Combining multiple QEEG features to estimate drug-independent sedation level using machine learning
The present disclosure describes systems and methods of estimating sedation level of a patient using machine learning. For example, the integration of multiple QEEG features into a single sedation level estimation system using machine learning could result in a significant improvement in the predictability of the levels of sedation, independent of the sedative drug used. The present disclosure advantageously allows for the incorporation of large numbers of QEEG features and machine learning into the next-generation monitors of sedation level. Different QEEG features may be selected for different sedation drugs, such as propofol, sevoflurane and dexmedetomidine groups. The sedation level estimation system can maintain a high performance for detecting MOAA/S, independent of the drug used.
1. A method for generating a sedation level estimate, the method comprising:
receiving an electroencephalography (EEG) signal from a sensor electrode attached to a patient, the EEG signal comprising a plurality of channels;
segmenting the EEG signal into smaller epochs for each channel;
extracting features of the EEG signal in each epoch, the features comprising time domain features, frequency domain features, and entropy domain features;
determining a median of features among the plurality of channels for each epoch;
determining, by a classifier, a probabilistic estimate of a patient sedation, wherein the classifier is trained using training data comprising MOAA/S scores, the training data selected to exclude MOAA/S scores in a center range of the MOAA/S scores;
generating, using a determined correlation, a sedation level estimate, the sedation level estimate comprising a continuous sedation score; and
displaying an indication of the sedation level estimate.
2. The method of claim 1 , wherein an epoch comprises 4 seconds.
3. The method of claim 1 , wherein the features comprise quantitative electroencephalogram (QEEG) features.
4. The method of claim 3 , wherein extracting features comprises extracting at least 44 QEEG features.
5. The method of claim 1 , wherein classifier comprises a binary classifier trained by machine learning.
6. The method of claim 5 , wherein the binary classifier is trained using awake and sedated epoch data, the awake and sedated epoch data comprising a plurality of epochs having sedation scores.
7. The method of claim 1 , wherein the determined correlation comprises a correlation between the probabilistic estimate of the patient sedation and a sedation score.
8. The method of claim 1 , wherein the center range comprises MOAA/S scores of 2 or 3.