CN103800003A - ECG detection method and detector - Google Patents

Abstract

The invention provides an electrocardiogram detection method and a detection instrument. An electrocardiographic detection method includes acquiring electrocardiographic signals of a subject. The characteristic parameters of the acquired ECG signal are extracted. The extracted characteristic parameters are matched with the standard ECG signal parameters in the preset templates in the template library. It is judged whether the extracted feature parameters are successfully matched with the standard ECG signal parameters in the preset template in the template library. If yes, start the reliability calculation; if not, update the acquired ECG signal as a new preset template to the template library. It avoids the problem that the traditional ECG detector cannot judge the credibility of the ECG signal, which makes the doctor unable to make an effective diagnosis and treatment judgment, and even misjudgments in severe cases.

Description

A kind of electrocardiogram detection method and detection instrument

technical field

The invention relates to the field of medical electronic equipment, and in particular to an electrocardiogram detection method and a detection instrument.

Background technique

Arrhythmias are associated with most cardiovascular diseases. For the diagnosis of arrhythmia, the common way in the hospital is to use an electrocardiogram machine or a holter system.

The electrocardiogram machine can accurately record the ECG waveform in a short period of time, but due to the uncertainty of heart disease, this method obviously has great limitations, and it is likely that it cannot measure abnormal waveforms. The holter system can continuously record the dynamic ECG information when the patient wears the handset for a long time (about 24 hours), and then transmit it through the network or the patient directly takes it to the hospital host system to complete the analysis. However, the real-time performance of this method is poor, and the sub-machine part can only record or transmit without analysis function, so it has no practical significance for patients; and the powerful host analysis system is expensive, and it is difficult for ordinary people to afford it.

At present, there are not many products with ECG detection and analysis functions for individual patients. They allow patients to conveniently monitor ECG waveforms and store ECG data, which meets the needs of personal ECG monitoring. But there are also some weak points in the above products. For the convenience of measurement, the above electrocardiograph does not use the traditional method of sticking ECG electrodes or using ECG clips; instead, the measurer actively puts the skin of the hands or chest and abdomen close to the metal electrodes on the surface of the electrocardiograph. In actual measurement, if the hands hold the metal electrodes too tightly or the skin of the chest and abdomen is too tightly attached to the metal electrodes, the corresponding muscles will enter a state of tension, which will generate great myoelectric interference and superimpose it on the ECG waveform. Conversely, if the grip is looser or the skin contact electrode is looser, the contact resistance becomes larger. In addition, the shaking of the human body will also bring great interference, and if there is too much interference, it is very likely that there will be errors in ECG detection and misjudgment of arrhythmia.

Doctors or experienced users can adjust the degree of contact between the human body and the metal electrodes according to the quality of the ECG waveform on the display screen of the electrocardiograph when measuring. Therefore, the detection effect of these users is generally relatively good. However, the vast majority of users do not understand the specific meanings of various actual ECG waveforms, so they cannot adjust the relevant posture and pressing force. It is very likely that there will be a large degree of interference during the measurement, resulting in errors in ECG detection and Misdiagnosis of arrhythmia. In addition, sometimes even if the interference range is not very large, it will still seriously affect the detection and judgment of the ECG because it just appears near the feature point of the ECG detection, giving wrong results. The waveform displayed on the LCD screen is used to judge whether the signal is good or bad.

Although the electrocardiometer can also store the ECG data in the measurement process and turn to the doctor for help. However, if the saved ECG data is greatly disturbed or the vicinity of the ECG feature points is affected although the interference is not large, doctors will also be unable to make effective judgments based on these "contaminated" signals , thereby losing the basis for diagnosis. Automatic ECG analysis and detection may cause errors and false positives, and it is not known whether the stored data can be used for doctor diagnosis, which greatly reduces the practical value of this type of product.

Contents of the invention

In order to overcome the problem that the existing electrocardiogram detector cannot judge the quality of the detected electrocardiogram signal, the present invention provides an electrocardiogram detection method and a detector. The electrocardiogram detection method and detector, while completing the normal electrocardiogram measurement function, also simultaneously measure the size of the skin contact impedance in the whole process, and according to the quality of the electrocardiogram signal in the measurement process, as well as the electrocardiogram detection and judgment The degree of influence of the interference is detected, and a prompt of the credibility of the ECG test result, that is, the reliability, is given. The user can judge whether the ECG test result or the ECG monitoring data stored in this period of time is credible according to the degree of reliability, and whether it can be provided to the doctor as a basis for diagnosis and treatment. Therefore, compared with the existing electrocardiographic products, the present invention can avoid some shortcomings of the existing products, such as frequent diagnosis errors due to large interference, but the user does not know, thereby reducing the occurrence of confidence in the instrument. Based on this, it can also be judged whether the preserved ECG data can be provided to the doctor as a basis for diagnosis and treatment. If not, wait until the ECG data with high reliability value.

In order to achieve the above object, the present invention provides an electrocardiographic detection method, comprising: acquiring the electrocardiographic signal of a subject. The characteristic parameters of the acquired ECG signal are extracted. The extracted characteristic parameters are matched with the standard ECG signal parameters in the preset templates in the template library. It is judged whether the extracted feature parameters are successfully matched with the standard ECG signal parameters in the preset template in the template library. If yes, start the reliability calculation; if not, update the acquired ECG signal as a new preset template to the template library.

The above-mentioned electrocardiographic detection method, wherein, the step of matching the extracted characteristic parameters with the standard electrocardiographic signal parameters in the preset template in the template library includes: calculating the extracted characteristic parameters and the standard electrocardiographic signal parameters in the preset template For the correlation coefficient between parameters, the template corresponding to the maximum correlation coefficient and exceeding the set threshold is used as the matching template.

The aforementioned ECG detection method, wherein the template library includes a current template library and a substitute template library, and the extracted feature parameters are first matched with preset templates in the current template library, and if the matched template is not in the current template library, then Matches preset templates in the alternate template library.

The above-mentioned electrocardiographic detection method, wherein the electrocardiographic detection method further includes obtaining the contact impedance between the electrocardiographic measurement electrode and the body surface of the subject. When the detection result indicates that the obtained contact impedance is stable and within the expected contact impedance threshold, the extracted feature parameters are matched with the standard ECG signal parameters in the preset template in the template library.

Corresponding to the above ECG detection method, the present invention also provides an ECG detector, comprising at least two ECG measurement electrodes, a characteristic parameter extractor, a template memory, a controller and a data processor. Wherein, the electrocardiogram measuring electrodes are used to acquire electrocardiogram signals of the subject. The characteristic parameter extractor is connected to the electrocardiographic measuring electrodes by telecommunication, and is used for extracting the characteristic parameters of the obtained electrocardiographic signal. The template memory is used for storing preset templates, and the preset templates are used for storing standard ECG signal parameters. The controller is electrically connected to the characteristic parameter extractor and the template memory, matches the extracted characteristic parameters with the standard ECG signal parameters in the preset template in the template memory, and judges whether the matching is successful, and if so, sends a control signal to the data processing If not, send a control signal to the template memory, and update the acquired ECG signal as a new preset template into the template memory. The data processor is electrically connected to the controller, receives the control signal sent by the controller, and performs reliability calculation.

The aforementioned ECG detector, wherein the ECG detector further includes an impedance monitor electrically connected to the controller for obtaining the contact impedance between the ECG measuring electrode and the body surface of the subject.

The above-mentioned electrocardiogram detector, wherein the impedance monitor includes impedance measuring electrodes equal in number to the electrocardiogram measuring electrodes and an impedance control unit.

The aforementioned ECG detector, wherein the impedance measuring electrode is arranged close to the ECG measuring electrode, so that the detection site of the subject can contact the ECG measuring electrode and the impedance measuring electrode at the same time.

The aforementioned electrocardiogram detector, wherein the impedance control unit is a comparator circuit, one input end of the comparator is electrically connected to the impedance measuring electrode, and the other input end is electrically connected to a threshold value setter composed of a variable resistor, and the output The terminal is electrically connected to the controller.

The aforementioned electrocardiograph, wherein the template memory includes a current template memory for storing the current template and a substitute template memory for storing the substitute template.

In summary, compared with the prior art, the present invention has the following advantages: the ECG detection method and detector provided by the present invention, by extracting the characteristic parameters of the ECG signal obtained, and combining it with the preset parameters in the template library Set the standard ECG signal parameters in the template for matching, find the matching template, and use the matching template as a reference to calculate the reliability of the detected ECG signal. The user can judge whether the ECG test result can be provided to the doctor as a basis for diagnosis and treatment according to the degree of reliability. It avoids the problem that the traditional ECG detector cannot judge the credibility of the ECG signal, which makes the doctor unable to make an effective diagnosis and treatment judgment, and even misjudgments in severe cases. Further, when no matching template can be found in the template library, the controller updates the detected electrocardiographic signal as a new preset template into the template library, so as to realize adaptive updating of templates.

In addition, in the process of template matching, the correlation coefficient method is used as a measure of the similarity of template matching. The set threshold is used as the matching benchmark, and the template corresponding to the maximum correlation coefficient exceeding the set threshold is used as the matching template to improve the matching accuracy and provide an accurate reference benchmark for the calculation of the credibility value. By setting the template library to include the current template library and the substitute template library, due to the huge number of templates in the template library, a large amount of computing time will be consumed during template matching. Therefore, matching with commonly used templates in the current template library is preferred, greatly reducing the time taken for template matching, improving detection efficiency, and improving product performance, which can better meet user needs. Further, the measurement of contact impedance is added, and whether the contact impedance is stable and whether it is within the expected value is used to characterize the good degree of contact between the electrocardiographic measurement electrode and the subject's skin in this test, avoiding the contact between the electrocardiographic measurement electrode and the subject. Low-reliability detection caused by bad contact between body surfaces, reduce factors affecting low reliability, and improve detection reliability. The impedance measurement electrode is arranged close to the electrocardiogram measurement electrode, and the detection part of the subject can be in contact with the electrocardiogram measurement electrode and the impedance measurement electrode at the same time, thereby improving the measurement accuracy of the impedance measurement electrode.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are described below in detail with accompanying drawings.

Description of drawings

FIG. 1 is a flow chart of the ECG detection method provided by Embodiment 1 of the present invention.

FIG. 2 is a schematic block diagram of the circuit of the ECG detector provided by Embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of the ECG detector provided by Embodiment 1 of the present invention.

FIG. 4 is a schematic diagram of the usage mode of the ECG detector provided by the present invention.

FIG. 5 is a schematic block diagram of the circuit of the ECG detector provided by Embodiment 2 of the present invention.

FIG. 6 is a circuit diagram of a compensation module provided by Embodiment 2 of the present invention.

Detailed ways

Embodiment one

FIG. 1 is a flow chart of the ECG detection method provided by Embodiment 1 of the present invention. FIG. 2 is a schematic block diagram of the circuit of the ECG detector provided by Embodiment 1 of the present invention. FIG. 3 is a schematic diagram of the ECG detector provided by Embodiment 1 of the present invention. FIG. 4 is a schematic diagram of the usage mode of the ECG detector provided by the present invention. Please refer to Figure 1 to Figure 4 together.

The basic process of the electrocardiographic detection method is: acquiring the electrocardiographic signal of the subject (such as step S101 ), and extracting the characteristic parameters of the acquired electrocardiographic signal (such as step S102 ). Matching the extracted characteristic parameters with the standard ECG signal parameters in the preset templates in the template library (such as step S103 ). Then, judge whether the matching is successful, if so, use the matching template as a reference, and calculate the reliability of the detected ECG signal (such as steps S104-S105); if not, use the acquired ECG signal as a new preset template Update to the template library (such as step S106). After the template library is updated, a prompt message is output to remind the user to retest (eg step S111 ). until the confidence value is calculated. After the reliability calculation is completed, the output and display of the reliability value and related ECG detection information is performed (such as step S110 ). The ECG detection method in this embodiment will be further described below in conjunction with FIG. 1 .

The method starts with step S101, which is used to obtain the electrocardiographic signal of the subject. The acquisition referred to here is by setting at least two electrocardiographic measurement electrodes 1 in contact with the user's body surface, and the two electrocardiographic measurement electrodes 1 form a differential input to eliminate common-mode interference and improve detection accuracy.

Because a normal ECG signal is mainly composed of P wave, QRS wave and T wave. Correspondingly, there are ECG feature points such as P, Q, R, S, and T. In step S102, feature parameter extractor 2 is used to extract feature parameters at feature points such as P, Q, R, and S.

Step S103, this step is used to select a matching template. How to realize the selection of the matching template is by calculating the correlation coefficient between the extracted feature parameters and the standard ECG signal parameters in the preset template in the template library, and comparing the correlation coefficient with the set threshold, and the correlation coefficient is the largest and the The template corresponding to exceeding the set threshold is a matching template. Specifically, for example, T represents the signal value at the R wave point in the QRS wave in the detected electrocardiographic signal, and S is the parameter at the corresponding R wave point in a certain preset template in the template library. The correlation coefficient between is:

$\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Cov</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; )</span>}{\sqrt{\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\text{<span class="notranslate"> T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; )</span>}}$

Among them, Cov(T,S) is the covariance of signals T and S, and D(T), D(S) are the variances of T and S respectively. By comparing R(T, S) with the set threshold, in this embodiment, the set threshold is 0.9. After calculation and comparison, the template corresponding to the maximum value of the correlation coefficient greater than 0.9 is selected as the matching template of the acquired ECG signal. By selecting the template corresponding to the largest correlation coefficient as the matching template, the matching accuracy is greatly increased, and an accurate benchmark is provided for the calculation of the credibility.

Step S104 is to judge whether there is R(T, S) greater than the set threshold of 0.9, and if so, it is considered that the template matching is successful. Step S105 is executed, and the credibility value of the acquired ECG signal is calculated using the matching template as a reference. The credibility calculation can be realized by methods such as probability weighted estimation method, mean value estimation method, variance estimation method, and mean value inspection method. In this embodiment, the mean value estimation method is used to calculate the reliability value. First, the obtained ECG signal value is subtracted from the parameters in the matching template to obtain a difference signal, and the difference signal is estimated by the mean value to obtain The confidence value for this measurement. The confidence value is displayed as a percentage. However, the present invention does not impose any limitation on the calculation method and display method of the reliability. In other embodiments, the reliability calculation method may be any one or a combination of several of the above methods or other statistical calculation methods. After the reliability calculation is completed, step 110 is executed to output and display the calculated reliability value and related ECG detection information. However, when step S104 judges that the matching is unsuccessful, step S106 is executed to update the obtained ECG signal into the template library as a new preset template, so as to realize adaptive updating of the template library, further expand the template library, and improve detection efficiency. precision. Step S111 is executed after the template library is updated, and a prompt message is output to remind the user that re-testing is required.

However, with the adaptive update of the template library, the number of templates in the template library will continue to increase. When performing template matching in step S103, the ECG detector needs to spend a lot of time to calculate the correlation coefficient between the extracted feature parameters and the corresponding standard ECG signal parameters in the preset template, the detection efficiency is low, and the user is inconvenient to use . To avoid the above problems, set the template library to include the current template library and the alternate template library. Due to the universal similarity of ECG signals, 20 commonly used templates are pre-stored in the current template library. The extracted feature parameters are first matched with the corresponding standard ECG signal parameters in the common templates in the current template library, and then matched with the corresponding parameters in the preset templates in the substitute template library if the matching is unsuccessful. The template matching is realized by adopting the two-level matching method, which greatly increases the matching efficiency, improves the detection efficiency of the electrocardiogram detector, and improves the detection performance of the electrocardiogram detector.

Further, in order to improve detection accuracy, reduce factors affecting reliability. The ECG detection method also includes obtaining the contact impedance between the ECG measurement electrode and the body surface of the subject (step S107 ), and determining whether the contact impedance is stable and within the expected contact impedance threshold (step S108 ). When the detection result indicates that the obtained contact impedance is stable and within the expected contact impedance threshold, step S103 is performed to match the extracted feature parameters with the standard ECG signal parameters in the preset template in the template library. Otherwise, the subject is reminded to check the contact state between the ECG measuring electrode 1 and the body surface of the subject until the detected contact impedance meets the requirements (step S109 ). Steps S107-S109 are added before step S103, avoiding the detection with low reliability caused by the bad contact between the ECG measurement electrodes and the body surface of the subject, reducing the factors affecting the low reliability and improving the detection efficiency. credibility.

Based on the above, the following describes an electrocardiogram detector provided by the present invention.

An electrocardiogram detector includes at least two electrocardiogram measuring electrodes 1 , a characteristic parameter extractor 2 , a template memory 3 , a data processor 5 and a controller 4 . Wherein, the electrocardiogram measuring electrode 1 is used to obtain the electrocardiogram signal of the subject. The feature parameter extractor 2 is used to extract the feature parameters of the acquired ECG signal. The template memory 3 is used for storing preset templates, and the preset templates are used for storing standard ECG signal parameters. The controller 4 is electrically connected to the characteristic parameter extractor 2 and the template memory 3 respectively, matches the extracted characteristic parameters with the standard ECG signal parameters in the preset template in the template memory 3, and judges whether the matching is successful. If yes, send the control signal to the data processor 5; if not, send the control signal to the template memory 3, and update the acquired ECG signal into the template memory 3 as a new preset template. The data processor 5 is electrically connected to the controller 4, receives the control signal sent by the controller 4, and performs reliability calculation.

An electrocardiogram detector includes a feature parameter extractor 2 electrically connected to an electrocardiogram measuring electrode 1 . Because a normal ECG signal is mainly composed of P wave, QRS wave and T wave. The feature parameter extractor 2 is used to extract feature parameters at feature points such as P, Q, R, and S. In this embodiment, the characteristic parameter extractor 2 is composed of an analog-to-digital converter and a data collector. The analog-to-digital converter can convert the analog signal detected by the electrocardiographic measuring electrode 1 into a digital signal, and the data collector extracts required characteristic parameters from the converted digital signal. However, the present invention does not make any limitation thereto.

An electrocardiogram detector includes a template memory 3 . Wherein, the template memory 3 includes a current template memory 31 for storing a current template and a substitute template memory 32 for storing a substitute template. In this embodiment, a FLASH memory that can store data for a long time is used as the template memory 3 to ensure that the templates in the template memory 3 can be stored for a long time. In addition, the template memory 3 is not only used to store preset templates, but also used to store detected ECG waveforms and detected data, which is convenient for users to view later.

An electrocardiogram detector includes a controller 4 and a data processor 5 . The controller 4 matches the extracted characteristic parameters with the standard ECG signal parameters in the preset template in the template memory 3, and judges whether the matching is successful. The specific matching method may be to calculate the correlation coefficient between the extracted feature parameters and the standard ECG signal parameters in the preset template, and select the template with the largest correlation coefficient and greater than the set threshold as the matching template. If the matching is successful, the controller 4 sends a control signal to the data processor 5, and the data processor 5 performs reliability calculation. After the calculation is completed, a feedback signal is sent to the controller 4, and the controller 4 sends a control signal to the output device 6 to output the reliability value and related ECG detection information. In this embodiment, the data processor 5 and the controller 4 are integrated into the same chip, and the chip model is TMS320F2802. However, the present invention does not make any limitation thereto. In other embodiments, the data processor 5 and the controller 4 can be set separately. And in this embodiment, the reliability value is displayed in the form of percentage.

Further, in order to avoid low-reliability detection caused by poor contact between the electrocardiographic measurement electrode 1 and the body surface of the subject, reduce factors affecting low reliability and improve detection reliability. An electrocardiogram detector also includes an impedance monitor 7 , the impedance monitor 7 has impedance measuring electrodes 71 equal in number to the electrocardiogram measuring electrodes 1 , and an impedance control unit 72 . In this embodiment, there are two ECG measuring electrodes 1 , and there are also two corresponding impedance measuring electrodes 71 . However, the present invention does not make any limitation thereto. The impedance control unit 72 is a comparator, one input end of the comparator is electrically connected to the impedance measuring electrode 71, and the other input end is electrically connected to a threshold value setter composed of a variable resistor for setting the expected threshold value of the contact impedance, and The output end of the comparator is electrically connected to the controller 4 . In actual use, since the contact impedance generated by the contact between the body surface and the ECG measuring electrode 1 of different subjects is different, the subject can obtain the contact impedance between the body surface and the ECG measurement electrode 1 through multiple measurements in advance. Measure the contact impedance generated by the contact of electrode 1, and input this value into the threshold value setter as a standard for contact impedance measurement. The adjustable impedance control unit 72 can greatly meet the needs of different subjects and improve the versatility of the ECG detector.

Because the contact resistance will increase continuously with the increase of the detection distance. Therefore, in this embodiment, the impedance measurement electrode 71 is arranged close to the ECG measurement electrode 1, so that the detection site of the subject can contact the ECG measurement electrode 1 and the impedance measurement electrode 71 at the same time, which greatly improves the detection accuracy. The said proximity setting can be understood as being as close as possible without overlapping. In addition, in order to facilitate users to use different detection parts, such as hands, head or other body parts, both the ECG measurement electrode 1 and the impedance measurement electrode 71 are set as external touch electrodes.

Further, an electrocardiogram detector also includes an output device 6 for outputting the detected electrocardiogram waveform and the reliability value output by the controller, and an input device 8 that is convenient for the user to control the working state of the electrocardiogram detector. The input device 8 includes four buttons: a switch button 81 , a start measurement button 82 , a stop measurement button 83 and a data upload button 84 . However, the present invention does not make any limitation thereto. Specifically, the user presses the start measurement button 82, and the ECG detector starts to measure ECG signals and contact impedance. When the output device outputs the reliability value and the corresponding detection data, the user presses the stop measurement button 83 to end the measurement. Using the data upload button 84, the user can upload the measurement result to the host computer through the USB interface 9. By setting the input device 8, it can select the working process and functions of the ECG detector.

Further, in order to improve the detection accuracy, the distortion of the ECG detection signal is prevented. In this embodiment, an ECG signal processor 10 and an impedance signal processor 11 are provided between the ECG measurement electrode 1 and the characteristic parameter extractor 2 and between the impedance measurement electrode 71 and the impedance control unit 72 . The ECG signal processor 10 includes an ECG signal filter 101 and an ECG signal amplifier 102 , while the impedance signal processor 11 includes an impedance signal filter 111 and an impedance signal amplifier 112 . The ECG signal filter 101 and the impedance signal filter 111 can filter out various interference signals, such as power frequency interference and the like. The ECG signal amplifier 102 and the impedance signal amplifier 112 can amplify the detected ECG signal and impedance signal to prevent signal distortion. Preferably, the models of the ECG signal amplifier 102 and the impedance signal amplifier 112 are both AD623. However, the present invention does not make any limitation thereto.

In order to better understand the ECG detector provided by the present invention, its specific working process is described as follows: turn on the switch button 81 to make the ECG detector in the working state. Then the subject's left and right hands hold the two ECG measuring electrodes 1 and the impedance measuring electrodes 71 tightly respectively, so as to extract the ECG signal and contact impedance. After pressing the start measurement button 82, the ECG measurement electrode 1 starts to detect the ECG signal, and the impedance measurement electrode 71 starts to measure the contact impedance between the ECG measurement electrode 1 and the body surface of the subject. At this time, the subject should keep the left and right hand posture constant. The impedance control unit 72 determines whether the detected contact impedance is stable and within a desired threshold. If not, send another signal to the controller 4, and the controller 4 controls the output device 6 to output a warning message to remind the subject to check the contact between the ECG measurement electrode 1 and the body surface until the detected contact impedance meets the requirements . If yes, the impedance control unit 72 sends a signal to the controller 4 . The controller 4 sends a control signal to the output device 6 to make it output prompt information, reminding the user to take his hands off the ECG detector. And matching the extracted feature parameters with the standard ECG parameters in the preset template in the template memory 3 (S103), and judging whether the matching is successful (S104). If yes, send a control signal to the data processor 5 to start the reliability calculation ( S105 ). If not, the controller 4 sends two control signals, one of which is sent to the template memory 3, and the acquired ECG signal is updated into the template memory 3 as a new preset template (S106), realizing the self-adaptation of the template memory 3 renew. Another control signal is sent to the output device 6 to output a prompt message that re-testing is required (S111). After the data processor 5 completes the reliability calculation, it sends a feedback signal to the controller 4 . The controller 4 sends a control signal to the output device 6 to make it output the reliability value and corresponding ECG detection information ( S110 ).

Embodiment two

As shown in FIG. 5 and FIG. 6 , this embodiment is basically the same as Embodiment 1 and its variations, except that the number of ECG measurement electrodes 1 and impedance measurement electrodes 71 is three. Two of the ECG measurement electrodes 1 are used to extract ECG signals, and the third ECG measurement electrode 1 is electrically connected to the compensation module 113 . The other end of the compensation module 113 is electrically connected to the feedback end of the ECG amplifier 112, and a common-mode negative feedback is established between the feedback end of the ECG amplifier 112 and the input end of the ECG signal, so as to offset power frequency interference to the greatest extent and improve detection accuracy. In this embodiment, the compensation module 113 is composed of a plurality of feedback resistors and operational amplifiers. The third electrocardiographic measurement electrode 1 can be arranged on the leg of the subject. However, the present invention does not make any limitation thereto.

To sum up, the present invention has the following advantages compared with the prior art: a kind of electrocardiogram detection method and the detector provided by the present invention, by extracting the characteristic parameter of the electrocardiogram signal that obtains, and it is compared with template library Match the corresponding characteristic curves in the preset template, find the matching template, and use the matching template as a reference to calculate the reliability of the detected ECG signal. The user can judge whether the ECG test result can be provided to the doctor as a basis for diagnosis and treatment according to the degree of reliability. It avoids the problem that the traditional ECG detector cannot judge the credibility of the ECG signal, which makes the doctor unable to make an effective diagnosis and treatment judgment, and even misjudgments in severe cases. Further, when no matching template can be found in the template library, the controller updates the detected electrocardiographic signal as a new preset template into the template library, so as to realize adaptive updating of templates.

In addition, in the process of template matching, the correlation coefficient method is used as a measure of the similarity of template matching. The set threshold is used as the matching benchmark, and the template corresponding to the maximum correlation coefficient exceeding the set threshold is used as the matching template to improve the matching accuracy and provide an accurate reference benchmark for the calculation of the credibility value. By setting the template library to include the current template library and the substitute template library, due to the huge number of templates in the template library, a large amount of computing time will be consumed during template matching. Therefore, matching with commonly used templates in the current template library is preferred, greatly reducing the time taken for template matching, improving detection efficiency, and improving product performance, which can better meet user needs. Further, the measurement of contact impedance is added, and whether the contact impedance is stable and within the expected value is used to characterize the good degree of contact between the electrocardiographic measurement electrode 1 and the skin of the subject in the detection center, avoiding the contact between the electrocardiographic measurement electrode 1 and the tested person. The low reliability detection caused by the bad contact between the patient's body surface can reduce the factors affecting the low reliability and improve the reliability of detection. The impedance measuring electrode 71 is placed close to the ECG measuring electrode 1, and the detection site of the subject can contact the ECG measuring electrode 1 and the impedance measuring electrode 71 at the same time, thereby improving the measurement accuracy of the impedance measuring electrode 71.

Although the present invention has been disclosed above by preferred embodiments, it is not intended to limit the present invention. Any skilled person can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be subject to the scope of protection required by the claims.

Claims (10)

1. A method for electrocardiogram detection, characterized in that, comprising: Obtain the ECG signal of the subject; Extracting the characteristic parameters of the acquired ECG signal; Match the extracted feature parameters with the standard ECG signal parameters in the preset template in the template library; Judging whether the extracted feature parameters and the standard ECG signal parameters in the preset template in the template library match successfully, if so, start the reliability calculation; if not, update the acquired ECG signal as a new preset template to the template library. 2. A kind of electrocardiogram detection method according to claim 1, is characterized in that: the described step of matching the extracted feature parameter with the standard electrocardiogram parameter in the preset template in the template storehouse comprises: calculating and extracting The correlation coefficient between the characteristic parameters and the standard ECG signal parameters in the preset template, the template corresponding to the largest correlation coefficient and exceeding the set threshold is used as the matching template. 3. A kind of electrocardiographic detection method according to claim 1, is characterized in that: described template storehouse comprises current template storehouse and substitute template storehouse, the feature parameter that extracts is at first with the preset template in described current template storehouse Perform matching, and if the matched template is not in the current template library, then match with the preset template in the substitute template library. 4. A kind of electrocardiographic detection method according to claim 1, is characterized in that: electrocardiographic detection method also comprises obtaining the contact impedance between the electrocardiographic measurement electrodes and the body surface of the subject, when the detection result characterizes the contact impedance obtained When the impedance is stable and within the expected contact impedance threshold, the extracted feature parameters are matched with the standard ECG signal parameters in the preset template in the template library. 5. An electrocardiogram detector, characterized in that, comprising: At least two electrocardiographic measuring electrodes for obtaining the electrocardiographic signal of the subject; A characteristic parameter extractor is used to extract the characteristic parameters of the obtained ECG signal; Template storage, for storing preset templates, and the preset templates are used for storing standard ECG signal parameters; The controller is electrically connected to the characteristic parameter extractor and the template memory respectively, matches the extracted characteristic parameters with the standard ECG signal parameters in the preset template in the template memory, and judges whether the matching is successful, and if so, sends a control signal to the data processor; if not, send a control signal to the template memory, and update the obtained ECG signal as a new preset template into the template memory; The data processor is electrically connected to the controller, receives the control signal sent by the controller, and performs reliability calculation. 6. A kind of electrocardiograph according to claim 5, is characterized in that, described electrocardiograph also comprises impedance monitor, and described impedance monitor is electrically connected with described controller, is used for obtaining described Electrocardiography measures the contact impedance between the electrodes and the body surface of the subject. 7 . The electrocardiogram detector according to claim 6 , wherein the impedance monitor comprises impedance measuring electrodes and an impedance control unit whose number is equal to that of the electrocardiogram measuring electrodes. 7 . 8. A kind of electrocardiogram detector according to claim 7, characterized in that, the impedance measuring electrode is arranged close to the electrocardiogram measuring electrode, so that the detection site of the subject can be in contact with the electrocardiogram measuring electrode at the same time. electrodes and the impedance measuring electrodes. 9. A kind of electrocardiogram detector according to claim 7, is characterized in that, described impedance control unit is a comparator circuit, and one input terminal of comparator is electrically connected with described impedance measuring electrode, and another input terminal is electrically connected to the impedance measuring electrode. The threshold value setter composed of variable resistors is electrically connected, and the output terminal is electrically connected to the controller. 10 . The electrocardiogram detector according to claim 1 , wherein the template memory includes a current template memory for storing a current template and a substitute template memory for storing a substitute template. 11 .

Images