Patent ID: 6801803
Filing Date: 2004-10-05
Classification: A61B,G06K

Abstract:
A method for ascertaining the cerebral state of a patient, including a state resulting from the administration of a drug, said method comprising the steps of:(a) obtaining biopotential signal data from the patient, the biopotential signal data containing EEG signal data and EMG signal data, the EMG signal data being primarily of a higher frequency than the EEG signal data which is primarily of a lower frequency; (b) collecting the biopotential signal data over a plurality of time periods of differing lengths; (c) subjecting the biopotential signal data of each of the time periods to spectral decomposition to obtain the frequency components of the collected biopotential signal data; (d) selecting frequency components in a selected frequency band from the decomposed biopotential signal data for each of the time periods; (e) analyzing the frequency components of a desired number of the frequency bands to obtain a measure of the complexity of the frequency components over a frequency range formed from the selected frequency bands; and (f) providing the measure so obtained as an indication of the cerebral state of the patient.