Patent No. 6868345 Monitoring auditory evoked potentials
Patent No. 6868345 Monitoring auditory evoked potentials (Jensen, Mar 15, 2005) Abstract A method and an apparatus for extracting signals which are indicative of the level of consciousness of a patient comprises subjecting the patient to a repetitive audio stimulus, monitoring AEP produced by the patient using an autoregressive model with exogenous input, and then calculating an index (AAI), which is displayed or used otherwise,indicative of the anaesthetic depth. Notes: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for extracting signals which are indicative of the level of consciousness of a patient comprising means for monitoring auditory evoked potentials (AEP) produced by the patient as a response to a repetitive acoustic click stimulus, means for extracting an AEP within a few repetitions, preferably more than 10 and less than 50 of the audio stimulus, means for using an autoreg