Steady, as She Goes – Consistent Low Impedance of Ultra Long-Term Subcutaneous EEG Ensures High-Quality Recordings
Abstract number :
1.183
Submission category :
3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year :
2023
Submission ID :
294
Source :
www.aesnet.org
Presentation date :
12/2/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Jonas Duun-Henriksen, PhD, MSc – UNEEG medical
Line Remvig, MSc – Senior Data Scientist, UNEEG medical
Rationale: Continuous monitoring of brain activity over extended periods of time can be achieved through ultra long-term subcutaneous EEG (sqEEG) recordings. Because these devices offer recordings during real-world everyday activities, a reliable and stable contact between the recording electrodes and the body tissue is required. Hence, the objective of this study is to the examine the temporal changes in the sqEEG signal impedance over ultra long-term recording periods using the 24/7 EEG™ SubQ system (UNEEG medical A/S, Denmark).
Methods: Analyses were conducted on sqEEG impedance measurements from a pooled multi-investigation cohort of 37 people with epilepsy. The recording duration had a median of 365 days, ranging from 21 to 465 days. The initial impedance measurement was typically recorded 7-21 days after the implantation procedure, and subsequent measurements were made at least once daily. Ultra long-term temporal patterns in recorded signal impedance were examined using subject-specific linear regression models.
Results: Throughout the studies of the cohort, all measurements of electrode impedance remained low (all below 4 kOhm) and exhibited a high level of stability within each subject, even from the beginning of the recording period. The subject-specific linear regression models revealed long-term trends that were close to zero, with a median absolute trendline gradient of 0.01 kOhm/month (ranging from 0.00007 to 0.13 kOhm/month).
Conclusions: By demonstrating that impedance measurements remain low and stable during ultra long-term everyday life monitoring periods lasting up to 465 days, our findings contribute to the assurance of the reliability of sqEEG recordings.
Funding: JDH and LSR are full-time employees at UNEEG medical
Neurophysiology