Self‐applied somnography: technical feasibility of electroencephalography and electro‐oculography signal characteristics in sleep staging of suspected sleep‐disordered adults

Abstract

SummarySleep recordings are increasingly being conducted in patients’ homes where patients apply the sensors themselves according to instructions. However, certain sensor types such as cup electrodes used in conventional polysomnography are unfeasible for self‐application. To overcome this, self‐applied forehead montages with electroencephalography and electro‐oculography sensors have been developed. We evaluated the technical feasibility of a self‐applied electrode set from Nox Medical (Reykjavik, Iceland) through home sleep recordings of healthy and suspected sleep‐disordered adults (n = 174) in the context of sleep staging. Subjects slept with a double setup of conventional type II polysomnography sensors and self‐applied forehead sensors. We found that the self‐applied electroencephalography and electro‐oculography electrodes had acceptable impedance levels but were more prone to losing proper skin–electrode contact than the conventional cup electrodes. Moreover, the forehead electroencephalography signals recorded using the self‐applied electrodes expressed lower amplitudes (difference 25.3%–43.9%, p < 0.001) and less absolute power (at 1–40 Hz, p < 0.001) than the polysomnography electroencephalography signals in all sleep stages. However, the signals recorded with the self‐applied electroencephalography electrodes expressed more relative power (p < 0.001) at very low frequencies (0.3–1.0 Hz) in all sleep stages. The electro‐oculography signals recorded with the self‐applied electrodes expressed comparable characteristics with standard electro‐oculography. In conclusion, the results support the technical feasibility of the self‐applied electroencephalography and electro‐oculography for sleep staging in home sleep recordings, after adjustment for amplitude differences, especially for scoring Stage N3 sleep.

Shorter total sleep time is associated with lower CD4+/CD8+ T cell ratios in virally suppressed men with HIV

“…Nevertheless, future studies utilizing longer-term monitoring to assess habitual sleep patterns, such as with actigraphy, would be helpful in confirming our results. Although all sleep stages were observed, participants in the study demonstrated a low proportion of N3 sleep, which is due to the limitations of using the self-applied forehead EEG signals that have higher impedances leading to attenuated voltages of observed delta waves [ 90 ]. Thus, the limited EEG utilized may have affected the study’s power to evaluate differences in this sleep stage on T lymphocyte subsets.…”

Sleep, Health Outcomes and Body Weight (SHOW) study: a measurement burst design study on sleep and risk factors for obesity in black emerging adults in North Carolina, USA

“…An alternative approach to the traditional EEG montage offered by Nox Medical is the Self Applied Somnography (SAS) setup (Nox Medical, Reykjavik, Iceland), which is a simplified EEG montage that positions 10 stick-on electrodes along the forehead and near the eyes to capture prefrontal cortex EEG (AF8, AF4, GND, AFz, AF3, AF7) and EOG (E1, E2, E3, E4) activity without recording the mastoid channels. 94 95 Chin EMG is also omitted, although an EMG signal derived from the eyes is available for analysis. 94 95 Since EEG setups may fail to accommodate thick hair types or various hairstyles, offering the SAS setup as an alternative, but valid, 94 95 approach to in-home sleep monitoring may promote a more culturally inclusive method for individuals who are unable to or prefer not to use the traditional PSG setup with Ten20 paste adhesion.…”

“… 94 95 Chin EMG is also omitted, although an EMG signal derived from the eyes is available for analysis. 94 95 Since EEG setups may fail to accommodate thick hair types or various hairstyles, offering the SAS setup as an alternative, but valid, 94 95 approach to in-home sleep monitoring may promote a more culturally inclusive method for individuals who are unable to or prefer not to use the traditional PSG setup with Ten20 paste adhesion.…”