由于棘波和/或动作伪迹等因素的影响,实际测得的胃电信号常常具有脉冲性。根据分数低阶统计量理论,本研究提出一种基于最小平均p范数盲信道辨识的韧性时间延迟估计算法(BCILMP),对胃电信号传导速率进行估计。与最小均方误差时间延迟估计算法(LMSTDE)比较,该算法在高斯和脉冲噪声环境下,均可以较好地估计出时间延迟,计算机仿真验证了其性能。运用该方法对四位胃轻瘫病人的胃电信号进行了传导速率的估计。结果表明:虽然胃轻瘫病人的胃慢波也由胃体大弯侧上1/3处向下端幽门处传播,但是其胃慢波的平均传导速率均比正常人的慢,速率的变化也不都是单调增加的。传导是胃电活动最重要的空间特征之一,时间延迟估计方法可以定量地评价胃慢波传导的速率和模式。
Due to the effects of spikes and /or motion artifacts,gastric electrical activities(GEA) often contain sharp transitions.Robust time delay estimation method based on least mean p-norm blind channel identification(BCILMP) was proposed and applied to estimate the propagation velocities of GEA.Compared with least mean square error time delay estimation(LMSTDE) algorithm,the BCILMP provides good performance in both Gaussian and impulsive noise environments.The performance of the novel method was investigated by using computer simulations.BCILMP was used to estimate the propagation velocities of four-channel gastric electrical recordings in gastroparetic patients.The results show that the average velocities of GEA in them are slower than those in normal subjects.The propagation of gastric slow waves was along the greater curvature from upper 1/3 of the corpus toward the pylorus,but not all of the variability of the propagation velocity increased monotonously.The propagation of the gastric slow wave is one of the most important spatial characteristics of GEA.The time delay estimation(TDE) is an approach to quantitatively assess the propagation velocity and pattern of GEA.