Adaptive filtering of canine electrogastrographic signals. Part 2: filter performance

The modified adaptive filter method described in Part 1 was applied to 16 stretches of (cutaneous) electrogastrographic signal of 17·07 min duration. A signal-to-noise ratio improvement of about 8 dB was achieved. The most characteristic feature of the filter method appeared to be that wave-form and phase of the gastric component of the electrogastrographic signal are preserved. It is concluded that the use of the modified adaptive filter forms a valuable tool in the study of the electrogastrographic signal.     

Detection and deletion of motion artifacts in electrogastrogram using feature analysis and neural networks

Electrogastrogram is a surface measurement of gastric myoelectrical activity, and electrogastrography has been an attractive method for physiological and pathophysiological studies of the stomach due to its nonivasive nature. Motion artifacts, however, ruin the electrogastrogram (EGG), and make the analysis very difficult and sometimes even impossible. They must be eliminated from EGG signals before analysis. Up to now, this can only be done by visual inspection, which is not only time-consuming but also subjective. In this study, a method using feature analysis and neural networks has been developed to realize automatic detection and elimination of the motion artifacts in EGG recordings by computer. Experiments were conducted to investigate the characteristics of different motion artifacts. Useful features were extracted, and different combinations of the features used as the input of the neural network were compared to obtain the optimal performance for the detection of motion artifacts using the artificial neural network.     

甲状腺机能亢进和减退患者的胃电图改变初探

目的通过胃电图(EGG)检查,观察32例甲状腺机能亢进(甲亢)病人,29名甲状腺机能减退(甲减)病人及30名正常健康人餐前和餐后30min的体表胃电频谱变化。结果3组内餐后胃电图主频(DF)、平均幅值(AP)、正常慢波百分比(N%)与餐前相比均有显著增加(P<0.01)。甲亢组主频和平均幅值与对照组相比,无显著差异(P>0.05),甲减组平均幅值与正常慢波百分比较对照组差异显著(P<0.01)。结论甲亢组食欲亢进在胃电图上无特殊反映,表现为主频正常,胃电节律正常,振幅亦无明显升高。甲减组食欲减退可能与胃动过缓,胃电节律紊乱增多有关。     

不同胎龄新生儿空腹体表胃电图特点

目的分析不同胎龄新生儿体表胃电图的临床特点。方法收集不同胎龄新生儿的体表胃电图资料。将收入我科不同胎龄的新生儿分为4组：Ⅰ组为胎龄≥37周；Ⅱ组为胎龄34～36^＋6周；Ⅲ组为胎龄32～33^＋6周；Ⅳ组为胎龄〈32周，在生后1周内进行体表胃电图检测，记录并分析胃电图参数。应用ANOVA方法对各组间的差异进行统计学分析。对其中部分早产儿在生后1周内、2、4周分别进行胃电图检测，应用配对t检验检测同一病例的胃电图参数的前后差异。结果对141例新生儿进行了胃电图检测，Ⅰ组25例；Ⅱ44例；HI组33例；Ⅳ组39例。与成人和儿童相比所有新生儿的正常胃电慢波百分比均较低，平均为30．6％，而胃电节律紊乱百分比较高。各组间正常胃电慢波百分比、胃电节律过缓百分比及胃电节律过速百分比差异无统计学意义。24例早产儿生后4周及生后2周的胃电图参数与生后1周内相比差异无统计学意义。结论与成人和儿童相比，新生儿的胃肌电活动不成熟，生后1周内不同胎龄的早产儿与足月儿的胃电形式比较，差异无统计学意义，新生儿的胃肌电活动在生后4周时仍处于发育成熟阶段。     

Topographical Electrogastrograms After Radical Esophagectomy with Colonic Replacement

Purpose. To characterize the functional substitution of colon for the esophagus, we compared the electrogastrogram (EGG) maps and spectral frequencies and power of preoperative controls with patients who had undergone colonic replacement.Methods. Monopolar EGGs were recorded and spectrally analyzed at 27 locations on the thoracoabdominal surface. The spectral powers of five frequency groups were converted into EGG maps.Results. In contrast to the epigastric concentrations of maximal power foci in a preoperative 3-cpm (cycles per minute) group, those of the colon replacement subjects seemed not to be concentrated in the epigastric region. Power in the 6-cpm colon replacement group were significantly greater and those in the 3-cpm colon replacement group were significantly less than those in the preoperative controls. Spectral frequencies in the 1- and 3-cpm colon replacement groups were significantly higher than those in the preoperative controls.Conclusions. The colonic and gastric EGG activities had 3-cpm, and probably 6-cpm in common. However, the colonic EGG activities were significantly different from the gastric EGG activities in frequency in the 3-cpm group, and in amplitude in both the 3- and 6-cpm groups. Thus, the replaced colon seems to preserve the original colonic EGG activity.     

胃食管反流病患者体表胃电节律的变化规律

目的观察胃食管反流病（GERD）患者的体表胃电节律变化规律及其与患者症状间的关系。方法采用PCPolyg。印hHR双电极胃电记录仪记录25例GERD患者（GERD组）和12例健康人（对照组）的餐前和餐后胃电正常节律的百分比、胃动过缓的百分比、胃动过速的百分比、主频率（DF）、餐后与餐前主功率之比（PR）、DF不稳定系数（DFIC），以及不同症状积分的GERD患者正常节律的百分比、DF、DFIC。结果GERD组患者餐前、餐后胃电正常节律的百分比、DF低于对照组，胃动过缓的百分比、胃动过速的百分比、DFIC均高于对照组，差异有统计学意义。GERD组患者餐前胃电正常节律的百分比、DF低于餐后，而胃动过缓的百分比、DFIC高于餐后，差异有统计学意义。不同症状积分的GERD组患者餐前、餐后胃电节律参数与对照组相比差异均有统计学意义，但各积分组间胃电节律参数差异无统计学意义。结论GERD患者存在胃电生理活动的异常，这种异常可能是GERD的发病机制之一。     

胃食管反流病胃电活动变化的研究

目的　探讨胃食管反流病 (GERD)的胃电活动变化。方法　主诉反流症状的患者 ,经 2 4小时食管酸、碱监测和 (或 )胃镜检查 ,GERD 43例 ,健康对照组 3 9例 ,进行餐前、餐后体表胃电图 (EGG)监测。结果　GERD组的平均正常胃电慢波百分比 ( 63 .40 %± 3 1.63 %)显著低于对照组 ( 80 .89%± 2 5 .42 %) ,餐前胃电节律异常的发生率 ( 5 8.1%)显著高于对照组 ( 17.0 %) ,餐前主频不稳定系数 ( 5 3 .6± 5 0 .8)也显著高于对照组 ( 3 4.2± 3 3 .1) ;GERD组的餐后胃电节律异常的发生率 ( 3 2 .6%)显著高于对照组 ( 12 .8%)。结论　GERD患者存在餐前、餐后胃电活动异常 ,体表EGG检查有助于了解GERD的胃运动功能情况     

功能性消化不良消化间期和消化期体表胃电变化规律

目的:观察正常人及消化不良病人消化间期和消化期EGG的动态变化规律及探讨餐后胃电与胃窦机械收缩之间的偶联关系。方法:采用PC Polygraph HR台式高分辨上消化道动力监测系统对11例正常人和14例功能性消化不良(FD)病人连续5小时同步记录体表胃电和胃窦幽门十二指肠压力变化。结果:正常人胃电功率随消化间期移行性复合运动(MMC)的周期变化而变化,Ⅱ期时增高,约为Ⅰ期的2倍,Ⅲ期最高,约为Ⅰ期的2.5倍,餐后功率与Ⅲ期接近,FD病人胃电功率只在餐后30分升高。消化间期胃电功率和胃窦动力指数呈正相关(正常组:r=0.87,P<0.01;FD组:r=0.79,P<0.01)。结论:体表胃电可以反映MMC周期性变化和胃窦运动功能。FD病人餐后胃电功率减低。     

Psychosocial distress is associated with abnormal gastric myoelectrical activity in patients with functional dyspepsia

Objective. Functional dyspepsia (FD) is a heterogeneous and loosely defined clinical syndrome that is characterized by persistent or recurrent abdominal pain or discomfort centered in the upper abdomen without any identifiable structural or biochemical basis. Gastric myoelectrical activity in functional dyspepsia patients with gastric reddish streaks as a subgroup has not previously been investigated and the potential role of psychosocial distress in the genesis of gastric dysrhythmia in patients with FD is unclear. Material and methods. Electrogastrography was performed in 45 patients with FD and 35 healthy controls for 30 min in the fasting state and 30 min postprandially. Psychological distress and the number and severity of stressful life events were measured using self-rating questionnaires. Results. FD patients had a higher percentage of pre- and postprandial dysrhythmia, lower dominant frequency, and a higher instability coefficient as compared to healthy controls. In FD patients, severity of stressful life events was positively correlated with the percentage of tachygastria in the fasting state (r=0.43, p=0.005) and marginally positively correlated with the percentage of postprandial tachygastria (r=0.253, p=0.098) and instability coefficient of the dominant frequency (r=0.256, p=0.093). Total number of stressful life events was marginally positively correlated with fasting tachygastria (r=0.25, p=0.098) and instability coefficient of the postprandial dominant frequency (r=0.287, p=0.056). Interpersonal sensitivity was found to be negatively correlated with fasting dominant frequency in FD patients (r=???0.311, p<0.05). Conclusions. FD patients with gastric reddish streaks have abnormal fasting and postprandial gastric myoelectrical activity. Perceived severity of stressful life events and interpersonal sensitivity are associated with disturbance of gastric myoelectrical activity.