Poincaré Plot Area of Gamma-Band EEG as a Measure of Emergence From Inhalational General Anesthesia

Abstract

The Poincaré plot obtained from electroencephalography (EEG) has been used to evaluate the depth of anesthesia. A standalone EEG Analyzer application was developed; raw EEG signals obtained from a bispectral index (BIS) monitor were analyzed using an on-line monitoring system. Correlations between Poincaré plot parameters and other measurements associated with anesthesia depth were evaluated during emergence from inhalational general anesthesia. Of the participants, 20 were adults anesthetized with sevoflurane (adult_SEV), 20 were adults anesthetized with desflurane (adult_DES), and 20 were pediatric patients anesthetized with sevoflurane (ped_SEV). EEG signals were preprocessed through six bandpass digital filters (f0: 0.5–47 Hz, f1: 0.5–8 Hz, f2: 8–13 Hz, f3: 13–20 Hz, f4: 20–30 Hz, and f5: 30–47 Hz). The Poincaré plot-area ratio (PPAR = PPA_fx/PPA_f0, fx = f1∼f5) was analyzed at five frequency ranges. Regardless of the inhalational anesthetic used, there were strong linear correlations between the logarithm of PPAR at f5 and BIS (R2 = 0.67, 0.79, and 0.71, in the adult_SEV, adult_DES, and ped_SEV groups, respectively). As an additional observation, a part of EMG activity at the gamma range of 30–47 Hz probably influenced the calculations of BIS and PPAR_f5 with a non-negligible level. The logarithm of PPAR in the gamma band was most sensitive to state changes during the emergence process and could provide a new non-proprietary parameter that correlates with changes in BIS during measurement of anesthesia depth.

Remimazolam and Remifentanil Anesthetics for an Adolescent Patient with Stiff-Person Syndrome: A Case Report

“…The electroencephalographic data were analyzed using the EEG analyzer version 49. 1 In the EEG analyzer system, raw electroencephalographic signals from a bispectral index (BIS) monitor were collected at a sampling rate of 128 Hz. Continuous data from the preceding 8-second epoch were bandpass-filtered (0.5–50 Hz), and each epoch was applied to a Blackman window function, followed by a fast Fourier transform for power spectrum analysis and bispectral analysis.…”

Changes in EEG frequency characteristics during sevoflurane general anesthesia: feature extraction by variational mode decomposition

“…At the phase of emergence from general anesthesia, sugammadex (4 mg/kg) was administered before extubation. To acquire EEG data, we used the software application EEG Analyzer [12,13], through which raw EEG signals via an RS-232 interface of a VISTA A-3000 BIS monitor (VISTA Application revision 3.22, Platform revision 2.03, Medtronic, Minneapolis, MN, USA) were recorded on a personal computer (Surface Pro 4, Microsoft Co., Redmond, WA, USA) as text les. Additionally, various parameters associated with anesthetic depth were acquired via a BIS Quatro sensor mounted on the frontal regions according to the manufacturer's recommendations.…”

Time-trend analysis of the center frequency of the intrinsic mode function from the Hilbert–Huang transform of electroencephalography during general anesthesia: a retrospective observational study

“…We previously developed a software application named “EEG Analyzer” to obtain raw EEG signals from a BIS A-2000 monitor (version 3.23; Medtronic, Minneapolis, MN, USA) through an RS-232 interface [ 12 ]. A BIS Quatro sensor was attached on the frontal region, in accordance with the manufacturer’s recommendations and single frontal channel EEG was recorded.…”