WO2018058930A1

WO2018058930A1 - Method and device for extracting qrs complex

Info

Publication number: WO2018058930A1
Application number: PCT/CN2017/079422
Authority: WO
Inventors: 郑慧敏
Original assignee: 深圳竹信科技有限公司
Priority date: 2016-09-27
Filing date: 2017-04-05
Publication date: 2018-04-05
Also published as: CN106419899A

Abstract

Provided are a method and device for extracting a QRS complex. The method comprises the following steps: acquiring an original signal (S10); performing structural element transformation on the original signal (S20); performing a morphological operation on the signal having undergone the structural element transformation to obtain a characteristic signal of the original signal (S30); and extracting a QRS complex from the characteristic signal (S40). The method and device for extracting a QRS complex can effectively extract a QRS complex from an originally collected electrocardio signal, thereby reducing a computation load, and increasing extraction accuracy.

Description

QRS wave group extraction method and device

Technical field

The present invention relates to the field of medical signal processing technologies, and in particular, to a QRS complex extraction method and apparatus.

Background technique

Currently monitoring human health, the method of extracting the QRS complex in the ECG signal through the wearable device (reacting the electrical activation process of the left and right ventricles) is based on two algorithms. The first one is PT, Pan-Tompkins algorithm, which mainly uses ECG, Electrocardiograph ECG signals through bandpass filters, differentiators and square modules, based on the first-order differential Hilbert transform method. The threshold is variable and is not subject to human interference; the second is the FDD algorithm, which mainly uses an FIR bandpass filter whose coefficients are related to the order of the fraction. The above two extraction methods are based on the detection method of the first-order differential signal, and other subsequent algorithms are the improvement methods of the two. Considering that wearable devices cannot be overly complicated due to the design of the circuit and do not use expensive sensors, the accuracy of QRS complex detection is often reduced.

The above content is only used to assist in understanding the technical solutions of the present invention, and does not constitute an admission that the above is prior art.

Summary of the invention

The main object of the present invention is to provide a QRS complex extraction method and device, which aims to solve the problem that the wearable device in the prior art cannot be overly complicated due to the design of the circuit and does not use expensive sensors, and the QRS complex is often reduced. The problem of the accuracy of the test.

To achieve the above object, a QRS complex extraction method provided by the present invention includes the steps of:

Obtain the original signal;

Structurally elementizing the original signal;

Using the morphological operational structure elementized signal to obtain the characteristic signal of the original signal;

A QRS complex is extracted from the signature signal.

Preferably, the step of extracting a QRS complex from the feature signal comprises:

Determining the start and end points of the QRS complex from the signature signal;

Determining a maximum point from the characteristic signal as an R1 point;

Determining the minimum point from the starting point in the characteristic signal to the point of the R1 point is the Q1 point;

Determining the minimum point from the point R1 to the end point in the characteristic signal is the point S1;

The QRS complex is determined based on the starting point of the QRS complex, the R1 point, the Q1 point, the S1 point, and the end point.

Determining a minimum point from the characteristic signal as an R2 point;

Determining the maximum point from the starting point in the characteristic signal to the range of R2 is the Q2 point;

The maximum point is determined from the R2 point in the characteristic signal to the end point range as the S2 point;

The QRS complex is determined based on the start of the QRS complex, R2, Q2, S2, and endpoint.

Preferably, the method further includes:

Calculate the value of the positive point as -Q1+(R1-Q1)+(R1-S1)-S1;

Calculate the value of the negative point as -Q2+(Q2-Q1)+(R1-S1)-S1;

Determining whether the value of the positive point is greater than the value of the negative point;

When the value of the positive point is smaller than the value of the negative point, R-peak=R1, and the QRS group of the original signal under the positive point;

When the value of the positive point is greater than or equal to the value of the negative point, R-peak=R2, and the QRS complex of the original signal under the negative point; where peak is the peak of the QRS complex.

Preferably, after the step of extracting the QRS complex from the feature signal, the method further includes:

Get the way the structural elements are updated, update the structural elements, and structure the original signals according to the updated structural elements.

In addition, in order to achieve the above object, the present invention further provides a QRS wave group extracting apparatus, including:

Obtaining a module for acquiring an original signal;

a processing module, configured to structurally elementize the original signal;

a calculation module for obtaining a characteristic signal of the original signal by using a signal elementized by the morphological operation structure;

And an extraction module, configured to extract a QRS complex from the feature signal.

Preferably, the extraction module comprises:

a determining unit for determining a start point and an end point of the QRS complex from the feature signal; the determining unit is further configured to

Determining the maximum point from the characteristic signal as the R1 point; the determining unit is also used for

The minimum point is determined from the starting point in the characteristic signal to the point of the R1 point as the Q1 point; the determining unit is also used for

An extracting unit configured to determine a QRS complex based on a starting point of the QRS complex, an R1 point, a Q1 point, an S1 point, and an end point.

Preferably, the determining unit is further configured to determine a minimum point from the feature signal as the R2 point; the determining unit is further configured to:

The maximum point is determined from the starting point in the characteristic signal to the range of R2 to be the Q2 point; the determining unit is also used for

The extracting unit is further configured to determine a QRS complex according to a starting point of the QRS complex, an R2 point, a Q2 point, an S2 point, and an end point.

Preferably, the device further includes: a determining module,

The calculation module is further configured to calculate a value of a positive point of -Q1+(R1-Q1)+(R1-S1)-S1; the calculation module is further used for

Calculate the value of the negative point as -Q2+(Q2-Q1)+(R1-S1)-S1;

The determining module is configured to determine whether a value of the positive point is greater than a value of the negative point;

The extracting unit is further configured to: when the value of the positive pole point is smaller than the value of the negative pole point, R-peak=R1, and the QRS wave group of the original signal under the positive pole point; the extracting unit is further used for

Preferably, the device further includes: an update module, configured to acquire an update manner of the structural element, and update the structural element;

The processing module is further configured to structure the original signal according to the updated structural element.

The invention can use the morphological method to highlight the QRS complex and suppress the other parts of the ECG signal, and can extract the QRS complex from the original collected ECG signal, the calculation amount is small, and the extraction is improved. Accuracy.

DRAWINGS

1 is a schematic flow chart of a first embodiment of a QRS complex extraction method according to the present invention;

2 is a schematic flow chart of determining a location of a QRS complex in an embodiment of the present invention;

3 is a schematic flow chart of determining a location of a QRS group in another embodiment of the present invention;

4 is a schematic diagram of a QRS complex extracted in an embodiment of the present invention;

5 is a schematic flow chart of a second embodiment of a QRS complex extraction method according to the present invention;

6 is a schematic diagram of functional modules of a first embodiment of a QRS complex extraction device according to the present invention;

7 is a schematic diagram of a refinement function module of an embodiment of the extraction module of FIG. 6;

FIG. 8 is a schematic diagram of functional modules of a second embodiment of the QRS complex extraction device of the present invention.

The implementation, functional features, and advantages of the present invention will be further described in conjunction with the embodiments.

detailed description

It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a QRS wave group extraction method.

Referring to FIG. 1, FIG. 1 is a schematic flow chart of a first embodiment of a QRS complex extraction method according to the present invention.

In an embodiment, the QRS complex extraction method includes:

Step S10, acquiring an original signal;

In this embodiment, the original signal may be an ECG signal collected by an ECG electrocardiograph, or may be other physiological signals collected. The original signal is obtained from the electrocardiograph when the acquired signal needs to be processed. In a preferred embodiment of the present invention, after the original signal is acquired, the original signal may be subjected to low-pass filtering processing to remove significant power frequency interference, and the low-pass filtering processing may be selected or not processed according to the setting.

Step S20, the elementalizes the original signal;

After the original signal is acquired, the structural element is initialized and the structure elements the original signal. Initialization of structural elements: The structural elements consist of five reference points: start point, Q, R, S, and end point. The length of the structural element is 90ms, and the amplitude of the structural element is the difference between the maximum and minimum values in the initial 2s signal segment of the ECG signal. In a preferred embodiment of the present invention, the rule of window sliding is: if no candidate area is detected, the starting point of the next window locates the starting point of the current window plus the position of the half-second window; If the QRS complex has been detected, the start of the next window locates the end of the QRS complex plus a 20 ms position.

Step S30, obtaining a characteristic signal of the original signal by using a signal elementized by the morphological operation structure;

After the structural element is initialized, a morphological operation is performed, and the characteristic signal of the original signal is obtained by using the signal elementized by the morphological operation structure. Specifically, the morphological operation is performed according to the following formula 1, FS=f-(f ⁰ g+f·g)/2------Form 1; the basic operations of morphology include:

Top_Hat: That(f)=f-fοg.

Where g is a structural element, f is ECG signal data with a window length of 1 s, and FS is a characteristic signal. Through the above morphological operations, it is possible to highlight the QRS complex and suppress the effects of other parts of the ECG signal.

Step S40, extracting a QRS complex from the feature signal.

After the feature signal is obtained, the QRS complex is extracted from the feature signal. A non-zero portion of the feature signal FS is found, and then a portion in which the duration is longer than 70 ms is selected as a candidate portion of the QRS, and then the position of the QRS is determined from the 70 ms candidate portion in the following manner. Specifically, referring to FIG. 2, the manner of determining the location of the QRS may include:

Step S41, determining a start point and an end point of the QRS complex from the feature signal;

Step S42, determining a maximum point from the feature signal as the R1 point;

Step S43, determining that the minimum point is the Q1 point from the starting point in the characteristic signal to the range of the R1 point;

Step S44, determining that the minimum point is the S1 point from the R1 point to the end point range in the characteristic signal;

In step S45, the QRS complex is determined based on the start point of the QRS complex, the R1 point, the Q1 point, the S1 point, and the end point.

Referring to FIG. 3, the manner of determining the location of the QRS may further include:

Step S46, determining a minimum point from the feature signal as the R2 point;

Step S47, determining a maximum point from the starting point in the characteristic signal to the point of the R2 point as the Q2 point;

Step S48, determining a maximum point from the R2 point to the end point range in the characteristic signal is S2 point;

In step S49, the QRS complex is determined according to the start point of the QRS complex, the R2 point, the Q2 point, the S2 point, and the end point.

Further, after obtaining the starting point of the QRS complex, R1, Q1, S1, the end point, R2, Q2, and S2, the value of the positive point is calculated as -Q1+(R1-Q1)+(R1-S1)-S1; The value of the point is -Q2+(Q2-Q1)+(R1-S1)-S1; comparing the value of the positive point with the value of the negative point, determining whether the value of the positive point is greater than the value of the negative point, and the value at the positive point is smaller than the negative When the value of the point is R-peak=R1, the QRS complex of the original signal is the QRS complex determined under the positive point; when the value of the positive point is greater than or equal to the value of the negative point, R-peak=R2, the original signal The QRS complex is the QRS complex determined under the negative point. The position of the QRS point is determined according to the judgment result of the positive and negative points, the QRS wave group of the original signal is obtained, and the operation of extracting the QRS wave group is completed. Where peak is the value of the peak and R is the value of R of the QRS complex. Referring to Figure 4, there is a schematic diagram of the extracted QRS complex, in which the R points of the QRS complex are circled.

In this embodiment, the morphological method can be used to highlight the QRS complex and suppress the other parts of the ECG signal. The QRS complex can be extracted from the original collected ECG signal with a small amount of calculation and improved. The accuracy of the extraction.

Referring to FIG. 5, FIG. 5 is a schematic flowchart diagram of a second embodiment of a QRS complex extraction method according to the present invention. Based on the first embodiment of the QRS complex extraction method, the method further includes:

Step S50: Acquire an update manner of the structural element, update the structural element, and structure the original signal according to the updated structural element. The structural elements are updated based on the information of the extracted QRS complex.

Structural element update: The QRS endpoints are based on the starting point and are updated according to the following formula:

Newloc=(1-a)*Curr_loc+a*extractedloc;

Newam==(1-a)*Curr_am+a*extractedam; where Curr_loc and Curr_am refer to the position and amplitude relative to the starting point in the existing structural elements, respectively; extracted loc and extractedam refer to the extracted QRS wave, respectively. The position and amplitude of the group relative to the starting point; and a is updated according to the following formula: a = ab, NPA > OPA * 1.1; a = a + b, NPA < OPA * 0.9; a = 0.3 other conditions, the initial value of a 0.9, b is 0.05, NPA and OPA refer to the current and previous PA values, respectively, PA = ∑ _{ie candidate part} |FS(i)|. In this embodiment, by continuously updating the structural elements, the accuracy of obtaining the position of the QRS complex is further improved, and the accuracy of medical signal detection is improved.

The invention further provides a QRS complex extraction device.

Referring to FIG. 6, FIG. 6 is a schematic diagram of functional modules of a first embodiment of a QRS complex extraction apparatus according to the present invention.

In an embodiment, the QRS complex extraction device includes an acquisition module 10, a processing module 20, a calculation module 30, an extraction module 40, and a determination module 50.

The obtaining module 10 is configured to acquire an original signal;

The processing module 20 is configured to structurally elementize the original signal;

After the original signal is acquired, the structural element is initialized and the structure elements the original signal. Initialization of structural elements: The structural elements consist of five reference points: start point, Q, R, S, and end point. The length of the structural element is 90ms, and the amplitude of the structural element is the difference between the maximum and minimum values in the initial 2s signal segment of the ECG signal. In a preferred embodiment of the present invention, the rule of window sliding is: if no candidate area is detected, the starting point of the next window locates the starting point of the current window plus the position of the half second window; if the QRS wave group has been detected, Then the starting point of the next window locates the end of the QRS complex plus 20ms.

The calculating module 30 is configured to obtain a characteristic signal of the original signal by using a signal elementized by the morphological operation structure;

Top_Hat: That(f)=f-fοg.

Where g is a structural element, f is an ECG signal data with a window length of 1 s, and FS is a characteristic letter number. Through the above morphological operations, it is possible to highlight the QRS complex and suppress the effects of other parts of the ECG signal.

The extraction module 40 is configured to extract a QRS complex from the feature signal.

After the feature signal is obtained, the QRS complex is extracted from the feature signal. A non-zero portion of the feature signal FS is found, and then a portion in which the duration is longer than 70 ms is selected as a candidate portion of the QRS, and then the position of the QRS is determined from the 70 ms candidate portion in the following manner. Specifically, referring to FIG. 7, the extraction module 40 includes: a determining unit 41 and an extracting unit 42,

The determining unit 41 is configured to determine a start point and an end point of the QRS complex from the feature signal; the determining unit 41 is further configured to

The maximum value point is determined from the feature signal as the R1 point; the determining unit 41 is also used for

The minimum point is determined from the starting point in the characteristic signal to the point of the R1 point as the Q1 point; the determining unit 41 is also used for

The extracting unit 42 is configured to determine a QRS complex according to a starting point of the QRS complex, an R1 point, a Q1 point, an S1 point, and an end point.

Further, the determining unit 41 is further configured to determine a minimum point from the feature signal as the R2 point; the determining unit 41 is further configured to:

Determining the maximum point from the starting point in the characteristic signal to the point of the R2 point is the Q2 point; the determining unit 41 is also used for

The extracting unit 42 is further configured to determine a QRS complex according to a starting point of the QRS complex, an R2 point, a Q2 point, an S2 point, and an end point.

Further, after obtaining the starting point of the QRS complex, R1, Q1, S1, the end point, R2, Q2, and S2, the value of the positive point is calculated as -Q1+(R1-Q1)+(R1-S1)-S1; 30, is also used to calculate the value of the negative point is -Q2+(Q2-Q1)+(R1-S1)-S1; the determining module 50 is configured to compare the value of the positive point with the value of the negative point, and determine whether the value of the positive point is More than the value of the negative point, the calculation module 30 is further configured to use R-peak=R1 when the value of the positive point is smaller than the value of the negative point, and the QRS group of the original signal is the QRS group determined under the positive point; When the value is greater than or equal to the value of the negative point, R-peak=R2, and the QRS complex of the original signal is the QRS complex determined under the negative point. The position of the QRS point is determined according to the judgment result of the positive and negative points, and the QRS wave group of the original signal is obtained, and the extraction is completed. The operation of the QRS complex. Where peak is the value of the peak and R is the value of R of the QRS complex.

Referring to Figure 8, Figure 8 is a functional diagram of a second embodiment of the QRS complex extraction device of the present invention. The device also includes an update module 60,

The update module 60 is configured to acquire an update manner of a structural element, and update a structural element;

The processing module 20 is further configured to structure the original signal according to the updated structural element. The structural elements are updated based on the information of the extracted QRS complex.

Newloc=(1-a)*Curr_loc+a*extractedloc;

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformations made by the description of the present invention and the drawings are directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

A QRS complex extraction method, comprising the steps of:

Obtain the original signal;

Structurally elementizing the original signal;

Using the morphological operational structure elementized signal to obtain the characteristic signal of the original signal;

A QRS complex is extracted from the signature signal.
The QRS complex extraction method according to claim 1, wherein the step of extracting a QRS complex from the feature signal comprises:

Determining the start and end points of the QRS complex from the signature signal;

Determining a maximum point from the characteristic signal as an R1 point;

Determining the minimum point from the starting point in the characteristic signal to the point of the R1 point is the Q1 point;

Determining the minimum point from the point R1 to the end point in the characteristic signal is the point S1;

The QRS complex is determined based on the starting point of the QRS complex, the R1 point, the Q1 point, the S1 point, and the end point.
The QRS complex extraction method according to claim 2, wherein the step of extracting a QRS complex from the feature signal comprises:

Determining a minimum point from the characteristic signal as an R2 point;

Determining the maximum point from the starting point in the characteristic signal to the range of R2 is the Q2 point;

The maximum point is determined from the R2 point in the characteristic signal to the end point range as the S2 point;

The QRS complex is determined based on the start of the QRS complex, R2, Q2, S2, and endpoint.
The method of extracting a QRS complex according to claim 3, wherein the method further comprises:

Calculate the value of the positive point as -Q1+R1-Q1+(R1-S1)-S1;

Calculate the value of the negative point as -Q2+Q2-Q1+(R1-S1)-S1;

Determining whether the value of the positive point is greater than the value of the negative point;

When the value of the positive point is smaller than the value of the negative point, R-peak=R1, and the QRS group of the original signal under the positive point;

When the value of the positive point is greater than or equal to the value of the negative point, R-peak=R2, and the QRS complex of the original signal under the negative point; where peak is the peak of the QRS complex.
The QRS complex extraction method according to any one of claims 1 to 4, further comprising: after the step of extracting a QRS complex from the feature signal, further comprising:

Get the way the structural elements are updated, update the structural elements, and structure the original signals according to the updated structural elements.
A QRS wave group extracting device, comprising:

Obtaining a module for acquiring an original signal;

a processing module, configured to structurally elementize the original signal;

a calculation module for obtaining a characteristic signal of the original signal by using a signal elementized by the morphological operation structure;

And an extraction module, configured to extract a QRS complex from the feature signal.
The QRS complex extraction device according to claim 6, wherein the extraction module comprises:

a determining unit for determining a start point and an end point of the QRS complex from the feature signal; the determining unit is further configured to

Determining the maximum point from the characteristic signal as the R1 point; the determining unit is also used for

The minimum point is determined from the starting point in the characteristic signal to the point of the R1 point as the Q1 point; the determining unit is also used for

Determining the minimum point from the point R1 to the end point in the characteristic signal is the point S1;

An extracting unit configured to determine a QRS complex based on a starting point of the QRS complex, an R1 point, a Q1 point, an S1 point, and an end point.
The QRS complex extraction device according to claim 7, wherein the determining unit is further configured to determine a minimum point from the feature signal as the R2 point; the determining unit is further configured to:

The maximum point is determined from the starting point in the characteristic signal to the range of R2 to be the Q2 point; the determining unit is also used for

The maximum point is determined from the R2 point in the characteristic signal to the end point range as the S2 point;

The extracting unit is further configured to determine a QRS complex according to a starting point of the QRS complex, an R2 point, a Q2 point, an S2 point, and an end point.
The QRS complex extraction device according to claim 8, wherein the device further comprises: a determination module,

The calculation module is further configured to calculate a value of a positive point of -Q1+R1-Q1+R1-S1-S1; the calculation module is further used for

Calculate the value of the negative point as -Q2+Q2-Q1+R1-S1-S1;

The determining module is configured to determine whether a value of the positive point is greater than a value of the negative point;

The extracting unit is further configured to: when the value of the positive pole point is smaller than the value of the negative pole point, R-peak=R1, and the QRS wave group of the original signal under the positive pole point; the extracting unit is further used for

When the value of the positive point is greater than or equal to the value of the negative point, R-peak=R2, and the QRS complex of the original signal under the negative point; where peak is the peak of the QRS complex.
The QRS group extraction device according to any one of claims 6 to 9, wherein the device further comprises: an update module, configured to acquire an update manner of the structural element, and update the structural element;

The processing module is further configured to structure the original signal according to the updated structural element.