CN107684423A - A kind of Fetal ECG separation method and device - Google Patents

Abstract

The invention provides a method and device for fetal electrocardiography separation. The method includes: performing QRS wave group detection on the received maternal abdominal wall electrocardiographic signal, determining the starting position of the QRS wave group and the starting position between the QRS wave groups; The segment is smoothed; the QRS wave group is linearly averaged to generate an average template; according to the correlation between the mother QRS wave group in the average template and the mother QRS wave group corresponding to the current ECG cycle, the The maternal QRS complex in the average template is dynamically amended to generate an estimated maternal abdominal wall ECG signal; the maternal abdominal wall ECG estimated signal is used as a reference signal, and the maternal abdominal wall ECG signal is used as an expected signal. An algorithm is used to separate the fetal ECG signal from the maternal abdominal wall ECG signal. The fetal electrocardiographic separation algorithm of the present invention is simple, and only one maternal abdominal wall electrocardiographic signal is needed, so the single-lead fetal electrocardiographic signal separation can be completed.

Description

A method and device for separating fetal heart electricity

technical field

The present invention relates to the technical field of biomedical engineering, in particular to a method and a device for separating fetal electrocardiograms, in particular to a method and a device for separating electrocardiograms of fetuses based on a smoothing window.

Background technique

This section is intended to provide a background or context for implementations of the invention that are recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section.

Fetal electrocardiogram (FECG) is one of the most important objective indicators of fetal intrauterine physiological activities. By analyzing fetal electrocardiogram signals, it can be used for early diagnosis of fetal hypoxia, intrauterine distress and congenital heart disease. Effectively reduce the morbidity and mortality of various diseases in newborns. Therefore, the clinical application of perinatal monitors will be one of the powerful measures to ensure the safety of the fetus in all stages of the perinatal period and ensure the eugenics of the fetus.

During the perinatal period, the fetus is surrounded by several layers of different electrical conductivity in the abdomen, such as placenta, amniotic fluid, maternal uterus and subcutaneous tissue of the maternal abdomen, among which amniotic fluid has the highest conductivity, while vernix has the lowest conductivity. In addition, the skin and subcutaneous fat of pregnant women also have weak conductivity, but the conductivity is about ten times smaller than that of muscle tissue. When collecting fetal ECG, since the fetal ECG signal needs to pass through the conductive layer, the already weak fetal ECG signal is more susceptible to external interference. These different tissues form the so-called "body volume conductor", which is not a stable conductor whose conductivity and geometry change continuously throughout gestation. Therefore, this will lead to the following characteristics of the maternal abdominal ECG mixed signal: 1) The signal-to-noise ratio is low, the fetal ECG component is too weak, only about 10-50uV, while the mother’s ECG signal can reach 750uV, the difference between the two can be different. More than ten times. Myoelectric noise and other interference are also very strong, and the signal is completely submerged in the noise. 2) In the time domain, the fetal QRS wave overlaps with the maternal QRS wave by 10-30%. 3) In the frequency domain, the fetal spectrum mostly overlaps with the maternal spectrum. 4) The signal is very random and is a non-stationary process, especially the time-varying nature of the fetal ECG transmission channel due to the free movement of the fetus.

The above-mentioned characteristics of the maternal abdominal ECG mixed signal create relatively large obstacles for obtaining high-precision fetal ECG signals. Therefore, the fetal ECG signal is extracted from the maternal abdominal wall mixed signal to realize the monitoring of fetal life information during the perinatal period , is currently a widely researched and concerned issue.

At present, there are mainly the following methods for extracting fetal ECG signals from the mixed signals of the maternal abdominal wall:

1) Matched filtering: Matched filtering mainly uses statistical characteristics such as autocorrelation and cross-correlation of the signal, but the situation to be faced in the actual environment is far more complicated than the hypothetical situation. The fetal ECG signal obtained by using matched filtering is not Ideal.

2) Independent component analysis (ICA): This method requires multiple abdominal wall signals and cannot realize the extraction of single-lead fetal ECG signals.

3) Fetal ECG signal extraction method filtering with wavelet threshold denoising: Using wavelet transform combined with prior signal knowledge can obtain a good fetal ECG signal, but the extraction process is easily disturbed by similar signals of amplitude and fetal ECG signal. It often leads to missed detection and false detection of the R wave in the fetal ECG signal, which will cause errors when calculating the fetal heart rate, which is not conducive to clinical diagnosis.

4) Neural network method: This method can detect the QRS complex wave of the ECG signal according to the prediction error of the neural network. The PT segment signal is flat and can be predicted better. For the QRS complex wave, the difference between adjacent points is large, which will cause a prediction error. Use this prediction error to train the network to predict the QRS complex wave. The artificial neural network used in the prediction With a multi-layer structure, it takes a long time to use the neural network to learn the training process, and the training samples are required to be representative, which is difficult to achieve in the actual application of abdominal wall ECG signal noise reduction.

5) Adaptive filtering method: The adaptive filtering method includes using one or several reference channels to train adaptive filtering to eliminate maternal ECG. Existing adaptive filtering methods to remove maternal ECG components require a maternal ECG reference channel morphologically similar to the submerged FECG signal, but existing adaptive cancellation methods require an additional reference signal, that is, in addition to abdominal wall electrodes , also needs to be equipped with additional electrodes connected to the maternal chest lead, and the adaptive method can eliminate the relevant maternal component in the chest lead and abdominal wall lead, which means that the maternal abdominal wall ECG signal and the maternal chest lead ECG signal need to be correlated, In addition, the conduction path of the maternal ECG signal is very complicated. In some cases, the correlation between the maternal ECG signal in the abdominal wall and the maternal ECG signal in the chest leads is poor. Therefore, using the existing adaptive filtering algorithm to cancel and extract the fetal ECG signal will cause a large amount of maternal ECG leakage, which will cause great interference to the correct identification of fetal ECG components. Moreover, the existing adaptive filter cancellation cannot realize single-lead fetal ECG signal extraction.

Contents of the invention

The present invention proposes a fetal electrocardiographic separation method and device, which are used to solve the problem that the existing fetal electrocardiographic separation algorithm is complex in calculation and unable to realize a single lead.

In order to achieve the above object, an embodiment of the present invention provides a fetal electrocardiographic separation method, including: performing QRS wave group detection on the received maternal abdominal wall electrocardiogram signal, determining the starting position of the QRS wave group and the starting point between the QRS wave groups start position; use the smoothing window to smooth the signal segments between the QRS complexes; carry out linear averaging to the QRS complexes to generate an average template; Correlation of the maternal QRS wave group corresponding to the electrical cycle, modifying the dynamic amplitude of the mother's QRS wave group in the average template to generate an estimated maternal abdominal wall electrocardiogram signal; using the maternal abdominal wall electrocardiographic estimated signal as a reference signal, Taking the maternal abdominal wall electrocardiographic signal as an expected signal, and separating the fetal electrocardiographic signal from the maternal abdominal wall electrocardiographic signal through an adaptive algorithm.

In order to achieve the above object, the embodiment of the present invention also provides a fetal electrocardiogram separation device, including: a wave group detection module, which is used to detect the QRS wave group of the received maternal abdominal wall ECG signal, and determine the start of the QRS wave group The starting position between the position and the QRS complex; the smoothing processing module, which is used to smooth the signal segment between the QRS complexes by using a smoothing window; the average processing module, which is used to linearly average the QRS complexes, Generating an average template; a wave group correction module, used to modify the maternal QRS wave group in the average template according to the correlation between the mother QRS wave group in the average template and the mother QRS wave group corresponding to the current ECG cycle Perform dynamic amplitude correction to generate an estimated maternal abdominal wall ECG signal; a separation module is configured to use the maternal abdominal wall ECG estimated signal as a reference signal, and use the maternal abdominal wall ECG signal as an expected signal, through an adaptive algorithm, from The fetal electrocardiographic signal is separated from the maternal abdominal wall electrocardiographic signal.

The fetal electrocardiogram separation method and device proposed by the present invention can estimate the maternal abdominal wall ECG by smoothing the maternal QRS inter-group signal, eliminating the fetal component of the maternal QRS inter-group signal segment, and correcting the amplitude of the maternal QRS wave group. signal, this method avoids the influence of incomplete maternal ECG suppression caused by the non-correlation of the maternal component in the chest lead and the abdominal wall lead, and has a better separation effect; the realization of the present invention only needs one maternal abdominal wall ECG signal , so single-lead fetal ECG signal separation can be completed; moreover, the design idea of the fetal separation algorithm of the present invention is simple and intuitive, and it is easy to find the cause and add a correction module for abnormal clinical data.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative efforts.

1 is a schematic diagram of the system structure of a method for fetal electrocardiography separation according to an embodiment of the present invention;

Fig. 2 is the schematic block diagram of the abdominal wall maternal ECG estimation mechanism based on the smoothing window of the embodiment of the present invention;

Fig. 3 is the processing flow diagram of the method for fetal electrocardiography separation according to the embodiment of the present invention;

4 is a schematic structural view of a fetal electrocardiography separation device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of the wave group correction module 104 of the embodiment shown in FIG. 4;

Fig. 6 is the oscillogram of the mixed electrocardiogram of 5 road maternal abdominal wall that the specific embodiment of the present invention adopts;

Fig. 7 is an analysis diagram of experimental results of a specific embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Those skilled in the art know that the embodiments of the present invention can be implemented as a system, device, device, method or computer program product. Therefore, the present disclosure may be embodied in the form of complete hardware, complete software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

The principle and spirit of the present invention will be explained in detail below with reference to several representative embodiments of the present invention.

The present invention proposes an adaptive single-lead fetal electrocardiographic separation method and device based on a smoothing window, which uses a smoothing window to smooth the QRS inter-group signal in the maternal abdominal wall signal, so as to smooth out the QRS inter-group signal segment The maternal QRS wave group in the abdominal wall ECG signal is segmented and extracted, and the extracted N consecutive maternal QRS wave groups are linearly averaged with the peak position of the maternal R wave as the positioning point to generate an average QRS wave Group template, which intercepts the maternal QRS complex in the currently input abdominal wall signal and the maternal QRS complex in the average template, and uses the correlation coefficient between the two to copy and correct the maternal QRS complex in the average template to obtain a dynamic maternal Abdominal wall ECG estimation signal. Moreover, through self-adaptive learning, the maternal component in the abdominal wall signal is eliminated. This scheme avoids the influence of the maternal component leakage caused by the non-correlation between the maternal component in the chest lead and the maternal component in the abdominal wall lead. At the same time, it can achieve a single Lead fetal electrocardiogram separation.

FIG. 1 is a schematic diagram of the system structure of the fetal electrocardiography separation method according to the embodiment of the present invention. As shown in Figure 1, y(n) represents the collected maternal abdominal wall ECG signal, f(n) represents the fetal ECG signal in the abdominal wall signal, x(n) represents the maternal ECG signal in the abdominal wall signal, and is the The expected signal of the adaptive filter, x'(n) is the abdominal wall maternal ECG estimated by the abdominal wall maternal ECG estimation mechanism, and the adaptive filter continuously "learns" and "tracks" the input signal, so that the output signal Maximize the approximation of the abdominal wall ECG signal, so that the error signal minimum, That is, the isolated fetal ECG signal.

That is to say, the adaptive fetal ECG separation algorithm requires two input signals, namely: one maternal abdominal ECG signal (main input signal), and one estimated abdominal wall maternal ECG signal (reference input signal). Compared with the prior art that requires access to one ECG signal of a chest lead as a reference input signal, a single lead is realized.

The core of the present invention is how to calculate the estimated abdominal wall maternal electrocardiogram signal as the reference input signal of the adaptive algorithm. Fig. 2 is a schematic block diagram of the abdominal wall maternal ECG estimation mechanism of the present invention. As shown in Fig. 2, the QRS wave group signal and the inter-QRS inter-group signal are processed separately, and the method based on the smoothing window is used to carry out the maternal QRS inter-group signal. The smoothing process eliminates the fetal ECG beat points in the signal segment between the maternal QRS complexes, and uses the average correlation method to correct the amplitude of the maternal QRS complexes, thereby estimating the abdominal wall maternal signal waveform.

Fig. 3 is a processing flow chart of the fetal electrocardiographic separation method according to the embodiment of the present invention. As shown in Figure 3, including:

Step S101, performing QRS wave group detection on the received maternal abdominal wall ECG signal, and determining the starting position of the QRS wave group and the starting position between the QRS wave groups;

Step S102, using a smoothing window to smooth the signal segments between the QRS complexes;

Step S103, linearly averaging the QRS complexes to generate an average template;

Step S104, according to the correlation between the maternal QRS complex in the average template and the maternal QRS complex corresponding to the current ECG cycle, perform dynamic amplitude correction on the maternal QRS complex in the average template to generate a maternal Abdominal wall ECG estimation signal;

Step S105, using the estimated maternal abdominal wall ECG signal as a reference signal and the maternal abdominal wall ECG signal as an expected signal, and using an adaptive algorithm to separate the fetal ECG signal from the maternal abdominal wall ECG signal.

In step S102, the signal segment between the QRS complexes is smoothed by using a fixed-length window, and the value of the fixed-length window is determined according to the signal sampling rate and the length of the fetal electrocardiogram group.

As shown in Figure 2, a fixed length window M is used to smooth the signal segment between QRS wave groups. The length of the fixed window is about the length of the fetal ECG QRS wave. The length of the fetal ECG wave group is generally 47ms to 85ms, so the value of M It can be (0.047*d, 0.085*d), where the parameter d is the signal sampling rate.

The inter-QRS signal can be expressed as: The amplitude of the maternal ECG is generally more than ten times that of the fetal ECG. After smoothing, there is almost no fetal QRS complex between the maternal QRS complexes.

In step S103, the QRS wave group is linearly averaged to generate an average segment, including: extracting the maternal ECG R wave peak position from the maternal abdominal wall ECG signal; and taking the R wave peak position as The central location point is used to linearly average the QRS complex to generate the average template.

During specific implementation, it is necessary to determine the peak position of the R wave in the maternal abdominal wall ECG signal. The method is: perform differential calculation on the received maternal abdominal wall ECG signal to obtain the slope curve of the abdominal wall ECG signal, and perform an absolute calculation of the slope curve. Sliding integral operation, record the maximum value in each second, and average the maximum value in the first 8 seconds, then the R wave judgment threshold = coefficient ratio * average of the maximum value in the previous 8 seconds, if the difference value is greater than the R wave judgment threshold In the segment, the maximum value of the R wave peak position is searched to determine the final R wave peak position point.

Then take the peak position of the R wave in the abdominal wall ECG signal as the central positioning point, and intercept the maternal QRS complex ECG waveform y ₁ , y ₁ =[y ₁ (1),y ₁ (2),...,y ₁ ( P)], where P is the length of the maternal QRS complex.

Linearly average the ECG signal segment corresponding to the current ECG cycle and the previous M-1 consecutive ECG signal segments, and the average template is obtained as:

In the embodiment of the present invention, whether the maternal QRS complex component can be effectively suppressed plays a decisive role in correctly identifying the fetal ECG component in the separation result. The maternal ECG waveform in the average template is the equal-weighted accumulation and linear average of the earlier ECG waveform and the latest waveform, and the estimated maternal ECG segment is not dynamic. Because, step S104 of the present invention performs dynamic amplitude correction on the maternal QRS complex in the average template according to the correlation between the latest maternal QRS complex and the maternal QRS complex in the average segment.

In specific implementation, the method is as follows:

First, calculate the correlation between the QRS complex segment corresponding to the current electrocardiographic cycle and the QRS complex segment in the average template, and generate a correlation coefficient. The specific steps are:

(1) Extract the maternal QRS complex segment in the current ECG cycle: y ₃ =[y ₃ (1), y ₃ (2),...,y ₃ (P)], where P is the maternal QRS complex the length of the segment;

(2) Extract the maternal QRS complex segment in the average template: y ₂ =[y ₂ (1),y ₂ (2),...,y ₂ (P)];

(3) Calculate the correlation coefficient r ₂₃ of the volume segment:

Secondly, according to the correlation coefficient, use the QRS wave group segment corresponding to the current electrocardiographic cycle to carry out dynamic amplitude correction to the maternal QRS wave group in the average template, and the adopted expression is as follows:

Since the average template generated by the average section has the signal of the corresponding maternal ECG waveform in the current abdominal wall ECG cycle, and basically eliminated the fetal ECG waveform, the averaged maternal ECG QRS wave group segment The dynamic amplitude correction can estimate the maternal abdominal wall ECG signal to the greatest extent.

In step S105, the abdominal electrode obtains the main input signal, and takes the estimated maternal abdominal wall ECG signal as the input signal, which basically does not contain the fetal ECG signal, but only includes the noise to be eliminated and the maternal ECG signal; The electrical signal is an expected signal. Through an adaptive algorithm, the relevant part of the input signal and the expected signal is eliminated, and the irrelevant part is retained. Therefore, the separation of the fetal ECG signal in the abdominal wall ECG signal can be extracted to the maximum extent.

In the embodiment of the present invention, the adaptive algorithm may be an adaptive least mean square (LMS) algorithm, an adaptive recursive least squares (RLS) algorithm, a least squares lattice (LSL) adaptive algorithm, and the like.

It should be noted that, although operations of the methods of the present invention are depicted in the drawings in a particular order, this does not require or imply that the operations must be performed in that particular order, or that all illustrated operations must be performed to achieve the desired results. . Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and/or one step may be decomposed into multiple steps for execution.

After introducing the method of the exemplary embodiment of the present invention, next, the fetal electrocardiographic separation device of the exemplary embodiment of the present invention will be introduced with reference to FIG. 6 . For the implementation of the device, reference may be made to the implementation of the above method, and repeated descriptions will not be repeated. The terms "module" and "unit" used below may be software and/or hardware that realize predetermined functions. Although the modules described in the following embodiments are preferably implemented in software, implementations in hardware, or a combination of software and hardware are also possible and contemplated.

Fig. 4 is a schematic structural diagram of a fetal electrocardiography separation device according to an embodiment of the present invention. As shown, including:

The wave group detection module 101 is used for performing QRS wave group detection on the received maternal abdominal wall electrocardiographic signal to determine the starting position of the QRS wave group and the starting position between the QRS wave groups; the smoothing processing module 102 is used to use smoothing The window smoothes the signal segments between the QRS complexes; the average processing module 103 is used to linearly average the QRS complexes to generate an average template; Correlation between the maternal QRS wave group and the maternal QRS wave group corresponding to the current ECG cycle, the dynamic amplitude correction is performed on the maternal QRS wave group in the average template, and the maternal abdominal wall ECG estimation signal is generated; the separation module 105 , for using the estimated maternal abdominal wall ECG signal as a reference signal and the maternal abdominal wall ECG signal as an expected signal, and using an adaptive algorithm to separate the fetal ECG signal from the maternal abdominal wall ECG signal.

Further, in the embodiment of the present invention, the smoothing processing module 102 performs smoothing processing on the signal segments between the QRS complexes by using a smoothing window, which specifically includes: using a fixed length window to smooth the signal segments between the QRS complexes The segment is smoothed, and the value of the fixed-length window is determined according to the signal sampling rate and the length of the fetal electrocardiogram group.

Further, in the embodiment of the present invention, the average processing module 103 performs linear average on the QRS complex to generate an average template, including: extracting the maternal ECG R wave peak from the maternal abdominal wall ECG signal Position: taking the position of the R wave peak as the central positioning point, performing linear average on the QRS complex to generate the average template.

Further, in the embodiment of the present invention, the complex correction module 104 adjusts the average template according to the correlation between the maternal QRS complex in the average template and the maternal QRS complex corresponding to the current ECG cycle. The dynamic amplitude correction of the maternal QRS complex is performed to generate the maternal abdominal wall ECG estimation signal, as shown in Figure 5, which specifically includes:

A correlation coefficient calculation unit 1041, configured to calculate the correlation between the QRS complex segment corresponding to the current ECG cycle and the QRS complex segment in the average template, and generate a correlation coefficient;

The dynamic correction unit 1042 is configured to use the QRS wave group segment corresponding to the current ECG cycle to perform dynamic amplitude correction on the maternal QRS wave group in the average template according to the correlation coefficient, so as to generate a maternal abdominal wall ECG estimation signal .

Further, in the embodiment of the present invention, the separation module 105 separates the fetal ECG signal from the maternal abdominal wall ECG signal through an adaptive algorithm, and the adaptive algorithm includes an adaptive least mean square algorithm, Adaptive recursive least squares algorithm, least squares lattice adaptive algorithm.

Furthermore, although several units of the fetal electrocardioseparation device are mentioned in the above detailed description, this division is merely not mandatory. Actually, according to the embodiment of the present invention, the features and functions of two or more units described above may be embodied in one unit. Likewise, the features and functions of one unit described above can also be further divided to be embodied by a plurality of units.

A specific example will be used below to illustrate the effect of using the method for separating fetal ECG signals based on the smoothing window of the present invention to separate fetal ECG signals.

Referring to FIG. 6 , it is a waveform diagram of 5 maternal abdominal wall mixed ECG signals used in this specific embodiment. As shown in Figure 6, the data length of each signal is 2500 sample points, and the sampling rate is 250Hz. It can be seen from Figure 6 that the first abdominal wall signal is the one with the largest fetal-maternal ECG signal-to-noise ratio, that is, this signal has the best effect, and the fourth and fifth abdominal wall ECG signals cannot be recognized by the naked eye. The position of the electric R wave peak, the extraction effect of these two signals can no longer be used by the algorithm of the present invention, so it is not within the scope of consideration of the algorithm of the present invention.

In this embodiment, the second channel signal is selected as the algorithm verification data, and the self-adaptive recursive least squares algorithm is used for the adaptive filtering. For the analysis of the experimental results, refer to FIG. 7 .

1. The fetal QRS complex is far from the maternal QRS complex:

The fetal QRS complex is far away from the maternal QRS complex, as marked a in Figure 7. It can be seen from Figure 7 that the fetal QRS complex components in this case are extracted, and the left and right maternal QRS complex components are suppressed. The positional relationship between the fetal QRS complex and the maternal QRS complex is the most common positional relationship in the abdominal wall ECG, and it is also the easiest positional relationship to extract.

2. The fetal QRS complex is next to the maternal QRS complex:

Fetal QRS complexes are adjacent to maternal QRS complexes, as shown by b in Figure 7. It can be seen from Figure 7 that the fetal QRS complex components in this case are extracted, and the adjacent maternal QRS complex components are suppressed. The identification of fetal ECG QRS complex is affected. This positional relationship between the fetal QRS complex and the maternal QRS complex is a positional relationship that exists in a small proportion of abdominal wall ECG, and it is also a positional relationship that is difficult to extract.

3. Fetal QRS complexes completely overlap with maternal QRS complexes:

The fetal QRS complex completely overlaps with the maternal QRS complex, as shown by c in Figure 7. It can be seen from Figure 7 that the fetal QRS complex components are extracted in this case, and the overlapping maternal QRS complex components are suppressed. This positional relationship between the fetal QRS complex and the maternal QRS complex is the positional relationship that exists in a small proportion of the abdominal wall ECG, and it is also the most difficult positional relationship to extract.

From the analysis of the above results, it can be known that by the method for fetal electrocardiogram separation based on the smoothing window of the present invention, the fetal QRS complexes are far away from the maternal QRS complexes, the fetal QRS complexes are close to the maternal QRS complexes, and the fetal QRS complexes are completely separated from the maternal QRS complexes. The three situations overlap, all of which have very ideal extraction effects.

The fetal electrocardiographic separation method and device proposed by the present invention have the following beneficial effects:

1. Single lead: The algorithm only needs one maternal abdominal wall ECG signal to complete the separation of fetal signals based on self-adaptation. The traditional adaptive fetal ECG signal separation algorithm requires two signals, namely: one abdominal wall ECG signal (main input signal), one chest lead ECG signal (reference input signal), through the main input signal Perform smoothing between maternal QRS complexes, eliminate the fetal component of the signal segment between maternal QRS complexes, and correct the amplitude of the maternal QRS complexes, thereby estimating the maternal signal waveform of the abdominal wall. The signal is input into an adaptive filter and is not processed The synchronous abdominal wall ECG signal is used as the expected signal for adaptive filtering. Therefore, the present invention only needs one abdominal wall ECG signal, which greatly simplifies the lead system of the system.

2. Good separation effect: through smoothing and maternal QRS wave group amplitude correction processing, the maternal abdominal wall ECG signal is estimated. This method avoids the maternal ECG inhibition caused by the non-correlation of the maternal component in the chest lead and abdominal wall lead Incomplete impact, with better separation effect.

3. The design idea of the algorithm is simple and intuitive. For abnormal clinical data, it is easy to find the cause and add a correction module.

An embodiment of the present invention also provides a computer-readable program, wherein when the program is executed, the program causes the computer to execute the method for fetal electrocardiography separation described in the embodiment of the present invention.

An embodiment of the present invention also provides a storage medium storing a computer-readable program, wherein the computer-readable program enables a computer to execute the method for fetal electrocardiography separation described in the embodiment of the present invention.

The above devices and methods of the present invention can be implemented by hardware, or by combining hardware and software. The present invention relates to such a computer-readable program that, when the program is executed by a logic component, enables the logic component to realize the above-mentioned device or constituent component, or enables the logic component to realize the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as hard disk, magnetic disk, optical disk, DVD, flash memory and the like.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

In the present invention, specific examples have been applied to explain the principles and implementation methods of the present invention, and the descriptions of the above examples are only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to this The idea of the invention will have changes in the specific implementation and scope of application. To sum up, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A kind of 1. Fetal ECG separation method, it is characterised in that including：

   QRS complex detection is carried out to the maternal abdominal electrocardiosignal received, determines the original position and QRS complex of QRS complex Between original position；

   The signal segment the QRS complex is smoothed using smoothing windows；

   Linear averaging is carried out to the QRS complex, generates average template；

   Parent QRS complex in the average template is related to parent QRS complex corresponding to the current cardiac electrical cycle Property, to the parent QRS complex Mobile state amplitude correction in the average template, generation maternal abdominal electrocardio estimation signal；

   Using maternal abdominal electrocardio estimation signal as reference signal, believe the maternal abdominal electrocardiosignal as expectation Number, by adaptive algorithm, Fetal ECG signal is isolated from the maternal abdominal electrocardiosignal.
2. 2. Fetal ECG separation method according to claim 1, it is characterised in that using smoothing windows to the QRS complex Between signal segment be smoothed, including：

   Using regular length window, the signal segment the QRS complex is smoothed, the value root of the regular length window Determined according to signal sampling rate and Fetal ECG wave group length.
3. 3. Fetal ECG separation method according to claim 1, it is characterised in that linearly put down to the QRS complex , average template is generated, including：

   From the maternal abdominal electrocardiosignal, parent electrocardio R ripple crest locations are extracted；

   With the centered about point of the R ripples crest location, linear averaging is carried out to the QRS complex, generates the average template.
4. 4. Fetal ECG separation method according to claim 3, it is characterised in that according to the parent in the average template The correlation of QRS complex parent QRS complex corresponding with the currently cardiac electrical cycle, to the parent QRS in the average template Wave group Mobile state amplitude correction, generation maternal abdominal electrocardio estimation signal, including：

   It is related to the QRS complex fragment in the average template to calculate QRS complex fragment corresponding to the current cardiac electrical cycle Property, generate coefficient correlation；

   According to the coefficient correlation, QRS complex fragment is to the mother in the average template corresponding to the current cardiac electrical cycle Body QRS complex carries out dynamic amplitudes amendment, generation maternal abdominal electrocardio estimation signal.
5. 5. Fetal ECG separation method according to claim 1, it is characterised in that by adaptive algorithm, from the mother Fetal ECG signal is isolated in body stomach wall electrocardiosignal, including：

   The adaptive algorithm includes adaptive least mean square algorithm, most adaptive RLS algorithm, a young waiter in a wineshop or an inn Multiplicative lattice shape adaptive algorithm.
6. A kind of 6. Fetal ECG separator, it is characterised in that including：

   Wave group detection module, for carrying out QRS complex detection to the maternal abdominal electrocardiosignal received, determine QRS complex Original position between original position and QRS complex；

   Smoothing module, for being smoothed using smoothing windows the signal segment the QRS complex；

   Average treatment module, for carrying out linear averaging to the QRS complex, generate average template；

   Wave group correcting module, it is corresponding with the current cardiac electrical cycle for the parent QRS complex in the average template The correlation of parent QRS complex, to the parent QRS complex Mobile state amplitude correction in the average template, generate maternal abdominal Electrocardio estimates signal；

   Separation module, for the maternal abdominal electrocardio to be estimated into as reference signal, the maternal abdominal electrocardio is believed for signal Number desired signal is used as, by adaptive algorithm, Fetal ECG signal is isolated from the maternal abdominal electrocardiosignal.
7. 7. Fetal ECG separator according to claim 6, it is characterised in that the smoothing module is using smoothly Window is smoothed the signal segment the QRS complex, is specifically included：

   Using regular length window, the signal segment the QRS complex is smoothed, the value root of the regular length window Determined according to signal sampling rate and Fetal ECG wave group length.
8. 8. Fetal ECG separator according to claim 6, it is characterised in that the average treatment module is to described QRS complex carries out linear averaging, generates average template, including：

   From the maternal abdominal electrocardiosignal, parent electrocardio R ripple crest locations are extracted；

   With the centered about point of the R ripples crest location, linear averaging is carried out to the QRS complex, generates the average template.
9. 9. Fetal ECG separator according to claim 8, it is characterised in that the wave group correcting module is according to The correlation of parent QRS complex parent QRS complex corresponding with the currently cardiac electrical cycle in average template, to described average Parent QRS complex Mobile state amplitude correction in template, generation maternal abdominal electrocardio estimation signal, including：

   Coefficient correlation computing unit, for calculating QRS complex fragment and the average template corresponding to the current cardiac electrical cycle In QRS complex fragment correlation, generate coefficient correlation；

   Dynamic corrections unit, for according to the coefficient correlation, QRS complex fragment to be to institute corresponding to the current cardiac electrical cycle State the parent QRS complex in average template and carry out dynamic amplitudes amendment, generation maternal abdominal electrocardio estimation signal.
10. 10. Fetal ECG separator according to claim 6, it is characterised in that the separation module passes through adaptive Algorithm, Fetal ECG signal is isolated from the maternal abdominal electrocardiosignal, including：

    The adaptive algorithm includes adaptive least mean square algorithm, most adaptive RLS algorithm, a young waiter in a wineshop or an inn Multiplicative lattice shape adaptive algorithm.