WO2018023697A1

WO2018023697A1 - Fetal electrocardiosignal separation method and device

Info

Publication number: WO2018023697A1
Application number: PCT/CN2016/093525
Authority: WO
Inventors: 张南南; 张金勇; 王磊; 李晖
Original assignee: 深圳先进技术研究院
Priority date: 2016-08-05
Filing date: 2016-08-05
Publication date: 2018-02-08

Abstract

Provided are a fetal electrocardiosignal separation method and a device. The fetal electrocardiosignal separation method comprises: detecting QRS complex on a received maternal abdominal wall electrocardiosignal to determine a starting position of the QRS complex and a starting position between QRS complexes (S101); smooth processing a signal segment between the QRS complexes using a smooth window (S102); linear averaging the QRS complex to generate an average template (S103); according to correlation between the maternal QRS complex in the average template and maternal QRS complex corresponding to the current electrocardiocycle, correcting the dynamic amplitude of the maternal QRS complex in the average template to generate a maternal abdominal wall electrocardio estimation signal (S104); taking the maternal abdominal wall electrocardio estimation signal as a reference signal, and the maternal abdominal wall electrocardiosignal as a desired signal, separating the fetal electrocardiosignal from the maternal abdominal wall electrocardiosignal by means of adaptive algorithm (S105). The fetal electrocardiosignal separation method and the device involve a simple fetal electrocardiosignal separation algorithm, in which only one stream of maternal abdominal wall electrocardiosignal is needed, such that single lead fetal electrocardiosignal separation can be achieved.

Description

Fetal ECG separation method and device

Technical field

The invention relates to the field of biomedical engineering technology, in particular to a method and a device for separating fetal ECG, in particular to a method and a device for separating fetal ECG based on a smooth window.

Background technique

This section is intended to provide a background or context for the embodiments of the invention set forth in the claims. The description herein is not admitted to be prior art as it is included in this section.

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

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

The above characteristics of the maternal abdominal ECG mixed signal create a relatively large obstacle 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 perinatal fetal life information. Is currently a widely studied 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: Matching filtering mainly uses statistical characteristics such as autocorrelation and cross-correlation of signals, but the situation to be faced in the actual environment is much more complicated than the assumption, and the fetal ECG signal obtained by matched filtering is used. Not very ideal.

2) Independent Component Analysis (ICA): This method requires multiple abdominal wall signals and cannot achieve single-lead fetal ECG signal extraction.

3) Wavelet threshold denoising fetal ECG signal extraction method filtering: Using wavelet transform combined with prior signal knowledge can obtain a good fetal ECG signal, but the extraction process is susceptible to amplitude and fetal ECG signal-like interference. It often leads to the occurrence of R wave miss detection and misdetection in the fetal ECG signal. It 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 of ECG signals according to the prediction error of the neural network. The PT segment signal is flat and can be predicted better. For the QRS complex, the difference between adjacent points is large, and the prediction error will be generated. Using this prediction error training network, the QRS complex is predicted, and the artificial neural network is predicted. With a multi-layer structure, it takes a long time to learn the training process by using the neural network, and the training sample is required to have a certain representativeness, which is difficult to realize in the actual abdominal wall ECG signal denoising application.

5) Adaptive filtering method: The adaptive filtering method includes training the adaptive filtering to eliminate the mother electrocardiogram using one or several reference channels. The existing adaptive filtering method removes the parent ECG component and requires a parent ECG reference channel that is morphologically similar to the submerged FECG signal, but the existing adaptive cancellation method requires an additional reference signal, that is, in addition to the abdominal wall electrode An additional maternal chest lead electrode is also required, and an adaptive method is used to eliminate the maternal component associated with the chest lead and the abdominal wall lead, which means that the maternal abdominal wall ECG signal and the maternal chest lead ECG signal need to be correlated, Only the better pair can be eliminated, and the conduction path of the maternal ECG signal is very complicated. In some cases, the maternal ECG signal in the abdominal wall is poorly correlated with the maternal ECG signal in the chest lead. Therefore, using the existing adaptive filtering algorithm to cancel the extraction of fetal ECG signals will have a large number of maternal ECG leakage, which will cause great interference to the correct identification of fetal ECG components. Moreover, the existing adaptive filtering cancellation cannot achieve single-lead fetal ECG signal extraction.

Summary of the invention

The invention provides a method and a device for separating fetal electrocardiogram, which are used to solve the problem that the existing fetal electrocardiographic separation algorithm is complicated in calculation and cannot realize single lead.

In order to achieve the above object, an embodiment of the present invention provides a method for separating a fetal electrocardiogram, comprising: performing QRS complex detection on a received abdominal wall electrocardiographic signal, determining a starting position of a QRS complex and a QRS complex; a start position; smoothing a signal segment between the QRS complexes by using a smoothing window; performing linear averaging on the QRS complex to generate an average template; and according to the parent QRS complex and the current center in the average template Electrical cycle correspondence Correlation of the parent QRS complex, correcting the dynamic amplitude of the parent QRS complex in the average template, generating a maternal abdominal wall ECG estimation signal; using the maternal abdominal wall ECG estimation signal as a reference signal, The maternal abdominal wall ECG signal is used as a desired signal, and the fetal ECG signal is separated from the maternal abdominal wall ECG signal by an adaptive algorithm.

In order to achieve the above object, an embodiment of the present invention further provides a fetal electrocardiographic separation device, comprising: a wave group detecting module, configured to perform QRS complex detection on a received parent abdominal wall electrocardiographic signal, and determine a start of a QRS complex; a starting position between the position and the QRS complex; a smoothing module for smoothing the signal segments between the QRS complexes using a smoothing window; and an averaging processing module for linearly averaging the QRS complexes, Generating an average template; a group correction module, configured to: according to the correlation between the parent QRS complex in the average template and the parent QRS complex corresponding to the current ECG cycle, the parent QRS complex in the average template The dynamic amplitude correction is performed to generate a maternal abdominal wall ECG estimation signal; the separation module is configured to use the maternal abdominal wall ECG estimation signal as a reference signal, and use the maternal abdominal wall ECG signal as a desired signal through an adaptive algorithm. The fetal ECG signal is separated from the maternal abdominal wall ECG signal.

The fetal electrocardiographic separation method and device proposed by the invention can eliminate the fetal component of the signal segment between the parent QRS groups by smoothing the signal between the parent QRS groups, and correct the amplitude of the parent QRS group to estimate the maternal abdominal wall electrocardiogram. Signal, this method avoids the incomplete influence of the maternal electrocardiogram caused by the uncorrelated maternal component in the chest lead and the abdominal wall lead, and has better separation effect; the realization of the present invention only needs one parent abdominal wall electrocardiogram signal Therefore, the single-lead fetal ECG signal separation can be completed; and the fetal separation algorithm design method of the present invention is simple and intuitive, and it is easy to find the cause and add the correction module for the abnormal clinical data.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings may also be obtained from those of ordinary skill in the art in light of the inventive work. In the drawing:

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

2 is a schematic block diagram of a mother window electrocardiographic estimation mechanism based on a smooth window according to an embodiment of the present invention;

3 is a flowchart of processing of a fetal electrocardiogram separation method according to an embodiment of the present invention;

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

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

6 is a waveform diagram of a 5-channel mother abdominal wall mixed ECG signal used in a specific embodiment of the present invention;

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

detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The illustrative embodiments of the present invention and the description thereof are intended to explain the present invention, but are not intended to limit the invention.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

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

The principles and spirit of the present invention are explained in detail below with reference to a few representative embodiments of the invention.

The invention provides an adaptive single-lead fetal electrocardiographic separation method and device based on smooth window, which uses a smoothing window to smooth the QRS inter-group signals in the maternal abdominal wall signal to smooth out the QRS inter-group signal segment. The fetal heartbeat beat point is extracted from the parent QRS complex in the abdominal wall ECG signal. The extracted N consecutive parent QRS complexes are linearly averaged by the parent R wave peak position, and the average QRS wave is generated. The group template intercepts the parent QRS complex in the input abdominal wall signal and the parent QRS complex in the average template, and uses the correlation coefficients of the two to copy and correct the parent QRS complex in the average template to obtain a dynamic matrix. Abdominal wall ECG estimation signal. Moreover, by adaptive autonomous learning, the maternal component in the abdominal wall signal is eliminated, and the scheme avoids the influence of the maternal component leakage caused by the maternal component of the chest lead and the non-correlation of the maternal component in the abdominal wall lead, and can realize the single Lead fetal ECG separation.

FIG. 1 is a schematic structural diagram of a system of a fetal electrocardiographic separation method according to an embodiment of the present invention. As shown in Figure 1, y(n) represents the acquired abdominal wall ECG signal, f(n) is the fetal ECG signal in the abdominal wall signal, and x(n) is the maternal ECG signal in the abdominal wall signal. The desired signal of the adaptive filter, x'(n) is the abdominal wall of the abdominal wall estimated by the abdominal wall ECG estimation mechanism, and the adaptive filter continuously "learns" and "tracks" the input signal to make the output signal

Maximum approximation of the abdominal wall ECG signal, thus making the error signal

Minimal,

This is the separated fetal ECG signal.

That is to say, based on the adaptive fetal ECG separation algorithm, two input signals are needed, namely: a parent abdominal wall ECG signal (main input signal), and an estimated abdominal wall ECG signal (reference input signal). Compared with the prior art, it is required to access a chest lead ECG signal as a reference input signal, and a single lead is realized.

The core of the invention is how to calculate the abdominal wall mother ECG estimation signal as a reference input signal to the adaptive algorithm. 2 is a schematic block diagram of the estimation mechanism of the abdominal wall mother body of the present invention. As shown in FIG. 2, the QRS complex signal and the QRS complex signal are separately processed, and the smoothing window based method is used to perform the signal between the parent QRS complexes. The smoothing process eliminates the fetal ECG beat point of the signal segment between the parent QRS complexes, and uses the average correlation method to correct the amplitude of the parent QRS complex to estimate the abdominal wall signal waveform.

FIG. 3 is a flowchart of processing of a fetal electrocardiographic separation method according to an embodiment of the present invention. As shown in Figure 3, it includes:

Step S101: performing QRS complex detection on the received abdominal wall ECG signal to determine a starting position between the QRS complex and a starting position between the QRS complexes;

Step S102: Smoothing a signal segment between the QRS groups by using a smoothing window;

Step S103, performing linear averaging on the QRS complex to generate an average template;

Step S104, according to the correlation between the parent QRS complex in the average template and the parent QRS complex corresponding to the current ECG cycle, correct the dynamic amplitude of the parent QRS complex in the average template to generate a matrix. Abdominal wall ECG estimation signal;

Step S105, using the mother abdominal wall ECG estimation signal as a reference signal, using the mother abdominal wall ECG signal as a desired signal, and separating the fetal ECG signal from the mother abdominal wall ECG signal by an adaptive algorithm.

In step S102, a 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 a signal sampling rate and a fetal ECG group length.

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

The QRS inter-group signal can be expressed as:

The maternal ECG amplitude is generally more than ten times the fetal ECG amplitude. After smoothing, the maternal QRS complex almost no longer contains the fetal QRS complex.

In step S103, linearly averaging the QRS complex to generate an average segment, comprising: extracting a parent ECG R wave peak position from the parent abdominal wall ECG signal; and using the R wave peak position as A central anchor point that linearly averages the QRS complex to generate the average template.

In the specific implementation, it is necessary to determine the position of the R wave peak in the mother abdominal wall ECG signal. The method is: performing a differential operation on the received abdominal wall ECG signal to obtain the slope curve of the abdominal wall ECG signal, and making the slope curve absolutely Sliding integral operation, recording the maximum value in each second, averaging the maximum value in the first 8 seconds, then the R wave determination threshold = coefficient ratio * the maximum value in the first 8 seconds, the difference value is greater than the R wave determination threshold The segment is subjected to a maximum search of the R wave peak position to determine the final R wave peak position point.

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

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

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

For specific implementation, the method is as follows:

First, calculating a correlation between the QRS complex segment corresponding to the current ECG cycle and the QRS complex segment in the average template, and generating a correlation coefficient, the specific steps are:

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

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

(3) Correlation coefficient r _{23 of the} calculated quantity segment:

Secondly, according to the correlation coefficient, the QRS complex corresponding to the current ECG cycle is used to perform dynamic amplitude correction on the parent QRS complex in the average template, and the expression used is as follows:

Since the average template generated by the average segment has the signal of the corresponding parent ECG waveform in the current abdominal wall electrocardiogram, and the fetal electrocardiogram waveform is substantially eliminated, the averaged parent ECG QRS cluster segment is obtained by the correlation coefficient. Dynamic amplitude correction can be used to estimate the maternal abdominal wall ECG signal to the maximum extent.

In step S105, the abdominal electrode obtains the main input signal, and the estimated mother abdominal wall ECG signal is used as an input signal, and the signal substantially does not contain the fetal ECG signal, and only contains the noise to be eliminated and the mother ECG signal; The electrical signal is the desired signal. The adaptive algorithm eliminates the correlation between the input signal and the desired signal, and preserves the uncorrelated portion. Therefore, the fetal ECG signal separation in the abdominal wall ECG signal can be maximized.

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, or the like.

It should be noted that although the operations of the method of the present invention are described in a particular order in the drawings, this is not required or implied that such 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 being combined into one step, and/or one step being broken down into multiple steps.

Having described the method of the exemplary embodiment of the present invention, next, a fetal electrocardiographic separation device according to an exemplary embodiment of the present invention will be described with reference to FIG. For the implementation of the device, reference may be made to the implementation of the above method, and the repeated description will not be repeated. The terms "module" and "unit" as used hereinafter may be software and/or hardware that implement a predetermined function. Although the modules described in the following embodiments are preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

4 is a schematic structural view of a fetal electrocardiographic separation device according to an embodiment of the present invention. As shown, it includes:

The wave group detecting module 101 is configured to perform QRS complex detection on the received parent abdominal wall electrocardiographic signal to determine a starting position between the QRS complex and the QRS complex; and a smoothing module 102 for utilizing smoothing The window smoothes the signal segments between the QRS groups; the averaging processing module 103 is configured to linearly average the QRS groups to generate an average template; the group correction module 104 is configured to be used according to the average template Correlation of the parent QRS complex with the parent QRS complex corresponding to the current ECG cycle, correcting the dynamic amplitude of the parent QRS complex in the average template, and generating a maternal abdominal wall ECG estimation signal; the separation module 105 The parental abdominal wall ECG estimation signal is used as a reference signal, and the mother abdominal wall ECG signal is used as a desired signal, and the fetal ECG signal is separated from the mother abdominal wall ECG signal by an adaptive algorithm.

Further, in the embodiment of the present invention, the smoothing processing module 102 performs smoothing on the signal segments between the QRS groups by using a smoothing window, and specifically includes: using a fixed length window, the signal between the QRS groups 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 ECG group.

Further, in the embodiment of the present invention, the averaging processing module 103 linearly averages the QRS complex to generate an average template, including: extracting a parent ECG R wave peak from the mother abdominal wall ECG signal Position: positioning the point of the R wave peak as a center, and linearly averaging the QRS group to generate the average template.

Further, in the embodiment of the present invention, the group correction module 104 compares the correlation between the parent QRS group in the average template and the parent QRS group corresponding to the current ECG cycle. In the parent QRS wave group, the dynamic amplitude correction is performed to generate the mother abdominal wall ECG estimation signal, as shown in FIG. 5, which specifically includes:

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

The dynamic correction unit 1042 is configured to perform dynamic amplitude correction on the parent QRS group in the average template by using the QRS complex corresponding to the current ECG cycle according to the correlation coefficient to generate a maternal abdominal wall ECG estimation signal. .

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

Moreover, although several elements of the fetal electrocardiographic separation device are mentioned in the detailed description above, such division is merely not mandatory. Indeed, in accordance with embodiments of the present invention, the features and functions of two or more units described above may be embodied in one unit. Also, the features and functions of one unit described above may be further divided into a plurality of units.

The effect of using the smooth window-based fetal electrocardiographic separation method of the present invention to achieve fetal ECG signal separation will be described below by way of a specific embodiment.

Referring to Figure 6, a waveform diagram of a mixed 5-channel maternal abdominal wall ECG signal used in this embodiment is shown. As shown in Figure 6, the data length of each signal is 2500 sample points, and the sampling rate is 250 Hz. It can be seen from Fig. 6 that the first road abdominal wall signal is the one signal with the largest telecommunication noise ratio of the fetal heart, that is, the signal of this road is the best, and the fourth and fifth abdominal wall ECG signals can not recognize the fetal heart with the naked eye. The position of the electric R peak, which is not used by the algorithm of the present invention, is not considered by the algorithm of the present invention.

In this embodiment, the second path signal is selected as the algorithm verification data, and the adaptive filtering adopts the adaptive recursive least squares algorithm, and the experimental result analysis is shown in FIG. 7.

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

The fetal QRS complex is far from the parent QRS complex, as labeled a in Figure 7, as can be seen from Figure 7, the tire in this case The QRS component is extracted and the left and right parent QRS components are suppressed. The positional relationship between the fetal QRS complex and the parent QRS complex is the most common positional relationship in the abdominal wall ECG and the most easily extracted positional relationship.

2. The fetal QRS complex is adjacent to the parent QRS complex:

The fetal QRS complex is adjacent to the parent QRS complex, as indicated by the mark b in Fig. 7. It can be seen from Fig. 7 that the fetal QRS component is extracted in this case, and the adjacent QRS component is suppressed. The identification of fetal ECG QRS complexes has an impact. The positional relationship between the fetal QRS complex and the parent QRS complex is a small number of positional relationships in the abdominal wall ECG, and it is also difficult to extract the positional relationship.

3. The fetal QRS complex and the parent QRS complex are completely coincident:

The fetal QRS complex is completely coincident with the parent QRS complex, as indicated by the reference c in Fig. 7, and it can be seen from Fig. 7 that the fetal QRS component is extracted in this case, and the coincident parent QRS component is suppressed. The positional relationship between the fetal QRS complex and the parent QRS complex is a small number of positional relationships in the abdominal wall ECG and the most difficult to extract positional relationship.

It can be seen from the above result analysis that, by the smooth window-based fetal electrocardiographic separation method of the present invention, the fetal QRS complex is far from the parent QRS complex, the fetal QRS complex is adjacent to the parent QRS complex, the fetal QRS complex, and the parent QRS complex are completely Coincident three cases, have a very good extraction effect.

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

1. Single lead: The algorithm only needs one way of the abdominal wall ECG signal to complete the adaptive fetal signal separation. Traditionally, based on adaptive fetal ECG signal separation algorithm, two signals are needed, namely: one abdominal wall ECG signal (main input signal), one chest lead ECG signal (reference input signal), through the main input signal The maternal QRS group smoothing process is performed to eliminate the fetal component of the signal segment between the parent QRS groups, and the amplitude correction of the parent QRS group is performed to estimate the abdominal wall signal waveform, and the signal is input into the adaptive filter while being unprocessed. The synchronized abdominal wall ECG signal serves as the desired signal for adaptive filtering. Therefore, the present invention requires only one abdominal wall ECG signal, which greatly simplifies the system lead system.

2, the separation effect is good: through the smooth and maternal QRS wave group amplitude correction processing, estimate the maternal abdominal wall ECG signal, this method avoids maternal electrocardiogram inhibition caused by the uncorrelated maternal component in the chest lead and abdominal wall lead Incomplete effects have a better separation effect.

3, the algorithm design idea is simple and intuitive, for abnormal clinical data, easy to find the cause and add correction module.

The embodiment of the present invention further provides a computer readable program, wherein when the program is executed, the program causes a computer to execute the fetal electrocardiographic separation method according to the embodiment of the present invention.

The embodiment of the present invention further provides a storage medium storing a computer readable program, wherein the computer readable program causes the computer to execute the fetal electrocardiographic separation method according to the embodiment of the present invention.

The above apparatus and method of the present invention may be implemented by hardware or by hardware in combination with software. The present invention relates to a computer readable program that, when executed by a logic component, enables the logic component to implement the apparatus or components described above, or to cause the logic component to implement the various methods described above Or steps. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, or the like.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can 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.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

The principles and embodiments of the present invention have been described in connection with the specific embodiments of the present invention. The description of the above embodiments is only for the understanding of the method of the present invention and its core ideas; In the above, the description of the present invention is not limited to the scope of the present invention.

Claims

A method for separating fetal ECG, characterized in that it comprises:

Performing QRS complex detection on the received abdominal wall ECG signal to determine the starting position of the QRS complex and the starting position between the QRS complexes;

Smoothing the signal segments between the QRS complexes using a smoothing window;

Performing a linear average on the QRS complex to generate an average template;

And according to the correlation between the parent QRS complex in the average template and the parent QRS complex corresponding to the current ECG cycle, correcting the dynamic amplitude of the parent QRS complex in the average template to generate the maternal abdominal wall electrocardiogram Estimated signal;

The maternal abdominal wall ECG estimation signal is used as a reference signal, and the maternal abdominal wall electrocardiographic signal is used as a desired signal, and the fetal ECG signal is separated from the maternal abdominal wall electrocardiographic signal by an adaptive algorithm.
The fetal electrocardiographic separation method according to claim 1, wherein the smoothing of the signal segments between the QRS complexes by using a smoothing window comprises:

The signal segment between the QRS complexes is smoothed by a fixed length window, and the value of the fixed length window is determined according to a signal sampling rate and a fetal ECG group length.
The fetal electrocardiographic separation method according to claim 1, wherein linearly averaging the QRS complex to generate an average template comprises:

Extracting the peak position of the parent ECG R wave from the maternal abdominal wall electrocardiographic signal;

The QRS complex is linearly averaged with the R wave peak position as a central positioning point to generate the average template.
The fetal electrocardiographic separation method according to claim 3, wherein said average template is based on a correlation between a parent QRS complex in said average template and a parent QRS complex corresponding to said current ECG cycle In the parent QRS complex, the dynamic amplitude correction is performed to generate the maternal abdominal wall ECG estimation signal, including:

Calculating a correlation between the QRS complex segment corresponding to the current ECG cycle and the QRS complex segment in the average template to generate a correlation coefficient;

And according to the correlation coefficient, the QRS complex corresponding to the current ECG cycle is used to perform dynamic amplitude correction on the parent QRS complex in the average template to generate a maternal abdominal wall ECG estimation signal.
The fetal electrocardiographic separation method according to claim 1, wherein the fetal ECG signal is separated from the maternal abdominal wall electrocardiographic signal by an adaptive algorithm, including:

The adaptive algorithm includes an adaptive least mean square algorithm, an adaptive recursive least squares algorithm, and a least squares lattice adaptive algorithm.
A fetal electrocardiographic separation device, comprising:

The wave group detecting module is configured to perform QRS complex detection on the received abdominal wall ECG signal to determine the starting position of the QRS group and the starting position between the QRS groups;

a smoothing processing module, configured to smooth a signal segment between the QRS groups by using a smoothing window;

An averaging processing module, configured to perform linear averaging on the QRS complex to generate an average template;

a group correction module, configured to: according to a correlation between a parent QRS group in the average template and a parent QRS group corresponding to the current ECG period, a dynamic amplitude of a parent QRS group in the average template Correction, generating a maternal abdominal wall ECG estimation signal;

a separation module, configured to use the mother abdominal wall ECG estimation signal as a reference signal, and use the mother abdominal wall ECG signal as a desired signal to separate a fetal ECG signal from the mother abdominal wall ECG signal through an adaptive algorithm .
The fetal electrocardiographic apparatus according to claim 6, wherein the smoothing processing module smoothes the signal segments between the QRS complexes by using a smoothing window, and specifically includes:

The signal segment between the QRS complexes is smoothed by a fixed length window, and the value of the fixed length window is determined according to a signal sampling rate and a fetal ECG group length.
The fetal electrocardiographic apparatus according to claim 6, wherein the averaging processing module linearly averages the QRS complex to generate an average template, including:

Extracting the peak position of the parent ECG R wave from the maternal abdominal wall electrocardiographic signal;

The QRS complex is linearly averaged with the R wave peak position as a central positioning point to generate the average template.
The fetal electrocardiographic apparatus according to claim 8, wherein said group correction module is based on a correlation between a parent QRS complex in said average template and a parent QRS complex corresponding to said current ECG cycle And correcting the dynamic amplitude of the parent QRS wave group in the average template to generate a maternal abdominal wall ECG estimation signal, including:

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

The dynamic correction unit is configured to perform dynamic amplitude correction on the parent QRS group in the average template by using the QRS complex corresponding to the current ECG cycle according to the correlation coefficient to generate a maternal abdominal wall ECG estimation signal.
The fetal electrocardiographic apparatus according to claim 6, wherein the separation module separates the fetal electrocardiographic signal from the maternal abdominal wall electrocardiographic signal by an adaptive algorithm, including:

The adaptive algorithm includes an adaptive least mean square algorithm, an adaptive recursive least squares algorithm, and a least squares lattice adaptive algorithm.