麻醉深度监测的实验研究

Experiment Research on the Method of Monitoring the Depth of Anesthesia

目前,麻醉深度定量监测的主要途径是EEG和AEP,它们的主要指标分别是双谱指数(BIS)和AEP指数,这两个指数各有所长。EEG的BIS是由多个子参数融合而成的,这暗示其稳定性欠佳;AEP指数比较可靠,但是长时间实时测量AEP会使病人因过多的单调声刺激而烦躁不安。因此,研究BIS子参数和AEP指数的一致性和互补性,就显得非常必要。本文的目的正在于此。我们研发了实验用信号采集系统,系统由两部分组成:单片机模块和PC机,单片机模块是硬件的核心,负责刺激和采集信号,以及与PC机通信。PC机控制软件用Labview编写,负责信号的简单处理和记录。信号的后处理用Matlab实现。动物实验:10只大耳白兔,麻醉剂使用3%戊巴比妥钠,按每公斤体重0.5ml,0.25ml,0.25ml,0.25ml的剂量于耳缘静脉注射,间隔为20分钟,注射麻剂5分钟后记录EEG和AEP。之后,每隔10分钟记录一次,共三次。结果:经过数据处理,我们初步发现BIS子参数和AEP指数具有较好的一致性。

The main methods to monitor the depth of anaesthesia are based on EEG and AEP measurement, and the important parameters are BIS and AEP index. Each of them has its predominance. BIS is formed by the subparameters of EEG in time domain, frequency domain and bispectrum domain by means of a nonlinear function. The process to setup the function is very complicated. This implies that its stability is not very good. AEP index is rather reliable, but the monotone click stimulus would make patients dysphoric. So it's necessary to study the consistency and complementarity between BIS's subparameters and AEP index. This is just the goal of this paper. Based on the clinic requirement, we develop a new instrument to do research. The prototype instrument is composed of two parts: SCM module and PC. The SCM module is the heart of the hardware, in charge of stimulation and data acquisition, which evokes the auditory potentials, sampling the EEG and AEP signal and communicating with PC. The operating software on PC is designed by the virtual instrument workbench-LabVIEW, and the signal processing is completed on Matlab. Experiment method: 10 rabbits, the anaesthetic is 3% pentobarbitol sodium, the dosage is 0.5, 0.25, 0.25, 0.25 ml/kg, the interval is 20 minutes, EEG and AEP is recorded 5 minutes after every injection. Then EEG and AEP is recorded with the interval of 10 minutes after the last injection, and total number is 3. Result: After the signal processing, it turns out that the consistency between BIS subparameters and AEP index is rather good.