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. Author manuscript; available in PMC: 2019 Jul 19.
Published in final edited form as: Crit Care Med. 2019 Apr;47(4):574–582. doi: 10.1097/CCM.0000000000003639

Figure 1.

Figure 1.

Representative continuous electroencephalography (cEEG) epoch demonstrating background classification. High-frequency filter=70 Hz, notch filter=60 Hz, and time constant=0.12 s. (A) I Normal: 9-Hz posterior dominant (alpha) rhythm during a period of relative wakefulness. (B) I Normal: N2 sleep with a prominent sleep spindle (bold line) and K-complex (box). (C) I Mild: predominant theta background activity. (D) I Mild: rudimentary N2 sleep transients (K-complex, box). (E) II Moderate: continuous, irregular 1 to 3-Hz delta activity without N2 sleep transients. (F) III Severe: bursts (>500ms and >3phases) of generalized activity on a suppressed (<10 μV) background, or burst-suppression pattern.