Feature Analysis of Evoked Potentials for Monitoring Depth of Anesthesia(I)——The Effects of Fentanyl on Middle Latency Auditory Evoked Potentials in Cats
Hong Cai · Hangtian yixue yu yixue gongcheng · 1991
Although the importance of monitoring depth of anesthesia has been recognized for a long time, there has been no simple, accurate and objective method to determine depth of anethesia. In this paper, the effects of fentanyl on the middle latency auditory evoked potentials (MLAEP), including the time domain, frequency domain and AR—model parameters, in cats are studied for the purpose of exploring the possibility of measuring anesthetic depth through MLAEP and proposing some new efficient and reliable techniques for clinical use. It is demonstrated that the parameters of AR—model, |A1| and an argument θ on pole distributions are more sensitive to fentanyl than those of time domain, such as latencies of Na and Pa and amplitude of Pa wave. As a result, we suggest that several feature parameters be considered simutaneously during surgery in order to obtain more reliable measurements.