Description: I could use a little fuel myself.
27 April 2022
The Bispectral Index (BIS) is intended to be a dimensionless measure of anaesthetic depth derived from spectral analysis of a frontal electroencephalogram (EEG) in patients undergoing anaesthesia involving neuromuscular block. The minimum value is 0 (isoelectric EEG) and the maximum is 100 (fully awake). BIS of 40-60 is considered adequately deep for general anaesthesia.
BIS is synthesised from frontal EEG data using an undisclosed proprietary algorithm. Morimoto and colleagues (2004) shed some light on the derivation of BIS by analysing its correlation with published formulae for the constituent analyses that are integrated into the final BIS value. In brief, the frontal EEG is processed to remove artefacts and noise, and then a fast Fourier transform is applied to facilitate analysis with respect to time of its constituent wave patterns. The relative prevalence of beta wa