健康人视网膜电图a波和b波数字滤波纯化研究  

The extraction and analysis of a- and b- wave from electroretinogram in human

作　　者：陈子和[1] 郑昌伟[1] 雷博[1] 

机构地区：[1]重庆医科大学附属第一医院眼科眼科学重庆市市级重点实验室重庆市眼科研究所,400016

出　　处：《中华眼科杂志》2013年第12期1064-1068,共5页Chinese Journal of Ophthalmology

基　　金：国家自然科学基金（81271033）

摘　　要：目的确定暗适应3．0和明适应3．0视网膜电图（ERG）中a—b复合波的频率范围，为临床提取纯净的a波和b波波形提供理论基础和方法。方法系列研究。2010年10至11月对8名健康受试者进行全视野视网膜电图检查。应用数字滤波技术提取暗适应3．0和明适应3．0ERG信号中的a波和b波，通过分别测量计算时域波形图上a波和b波的周期并且对a波和b波进行傅里叶频谱分析，确定暗适应3．0和明适应3．0ERG中a—b复合波的频率范围。同时对数字滤波器的阶对a—b复合波的波形及频率的影响进行了比较。对明适应3．0及暗适应3．0ERG中a—b复合波频率范围的比较采用Student—t检验。结果暗适应3．0ERG中a—b复合波的频率范围为（14．99±2．39）～（25．35±3．77）Hz；明适应3．0ERG中a—b复合波的频率范围为（25．22±6．56）～（32．47±3．68）Hz。经Student—t检验发现，暗适应3．0ERG中a—b复合波的频率小于明适应3．0ERG中a—b复合波的频率（t=7．910，7．693，P值均〈0．01）。选择第三阶可以有效地从ERG中滤去振荡电位，同时又兼顾振幅的大小和时相位移的影响。结论健康人群ERG可以利用a—b复合波低频率和振荡电位高频率的特征，通过数字滤波器进行分离。选取数字滤波器第三阶，将通频带设定于1—45Hz，可以将振荡电位从ERG波形中滤去，获得光滑的a波和b波波形图。Objective To determine the frequency range of a-b wave complex in the dark- and light-adapted electroretinogram（ERG） and to isolate the pure a- and b- waves. Methods Case series study. Full-field ERGs were recorded in 16 eyes of 8 normal volunteers from October to November 2011. Digital filtering technique was used to extract the a- and b-waves from dark- and light-adapted ERG responses. The timings of a- and b-wave were measured to determine the frequency range of a-b wave complex. Major frequency components were determined from power spectra using fast Fourier transform（FFF）. The effect of different order settings in the digital filter were compared to investigate the optimum condition, where the oscillatory potential（OP） was completely removed while the amplitudes and phases of the a- and b- waves were less affected. The Student-t test was used to compare the frequency range of a-b wave complex in dark- and light-adapted ERG. Results The averaged frequency range of the dark-adapted a-b wave complex was from （14.99 -＋ 2.39） to （25.35 -＋ 3.77） Hz,compared with （25.22 ＋ 6.56） to （32.47 _＋ 3.68） Hz for the light-adapted a-b wave complex, respectively, indicating the frequency range of the dark-adapted a-b wave complex was significantly less than the light-adapted a-b wave complex （t = 7. 910,7. 693 ;both P 〈 0. 01 ）. The third order of the digital filter and a passband of 1 to 45 Hz was the best choice in term of removing the high frequency OP from the waveform of ERG and keeping the amplitude and phase of the a- and b- waves. Conclusions The frequency of a-b wave complex is lower than that of OP. Therefore the a- and b- waves can be isolated from OP using different digital filter settings in human ERG. A third order and a passband of 1 to 45 Hz is the best choice to extract pure a- and b- waves from the original ERG.

关 键 词：视网膜电描记术 适应 眼 电生理学 

分 类 号：R774[医药卫生—眼科]