Journal: Device
Article Title: Design of an injectable, self-adhesive, and highly stable hydrogel electrode for sleep recording
doi: 10.1016/j.device.2023.100182
Figure Lengend Snippet: Comparison of Long-term EEG signal quality between AIRTrodes and the commercial EEG gel electrodes (A) The time-series EEG signals were recorded from the volunteer by AIRTrode (top) and commercial EEG gel (bottom) during the 100 s of the eyes-open (EO) and eyes-closed (EC) paradigm before overnight sleep. The [1, 30] Hz band-pass filter was applied to remove any direct current (DC) offset. (B) The spectrograms for EEG signals in (A). (C) The PSD analysis of the grand average of all EC and EO epochs for both types of electrodes. The AIRTrode shows an overall lower background signal (frequencies outside of the alpha band [8, 13] Hz) compared with the commercial EEG gel at the specific channel (PO4) before overnight sleep. (D) The mean power spectral density (PSD) analysis derived from the alpha rhythm for the AIRTrode and commercial EEG gel to detect differences in EEG activity between EO and EC periods (****p < 0.0001, n = 5). (E) Signal-to-noise ratio (SNR) comparison between AIRTrodes and commercial EEG gel electrodes. The signal of interest is defined as alpha rhythm, and the background signal is defined as 5–30 Hz, excluding the alpha rhythm. (F) The time-series EEG signals recorded by the AIRTrode (top) and commercial EEG gel (bottom) during the 100 s of the EO-EC paradigm after overnight sleep. The same setting as in (A) was applied. (G) The spectrograms for the EEG signals in (F). Compared with before sleep, the signal quality improved with both types of electrodes. (H) PSD analysis of the grand average of all EC and EO epochs for both types of electrodes. The PSD variation between epochs is greater than before sleep. (I) PSD from the alpha rhythm to show the capability of both types of electrodes to detect differences in EEG activity between EO and EC periods (***p < 0.001, n = 5). (J) SNR comparison between AIRTrodes and commercial EEG gel electrodes after sleep. (***p < 0.001, n = 5).
Article Snippet: All EEG signal data processing, analyses, and visualizations were performed in MATLAB.
Techniques: Comparison, Derivative Assay, Activity Assay
MathWorks Inc is a verified supplier 
![Comparison of Long-term <t>EEG</t> <t>signal</t> quality between AIRTrodes and the commercial EEG gel electrodes (A) The time-series EEG signals were recorded from the volunteer by AIRTrode (top) and commercial EEG gel (bottom) during the 100 s of the eyes-open (EO) and eyes-closed (EC) paradigm before overnight sleep. The [1, 30] Hz band-pass filter was applied to remove any direct current (DC) offset. (B) The spectrograms for EEG signals in (A). (C) The PSD analysis of the grand average of all EC and EO epochs for both types of electrodes. The AIRTrode shows an overall lower background signal (frequencies outside of the alpha band [8, 13] Hz) compared with the commercial EEG gel at the specific channel (PO4) before overnight sleep. (D) The mean power spectral density (PSD) analysis derived from the alpha rhythm for the AIRTrode and commercial EEG gel to detect differences in EEG activity between EO and EC periods (****p < 0.0001, n = 5). (E) Signal-to-noise ratio (SNR) comparison between AIRTrodes and commercial EEG gel electrodes. The signal of interest is defined as alpha rhythm, and the background signal is defined as 5–30 Hz, excluding the alpha rhythm. (F) The time-series EEG signals recorded by the AIRTrode (top) and commercial EEG gel (bottom) during the 100 s of the EO-EC paradigm after overnight sleep. The same setting as in (A) was applied. (G) The spectrograms for the EEG signals in (F). Compared with before sleep, the signal quality improved with both types of electrodes. (H) PSD analysis of the grand average of all EC and EO epochs for both types of electrodes. The PSD variation between epochs is greater than before sleep. (I) PSD from the alpha rhythm to show the capability of both types of electrodes to detect differences in EEG activity between EO and EC periods (***p < 0.001, n = 5). (J) SNR comparison between AIRTrodes and commercial EEG gel electrodes after sleep. (***p < 0.001, n = 5).](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_6683/pmc11376683/pmc11376683__nihms-1970430-f0005.jpg)