Real-time depth of anaesthesia assessment using strong analytical signal transform technique

This paper introduces a new method addressing depth of anaesthesia (DoA) assessment for real-time monitoring. The new method uses a combination of phase and amplitude of electroencephalogram (EEG) signals to assess the DoA level. A strong analytical signal transform is applied to extract the phase and amplitude information of the recorded EEG signals. Based on the extracted features from the EEG signal in each different frequency band, a new DoA index is developed. The proposed new DoA index is evaluated using data from adult patients in an age range from 22 to 75 years. The results show that the new DoA index is able to detect the changing pattern of EEG signals early and agree with the clinical notes of an attending anaesthetist. The results are also closely correlated with the popular BIS index. Furthermore, the proposed new DoA index is able to detect the state changes earlier than the BIS index.