ID 405 – Ultra-long term subcutaneous recording system for EEG surveillance

Objective We present a novel subdermal two-channel EEG recording device which promises robust and unobtrusive measurements. Methods Data quality is validated against a state-of-the-art surface EEG electrode technology, as well as a longitudinal comparison of the EEG power in standard frequency band (delta, theta, alpha and beta) over a one month period. Surface electrodes were placed at sites corresponding to the subcutaneous electrodes, and the EEG signals were evaluated quantitatively (power spectral density and coherence analysis) both one week and four weeks after implantation. Results Based on a preliminary trial of two subjects, the quantitative measures were very similar during recordings of resting EEG both at week one and week four. The longitudinal comparison showed no tendency to power change of the different frequency band over time. A full dataset of 10 patients will be shown at the congress. Conclusion and key message The ultra-long term EEG recorder is an unmet clinical need. The subdermal signal recorded by the new convenient and minimally invasive device is comparable to surface EEG in multiple aspects and provides a method of ultra-long term EEG recording in situations where this is required and where a small number of EEG electrodes are sufficient.