Evaluation of Dry Sensors for Neonatal EEG Recordings

Abstract

Introduction Neonatal seizures are a common neurologic diagnosis in Neonatal Intensive Care Units (NICUs), occurring in approximately 14,000 newborns annually in the US. While the only reliable means of detecting and treating neonatal seizures is with an EEG recording, many neonates do not get an EEG or experience delays in getting them. Barriers to obtaining neonatal EEGs include: 1) lack of skilled EEG technologists to apply conventional wet electrodes to delicate neonatal skin, 2) poor signal quality due to improper skin preparation and artifact, 3) extensive time needed to apply electrodes. Dry sensors have the potential to overcome these obstacles but have not been previously evaluated on neonates. Methods Sequential and simultaneous recordings with wet and dry sensors were performed for one hour on 27 neonates from 35-42.5 weeks postmenstrual age. Recordings were analyzed for correlation and amplitude, and were reviewed by neurophysiologists. Performance of dry sensors on simulated vernix was examined. Results Analysis of dry and wet signals showed good time-domain correlation (reaching >0.8) given the non-superimposed sensor positions, and similar power spectral density curves. Neurophysiologist reviews showed no statistically significant difference between dry and wet data on most clinically-relevant EEG background and seizure patterns. There was no skin injury after 1 hr of dry sensor recordings. In contrast to wet electrodes, impedance and electrical artifact of dry sensors were largely unaffected by simulated vernix. Conclusions Dry sensors evaluated in this study have the potential to provide high-quality, timely EEG recordings on neonates with less risk of skin injury.

Long term electroencephalography in preterm neonates: Safety and quality of electrode types

“…Other electrode types have been used for neonatal EEG studies. A recent study compared wet and dry sensors in EEG recordings of newborns born at 35–42 weeks postmenstrual age (Fridman et al, 2016). The authors found a good correlation between dry and wet signal recordings in power spectral density curves, and similar interpretation of EEG background and seizure patterns.…”

Revisión de electroencefalografía portable y su aplicabilidad en neurociencias.

“…Gracias a que los sensores secos de QUASAR hacen un contacto eléctrico de alta impedancia con la piel y registran sin necesidad de preparar la piel fueron utilizados en pacientes neonatales con la idea de diagnosticar las convulsiones en dichos pacientes [57] y resultaron ser prácticos y eficientes para el uso en este tipo de pacientes.…”

Analysis of a Low-Cost EEG Monitoring System and Dry Electrodes toward Clinical Use in the Neonatal ICU

“…The task of acquiring high quality EEG signals is non-trivial and requires the expertise of a neurophysiologist or EEG technician. Additionally, it is time-consuming, taking up to an hour in some cases [5,6]. EEG signals are very small in amplitude (±100 µV) and are susceptible to many types of artefacts, such as physiological, electrical, and movement artefacts that can often saturate the EEG signals with noise [7].…”

“…Several studies assessing the performance of dry electrodes have shown comparable results between wet and dry electrodes using multiple evaluation experiments on adults. Such tests include simultaneously recording wet and dry channels and comparing correlation and coherence [6,20], or performing tasks such as generating an EEG alpha rhythm [19] and other neurological tasks [22,23].…”

“…Clinically validating such systems requires using uncertified electronics on patients, which is often restricted by patient safety and ethical barriers [34]. In particular for newborns, there has been minimal development and evaluation of dry electrodes [6].…”