Time Delay of Index Calculation

Abstract

The time delays of the tested indices may limit their value in prevention of recall of intraoperative events. Furthermore, different latencies for decreasing and increasing values may indicate a limitation of these monitors for pharmacodynamic studies.

Estimating the Plasma Effect-Site Equilibrium Rate Constant (<i>K</i>_e0) of Propofol by Fitting Time of Loss and Recovery of Consciousness

“…Zhang determined the effects of propofol using AAI and BIS on the same population and obtained K e0 values of 0.64 and 1.87 min −1 , respectively. 21) Four factors could lead to such differences in K e0 . First, commonly used EEG-derived parameters cannot simultaneously reflect the effects of drugs.…”

“…Zhang et al reported that AAI or BIS values could not provide evident minimum recordings in some patients because of disturbances. 21) Finally, the Tpeak approach can only fit one dataset because of the three reasons discussed above. If the unique data are inaccurate, the values of K e0 are unreliable.…”

Improving the accuracy of depth of anaesthesia using modified detrended fluctuation analysis method

“…The BIS Index is updated every one second. The BIS trend is updated every 10 s. Time delay of index calculation for the Cerebral State Index, the Bispectral Index, and the Narcotrend Index was studied by Pilge et al [19]. In this paper, we apply the Lagrange method for monitoring the DoA on real signals.…”

EEG Based Monitoring of General Anesthesia: Taking the Next Steps

“…By using spectral power, or parameters derived from it, as key parameters, the monitoring systems may dismiss signal information content by neglecting the phase component of the signals' frequency and only exploiting information from the amplitude spectrum (Callegaro, 2012). Further, the devices susceptibility to muscle activity (Messner et al, 2003; Schuller et al, 2015), especially by including high EEG frequencies as well as the time delay, necessary for index calculation (Pilge et al, 2006; Zanner et al, 2009; Kreuzer et al, 2012) may present a limiting factor in performance to reliably track the anesthetic state.…”