Quantitative multichannel EEG measure predicting the optimal weaning from ventilator in ICU patients with acute respiratory failure  Christos Papadelis, Nikos Maglaveras, Chrysoula Kourtidou-Papadeli, Panagiotis Bamidis, Maria Albani, Kyriazis Chatzinikolaou, Konstantinos Pappas  Clinical Neurophysiology  Volume 117, Issue 4, Pages 752-770 (April 2006) DOI: 10.1016/j.clinph.2005.12.009 Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 1 Electrode positions. There were 8 electrodes placed according to the 10–20 international system: Fp1, Fp2, Fz, C3, C4, T5, T6, and Pz. EEG was recorded monopolarly with reference to the linked earlobes (A1 and A2). Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 2 Segments of EEG before and after ICA artifact rejection. The upper window represents a segment of the initial, non-processed EEG recordings in the mechanical ventilation session. The middle window represents the elimination of the second independent component due to eye blink artifacts, and the lower window represents the processed EEG after ICA application. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 3 Eight-channel EEG segments with 4s time duration from all analysed sessions: mechanical ventilation, weaning, early recovery, recovery 1, and recovery 2. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 4 Comparative results between SBC and FPE for different model orders. In the y-axis the values of the Akaike Final Prediction Error and the Schwarz's Bayesian Criterion are presented. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 5 Global Field Damping Time in seconds versus the segment window size with a range of 100–1400 samples. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 6 Comparison of GFDT (in seconds) of signals with known probability functions for different model orders. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 7 The GFDT (in seconds) estimated by multivariate AR (mAR) modelling time trends from various sessions of the experiment (1–30: mechanical ventilation, 30–35: weaning, 35–40: early recovery, 40–45: recovery 1, and 45–50: recovery 2) for 3 characteristic cases of patients: patient 5 with good recovery (group A), patient 10 who was impaired and required long-term institutional care (group B), and patient 11 with no recovery (group C). Grey line represents a moving average trend line with sample period of 15. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 8 The GFDT (in seconds) estimated by scalar AR (sAR) modelling time trends from various sessions of the experiment (1–30: mechanical ventilation, 30–35: weaning, 35–40: early recovery, 40–45: recovery 1, and 45–50: recovery 2) for 3 characteristic cases of patients: patient 5 with good recovery (group A), patient 10 who was impaired and required long-term institutional care (group B), and patient 11 with no recovery (group C). Grey line represents a moving average trend line with sample period of 15. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 9 Group variation of mean GFDT (in seconds) estimated by multivariate AR (mAR) modelling in 4 different experimental conditions (mechanical ventilation, weaning, early recovery, and recovery 1. Asterisks (*), and (**) represent statistically significant differences of mechanical ventilation session with other 3 sessions, with P<0.05 and 0.01, respectively. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 10 Group variation of mean GFDT (in seconds) estimated by scalar AR (sAR) modelling in 4 different experimental conditions (mechanical ventilation, weaning, early recovery, and recovery 1. Asterisks (*), and (**) represent statistically significant differences of mechanical ventilation session with other 3 sessions, with P<0.05 and 0.01, respectively. Clinical Neurophysiology 2006 117, 752-770DOI: (10.1016/j.clinph.2005.12.009) Copyright © 2006 International Federation of Clinical Neurophysiology Terms and Conditions