array (trEEGrid) without prior training. We developed a prototype with pre-gelled neonatal ECG electrodes placed on a self-adhesive grid shape that guided the fast and correct positioning of a total of nine electrodes on the face and around the ear. Positioning of the sensors was based on the results of a previous ear-EEG sleep study (da Silva Souto et al., 2021), and included electrodes around the ear, one eye, and the chin. For comparison, EEG and electrooculogram channels placed according to the American Academy of Sleep Medicine criteria, as well as respiratory inductance plethysmography on thorax and abdomen, oxygen saturation, pulse and body position were included with a mobile polysomnography (PSG) system. Two studies with 32 individuals were conducted to compare the signal quality of the proposed flex-printed grid with PSG signals and to explore self-application of the new grid at home. Results indicate that the new array is self-applicable by healthy participants without on-site hands-on support. A comparison of the hypnogram annotations obtained from the data of both systems revealed an overall substantial agreement on a group level (Cohen’s κ = 0.70 ± 0.01). These results suggest that flex-printed pre-gelled sensor arrays designed for sleep EEG acquisition can facilitate self-recording at home.

The evaluation of cEEGrids for fatigue detection in aviation

“…In practical field settings, such as cockpits or air traffic control operations rooms, a smaller set of electrodes suffices, offering advantages in terms of user convenience and mobility [ 3 , 4 ]. However, despite its fast application, self-applying cEEGrids without training in a naturalistic setting can be challenging due to the necessary preparation steps, the use of gel, and limited adaptability of the sticker [ 84 ]. Therefore, improvements could include employing dry electrodes, lightweight portable recording equipment, or completely integrating EEG technology into headphones or headwear.…”

The future of wearable EEG: a review of ear-EEG technology and its applications

“…For instance, Guermandi et al [60] created an aroundear EEG system that incorporates their own C-shaped electrode arrays made from flexible polyimide PCB resembling cEEGrids but their reference and ground electrodes are in a rectangle shape and located parallel to each other. Souto et al [61] made direct modifications to the cEEGrid array. Based on their work conducting a sleep analysis using ear-EEG acquired from the cEEGrid [62], they developed a novel electrode array called trEEGrid, which is specifically designed for sleep analysis.…”

Recent Progress in Long-Term Sleep Monitoring Technology

“… ( a ) The use of PSG [ 32 , 33 ]. Reproduced under the terms of the CC-BY Creative Commons Attribution License, Copyright 2022 by the authors, published by FRONTIERS MEDIA SA.…”

“…( b ) A home PSG that divides the sleep stages by monitoring several pieces of physiological information. Heart rate, respiratory rate, and movement are recorded and compared with the sleep cycle of a professional PSG [ 32 , 34 ]. Reproduced under the terms of the CC-BY Creative Commons Attribution License, Copyright 2022 by the authors, published by MDPI.…”