[A monitoring technique in detecting the depth of anesthesia by bispectral index]

At the present time, a kind of monitoring technology assuring highly effectual anesthesia is urgently required in the clinical practice. Electroencephalogram (EEG) assumes a dominant position in the current research of the depth detection of anesthesia. In this paper, the monitoring technique of the depth detection of anesthesia by bispectral index (BIS) is systematically showed. The bispectral index is a compound parameter which is composed of time domain, frequency domain, and high order spectral subparameters of the electroencephalograph. This nonlinear compound calculation method is worth research and is of great significance to the development of a new monitor of closed-loop control of anesthesia.