视网膜电流图振荡电位的计算机处理及临床应用

Digital signal processing of oscillatory potentials and its clinical application

目的 研究视网膜电流图 (electroretinogram,ERG)振荡电位 (oscillatory po-tentials,OPs)的提取和分析方法及其临床应用。方法 测试了 40只 (4 0例 )正常对照眼、33只 (33例 )糖尿病视网膜病变 (diabetic retinopathy,DR)患眼、9只视网膜中央静脉阻塞(central retinal vein occlusion,CRVO)患眼和 9只视网膜分支静脉阻塞 (branch retinalvein occlusion,BRVO)患眼的振荡电位。用快速傅里叶变换计算 OPs的 10～ 2 90 Hz频谱 ,计算频谱的功率总和以及最大功率。通过快速傅里叶逆变换用 110～ 2 5 0 Hz频谱成分重构时域的 OPs。测量重构的 OPs4个子波的潜伏期、振幅和振幅总和。结果 与正常对照组比较 ,早期 DR患眼 140～ 2 10 Hz振幅谱、功率总和以及最大功率下降 ,4个子波的潜伏期延长 ,振幅和振幅总和下降 ;CRVO患眼 15 0～ 180 Hz振幅谱、功率总和以及最大功率下降 ,第 1到第 3个子波的潜伏期延长 ,振幅和振幅总和下降 ;BRVO患眼功率总和以及最大功率下降 ,第 2和第 3个子波的潜伏期延长、第 1到第 3个子波的振幅和振幅总和下降。结论 该文阐述的 OPs分析方法可为 DR、CRVO和BRVO的诊断提供有效的客观指标。

Objective To study the analyzing method of oscillatory potentials (OPs) and its clinical application.Methods OPs from 40 normal control eyes, 33 eyes (33 cases) with early (0~Ⅱ stage) diabetic retinopathy (DR), 9 eyes (9 cases) with central retinal vein occlusion (CRVO) and 9 eyes (9 cases) with branch retinal vein occlusion (BRVO) were tested. In each OPs waveform, the frequency spectra from 10 to 290 Hz were derived by Fast Fourier Transform (FFT). The sum of power and the maximum power were calculated. The OPs in time domain was re constructed by counter FFT with the components from 110 to 250 Hz in the frequency spectrum. The latencies, the amplitudes and the sum of amplitudes of wavelets in the re constructed OPs were measured by the computer.Results Comparing with normal control eyes, in the OPs of early DR, the mean frequency spectra from 140 to 210 Hz were reduced; the sum of power and the maximum power were reduced; the latencies of the four wavelets were prolonged; the amplitudes of the four wavelets and the sum of the amplitudes were attenuated. In the OPs of CRVO, the mean frequency spectra from 150 to 180 Hz were reduced; the sum of power and the maximum power were reduced; the latencies from the first to the third wavelets were prolonged; the amplitudes from the first to the third wavelets and the sum of amplitudes were attenuated. In the OPs of BRVO, the sum of power and the maximum power were reduced; the latencies from the second to the third wavelets were prolonged; the amplitudes from the first to the third wavelets and the sum of amplitudes were attenuated.Conclusion The analysis of OPs in the present study can provide effective and objective indices for diagnosis of DR, CRVO and BRVO.