Fig 1.
The graphical representation of the pharmacokinetics-neural mass model (PK-NMM).
The compartments of the PK model and the drug transfer rate are shown, as well as the macrocolumn incorporated into the neural mass model.
Table 1.
The PK parameters of the Schnider propofol model.
Fig 2.
Time course for excitatory (blue curve), inhibitory (red curve), and anesthetic-modified inhibitory (dashed) postsynaptic potential.
λ is the dimensionless anesthetic-effect scale factor giving the lengthening of the IPSP duration.
Fig 3.
Diagram of the experimental design.
The circle depicts the last object that could be recalled (the “object time”). The triangle depicts the time corresponding to the first number remembered during awakening (the “number time”).
Table 2.
The individual information for all the subjects.
Table 3.
The time events for each subject.
Fig 4.
Results from propofol infusion of a single representative subject.
(A) Time course of propofol infusion. The propofol infusion rate is 25mg/min. (B) Time course of the propofol concentration at the effect site obtained from the PK model for the same subject. “object time”, “syringe-drop time”, “number time”, and “command time” are marked with dashed lines.
Fig 5.
Computational processing of simulated EEG.
(A) Model predictions for the stationary states for he (blue line) and hi (red line). The superscript 0 in the legend represents stationary states. (B) The fluctuations of real-time he. The blue line in between is the stationary values for he. sEEG is calculated by using real-time he minus the values of he at stationary states. The fluctuations are displayed at 100*actual-size, and the line in between is the stationary state for excitatory neurons. The event time points are marked by dashed lines.
Fig 6.
(A) rEEG time series and (B) sEEG time series for a single subject. (C) and (D) show the EEG frequency spectrum of the two EEG signals. The dark red color denotes higher power and the blue color denotes lower power. (E), (F) and (G) show rEEG series of 10 s during consciousness (rEEG_consciousness), unconsciousness (rEEG_unconsciousness), recovery (rEEG_recovery) and the corresponding power spectra, respectively. (H), (I) and (J) show sEEG of 10 s during consciousness (sEEG_consciousness), unconsciousness (sEEG_unconsciousness), recovery (sEEG_recovery) and the corresponding power spectra, respectively. The 10 s EEG epochs extracted are labeled as I,II, III in the integral signal.
Fig 7.
Permutation entropy and SynchFastSlow measures versus time.
(A) Time course of PE with an embedding dimension m = 6 and lag τ = 1. The interval is 10 s and the overlapping size is 7.5s. The solid line represents the PE measure of rEEG (PE_rEEG) and dashed line represent the PE measure of sEEG (PE_sEEG), respectively. (B) Time course of SynchFastSlow. SFS_rEEG represents the SynchFastSlow of rEEG signal and SFS_sEEG represents the SynchFastSlow of sEEG signal. The event time points are marked by dashed lines.
Fig 8.
Boxplot of PE for rEEG and sEEG.
(A) and (B) are boxplots for rEEG and sEEG at conscious, unconscious and RoC states, respectively.
Fig 9.
The effect-site concentration of propofol for one subject under four weights.
(A) is the Ceff for one single subject under four weights (60, 80, 100, 120kg), (B) is the corresponding rCeff under the four weights.
Fig 10.
The effect-site concentration of propofol for all nine subjects.
(A) is the Ceff for all subjects depending on time, (B) is the corresponding rCeff, and (C) represents the rCeff with the time divided by their respective syringe-drop time.