胃电慢波节律百分比计算方法改进

目的 从功率谱估计和计算规则两方面对胃电慢波节律百分比的计算方法进行改进.方法 首先引入线性调频Z变换估计功率谱,即具有较高频域分辨率,又能很好地估计能量;其次在计算百分比时引入主要频率成分的能量信息,用以反映各成分的大致时间分配情况.结果 与传统方法相比,新方法计算结果的方差约减小为原来的1/8,算法更稳定.结论 本文提出的新方法受到分帧情况的影响明显小于传统方法,在计算异常慢波频发的胃电数据的慢波节律百分比时,具有一定的意义.

Estimation of Percentage of Electrogastrogram Slow Wave Rhythm

Objective To improve the estimation and the percentage of electrogastrogram(EGG)slow wave rhythm with power spectrum estimation and calculation rule set.Methods Chirp Z-transformation was introduced for estimation power spectrum of EGG,which can obtain both high frequency resolution and accurate estimation of power;while the power proportion of main frequency components in each segment was used to substitute for conventional method in time domain.Results The variance of proposed method was about one-eighth of that of conventional method.Incorporating the power proportion of main frequency components,the proposed method gave better results especially for those EGG signals in which abnormal frequencies appeared frequently.Conclusion As compared with the conventional method,the proposed method is less affected by segmentation process in estimating the percentage of EGG slow wave rhythm,which may promote future clinical applications.