听觉诱发电位检测及分析

Detecting and Analysis of Brain Stem Auditory Evoked Potentials

脑干听觉诱发电位(BAEP)是受试者的听觉系统在具有一定特征的短声刺激作用之后,在其颅顶上检测到的一系列反应波,在电测听和神经电生理上具有独特的临床意义.研究中通过专门设计具有高输入阻抗、低噪声与高共模抑制比的BAEP放大器,建立起一套脑干听觉诱发电位检测系统,在系统的数据分析过程中采用了平均叠加、小波变换等算法,并从临床应用的角度出发提出了规一化系数加权平均算法.经实际检测实验表明,本系统在没有屏蔽室和专用接地线的条件下对受试者均成功地检测出了BAEP波,具有较好的应用价值.

The brain stem auditory evoked potential (BAEP) is a bioelectric action of the central nervous system in the process of stimulation. It can reveal the activity of neuron groups along the corresponding sensory path, which is very useful for clinical detection. But the amplitude of BAEP is very small (about 0.1 μV to 0.6 μV) and it is covered with a large quantity of the background noise of self-bioelectricity and all kinds of artifacts. So it is difficult to detect BAEP by means of a usual technique.In this paper, firstly, we discuss the meaning of detecting the evoked potential and the direction of its development. Then we introduce a BAEP detecting instrument we have designed and made. We describe the components of this instrumen as four parts: a specialy-designed amplifier with high input impedance and common mode rejection ratio (CMRR), sound stimulation circuits, the analog to digital converter and computer control system, the description of parameters of the instrument. Secondly, in order to detect BAEP efficiently, both algorithms of standardize weighted averaging and wavelet transformation are employed in the mathematical calculation of data acquisition. With these methods, we can reduce average times 'to ' or 'by' less than five hundreds and highly increase the accuracy of results. After that, we discuss the principle of standardize weighted averaging. In the end, we introduce some instances, all of which are generated by this instrument and data acquisition methods. These instances indicate that this instrument can detect BAEP successfully without high-grade earthing or shield room. They also suggest that it has fairly good value in the clinical practice.