Automatic detection of artefacts during intraoperative EEG monitoring

The quality of intraoperative EEG monitoring is decisively influenced by automatic detection of artefacts. Undetected artefacts can mimic non-existing trends thus leading to misinterpretations of the EEG. Methods of computer-assisted artefact detection are developed and described: On the one hand the algorithms include simple threshold values of atypical parameters, on the other, they rely on situation-dependent smoothing of the EEG signal. Too strong a deviation of an artefact-relevant parameter from its smoothed value results in exclusion of the EEG segment (epoch) from further computation trends. The algorithms can clearly reduce the misclassification of highly artefact-contaminated epochs in the awake patient, without allowing anaesthesia-relevant changes to escape notice.