CN103876730B - Blind extraction method for electrocatdiogram of mother and electrocardiogram of fetus based on second-order statistical properties - Google Patents

Blind extraction method for electrocatdiogram of mother and electrocardiogram of fetus based on second-order statistical properties Download PDF

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CN103876730B
CN103876730B CN201410140711.9A CN201410140711A CN103876730B CN 103876730 B CN103876730 B CN 103876730B CN 201410140711 A CN201410140711 A CN 201410140711A CN 103876730 B CN103876730 B CN 103876730B
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ecg
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mother
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fetal
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CN103876730A (en
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张伟涛
杨若男
袁晓光
楼顺天
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西安电子科技大学
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Abstract

本发明公开一种基于二阶统计特性的母亲和胎儿心电盲提取方法,解决了信噪比较小的混合信号,不能较好提取和提取过程工作在离线方式的问题。 Maternal and fetal ECG blind extraction method of the present invention discloses a method based on second-order statistical characteristics to solve the smaller mixed-signal to noise ratio, and the problem can not be better to extract in the extraction process work offline. 本发明的步骤为:(1)获取电生理混合信号;(2)预处理;(3)选出信噪比最大的一路混合信号;(4)估计周期;(5)获得最优的心电信号向量;(6)提取心电信号。 Step of the present invention are: (1) obtaining electrophysiological mixed signal; (2) pretreatment; (3) selecting the maximum way mixed signal to noise ratio; (4) the estimated period; (5) for optimal ECG signal vector; (6) extracting ECG. 本发明相比现有技术母亲和胎儿心电信号提取的方法,在保证提取信号精确度的同时,还具有实时在线提取、提取效率高的优点,本发明可用于对从心电监测机采集到的母体心电信号中提取出母亲和胎儿心电信号。 The method of the present invention compared to the prior art maternal and fetal ECG extraction, to ensure the accuracy of the signal extraction, while also having a real-time online extraction, extraction efficiency advantages of the present invention may be used to collect from the machine to a heart monitor maternal ECG signal extracted maternal and fetal ECG.

Description

基于二阶统计特性的母亲和胎儿心电盲提取方法 Blind extraction method of second-order statistical characteristics of the mother and fetus ECG-based

技术领域 FIELD

[0001] 本发明涉及信号处理技术领域,更进一步涉及生物医学信号处理技术领域中的一种基于二阶统计特性的母亲和胎儿心电信号盲提取方法。 [0001] The present invention relates to signal processing technologies, and further relates to a biomedical signal processing technologies based on an electric signal extraction blind mother and fetus second order statistical properties of the heart methods. 本发明可用于对从心电监测机采集到的母体心电信号中提取出母亲和胎儿心电信号。 The present invention may be used to collect ECG signals from maternal ECG monitoring unit to extract the maternal and fetal ECG.

背景技术 Background technique

[0002] 人体心电图(ECG)是反映人体生理活动的一个客观指标。 [0002] human electrocardiogram (ECG) is a reflection of objective indicators of human physiological activities. 从孕妇体表测量得到的电信号一般包括母亲心电(MECG),胎儿心电(FECG)和人体其他电信号(例如肌电信号EMG等)以及观测背景噪声的混合信号。 Obtained from the pregnant mother generally comprises the body surface electrical signal measuring ECG (MECG), mixed FECG signal (to FECG) and other body electrical signal (e.g., EMG EMG, etc.) and an observation of the background noise. 在获取的孕妇体表测量电信号中,由于母亲心电信号一般强度较大,采用常规的滤波技术便可以提取母亲心电信号。 Measuring the electrical signal acquired in the body of pregnant women, since the strength of large mother ships ECG signal using conventional filtering techniques can extract mother ECG. 而胎儿心电信号相当微弱,其强度不及母亲心电信号的十分之一,而且胎儿心电信号与母亲心电信号的频谱相互重叠,因此一般的滤波技术很难提取出清晰稳定的胎儿心电信号。 Fetus ECG quite weak, which is less than one-tenth the strength of the mother's ECG signal, and the spectrum of Fetal ECG ECG mother overlap each other, it is generally difficult to extract the filtering technique a clear stable Fetal electric signal.

[0003] 广东工业大学拥有的专利技术"一种基于时频变换的胎儿心电盲提取方法"(专利申请号:201110144487. 7,授权公布号CN 102160787B)公开了一种基于时频变换的胎儿心电盲提取方法。 [0003] Guangdong University have patented technology, "blind fetal ECG extraction method based on frequency transformation" (patent application number: 2011101444877 authorizing Publication No. CN 102160787B) discloses a frequency transform based on the fetus ECG blind extraction method. 该方法采集获得包含母亲和胎儿电生理信号的混合信号,挑选混合信号中母亲和胎儿心电信号相对稀疏的时间段,利用模糊函数将得到的相对稀疏时间段变换到时频域中,再利用广义瑞利熵构造对照函数,从而提取出胎儿心电信号。 The obtained mixed signal acquisition method comprising the mother and fetus electrophysiological signals, selection signals mixed maternal and fetal ECG relatively sparse period, using the fuzzy function obtained relatively sparse period into the time frequency domain, and then using control generalized Rayleigh entropy function configured to extract the fetal ECG. 该专利技术利用母亲和胎儿心电混合信号时域相对稀疏的特性,解决了母亲和胎儿心电信号频谱相互重叠难以分离的问题,但是仍然存在的不足是,该方法工作在离线方式,无法反映胎儿心电信号的时变特性。 The patented technology uses mixed maternal and fetal ECG signal is relatively sparse domain characteristics to solve the maternal and fetal ECG spectral overlap difficult to isolate the problem, but there are still shortcomings that the method works in offline mode and can not reflect fetal ECG signal varying characteristics.

[0004] 上海海事大学所提出的专利申请"基于广义特征值最大化的胎儿心电信号自适应盲提取方法"(专利申请号:201310729736. 8,公布号CN 103627796A)公开了一种胎儿心电信号自适应盲提取方法。 [0004] Shanghai Maritime University proposed patent application (patent application number: 2013107297368, publication No. CN 103627796A) "generalized eigenvalue maximize adaptive blind extraction of fetal ECG based on the" discloses a fetal ECG adaptive blind signal extraction method. 该方法采集获得包含母亲及胎儿电生理信号的混合信号,基于自适应实时算法,计算设定的周期范围内获取混合信号不同延迟协方差矩阵的特征值及特征向量,并选择最大特征值对应的特征向量为盲分离向量,从而提取出胎儿心电信号。 The obtained mixed signal acquisition method comprising the mother and fetus electrophysiological signals, real-time adaptive algorithm, obtaining eigenvectors and eigenvalues ​​mixed signals with different delays calculated covariance matrix is ​​set within the period range, and selects the maximum eigenvalue corresponding separation vector as a blind feature vector to extract the fetal ECG. 该方法虽然利用信号的二阶统计特性,简化计算复杂度,提高了胎儿心电信号盲分离的效率,但是仍然存在的不足是,该方法对心电信号的周期估计不够精确,且由于过分依赖于采集的母体与胎儿心电混合信号不同延迟协方差矩阵的可对角化性,导致对于信噪比较小的采集混合信号,提取效果不佳。 Although this method using the second-order statistical properties of the signal, simplify computational complexity, improve the fetal ECG signal blind separation efficiency, but there are still shortcomings, the method of ECG cycle estimate is not precise enough, and because of over-reliance mixed maternal and fetal ECG signal acquisition to a different delay of the covariance matrix can be diagonalized, leading to a small collection mixed signal to noise ratio, poor extraction effect.

发明内容 SUMMARY

[0005] 本发明的目的在于克服上述现有方法的不足,提出了一种基于二阶统计特性的心电信号盲提取的方法,实现了母亲和胎儿心电信号的自适应实时提取。 [0005] The object of the present invention is to overcome the above disadvantages of the conventional methods, a method is proposed blind cardiac electrical signal based on second order statistical properties of the extracted, and the mother for adaptive real-time extraction of the fetal ECG.

[0006] 实现本发明的基本思想是首先对获取的多路电生理混合信号预处理,再从获取的多路电生理混合信号中选出信噪比最大的一路混合信号,然后估计该路混合信号的周期, 从该路混合信号中提取最优分离向量,最终使用最优分离向量从预处理后的混合信号中提取心电信号。 [0006] The basic idea of ​​the invention is to first obtain the multiplexed electrical signal preprocessing physiological mixed, then the mixed signal all the way to the maximum SNR is selected from the multiple electrophysiological mixed signal acquisition, and then estimating the Mixture periodic signal, the mixed signal vector is extracted from the most optimum separation path, the final extract using the optimum separation vector ECG signals from the mixed signal preprocessing.

[0007] 本发明的具体步骤如下: [0007] The specific steps of the present invention are as follows:

[0008] (1)获取电生理混合信号: [0008] (1) the mixed signal acquired electrophysiological:

[0009] 获取同步采集的母体胸部和腹部多路电生理混合信号; [0009] acquiring physiological signals mixed maternal abdomen and chest electrical multiplex synchronous collection;

[0010] (2)预处理: [0010] (2) Pretreatment:

[0011] (2a)使用有限长数字低通滤波器,对多路电生理混合信号进行肌电干扰和噪声滤除,得到滤除肌电干扰和噪声后的多路电生理混合信号; [0011] (2a) using a finite length digital low pass filter, the mixing of multiple electrophysiological EMG signal interference and noise filtering, to obtain the multiplexed electrical interference and noise filtered EMG physiological mixed signal;

[0012] (2b)使用有限长数字陷波器,对肌电干扰和噪声滤除后的多路电生理混合信号进行50Hz工频干扰滤除,得到预处理后的多路电生理混合信号; [0012] (2b) using the finite length digital notch filter, the multi-channel electrical interference and noise filter physiological EMG mixed 50Hz frequency interference signal filtered to give multiple electrophysiological preprocessed downmix signal;

[0013] (3)得到每路电生理混合信号的信噪比: [0013] (3) Each SNR obtained mixed physiological electrical signals:

[0014] (3a)将预处理后每路电生理混合信号中母亲心电信号作为信号,胎儿心电信号作为噪声,得到母亲心电信号和胎儿心电信号的信噪比; [0014] (3a) after pre-mixed electrophysiological Each ECG signal as a signal in the mother, fetus ECG as noise, signal to noise ratio to obtain the mother and fetus ECG ECG signals;

[0015] (3b)将预处理后每路电生理混合信号中胎儿心电信号作为信号,母亲心电信号作为噪声,得到胎儿心电信号和母亲心电信号的信噪比; [0015] (3b) The pretreated Each electrophysiological mixed signal as a signal of fetal ECG, ECG mother as noise, signal to noise ratio obtained Fetal ECG and maternal ECG signals;

[0016] (4)估计周期: [0016] (4) estimation period:

[0017] (4a)选出母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号,将其中母亲心电信号相邻两个R波的时间间隔,作为母亲心电信号周期的预估计值; [0017] (4a) selecting mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal, in which two adjacent mother ECG R wave interval, as a mother ECG cycle pre-estimated value;

[0018] (4b)采用自相关系数公式,计算母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的自相关系数; [0018] (4b) using the autocorrelation coefficients formula to calculate the autocorrelation coefficient mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal;

[0019] (4c)将母亲心电信号周期的预估计值上下浮动误差0. 2秒作为搜索时间段,搜索自相关系数的绝对值的最大值,将自相关系数的绝对值取最大值的时刻作为母亲心电信号周期的精确估计值; [0019] (4c) the pre-estimate the mother's heart electrical cycles error of plus or minus 0.2 seconds as the search period of the search from the maximum absolute value of the correlation coefficient, the maximum value from the absolute value of the correlation coefficient time as a mother's heart electrical cycles accurate estimate;

[0020] (4d)选出胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号,将其中胎儿心电信号相邻两个R波的时间间隔,作为胎儿心电信号周期的预估计值; [0020] (4d) selected Fetal ECG and maternal ECG way maximum signal to noise ratio electrophysiological mixed signal, wherein the fetal ECG two adjacent R wave interval, as the period of the fetal ECG pre-estimated value;

[0021] (4e)采用自相关系数公式,计算胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号的自相关系数; [0021] (4e) autocorrelation coefficients using autocorrelation coefficient formula, the fetal ECG and maternal ECG way maximum signal to noise ratio electrophysiological mixed signal;

[0022] (4f)将胎儿心电信号周期的预估计值上下浮动误差0. 15秒作为搜索时间段,搜索自相关系数的绝对值的最大值,将自相关系数的绝对值取最大值的时刻作为胎儿心电信号周期的精确估计值; [0022] (4f) pre-estimate the fetal heart electrical cycles of error of plus or minus 0.15 seconds as a search time, the search from the maximum absolute value of the correlation coefficient, the maximum value from the absolute value of the correlation coefficient as the time period of the fetal heart electrical accurate estimate;

[0023] (5)获得最优的心电信号向量: [0023] (5) to obtain the optimal ECG vector:

[0024] (5a)采用最速下降方法,获得最优的母亲心电信号向量; [0024] (5a) using the steepest descent method, to obtain optimal mother ECG vector;

[0025] (5b)采用修正牛顿方法,获得最优的胎儿心电信号向量; [0025] (5b) correction using Newton's method to obtain optimal fetal ECG vector;

[0026] (6)提取心电信号: [0026] (6) extracting ECG:

[0027] (6a)采用投影方法,使用最优的母亲心电信号向量从预处理后的多路电生理混合信号中提取出母亲心电信号; [0027] (6a) using the projection method, using the optimum vector ECG signal from the mother multiple electrophysiological preprocessed downmix signal extracted ECG mother;

[0028] (6b)采用投影方法,使用最优的胎儿心电信号向量从预处理后的多路电生理混合信号中提取出胎儿心电信号。 [0028] (6b) using the projection method, using the optimum vector physiological fetal ECG signal from the multiplexer mixed electrical preprocessed to extract the fetal ECG.

[0029] 本发明与现有技术相比具有如下优点: [0029] The prior art and the present invention has the following advantages:

[0030] 第一,由于本发明通过对获取的多路电生理混合信号先进行预处理,再从预处理后的电生理混合信号中获取母亲和胎儿心电信号最优向量,克服了现有技术对信噪比较小的电生理混合信号不能较好提取母亲和胎儿心电信号的不足,使得本发明无需电生理混合信号信噪比大小的附加条件。 [0030] First, since the present invention is by mixing multiple electrophysiological signal acquired was pretreated, reacquisition maternal and fetal ECG optimum vector Electrophysiological mixed signal preprocessing, to overcome the existing eLECTRICAL smaller SNR physiological mixed signal extraction is preferably not less than maternal and fetal ECG signal, such that the present invention is mixed an additional condition signal to noise ratio without electrophysiological size.

[0031] 第二,由于本发明通过电生理混合信号的二阶统计特性获取最优的母亲和胎儿心电信号向量,克服了现有技术工作在离线方式的不足,实现了母亲和胎儿心电信号的实时在线提取,使得提取母亲和胎儿心电信号的效率高,能够更好的反映母亲和胎儿心电信号的时变特性。 [0031] Second, since the present invention is the electrical physiological signal by the mixed second order statistical properties of the mother and the fetus obtain the optimal ECG vectors, it overcomes the disadvantages of the prior art work off-line, to achieve the mother and fetus ECG online real-time signal is extracted, so that the high maternal and fetal ECG extraction efficiency, to better reflect when maternal and fetal ECG signal varying characteristics.

[0032] 第三,由于本发明通过对信噪比最大的电生理混合信号中母亲和胎儿心电信号的周期先进行预估计,再设置误差进行精确估计,克服了现有技术对母亲和胎儿心电信号周期估计不够精确的不足,使得本发明对母亲和胎儿心电信号的提取效果更加良好。 [0032] Third, since the present invention is the maximum signal to noise ratio by periodic physiological electrical signals mixed maternal and fetal ECG signal prior to pre-estimate, then set accurately estimate the error, the prior art overcomes the mother and fetus ECG cycle estimate is not precise enough deficiencies, so that the effect of the present invention is to extract the mother and fetus ECG is more favorable.

附图说明 BRIEF DESCRIPTION

[0033] 图1为本发明的流程图; [0033] FIG. 1 is a flowchart of the present invention;

[0034] 图2为本发明输入的8路电生理混合信号波形图; 8 is electrically [0034] FIG. 2 of the present invention, the input signal waveform diagram physiological mixed;

[0035] 图3为采用本发明获取到的第1路信号的自相关系数示意图; [0035] FIG. 3 is a schematic diagram of the present invention using the autocorrelation coefficients obtained in the first signal path;

[0036] 图4为采用本发明获取到的第8路信号的自相关系数示意图; [0036] FIG. 4 is a schematic diagram of the present invention using the autocorrelation coefficients obtained in the first signal path 8;

[0037] 图5为采用本发明和现有技术的四种方法提取母体心电信号波形对比图; [0037] FIG. 5 extracts the parent ECG waveform is a comparison chart using the four methods of the present invention and the prior art;

[0038] 图6为采用本发明和现有技术的四种方法提取胎儿心电信号波形对比图。 [0038] FIG. 6 is four methods of the present invention and the prior art to extract the fetal ECG waveforms can be compared to FIG.

具体实施方式 Detailed ways

[0039] 下面结合附图对本发明做进一步的描述: [0039] DRAWINGS further description of the invention:

[0040] 参照图1,本发明的具体实施步骤如下: [0040] Referring to FIG. 1, the specific embodiment of the present invention, the following steps:

[0041] 步骤1,输入电生理混合信号。 [0041] Step 1, the input signal electrophysiological mixed.

[0042] 本发明的实施例是输入8路电生理混合信号,该电生理混合信号同步采集自母体胸部的5路电生理混合信号和母体腹部的3路电生理混合信号。 [0042] Example embodiments of the present invention is the input 8 electrophysiological mixed signal, mixing the signal synchronized electrophysiological collected from the 3-way mix electrophysiological signal path 5 electrical physiological precursor mix signal and the chest of the maternal abdomen. 参照附图2所示输入了8 路电生理混合信号波形图,图2中的横坐标表示时间,纵坐标表示信号幅值,图2(a)、(b)、 (c)、(d)、(e)为采集自母体胸部的5路电生理混合信号,图2(f)、(g)、(h)为采集自母体腹部的3路电生理混合信号。 Referring to the drawings in Figure 2 the input signal waveform diagram electrophysiological mixed eight, in FIG. 2 the abscissa represents time, the ordinate indicates the signal amplitude, FIG. 2 (a), (b), (c), (d) , (e) mixing a physiological signal acquired from the 5-way electrical parent chest, FIG. 2 (f), (g), (h) mixing a physiological signal from the 3-way power acquisition maternal abdomen. 由图2可以看出,来自胸部的5路电生理混合信号主要是母亲心电信号,而来自腹部的3路电生理混合信号中有微弱的胎儿心电信号。 As can be seen from Figure 2, 5-way mixed electrophysiological signal from the primary mother chest ECG, and the power from the 3-way physiological abdomen mixed signal weakly fetal ECG.

[0043] 步骤2,预处理。 [0043] Step 2 pretreatment.

[0044] 第一步,采用基于汉明窗的8阶有限长数字低通滤波器,对获取到的多路混合信号进行肌电干扰和噪声滤除,得到滤除肌电干扰和噪声后的多路混合信号; [0044] The first step, based Hamming window of 8-order finite length digital low pass filter, for mixing the acquired multiplexed signal to interference and noise filtering EMG, EMG interference and noise filtered off to give the mixed multiplex signal;

[0045] 第二步,采用基于汉明窗的40阶有限长数字陷波器,对肌电干扰和噪声滤除后的多路混合信号进行50Hz工频干扰滤除,得到预处理后的多路混合信号。 [0045] The second step, using the notch filter 40 based on the order of finite length digital Hamming window, the multi-channel noise filter and EMG interference signal mixed 50Hz frequency interference filtered off, the obtained multi pretreatment mixed-signal path.

[0046] 步骤3,得到每路电生理混合信号的信噪比。 [0046] Step 3, to give the mixed signal to noise ratio for each channel of the electrical physiological.

[0047] 第一步,将预处理后每路电生理混合信号中母亲心电信号作为信号,胎儿心电信号作为噪声,得到母亲心电信号和胎儿心电信号的信噪比; [0047] The first step, after the pre-mixed electrophysiological Each ECG signal as a signal in the mother, fetus ECG as noise, signal to noise ratio to obtain the mother and fetus ECG ECG signals;

[0048] 第二步,将预处理后每路电生理混合信号中胎儿心电信号作为信号,母亲心电信号作为噪声,得到胎儿心电信号和母亲心电信号的信噪比。 [0048] The second step, after the pre-mixed signal for each channel electrophysiological as fetal ECG signal, the ECG signal as noise mother, fetus ECG signal to noise ratio and to obtain the mother's ECG.

[0049] 步骤4,估计周期。 [0049] Step 4, estimation period.

[0050] 估计母亲心电信号周期α,具体步骤包括: [0050] ECG cycle mother estimate α, specific steps comprising:

[0051] 第一步,从预处理后的多路混合信号中选出母亲心电信号和胎儿心电信号信噪比最大的一路混合信号,将t时刻的该混合信号记为X (t),将X (t)中母亲心电信号相邻两个R波的时间间隔作为母亲心电信号周期的预估计值。 [0051] The first step, selecting the maximum of the way the mother and fetus ECG ECG signal from the multiplexed signal to noise mixed after the pre-mixed signal, the mixed signal that is referred to at time t X (t) , in the X (t) two adjacent mother ECG R-wave interval as the estimated value pre mother electrical cycles of the heart. 从x(t)中得到母亲心电信号周期的预估计值α 0. 8秒; ECG cycle mother obtained from x (t) pre-estimated value α 0. 8 s;

[0052] 第二步,x(t)的自相关系数计算公式如下: [0052] The second step, x (t) is the autocorrelation coefficients calculated as follows:

Figure CN103876730BD00081

[0054] 其中,r( δ)表示延迟时间为δ时的母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的自相关系数,δ表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号相对t时刻的延迟时间,x(t)表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号,t表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的采样时刻,J (· )dt表示对采样时刻t的积分操作,[· ]2表示取平方操作; [0054] wherein, r (δ) represents the delay time for the mother and fetus ECG ECG signal to noise ratio of the maximum autocorrelation coefficients physiological way when mixed electrical signal δ, δ represents the mother and fetus ECG ECG the ratio of maximum signal delay time of the mixed signal corresponding electrophysiological way time t, x (t) represents the mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal, t represents the mother and ECG fetal ECG way maximum signal to noise ratio mixed electrophysiological signal sampling timing, J (·) dt represent the integral operation of the sampling time t, [·] represents 2 squaring operation;

[0055] 第三步,在a Q-〇. 2彡δ彡a Q+〇. 2时间范围内搜索r ( δ )的最大取值时刻为α = 0.74秒,则α为母亲心电信号周期的精确估计值。 [0055] The third step, in a Q-square. [Delta] 2 San San a Q + square. 2 search time r (δ) of the maximum value of time for α = 0.74 seconds, [alpha] is a mother ECG cycle an accurate estimate.

[0056] 估计胎儿心电信号周期β,具体步骤包括: [0056] estimated fetal ECG period β, the specific steps include:

[0057] 第一步,从预处理后的多路混合信号中选出胎儿心电信号和母亲心电信号信噪比最大的一路混合信号,将t时刻的该混合信号记为y (t)。 [0057] The first step, selecting the maximum way Fetal ECG and maternal ECG signals from the multiplexed signal to noise mixed after the pre-mixed signal, the mixed signal that is referred to at time t y (t) . 将y (t)中胎儿心电信号相邻两个R波的时间间隔作为胎儿心电信号周期的预估计值。 In the y (t) fetal ECG two adjacent R wave interval as the pre-estimated value of fetal ECG cycle. 从y(t)中粗略估计出胎儿心电信号R 波的周期为β〇= 〇.5秒; From y (t) roughly estimated fetal ECG R-wave period β〇 = 〇.5 seconds;

[0058] 第二步,计算y(t)的自相关函数 [0058] The second step, calculating y (t) autocorrelation function

Figure CN103876730BD00082

[0060] 其中,f ( ε )表不延迟时间为ε时的胎儿心电彳目号和母亲心电彳目号彳目噪比最大的一路电生理混合信号的自相关系数,ε表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号相对t时刻的延迟时间,y (η)表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号,η表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号的采样时刻,J (· )dn表示对采样时刻η的积分操作,[· ]2表示取平方操作; [0060] where, f (ε) Table no delay FECG left foot mesh number and mother ECG left foot mesh number left foot mesh noise at time [epsilon] Physiological autocorrelation coefficients of the mixed signal is smaller than the maximum way power, ε represents the fetal heart mother ECG electrical signal and the maximum signal to noise ratio electrophysiological way mixed signal delay time relative to the time t, y (η) represents fetal ECG and maternal ECG way maximum signal to noise ratio electrophysiological mixed signal, η represents fetal ECG and maternal ECG signal to noise ratio of the maximum way mixed electrophysiological signal sampling timing, J (·) dn represents a sampling of the integral operation time η, [·] represents 2 squaring operation;

[0061] 第三步,在f3Q-0. 15彡ε彡βα+0. 15时间范围内搜索f ( ε )的最大取值时刻为β = 0.448秒,则β为胎儿心电信号周期的精确估计值。 [0061] The third step, in f3Q-0. 15 [epsilon] San San βα + 0. 15 search time f (ε) is the maximum value of the moment β = 0.448 seconds, the heart electrical cycles fetal beta] Exact estimated value.

[0062] 步骤5,获得最优的心电信号向量。 [0062] Step 5, to obtain optimal ECG vectors.

[0063] 采用最速下降方法对母亲心电信号向量与最优的母亲心电信号向量的逼近度进行最小化,从而获得母亲心电信号的最优向量e。 [0063] steepest descent method of approximation of the optimal vector ECG mother mother's heart for an electric signal vector minimized, thereby obtaining an optimal ECG signal vector e mother.

[0064] 按照下式,得到母亲心电信号向量与最优母亲心电信号向量的逼近度: [0064] according to the following formula, to obtain the optimal vector ECG mother mother ECG vector approximation degree:

[0065] min J(w) = wrR(0)w - log[wTR(a)w] w [0065] min J (w) = wrR (0) w - log [wTR (a) w] w

[0066] 其中,J(w)表示母亲心电信号向量与最优母亲心电信号向量的逼近度,w表示母亲心电信号向量,1ΐ+ί表示关于母亲心电信号向量W的最小化操作,R(O)和R(a)分别表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号时延分别为〇和α的自相关矩阵,α表示母亲心电信号周期的精确估计值,l〇g[ ·]表示取对数操作,(·)τ表示转置操作。 [0066] wherein, J (w) represents the degree of approximation to the optimal vector mother mother ECG heart electrical signal vector, w denotes the mother ECG vectors, 1ΐ + ί represents a minimum operation on the mother's ECG vector W , R (O) and R (a) respectively represent the mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological signal delay are mixed and square autocorrelation matrix of [alpha], α represents the mother ECG cycle accurate estimates l〇g [·] represents a logarithmic operation, (*) [tau] represents the transpose operation.

[0067] 最优的母亲心电信号向量e按如下步骤递推计算: [0067] Optimal mother ECG signal vector e is calculated according to the following recursive steps:

[0068] 第一步,初始化母亲心电信号向量w(0) = [1,1,…,1]τ,初始化x(t)时延分别为〇和α的自相关矩阵RlPRa为零矩阵; [0068] The first step, the mother ECG initialization vector w (0) = [1,1, ..., 1] τ, initialization x (t) are the delay autocorrelation matrix RlPRa square matrix, and α is zero;

[0069] 第二步,按照下式,更新相关矩阵Rci: [0069] The second step, according to the following formulas, updates the correlation matrix Rci:

[0070] Ra (k) = λ Ra (k~l)+X (k) xT (ka ) [0070] Ra (k) = λ Ra (k ~ l) + X (k) xT (ka)

[0071] 其中,IT (k)表示第k次迭代的x(t)时延为a的自相关矩阵,k表示母亲心电信号向量的迭代次数,Rci (k_l)表示第k-Ι次迭代的x(t)时延为a的自相关矩阵,x(k)表示时间为k时的母亲心电和其它信号信噪比最大的一路混合信号,x(k_ a )表示时间为k_ a时的母亲心电和其它信号信噪比最大的一路混合信号,λ为遗忘因子,本实例取λ =0.96, (·"表示转置操作; [0071] wherein, IT (k) denotes the k-th iteration x (t) a time delay of the autocorrelation matrix, k represents the number of iterations of the mother's heart electrical signal vector, Rci (k_l) denotes the k-th iteration iota the x (t) is a delay autocorrelation matrix, x (k) represents the time when the mother ECG signals and other noise ratio k of the maximum way mixed signal, x (k_ a) represents the time when a K_ mother ECG signals and other mixed signal to noise ratio all the way to the maximum, a forgetting factor [lambda], the present examples take λ = 0.96, (· "denotes a transpose operation;

[0072] 第三步,按照下式,更新相关矩阵R°: [0072] The third step, according to the following formulas, updates the correlation matrix R °:

[0073] R0 (k) = λ R0 (k~l)+X (k) xT (k) [0073] R0 (k) = λ R0 (k ~ l) + X (k) xT (k)

[0074] 其中,R°(k)表示第k次迭代的x(t)时延为0的自相关矩阵,k表示母亲心电信号向量的迭代次数,R(kl)表示第k-Ι次迭代的x(t)时延为0的自相关矩阵,x(k)表示时间为k时的母亲心电和其它信号信噪比最大的一路混合信号,λ为遗忘因子,本实例取λ = 〇· 96,( · "表不转置操作; [0074] wherein, R ° (k) denotes the k-th iteration x (t) is the time delay of the autocorrelation matrix 0, k represents the number of iterations of the mother's heart electrical signal vector, R (kl) is the k-times iota iteration x (t) is the time delay of the autocorrelation matrix 0, x (k) represents the time for mothers ECG signals and other mixed signal to noise ratio all the way to the maximum when k, λ is a forgetting factor, the present examples take λ = 1.96 billion, (· "table does not transpose operation;

[0075] 第四步,按照下式,迭代计算母亲心电信号向量: [0075] The fourth step is calculated according to the following formula mother ECG, vector iteration:

[0076] w (k+1) = w (k) - μ [R (0) w (k) - [w (k) tR ( a ) w (k) ] 1R ( a ) w (k)] [0076] w (k + 1) = w (k) - μ [R (0) w (k) - [w (k) tR (a) w (k)] 1R (a) w (k)]

[0077] 其中,w(k+l)表示第k+1次迭代的母亲心电信号向量,w(k)表示第k次迭代的母亲心电信号向量,k表示母亲心电信号向量的迭代次数,μ表示母亲心电信号向量的迭代步长,R(O)和R(a)分别表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号时延分别为〇和a的自相关矩阵,a表示母亲心电信号周期的精确估计值,(•) 1表示转置操作,(· Γ1表示求逆操作; [0077] wherein, w (k + l) represents the k + 1 th iteration mother ECG signal vector, w (k) represents the mother of the ECG vector iteration k, k represents the iteration mother's heart an electrical signal vector number, μ denotes the iteration step the mother's heart long electrical signal vector, R (O) and R (a) respectively represent the mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal delay are square and a self-correlation matrix, a represents an accurate estimate of the mother's heart electrical cycles, (•) 1 denotes a transpose operation, (· Γ1 represents inverse operation;

[0078] 第五步,令k = k+Ι,重复第二步到第五步直到收敛。 [0078] The fifth step, so that k = k + Ι, repeat the second step to the fifth step until convergence.

[0079] 采用修正牛顿方法对胎儿心电信号向量与最优的胎儿心电信号向量的逼近度进行最小化,从而获得最优的胎儿心电信号向量f。 [0079] The Newton's method of approximation of the correction fetal ECG electrical signal vector and the optimum vector minimizing the fetal heart, so as to obtain optimal fetal ECG vector f.

[0080] 按照下式,得到胎儿心电信号向量与最优的胎儿心电信号向量的逼近度: [0080] according to the following formula, to obtain fetal ECG vectors with the best approximation of the fetal ECG vectors of:

[0081 ] min jL(u) = urV(0)u - log[uTV(,ii)u] U [0081] min jL (u) = urV (0) u - log [uTV (, ii) u] U

[0082] 其中,L(u)表不胎儿心电信号向量与最优的胎儿心电信号向量的逼近度,u表不胎儿心电信号向量,mUillM表示关于胎儿心电信号向量u的最小化操作,V (0)和V ( β )分别表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号时延分别为〇和β 的自相关矩阵,β表示胎儿心电信号周期的精确估计值,l〇g[ ·]表示取对数操作,(*)7表示转置操作。 [0082] wherein the approximation degree L (u) Table fetal ECG vectors are not the best fetal heart electrical signal vector, u the vector table is not a fetal electrocardiogram, mUillM expressed on fetal ECG minimize vector u operation, V (0) and V (β) represent fetal ECG and maternal ECG signal to noise ratio of the maximum signal delay along electrophysiological mixed beta] are square and the autocorrelation matrix, β represents fetal ECG an accurate estimate of the period, l〇g [·] represents a logarithmic operation (*) 7 denotes a transpose operation.

[0083] 最优的胎儿心电信号向量f按如下步骤递推计算: [0083] Optimal fetal ECG vector f recursive calculation as follows:

[0084] 第一步,初始化胎儿心电信号向量W(〇) = [1,1,…,1]τ,初始化y(t)时延为0的自相关矩阵的逆矩阵Q和y(t)时延β的自相关矩阵V e为单位矩阵; [0084] The first step, fetal ECG initialization vector W (square) = [1,1, ..., 1] τ, initialization y (t) is the delay of the inverse matrix of the autocorrelation matrix Q 0 and y (t ) β delay autocorrelation matrix V e is a unit matrix;

[0085] 第二步,按照下式,更新矩阵Ve : [0085] The second step, according to the following formula, update matrices Ve:

[0086] Vp ( η ) = λ Vp ( η-1)+χ( η )χτ( η-β ) [0086] Vp (η) = λ Vp (η-1) + χ (η) χτ (η-β)

[0087] 其中,Rfi (η)表示第η次迭代的y(t)时延为β的自相关矩阵,τι表示母亲心电信号向量的迭代次数,Re (η -1)表示第η -1次迭代的y (t)时延为β的自相关矩阵,XU) 表不时间为rI时的胎儿心电和其它信号信噪比最大的一路混合信号,x( rI-β)表不时间为η-β时的胎儿心电和其它信号信噪比最大的一路混合信号,λ为遗忘因子,本实例取λ = 0. 96,( ·)1¾示转置操作; [0087] wherein, Rfi (η) denotes the iteration [eta] y (t) is the time delay of the autocorrelation matrix β, τι electrical signal vector represents the number of iterations of the mother's heart, Re (η -1) represents η -1 iterations y (t) is the time delay of the autocorrelation matrix beta], XU) table is not the maximum time during fetal ECG signals and other noise ratio rI way mixed signal, x (rI-β) is not time table FECG η-β and the time of the maximum signal to noise ratio all the way to the other mixed signal, [lambda] is the forgetting factor, the present examples take λ = 0. 96, (·) 1¾ illustrating a transpose operation;

[0088] 第三步,按照下式,更新矩阵Q : [0088] The third step, according to the following formula, update matrices Q:

Figure CN103876730BD00101

[0090] 其中,QU)表示第η次迭代的y(t)时延为0的自相关矩阵的逆矩阵,η表示母亲心电信号向量的迭代次数,Q(nl)表示第nl次迭代的y(t)时延为0的自相关矩阵的逆矩阵,χ(η)表示时间为η时的胎儿心电和其它信号信噪比最大的一路混合信号,λ 为遗忘因子,本实例取λ = 〇. 96,(·)τ表示转置操作; [0090] wherein, QU) represents the first iteration [eta] y (t) is the delay of the inverse matrix of the autocorrelation matrix 0, η represents the number of iterations of the mother's heart electrical vectors, Q (nl) represents the iteration nl y (t) is the delay of the inverse matrix of the autocorrelation matrix 0, χ (η) represents the time for the fetus ECG signals and other noise ratio of the maximum way mixed signal [eta], [lambda] is the forgetting factor [lambda] of the present example taking . = square 96, (·) τ denotes a transpose operation;

[0091] 第四步,按照下式,迭代计算胎儿心电信号向量: [0091] The fourth step, the fetal ECG is calculated according to the following formula vector, iteration:

Figure CN103876730BD00102

[0093] 其中,u(n+i)表示第n+i次迭代的胎儿心电信号向量,uU)表示第η次迭代的胎儿心电信号向量,η表示胎儿心电信号向量的迭代次数,v(o)和ν(β)分别表示胎儿心电和其它信号信噪比最大的一路混合信号时延分别为〇和β的自相关矩阵,β表示胎儿心电信号周期的精确估计值,Q表示胎儿心电和其它信号信噪比最大的一路混合信号时延为〇的自相关矩阵的逆矩阵,(· "表示转置操作,(·)4表示求逆操作,(·)_2表示求负二次方操作; [0093] wherein, U (n + i) n + represents fetal ECG vector iteration i, uU) represents fetal ECG vector iteration of [eta], [eta] represents the number of iterations fetal heart electrical signal vector, v (o) and ν (β) represent fetal ECG signals and other mixed signal to noise ratio all the way to the maximum delay beta] are square and the autocorrelation matrix, β represents an accurate estimate of fetal heart electrical cycles, Q represents fetal ECG signals and other mixed signal to noise ratio all the way to the maximum delay of the inverse square matrix of the autocorrelation matrix, (· "denotes a transpose operation, (·) represents inverse operation 4, (*) indicates finding _2 inverse square operation;

[0094] 第五步,令η = η+ι,重复第二步到第五步直到收敛。 [0094] The fifth step, so that η = η + ι, repeat the second step to the fifth step until convergence.

[0095] 步骤6,提取心电信号。 [0095] Step 6, extracting ECG.

[0096] 采用投影方法,使用最优的母亲心电信号向量从预处理后的多路电生理混合信号中提取出母亲心电信号。 [0096] The projection method, using the optimum vector ECG mother mother extracted ECG physiological mixed signal from the multiplexer electrically pretreated. 按照下式,得到母亲心电信号: According to the formula, mothers get ECG:

[0097] h (t) = eTd (t) [0097] h (t) = eTd (t)

[0098] 其中,h(t)表示t时刻提取的母亲心电信号,e表示最优的母亲心电信号向量, d(t)表示t时刻预处理后的混合信号,(·)τ表示转置操作。 [0098] where, h (t) represents the time t mother extracted ECG, e represents the optimal mother ECG vector, d (t) represents the time t after the mixed signal preprocessing, (·) τ denotes transpose transpose operation.

[0099] 采用投影方法,使用最优的胎儿心电信号向量从预处理后的多路电生理混合信号中提取出胎儿心电信号。 [0099] The projection method, using the optimum vector physiological fetal ECG signal from the multiplexer mixed electrical preprocessed to extract the fetal ECG. 按照下式,得到胎儿心电信号: According to the following formula, to obtain fetal ECG:

[0100] ζ (t) = fTd (t) [0100] ζ (t) = fTd (t)

[0101] 其中,z(t)表示t时刻提取的胎儿心电信号,f表示最优的胎儿心电信号向量, d(t)表示t时刻预处理后的混合信号,(·)τ表示转置操作。 [0101] wherein, z (t) represents the time t Fetal ECG extraction, f denotes the optimal fetal ECG vector, d (t) represents the pre-mixed signal at time t, (·) τ denotes transpose transpose operation.

[0102] 下面结合附图对本发明的效果做进一步的描述。 [0102] The following figures further described in conjunction with the effects of the present invention.

[0103] 1.仿真条件 [0103] 1. The simulation conditions

[0104] 本发明的仿真运行系统为Intel (R)Core(TM) i7-2600CPU 65003. 40GHz,32 位Windows操作系统,仿真软件采用MATLAB (R2008a)。 [0104] System simulation run of the present invention is a Intel (R) Core (TM) i7-2600CPU 65003. 40GHz, 32 bit Windows operating system, using the simulation software MATLAB (R2008a).

[0105] 2.仿真内容与结果分析 [0105] 2. Content and simulation results analysis

[0106] 对附图2中所示的输入的8路电生理混合信号中第1路电生理混合信号进行仿真搜索母亲心电信号周期的精确估计值,设定预估计周期值a 0.8秒,搜索时间段0.6< δ <1.0,得到第1路电生理混合信号的自相关系数示意图如附图3所示。 [0106] 8 electrical input of FIG. 2 in the drawings physiological mixed signal of the first channel signal is mixed electrophysiological accurate estimate of electrical cycles simulated search mother's heart, the pre-set value of the estimated period a 0.8 sec search period 0.6 <δ <1.0, the autocorrelation coefficients to obtain a first mixed signal electrophysiological way as shown in the drawings is a schematic view 3.

[0107] 对附图2中所示的输入的8路电生理混合信号中第8路电生理混合信号进行仿真搜索胎儿心电信号周期的精确估计值,设定预估计周期值β〇= 〇.5秒,搜索时间段0.35S ε <0.45,得到第8路电生理混合信号的自相关系数示意图如附图4所示。 [0107] accurate estimate of 8 electrophysiological mixed signal simulation fetal electrocardiogram cycle search electrophysiological eight inputs of mixing 2 shown in the figures in the signal, the pre-set period estimated value = square β〇 .5 seconds, a search period 0.35S ε <0.45, to obtain a first mixed signal electrophysiological 8 is a schematic view of the autocorrelation coefficients as illustrated in Figure 4.

[0108] 采用本发明和现有技术的四种方法对附图2中所示的输入的8路电生理混合信号仿真提取母亲和胎儿心电信号,提取母亲心电信号波形对比图如图5所示,提取胎儿心电信号波形对比图如图6所示。 [0108] 8 electrophysiological four kinds of mixed-signal simulation method of the present invention and the prior art shown in FIG. 2 in input to the drawings extraction mother and fetus ECG, ECG waveform extraction mother comparison is shown in Figure 5 , the ECG waveform of the fetus extracted comparison is shown in Figure 6.

[0109] 参照图3所示的第1路电生理混合信号的自相关系数示意图,图3中的纵坐标表示自相关系数的大小,横坐标表示时间。 The first electrical path shown in [0109] Referring to FIG 3 mixed physiological signal autocorrelation coefficients schematic, in Figure 3 the ordinate represents the size of the self correlation coefficients, the abscissa represents time. 在横坐标所表示的时间范围〇.6< δ <1.0内可以看到自相关系数的最大值为图中标注点所在位置,则图中标注点的横坐标α =0.74秒为母亲心电信号周期的精确估计值。 In the time range indicated by the abscissa 〇.6 <δ <1.0 can be seen in FIG label point location of the maximum autocorrelation coefficient, the marked points in FIG abscissa α = 0.74 seconds mother ECG an accurate estimate period.

[0110] 参照图4所示的第8路电生理混合信号的自相关系数示意图,图4中的纵坐标表示自相关系数的大小,横坐标表示时间。 The first electrical path 8 shown in [0110] Referring to FIG. 4 Physiological mixed signal autocorrelation coefficients schematic in FIG. 4 the ordinate represents the size of the self correlation coefficients, the abscissa represents time. 在横坐标所表示的时间范围〇.35< ε <0.45内可以得到自相关系数的最大值为图中标注点所在位置,则图中标注点的横坐标β = 0.448 秒为胎儿心电信号周期的精确估计值。 The maximum autocorrelation coefficients obtained in the time range indicated by the abscissa 〇.35 <ε <0.45 was noted in the figures location points, the points labeled in FIG abscissa β = 0.448 seconds Fetal ECG cycle the accurate estimate.

[0111] 参照附图5,本发明和现有技术的四种方法仿真提取的母亲心电信号波形对比图,参照附图6,本发明和现有技术的四种方法仿真提取的胎儿心电信号波形对比图。 FECG [0111] Referring to Figure 5, four methods of the present invention and the prior art simulated ECG waveform extraction mother FIG comparison, referring to Figure 6, four methods of the present invention and the prior art emulation extracted FIG comparison signal waveform. 图5(a)和图6(a)中的曲线分别为米用AKBarros and A.Cichocki在文章"Extraction of specific signals with temporal structure"(Neural Comput. , vol. 13,no.9, pp. 1995 - 2003, 2001)中公开的奇异值分解批处理方法,提取的母亲和胎儿心电信号的波形。 FIG 5 (a) and 6 (a) is a graph meter, respectively with AKBarros and A.Cichocki in the article "Extraction of specific signals with temporal structure" (Neural Comput., Vol. 13, no.9, pp. 1995 --2003, 2001) singular value decomposition disclosed in the batch method, maternal and fetal ECG waveform extracted. 图5 (b)和图6 (b)中的曲线分别为采用X. -L. Li and X. -D. Zhang在文章"Sequential blind extraction adopting second-order statistics" (IEEE Signal Process. Lett.,vol. 14, no. 1,pp. 58 - 61,2007)中公开的基于二阶统计量的序贯联合对角化方法,提取的母亲和胎儿心电信号的波形。 In FIG. 5 (b) and 6 (b) are employed curve X. -L. Li and X. -D. Zhang in the article "Sequential blind extraction adopting second-order statistics" (IEEE Signal Process. Lett., .. vol 14, no 1, pp 58 -. in 61,2007) disclosed in second order statistics based joint diagonalization sequential method of extracting a waveform of maternal and fetal ECG. 图5(c)和图6(c)中的曲线分别为采用W. Liu, DP Mandic, and A. Cichocki 在文章"Analysis and online realization of the CCA approach for blind source separation"(IEEE Trans. Neural Netw. , vol. 18, no. 5, pp. 1505 - 1510, 2007)中公布的基于经典CCA准则的自适应梯度下降方法,提取的母亲和胎儿心电信号的波形。 (C) a graph in FIG 5 (c) and FIG. 6 are employed W. Liu, DP Mandic, and A. Cichocki in the article "Analysis and online realization of the CCA approach for blind source separation" (IEEE Trans. Neural Netw ., 18, no 5, pp 1505 vol -.. 1510, 2007) published in the fall classic CCA guidelines based on adaptive gradient method to extract the waveform maternal and fetal ECG. 图5(d)和图6(d)中的曲线分别为采用A. Cichocki and R. Thawonmas 在文章"On-line algorithm for blind signal extraction of arbitrarily distributed but temporally correlated sources using second order statistics"(Neural Process. Lett.,vol. 12, no. 1,pp. 91 - 98, 2000)中公布的基于最小预测误差准的自适应提取方法,提取的母亲和胎儿心电信号的波形。 (D), graph 5 (d) and FIG. 6 are employed A. Cichocki and R. Thawonmas in the article "On-line algorithm for blind signal extraction of arbitrarily distributed but temporally correlated sources using second order statistics" (Neural Process ... Lett, vol 12, no 1, pp 91 -.. 98, the minimum prediction error based on an adaptive extraction quasi 2000) published extracted waveform of maternal and fetal ECG. 图5(e)和图6(e)的曲线分别为采用本发明提取的母亲和胎儿心电信号的波形。 FIG. 5 (e) and 6 (e) is a waveform of the curves mother and fetus ECG of the present invention is extracted.

[0112] 参照附图5所示的本发明和现有技术的四种方法仿真提取的母亲心电信号波形对比图。 Simulation of the extracted ECG waveform mother FIG Comparative [0112] Referring to the drawings the four methods of the present invention and the prior art shown in FIG. 5. 图5(a)、(b)、(c)、(d)、(e)中的横坐标表示时间,纵坐标表示信号幅值。 FIG 5 (a), (b), (c), (d), (e) the abscissa represents time and the ordinate represents signal amplitude. 通过对比可以看出,其它四种方法提取的母亲心电信号的波形不够清晰,且有失真,本发明方法提取的母亲心电信号很好地抑制了胎儿心电信号和噪声。 Can be seen by comparing the waveforms of the other four mother ECG extraction method is not clear enough, and there is a distortion, the method of the present invention, the extracted ECG mother well suppressed fetal ECG and noise.

[0113] 参照附图6所示的本发明和现有技术的四种方法仿真提取的胎儿心电信号波形对比图。 Four methods of the present invention and prior art [0113] FIG. 6 with reference to the accompanying drawings simulation extracted fetal ECG waveforms can be compared to FIG. 图6(a)、(b)、(c)、(d)、(e)中的横坐标表示时间,纵坐标表示信号幅值。 FIG 6 (a), (b), (c), (d), (e) the abscissa represents time and the ordinate represents signal amplitude. 通过对比可以看出,其它四种方法提取的胎儿心电信号的波形不够清晰,胎儿心电信号噪声较大,且掺杂母亲心电信号,本发明方法提取的胎儿心电信号更好地抑制了母体心电信号和噪声。 Can be seen by comparing the waveforms of the other four methods to extract the fetal ECG is not clear enough, the fetal ECG noisy, and the doping mother ECG, the method of the present invention to extract the fetal ECG better suppress maternal ECG signal and noise.

Claims (7)

1. 一种基于二阶统计特性的母亲和胎儿心电盲提取方法,包括如下步骤: (1) 获取电生理混合信号: 获取同步采集的母体胸部和腹部多路电生理混合信号; (2) 预处理: (2a)使用有限长数字低通滤波器,对多路电生理混合信号进行肌电干扰和噪声滤除, 得到滤除肌电干扰和噪声后的多路电生理混合信号; (2b)使用有限长数字陷波器,对肌电干扰和噪声滤除后的多路电生理混合信号进行50Hz工频干扰滤除,得到预处理后的多路电生理混合信号; (3) 得到每路电生理混合信号的信噪比: (3a)将预处理后每路电生理混合信号中母亲心电信号作为信号,胎儿心电信号作为噪声,得到母亲心电信号和胎儿心电信号的信噪比; (3b)将预处理后每路电生理混合信号中胎儿心电信号作为信号,母亲心电信号作为噪声,得到胎儿心电信号和母亲心电信号的信噪比; (4) 估计 CLAIMS 1. A method of extracting the mother and fetus ECG second order statistical properties based blind, comprising the steps of: (1) the mixed signal acquired electrophysiological: acquiring maternal abdomen and chest multiple electrophysiological signal synchronized acquisition mixed; (2) pretreatment: (2a) using a finite length digital low pass filter, the mixing of multiple electrophysiological EMG signal interference and noise filtering, to obtain the multiplexed electrical interference and noise filtered EMG physiological mixed signal; (2B ) using finite length digital notch filter, the multi-channel electrical interference and noise filter physiological EMG mixed 50Hz frequency interference signal filtered off, to obtain multiple physiological electrical preprocessed downmix signal; (3) each obtained physiological mixed signal to noise ratio of the electric path: (3a) each channel mixed signal electrophysiological mother pretreatment ECG signal as a fetal ECG as noise, to give the mother and fetus ECG ECG letter noise ratio; (3B) each channel mixed signal electrophysiological pretreated as fetal ECG signal, the ECG signal as noise mother, fetus ECG signal to noise ratio and to obtain the mother's ECG; (4) estimation 周期: (4a)选出母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号,将其中母亲心电信号相邻两个R波的时间间隔,作为母亲心电信号周期的预估计值; (4b)采用自相关系数公式,计算母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的自相关系数; (4c)将母亲心电信号周期的预估计值上下浮动误差0. 2秒作为搜索时间段,搜索自相关系数的绝对值的最大值,将自相关系数的绝对值取最大值的时刻作为母亲心电信号周期的精确估计值; (4d)选出胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号,将其中胎儿心电信号相邻两个R波的时间间隔,作为胎儿心电信号周期的预估计值; (4e)采用自相关系数公式,计算胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号的自相关系数; (4f)将胎儿心电信号周期的预 Period: (4a) selecting mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal, in which two adjacent mother ECG R wave interval, as a mother heart electrical cycles pre-estimated value; (4B) using the autocorrelation coefficients formula to calculate the autocorrelation coefficient mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal; (4C) a pre-estimate the mother's heart electrical cycles error value minus 0.2 seconds as the search period, the absolute value of the maximum autocorrelation coefficient of the search, the mother takes the maximum value as the center of electrical cycles accurate estimate of the absolute value of the self correlation coefficients; (4D) selected fetal ECG and maternal ECG way maximum signal to noise ratio electrophysiological mixed signal, wherein the fetal ECG two adjacent R wave interval, as the pre-estimate the fetal heart electrical cycles; ( 4e) using autocorrelation coefficient formula, the maximum autocorrelation coefficient of the mixed signal along electrical physiological fetal ECG and maternal ECG signal to noise ratio; (4F) pre fetal heart electrical cycles 计值上下浮动误差0. 15秒作为搜索时间段,搜索自相关系数的绝对值的最大值,将自相关系数的绝对值取最大值的时刻作为胎儿心电信号周期的精确估计值; (5) 获得最优的心电信号向量: (5a)采用最速下降方法,获得最优的母亲心电信号向量; (5b)采用修正牛顿方法,获得最优的胎儿心电信号向量; (6) 提取心电信号: (6a)采用投影方法,使用最优的母亲心电信号向量从预处理后的多路电生理混合信号中提取出母亲心电信号; (6b)采用投影方法,使用最优的胎儿心电信号向量从预处理后的多路电生理混合信号中提取出胎儿心电信号。 Error count value plus or minus 0.15 seconds as a search time, the search from the maximum absolute value of the correlation coefficient, and takes the maximum value as the fetal heart electrical cycles accurate estimate of the absolute value of the self correlation coefficients; (5 ) for optimal ECG signal vector: (5a) by steepest descent method, for optimal mother ECG signal vector; (5b) by the modified Newton method for optimal fetal ECG signal vector; (6) extract ECG: (6a) using the projection method, using the optimum vector ECG mother mother extracted ECG physiological mixed signal from the multiplexer electrically pretreated; (6B) using the projection method, the best use of fetal ECG extraction fetal ECG vector physiological mixed signal from the multiplexer electrically pretreated.
2. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(4b)中所述的自相关系数公式如下: 2. The method of claim extracting statistical properties of the mother and the fetal ECG blind second order based on 1 wherein said autocorrelation coefficients of the equations in step (4b) as follows:
Figure CN103876730BC00031
其中,r(S)表示延迟时间为S时的母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的自相关系数,S表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号相对t时刻的延迟时间,X(t)表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号,t表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号的采样时刻,J(• )dt表示对采样时刻t的积分操作,[• ]2表示取平方操作。 Wherein, r (S) represents the delay time for the mother and fetus ECG ECG signal to noise ratio of the maximum autocorrelation coefficients of the mixed signal along electrical physiological when S, S represents the mother and fetus ECG ECG signal to noise than the maximum delay time of the mixed signal corresponding electrophysiological way time t, X (t) represents the mother and fetus ECG ECG way maximum signal to noise ratio electrophysiological mixed signal, t represents the mother and fetus ECG ECG the ratio of maximum signal is the mixed signal electrophysiological way sampling time, J (•) dt represent the integral operation of the sampling time t, [•] 2 represents the squaring operation.
3. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(4e)中所述的自相关系数公式如下: 3. The method of blind extraction mother and fetus ECG based on second order statistical properties, characterized according to claim 1, step (4E) autocorrelation coefficients according to the following formula:
Figure CN103876730BC00032
其中,f(e)表示延迟时间为e时的胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号的自相关系数,e表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号相对t时刻的延迟时间,y(n)表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号,n表示胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号的采样时刻,J(• )dn表示对采样时刻n的积分操作,[• ]2表示取平方操作。 Wherein, f (e) represents fetal ECG and maternal ECG signal to noise ratio at the maximum delay time e electrophysiological way mixed signal autocorrelation coefficients, e represents the fetal and maternal ECG heart electrical noise channel than the maximum delay time of the mixed signal corresponding electrophysiological way time t, y (n) represents the fetal ECG and maternal ECG way maximum signal to noise ratio electrophysiological mixed signal, n represents fetal ECG and maternal ECG the ratio of maximum signal is the mixed signal electrophysiological way sampling time, J (•) dn represents the integral operation of the sampling time n, [•] 2 represents the squaring operation.
4. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(5a)中所述的最速下降方法的步骤如下: 第一步,按照下式,得到母亲心电信号向量与最优的母亲心电信号向量的逼近度: 4. Extraction of the mother and the fetal ECG blind statistical characteristics based on second order, characterized in that said claim 1, the step steepest descent method in the step (5a) as follows: First, according to the following formula give the mother the best ECG signal vector and vector mother ECG approximation degree:
Figure CN103876730BC00033
其中,J(w)表示母亲心电信号向量与最优母亲心电信号向量的逼近度,w表示母亲心 Wherein, J (w) represents the degree of approximation to the optimal vector mother mother ECG heart electrical signal vector, w denotes the mother heart
Figure CN103876730BC00034
亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号时延分别为〇和a的自相关矩阵,a表示母亲心电信号周期的精确估计值,l〇g[ •]表示取对数操作,(•)T表示转置操作; 第二步,按照下式,迭代计算母亲心电信号向量: w(k+1) =w(k) -y[R(O)w(k) -[w(k)tR(a ) w(k) ]1R(a ) w(k)] 其中,w(k+l)表示第k+1次迭代的母亲心电信号向量,w(k)表示第k次迭代的母亲心电信号向量,k表示母亲心电信号向量的迭代次数,y表示母亲心电信号向量的迭代步长, R(O)和RU)分别表示母亲心电信号和胎儿心电信号信噪比最大的一路电生理混合信号时延分别为〇和a的自相关矩阵,a表示母亲心电信号周期的精确估计值,(*)T表示转置操作,(•r1表示求逆操作; 第三步,迭代母亲心电信号直至收敛,得到最优的母亲心电信号向量。 Affinity ECG and fetal ECG signal to noise ratio of the maximum electrophysiological way signal delay are mixed and a square of the autocorrelation matrix, a represents an accurate estimate of the mother's heart electrical cycles, l〇g [•] represents logarithmic operation, (•) T denotes a transpose operation; the second step, according to the following equation, iterative mother ECG vector: w (k + 1) = w (k) -y [R (O) w ( k) - [w (k) tR (a) w (k)] 1R (a) w (k)] where, w (k + L) represents the mother ECG vector k + 1 iteration, w ( k) represents the k th iteration mother ECG signal vector, k represents the number of iterations mother heart electrical signal vector, y denotes the vector iteration step the mother's heart electrical length, R (O) and RU) represent the mother ECG fetal ECG signal to noise ratio and the maximum way electrophysiological signal delay are mixed and a square of the autocorrelation matrix, a represents an accurate estimate of the mother's heart electrical cycles, (*) T denotes a transpose operation, (• r1 represents the inverse operation; a third step iteration until convergence mother ECG, ECG mother optimal vector.
5. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(5b)中所述的修正牛顿方法步骤如下: 第一步,按照下式,得到胎儿心电信号向量与最优的胎儿心电信号向量的逼近度: The extraction mother and second order statistical properties of fetal ECG based blind, characterized according to claim 1, step (5b) in the Newton's method of correcting the following steps: a first step according to the following formula, get approximation of the fetal ECG signal vector and optimal electrical signal vector fetal heart:
Figure CN103876730BC00041
其中,L(u)表示胎儿心电信号向量与最优的胎儿心电信号向量的逼近度,u表示胎儿 Wherein, L (u) represents the fetal ECG vector optimal approximation of the fetal heart electrical signal vectors, u represents the fetus
Figure CN103876730BC00042
胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号时延分别为〇和e的自相关矩阵,e表示胎儿心电信号周期的精确估计值,i0g[ •]表示取对数操作,(•)T表示转置操作; 第二步,按照下式,迭代计算胎儿心电信号向量: Fetal ECG and maternal ECG signal to noise ratio of the maximum delay of the mixed signal electrophysiological way are square autocorrelation matrix and e, e represents an accurate estimate of electrical cycles fetal heart, i0g [•] represents taking the operands, (•) T denotes a transpose operation; a second step of calculating the fetal ECG vector according to the following formula, iteration:
Figure CN103876730BC00043
其中,U(n+1)表示第n+i次迭代的胎儿心电信号向量,u(n)表示第n次迭代的胎儿心电信号向量,n表不胎儿心电信号向量的迭代次数,v(o)和v(|3)分别表不胎儿心电信号和母亲心电信号信噪比最大的一路电生理混合信号时延分别为〇和e的自相关矩阵, e表示胎儿心电信号周期的精确估计值,(•)T表示转置操作,(•)<表示求逆操作,(•)j 表示求负二次方操作; 第三步,迭代胎儿心电信号直至收敛,得到最优的胎儿心电信号向量。 Wherein, U (n + 1) n + i represents the iteration fetal ECG vectors, U (n) represents the fetal ECG vector iteration n, n is the number of iterations electrical signal vector table is not Fetal, v (o) and v (| 3) respectively, the table does not fetal ECG and maternal ECG signal to noise ratio of the maximum delay of the mixed signal electrophysiological way are square autocorrelation matrix and e, e represents fetal ECG an accurate estimate of the period, (•) T denotes a transpose operation, (•) <showing inverse operation, (•) j represents the square of the negation operation; a third step iteration until convergence fetal ECG, the most preferably fetal ECG vectors.
6. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(6a)中所述的投影方法是指按照下式,得到母亲心电信号: h(t) =eTd(t) 其中,h⑴表示t时刻提取的母亲心电信号,e表示最优的母亲心电信号向量,d⑴表示t时刻预处理后的电生理混合信号,(•)T表示转置操作。 6. The method of blind extraction mother and fetus ECG based on second order statistical properties, characterized in that said claim 1, the step (6a) in the projection method refers to the following formula, to obtain mother ECG: h (t) = eTd (t) where, h⑴ represents mother ECG extraction time t, e represents the optimal mother ECG vector, d⑴ electrophysiological mixed signal represents time t after pretreatment, (•) T It represents a transpose operation.
7. 根据权利要求1所述的基于二阶统计特性的母亲和胎儿心电盲提取方法,其特征在于,步骤(6b)中所述的投影方法是指按照下式,得到胎儿心电信号: z(t) =fTd(t) 其中,z(t)表示t时刻提取得到的胎儿心电信号,f•表示最优的胎儿心电信号向量,d(t)表示t时刻预处理后的电生理混合信号,(•)T表示转置操作。 7. The method of extracting statistical properties of the mother and the fetal ECG second order blind basis, wherein in said claim 1, the step (6b) in the projection method refers to the following formula, to obtain fetal ECG: z (t) = fTd (t) where, z (t) represents the time t fetal ECG extraction obtained, f • fetal ECG represents the optimal vector, d (t) represents the time t electrically pretreated physiological mixed signal, (•) T represents a transpose operation.
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CN106889981B (en) * 2017-01-26 2018-04-20 浙江铭众科技有限公司 A method for extracting the fetal heart rate intelligent terminal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1520272A (en) * 2001-05-29 2004-08-11 生殖健康技术公司 System for detection and analysis of material uterine, material and fetal cardiac and fetal brain activity
CN102160787A (en) * 2011-05-31 2011-08-24 广东工业大学 Time-frequency-transformation-based blind extraction method of fetal electrocardiography
CN103637796A (en) * 2013-12-26 2014-03-19 上海海事大学 Fetal electrocardiosignal self-adaptive blind extraction method based on generalized eigenvalue maximization

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006081447A2 (en) * 2005-01-27 2006-08-03 The Board Of Trustees Of The University Of Illinois Blind adaptive filter extraction of fetal electrocardiogram signal estimate
DK2185068T3 (en) * 2007-07-20 2017-01-02 Stichting Technische Wetenschappen Foster Monitoring

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1520272A (en) * 2001-05-29 2004-08-11 生殖健康技术公司 System for detection and analysis of material uterine, material and fetal cardiac and fetal brain activity
CN102160787A (en) * 2011-05-31 2011-08-24 广东工业大学 Time-frequency-transformation-based blind extraction method of fetal electrocardiography
CN103637796A (en) * 2013-12-26 2014-03-19 上海海事大学 Fetal electrocardiosignal self-adaptive blind extraction method based on generalized eigenvalue maximization

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