ABSTRACT
In recent years, 40Hz auditory steady state response (ASSR) has been paid more attention when the depth of anaesthesia monitored because its same source with the middle latency auditory evoked potential (MLAEP), strong anti-jamming ability and close relationship with consciousness level. This article brings forward some effective and steady methods for extracting ASSR according to its characteristics. The results of these methods are analyzed and compared based on the actual records from clinical practice. And thus an extraction method fit for monitoring the depth of anaesthesia is determined.
ABSTRACT
It is very significative to perform real-time and effective monitor of the depth of anesthesia during the clinical operation. With the introduction of muscle-relaxing agents in general anesthesia, the two major indices to judge the depth of anesthesia have been obscured, which makes it more difficult to judge the depth of anesthesia. In recent years it has been found that 40Hz Auditory Steady State Response (ASSR) has a very good characteristic to monitor the depth of anesthesia. This article makes use of parametric-model method to extract 40Hz ASSR, which has a higher speed than Moving Time Average (MTA) when tracing the transition process of the patient from being conscious to being unconscious.