腹壁胎儿心电图正常值的测定及临床应用研究

经孕妇腹壁测试了１３００例胎儿心电图（ＦＥＣＧ），成功率为９１．５％。建立了一套腹壁ＦＥＣＧ各波段的正常值，为判断正常与异常ＦＥＣＧ提供了客观依据。共发现异常ＦＥＣＧ４７例，其中妊高征组１２例（１２／１００）：妊娠贫血组７例（７／１００）；正常孕妇组２８例（２８／１１００）。结合生后随访，探讨了异常ＦＥＣＧ的发生机理及临床意义，提示对有妊娠合并症的孕妇应加强孕期监护。     

异常胎儿心电图的新生儿心电图追踪分析

本文收集了２０６７例晚期妊娠的胎儿心电图（ＦＥＣＧ），其中异常７８１例占３７．７％，分娩时多见于脐绕颈，羊水混浊，羊水过少，胎儿宫内窘迫，胎盘钙化等。本文对该７８１例异常胎儿心电图（ＦＥＣＧ）的新生儿进行追踪分析，记录了新生儿出生２４小时内心电图（ＥＣＧ），发现异常ＥＣＧ１６６例低电压，进一步说明异常ＦＥＣＧ，并不是反映胎儿心脏本身病变，而是客观反映了胎儿在宫内的瞬间变化及宫内环境对胎儿的影响。     

160例胎儿心电图异常的临床分析

本文监测了异常胎儿心电图（ＦＥＣＧ）１６０例，孕妇平均年龄２８．９８±１．７５岁，孕龄平均３９．４５±２．３６周，监测时间距分娩１小时至３天内，在无宫缩时进行。头位１４９例，臀位１１例。异常ＦＥＣＧ诊断标准为：胎心率＞１６０、＜１２０ｂｐｍ，ＦＱＨＳ时限≥０．０５ｓ，ＦＳＴ段上移或下移＞５μＶ，ＦＯＲＳ振幅＞３０μＶ，ＦＯＨＳ波间断出现。通过１６０例临床观察，单项异常５６例，占３５％，两项异常６５例，占４０．６％，三项异常３７例，占２３．１％，四项异常２例，占１．２％。对ＦＥＣＧ各种异常，进行了分析。本文还通过母波了解孕妇心脏情况，本文遇到母波异常４例，２例频繁早搏，２例心动过速，及时治疗适时终止妊娠，从而减少了母体并发症的发生。     

227例晚期妊娠胎儿心电图监测分析

胎儿心电图（ＦＥＣＧ）是目前产科了解胎儿宫内状况的重要手段。我院于１９９６年５月开始用ＦＥＣＧＤ型仪对孕产妇进行监测，现将２２７例孕晚期胎儿心电图分析报告如下。资料与方法１．资料来源：来我院产科门诊及住院待产、孕周在３５周以上的部分孕妇，共测定２３２例，成功的为２２７例。２．方法：受监测者排空膀胱，取平卧位，放置电极的局部皮肤用７５％酒精涂擦至微红，用０．９％生理盐水作导电液，正极置于宫底部，负极置于耻骨联合上方，地线置于大腿内侧。３．ＦＥＣＧ判断标准：根据第二届全国胎儿心电图学术研讨会提出并…     

胎儿心电图的临床应用及意义

为了研究胎儿心电图在临床上的应用意义，本文对６０例单胎孕妇经腹壁测定胎儿心电图（ＦＥＣＧ），针对所检出的７例异常ＦＥＣＣ进行分析，分析中多见原因为脐带绕颈、羊水混浊、羊水过少等。并结合临床其它检查。从而诊断有无宫内缺氧情况。ＦＥＣＧ具有操作简单，对母儿无害，能早期反映胎儿宫内缺氧，值得临床推广应用。     

胎儿心电图临床应用价值（附260例分析）

本文总结了２６０例≥３６孕周住院分娩的胎儿心电图（ＦＥＣＧ），同时分别作胎儿监护无负荷试验（ＮＳＴ）和胎儿脐动脉血流速率波收缩期／舒张期比率平均值（Ｓ／Ｄ值）测定，并以上述两项结果作对照。经过分析认为：ＦＥＣＧ是反映胎儿在子宫内安危的一种客观检查指标。异常ＦＥＣＧ提示，胎儿宫内缺氧、脐带缠绕、羊水污染。ＦＥＣＧ诊断胎儿宫内窘迫的敏感性明显高于ＮＳＴ和Ｓ／Ｄ值，差异有显著性（Ｐ＜０．０１）。具有临床应用价值。     

高频心电图对小儿川崎病心脏损害的敏感性研究

应用高频心电图（ＨＦＥＣＧ）技术对４８例川崎病患儿和１２１例正常儿童作对照检测，进行川崎病致心脏损害的敏感性研究。结果表明川崎病组６导联组合切迹计数的阳性率（７９．１６％）与正常组相比，有非常显著性差异（Ｐ＜０．０１）；川崎病组在病程不同时期内高频心电图均表现出不同程度的异常，尤以１－８周内比较，有非常显著性差异（Ｐ＜０．０１）；ＨＦＥＣＧ检测阳性率高于二维超声心电图（２ＤＥ），尤在患病１－８周九两组比较有显著性差异（Ｐ＜０．０１）；两对照组ＨＦＥＣＧ切迹数分布规律均为中间部＞终末部＞起始部，而以起始部具有显著性差异（Ｐ＜０．０１）。     

胎儿早搏临床观察

本文分析胎心早搏３０例,胎心早搏分频发早搏组与偶发早搏组。结果：（１）脐带异常占４０％,羊水过少占４０％,羊水Ⅱ－Ⅲ度粪染占３３．３３％,两组差异显著（Ｐ〈０．０５）;（２）孕期孕妇有感冒及病毒感染史,新生儿发生病毒性肌炎,两组差异异常（Ｐ〈０．０１）;（３）孕妇有产科并发症,其胎儿发生宫内窘迫的发生率高。表明胎心早搏对于诊断胎儿宫内缺氧具有十分重要的意义。胎儿心电图（ＦＥＣＧ）对于围产期保健的监     

高频心电图对冠心病诊断的评价──与SPECT结果对比

本文通过对临床诊断为冠心病，ＳＰＥＣＴ检查阳性的５１例患者，进行ＨＦＥＣＧ、ＥＣＧ检查。结果显示：ＨＦＥＣＧ６个及１２个导联检查阳性率分别为９６％和９４％，与ＳＰＥＣＴ比较无明显差异，而ＥＣＧ检查的阳性率仅为３９．２％，与ＨＦＥＣＧ比较有明显差异。ＨＦＥＣＧ的高频切迹数与冠心病病变程度呈正相关，其定位诊断不如ＳＰＥＣＴ的准确。本文提示ＨＦＥＣＧ在诊断冠心病方面，是一种具有一定临床实用价值的辅助检查方法。     

100例冠心病患者高频心电图与常规心电图、心脏超声的对比

本文对１００例冠心病及２０例正常人进行高频心电图（ＨＦＥＣＧ），常规心电图、二维超声心动图（２一ＤＥ）三项检查。结果显示：ＨＦＥＣＧ的敏感性为８Ｏ％，特异性为８５％；ＥＣＧ的敏感性５７％，特异性１００％；２一ＤＥ的敏感性８１％，特异性９０％。提示ＨＦＥＣＧ诊断冠心病的敏感性较ＥＣＧ高（Ｐ＜０．０１），与２一ＤＥ相接近（Ｐ＞０．０５），对冠心病的早期诊断有一定的临床价值。     

1519例胎儿心电图的临床价值和相关因素分析

目的对1519例胎儿全部实行常规胎儿心电图(FECG)监测工作,探讨胎儿心电图应用情况,并对异常FECG结合临床,进行临床原因分析.方法采用随机湘样方法,应用杭州产FECG-D型胎儿心电图分析仪进行监测.结果发现采用横导联方式进行监测检出率为53.5%:在孕22w进行监测检出率为45.8%;异常FECG检出率为7.64%.结论对1519例FECG的监测发现采用横导联方式并在孕22w～26w期间进行监测检出率最高、波形效果好.并对监测发现的导致FECG异常改变的临床原因与胎儿宫内窘迫的关系进行浅要分析.     

一种基于单通道腹部信号的胎儿心电提取算法

设计一种基于单通道孕腹部信号的胎儿心电提取算法,分别提取出母亲心电和胎儿心电,并计算出母亲心率和胎儿心率。首先对单通道孕腹部信号进行k-TEO(k=19)变换,突出母亲心电的QRS波,从而通过简单的阈值法确定母亲心电的R波位置,接着通过在相邻R波间重采样以获得相同的R-R间期T,这样经过一个间隔为T的梳状滤波器就可以分离出相同R-R间期的母亲心电,然后再一次在相邻R波间进行重采样恢复原来的R-R间期就可以获得实际的母亲心电了。原始腹部信号减去上面提取的母亲心电后,胎儿心电QRS波的信噪比大大提高,通过再次应用提取母亲心电的算法即可得到“干净”的胎儿心电波形。选取Physionet数据库中的8 组(26 通道)孕腹部信号数据进行分析,计算每个通道数据的胎儿心电QRS波位置识别灵敏度、阳性检测率和准确性。结果表明,胎儿心电QRS波的识别准确率达到87.1%,其中有6 个通道达到100%。另外计算每个通道的母亲心率和胎儿心率并做统计分析,发现每一组中各个通道的母亲平均心率和胎儿平均心率都非常接近,同一组中各通道间母亲平均心率最大误差为0.1次/min, 而胎儿平均心率最大误差也只有0.9次/min,进一步证明算法的可靠性。     

基于盲信号分离的胎儿心电提取

本文提出了用盲信号分离提取胎儿心电的方法。首先研究了孕妇心电导联的特性 ,然后在此基础上设计了一个胎儿心电实时监护系统。由于使用了实时的盲信号分离算法 ,胎儿心电可以实时的被提取。一些试验结果表明该系统是有效的     

The fetal electrocardiogram by independent component analysis and wavelets

Once the fetal electrocardiogram (FECG) waveforms from ECG on the maternal abdomen are detected, the fetal P wave and T wave cannot always be identified by using continuous wavelet transform (CWT). We took noninvasive FECG from the maternal abdomen, extracted it from the maternal electrocardiogram waveforms after an Independent Component Analysis (ICA), and identified the features of those waveforms by using CWT. We also simultaneously analyzed the observed signals by Primary Component Analysis (PCA). FECG has been extracted by ICA from 25 of 30 pregnant women. The fetal P wave and T wave could be identified in 21 of the 25 cases. FECG was extracted by PCA in only one case. ICA is superior to PCA, whose separation quality highly depends on the careful positioning of the electrodes. We believe that after ICA, FECG obtained by the wavelet theory based method will become a powerful tool for the differential diagnosis of fetal arrhythmias.     

基于快速定点独立分量分析算法的母胎心电信号分离

研究快速定点独立分量分析方法在母胎心电信号分离中的应用。采用此算法,在胎儿心电信号与母体心电信号可以视为相互独立的信号源的前提下,对来源于同一孕妇的观测信号进行独立分量分离。快速定点独立分量算法可以有效地分离出单个独立分量,得到的胎儿心电信号(FECG)较理想。采用独立分量分析方法,实现母胎心电信号分离,是一种值得尝试的信号处理方法。     

A Comparison of Single Channel Fetal ECG Extraction Methods

The abdominal electrocardiogram (ECG) provides a non-invasive method for monitoring the fetal cardiac activity in pregnant women. However, the temporal and frequency overlap between the fetal ECG (FECG), the maternal ECG (MECG) and noise results in a challenging source separation problem. This work seeks to compare temporal extraction methods for extracting the fetal signal and estimating fetal heart rate. A novel method for MECG cancelation using an echo state neural network (ESN) based filtering approach was compared with the least mean square (LMS), the recursive least square (RLS) adaptive filter and template subtraction (TS) techniques. Analysis was performed using real signals from two databases composing a total of 4 h 22 min of data from nine pregnant women with 37,452 reference fetal beats. The effects of preprocessing the signals was empirically evaluated. The results demonstrate that the ESN based algorithm performs best on the test data with an F1 measure of 90.2% as compared to the LMS (87.9%), RLS (88.2%) and the TS (89.3%) techniques. Results suggest that a higher baseline wander high pass cut-off frequency than traditionally used for FECG analysis significantly increases performance for all evaluated methods. Open source code for the benchmark methods are made available to allow comparison and reproducibility on the public domain data.     

基于独立成分分析和量子粒子群算法的胎儿心电提取

胎儿心电图(FECG)是反映胎儿心脏电生理活动的一项客观指标,获取的FECG受到母体心电图(MECG)的干扰,如何快捷、有效的提取FECG成为重要的研究课题。在非侵入方式下,FECG的提取算法中独立成分分析(ICA)算法被认为是效果最好的方法,但现有求解其分解矩阵的算法收敛性能都不太高。量子粒子群(QPSO)算法是一种收敛于全局的智能优化算法。因此,提出了一种结合QPSO的ICA方法。研究结果表明,与其他在非侵入方式下的主要提取算法相比,这种方法能更清晰准确地提取出有用信号,为胎儿的健康检测提供了更好的方法。     

Fetal heart rate monitoring based on independent component analysis

In this paper, an algorithm based on independent component analysis (ICA) for extracting the fetal heart rate (FHR) from maternal abdominal electrodes is presented. Three abdominal ECG channels are used to extract the FHR in three steps: first preprocessing procedures such as DC cancellation and low-pass filtering are applied to remove noise. Then the algorithm for multiple unknown source extraction (AMUSE) algorithm is fed to extract the sources from the observation signals include fetal ECG (FECG). Finally, FHR is extracted from FECG. The method is shown to be capable of completely revealing FECG R-peaks from observation leads even with a SNR=-200dB using semi-synthetic data.     

ECG-changes in the fetal lamb during asphyxia in relation to beta-adrenoceptor stimulation and blockade.

Progressive changes in the S-T interval of the fetal electrocardiogram (FECG) were studied in 14 lamb fetuses, acutely exteriorized and subjected to graded hypoxia. The aims of the study were to investigate whether beta-adrenoceptor stimulation and hypoxia exerted additive or potentiating effects on the FECG and several cardiovascular parameters and whether the hypoxic changes of the FECG could be blocked by beta-adrenoceptor blocking agents. The FECG changes were studied in order to correlate them with cardiovascular function, as measured by heart rate, mean arterial pressure, end diastolic pressure, maximum dP/dt and combined cardiac output, estimated by the thermodilution method, as well as with blood gases, acid base status, blood lactate and glucose. Injections of small doses (0.02 to 0.4 microg kg-1 min-1) of isoprenaline induced the same pattern of changes in the FECG as we have previously recorded during hypoxia. By increasing the isoprenaline dose an increase in the duration of the FECG changes and amplitude of the T-wave changes was obtained. Propranolol was found to completely abolish the FECG changes induced by isoprenaline, as well as by mild hypoxia. During severe hypoxia the FECG changes could not be abolished by propranolol. Our previous findings indicated that the hypoxic changes could be regarded as a sign of myocardial glycolysis. Thus, the present finding that even small doses of isoprenaline given to the fetus, initiates the same pattern of FECG changes corroborate this hypothesis.     

Antepartum non-invasive evaluation of opening and closing timings of the cardiac valves in fetal cardiac cycle

In this study, we propose a non-invasive algorithm to recognize the timings of fetal cardiac events on the basis of analysis of fetal ECG (FECG) and Doppler ultrasound signals. Multiresolution wavelet analysis enabled the frequency contents of the Doppler signals to be linked to the opening (o) and closing (c) of the heart’s valves (Aortic (A) and Mitral (M)). M-mode, B-mode and pulsed Doppler ultrasound were used to verify the timings of opening and closure of these valves. In normal fetuses, the time intervals from Q-wave of QRS complex of FECG to opening and closing of aortic valve, i.e., Q-Ao and Q-Ac were found to be 79.3 ± 17.4 and 224.7 ± 13.3 ms, respectively. For the mitral valve, Q-Mc and Q-Mo were found to be 27.7 ± 9.4 and 294.6 ± 21.3 ms, respectively. Correlations among the timings in opening and closing of cardiac valves were found to be higher in abnormal fetuses than that in normal ones.