JP6562443B2 - Method of operating electrocardiogram examination apparatus and electrocardiogram examination system - Google Patents

Description

  The present invention relates to an electrocardiogram inspection method and an electrocardiogram inspection system for specifying a cardiac region where an abnormality such as premature ventricular contraction (VPC) occurs from an electrocardiogram waveform when an electrical stimulus is applied.

  Currently, treatment is performed to suppress the occurrence of tachyarrhythmia by ablating the myocardium for tachyarrhythmias such as ventricular tachycardia (VT) and frequent premature ventricular contractions (VPC). Yes. At this time, the myocardium is electrically stimulated, and by confirming whether the electrocardiogram waveform of the spontaneous tachyarrhythmia is the same as the electrocardiogram waveform of the tachyarrhythmia caused by the electrical stimulation, it is possible to determine where the heart muscle should be cauterized. to decide. Incidentally, as this electrocardiographic waveform, for example, a body surface 12-lead electrocardiogram is used.

  If the two electrocardiographic waveforms have the same shape, the site of electrical stimulation is determined to be the origin of tachyarrhythmia, and the physician ablate the site. The correlation coefficient method is mainly used as an index indicating the similarity between electrocardiographic waveforms. Such a method for detecting an abnormal cardiac site based on the similarity between electrocardiographic waveforms is described in Patent Documents 1 and 2, for example.

JP 05-031087 A JP 2006-025836 A

  By the way, the conventional abnormal part inspection based on the correlation coefficient of the electrocardiogram waveform is still insufficient in terms of reliability of similarity.

  The present invention has been made in consideration of the above points, and provides an electrocardiogram examination method and an electrocardiogram examination system that can more accurately identify an abnormal part of the heart.

One aspect of the operation method of the electrocardiogram examination apparatus of the present invention is:
An operation method of an electrocardiogram examination apparatus having a similarity calculation unit,
In the similarity calculation unit, obtaining an electrocardiogram corresponding to the examination site that appears when an electrical stimulus is applied to the examination site of the heart;
In the similarity calculation unit, calculating a correlation coefficient between a pre-stored template waveform at the time of abnormal heart and an electrocardiogram waveform corresponding to the examination site;
In the similarity calculation unit, calculating an amplitude ratio between the template waveform and an electrocardiogram waveform corresponding to the examination site;
In the similarity calculation unit, using the correlation coefficient and the amplitude ratio, obtaining a similarity between the template waveform at the time of the heart abnormality and the electrocardiogram waveform corresponding to the examination site;
including.

One aspect of the electrocardiogram examination system of the present invention is:
An electrical stimulation device for applying electrical stimulation to the examination site of the heart;
An electrocardiogram measuring device;
An electrocardiogram examination apparatus having a display unit for displaying an electrocardiogram waveform obtained by the electrocardiogram measurement apparatus;
An electrocardiogram examination system comprising:
The electrocardiogram inspection apparatus comprises:
Correlation between pre-stored template waveform at the time of abnormal heart and electrocardiogram waveform corresponding to the examination site obtained by the electrocardiogram measurement device when electrical stimulation is given to the examination site of the heart by the electrical stimulation device The number and the amplitude ratio are obtained, and further, using the correlation coefficient and the amplitude ratio, the similarity between the template waveform at the time of the heart abnormality and the electrocardiographic waveform corresponding to the examination site is obtained .

  According to the present invention, in addition to the correlation coefficient indicating the correlation between the shape of the template waveform and the electrocardiogram waveform corresponding to the examination site, the amplitude ratio between the template waveform and the electrocardiogram waveform corresponding to the examination site is obtained. Therefore, the abnormal part of the heart can be determined based on the two indexes such as the correlation coefficient and the amplitude ratio, and as a result, the abnormal part of the heart can be identified more accurately.

Schematic showing the overall configuration of the polygraph according to the embodiment The block diagram which shows the structure for calculating | requiring the similarity of an electrocardiogram waveform The flowchart which shows the process sequence of the similarity determination process by embodiment Diagram for explaining similarity calculation between template waveform and pacing waveform

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall configuration of polygraph>
FIG. 1 is an external view showing an overall configuration of a polygraph 100 according to the present embodiment. The polygraph 100 of the present embodiment is a polygraph used as a cardiac catheter inspection device. The polygraph 100 has a function of measuring and analyzing a body surface electrocardiogram and an intracardiac electrocardiogram. For this reason, the polygraph 100 can also be called an electrocardiogram inspection system.

  The polygraph 100 includes a main body unit 200, an interface unit 300, and an EPS (Electrophysiological Study) unit 400. The main unit 200 and the interface unit 300 are connected by a cable L1, and the interface unit 300 and the EPS unit 400 are connected by a cable L2. Although the figure shows an example in which the main unit 200 and the EPS unit 400 are connected via the interface unit 300, the main unit 200 and the EPS unit 400 may be directly connected by the cable L2.

  The main unit 200 is connected to an input device 10 such as a dedicated keyboard 11, keyboard 12, mouse 13, a plurality of displays 20 (21, 22, 23), and a recording device such as a thermal recorder 30. The interface unit 300 is connected to the main unit 200. The main unit 200 has a function as a central processing unit of the polygraph 100. The main unit 200 displays each biological information on the display 20 in a desired display form by performing arithmetic processing and analysis processing according to the program on each biological information input via the interface unit 300. The main unit 200 controls the display form of each biological information, the operation of the interface unit 300 and the EPS unit 400, and the devices connected to them based on the operation signal input from the input device 10. It has become.

The interface unit 300 includes a biological information input terminal group 310 including an ECG (electrocardiogram) input terminal, a non-invasive blood pressure input terminal, an SpO ₂ input terminal, and a body temperature input terminal. The interface unit 300 includes an ECG output terminal 311 and an open blood pressure output terminal 312. The interface unit 300 has an input terminal 313 for connecting a dedicated keyboard.

  The interface unit 300 includes an amplifier, and a predetermined signal input from the biological information input terminal group 310 is amplified by the amplifier and then output to the main unit 200.

  The EPS unit 400 includes a terminal 411 to which a stimulation cable is connected and a terminal 412 to which an ablator cable is connected. The EPS unit 400 is connected to a stimulation device (not shown) via these terminals 411 and 412. ) And an ablator device (not shown). The EPS unit 400 has a body surface electrocardiogram input terminal 413, to which an electrode attached to the body surface of the subject is connected. Thereby, a body surface electrocardiogram when a stimulus is applied to a predetermined part of the heart by the stimulation device can be obtained. In this embodiment, an electrode for obtaining a 12-lead electrocardiogram is connected to the body surface electrocardiogram input terminal 413.

  Furthermore, the EPS unit 400 includes terminals 414 and 415 to which the relay boxes 500 and 510 are connected. Each relay box 500, 510 is provided with a number of terminals 600 for connecting terminals corresponding to the electrodes provided on the electrode catheter.

  In the case of this embodiment, one relay box 500 (510, 520, 530) is provided with 40 channels (that is, 80 terminals 600) in a bipolar manner. The EPS unit 400 can connect two relay boxes 500 and 510. Therefore, the EPS unit 400 can input an intracardiac electrocardiogram for 80 (= 2 × 40) channels.

  Further, an EPS unit 410 for expansion can be connected to the EPS unit 400. The expansion EPS unit 410 can also connect the two relay boxes 520 and 530. Therefore, when the expansion EPS unit 410 is connected to the EPS unit 400, the intracardiac radio waves for 160 (= 4 × 40) channels. Shape signal can be input.

  The EPS unit 400 and the expansion EPS unit 410 incorporate an amplifier, and the intracardiac electrocardiogram waveform input from the relay boxes 500, 510, 520, and 530 is amplified by the amplifier and then passed through the interface unit 300. To the main unit 200. A stimulation signal from a stimulation device (not shown) input from a terminal 411 to which a stimulation cable is connected is output to an electrode catheter (not shown) via a relay box 500 (510, 520, 530). Is done. Furthermore, the stimulation waveform based on the stimulation signal actually applied from the electrode catheter to the heart is amplified by the amplifier of the EPS unit 400 and the expansion EPS unit 410 together with the intracardiac electrocardiogram waveform, and then via the interface unit 300. It is sent to the main unit 200. The EPS unit 400 includes an ECG output terminal 416 and a speaker 417.

<Calculation of ECG waveform similarity>
As shown in FIG. 2, the main unit 200 includes a template waveform storage unit 201, a pacing waveform storage unit 202, and a similarity calculation unit 203.

  The template waveform storage unit 201 stores an electrocardiographic waveform at the time of heart abnormality such as VPC as a template waveform. The pacing waveform storage unit 202 stores an electrocardiogram waveform as a pacing waveform when electrical stimulation is applied to each examination site of the heart by the stimulation device. In the polygraph 100 of FIG. 1, a 12-lead ECG waveform obtained based on an electrical signal from a 12-lead ECG electrode connected to the interface unit 300 or the EPS unit 400 is a template waveform storage unit 201 as a template waveform and a pacing waveform, respectively. And stored in the pacing waveform storage unit 202. The template waveform stored in the template waveform storage unit 201 is not limited to that measured by the polygraph 100, but is an electrocardiogram waveform at the time of cardiac abnormalities such as VPC and VT measured in advance by another electrocardiograph. Also good.

  The template waveform is an electrocardiographic waveform at the time of abnormal heart acquired in advance without applying electrical stimulation from the same subject who obtained an electrocardiographic waveform (pacing waveform) by electrical stimulation.

  The similarity calculation unit 203 calculates the similarity between the template waveform and the pacing waveform.

  FIG. 3 shows a processing procedure of similarity determination processing according to the present embodiment. First, in step S1, a range for calculating a correlation coefficient (which may be referred to as a range for calculating similarity) is manually set. This is shown in FIG. The display 20 displays the template waveform stored in the template waveform storage unit 201 and the pacing waveform stored in the pacing waveform storage unit 202. A medical worker such as a doctor sets the range (start point and end point) for calculating the correlation with the mouse 13 while viewing the displayed template waveform. This correlation value calculation range is a QRS wave range in which a ventricular extrasystole waveform appears.

  Next, in step S2, the similarity calculation unit 203 aligns the template waveform and the pacing waveform while calculating the correlation coefficient (ρ) between the template waveform and the pacing waveform. Specifically, with the template waveform fixed, the correlation coefficient between the template waveform and the pacing waveform is calculated in the correlation calculation range set in step S1 while shifting the pacing waveform back and forth. Adjust the position of the pacing waveform to a larger position.

  Next, in step S3, the similarity calculation unit 203 calculates an amplitude value (that is, maximum value−minimum value) within the correlation calculation range for each of the template waveform and the pacing waveform.

  Next, in step S4, the similarity calculation unit 203 calculates the amplitude ratio (R). The amplitude value is calculated using the larger one of the amplitude values of the template waveform and the pacing waveform calculated in step S3 as the denominator and the smaller one as the numerator. Of course, it is assumed that the template waveform and the pacing waveform for obtaining the amplitude ratio (R) are obtained under the same amplification factor (sensitivity). Therefore, the template waveform and the pacing waveform are preferably measured by setting the same sensitivity in the same measuring device.

  Next, in step S5, the similarity calculation unit 203 calculates the pacing waveform similarity to the template waveform. The similarity calculation unit 203 calculates the similarity (S) by calculating similarity (S) = correlation coefficient (ρ) × amplitude ratio (R). The correlation coefficient may be calculated by the following Pearson equation.

ここで、ｘ_ｉは時点ｉでのテンプレート波形の値（振幅値）、ｙ_ｉは時点ｉでのペーシング波形の値（振幅値）、Ｅ（ｘ）は変数ｘ_ｉの平均、Ｅ（ｙ）は変数ｙ_ｉの平均を表す。

Here, x _i is the value (amplitude value) of the template waveform at time point i, y _i is the value (amplitude value) of the pacing waveform at time point i, E (x) is the average of variables x _i , and E (y) Represents the average of the variables y _i .

  The similarity calculated by the similarity calculation unit 203 is displayed on the display 20 together with the template waveform and the pacing waveform.

  As described above, according to the present embodiment, when the similarity of the pacing waveform to the template waveform is calculated based on the correlation coefficient and the amplitude ratio, the similarity is calculated using only the correlation coefficient. Compared to the above, the reliability of the similarity can be improved, and the abnormal part of the heart can be specified more accurately. In other words, since a similar degree of similarity can be displayed as compared with the conventional case, it is possible to reduce the possibility that a doctor will determine that it is the origin site even though it is not the origin site of cardiac abnormalities such as VPC.

  Also, by calculating the similarity by multiplying the correlation coefficient and the amplitude ratio, it is possible to obtain a calculation result that increases the similarity only when both the waveform shape and amplitude are similar. The degree of reliability can be increased.

  Also, the amplitude ratio used to determine the similarity is obtained using the larger amplitude value of the template waveform and pacing waveform as the denominator and the smaller amplitude value as the numerator. As a result, the degree of similarity can be reduced as the difference in amplitude between the template waveform and the pacing waveform increases.

  In the above-described embodiment, the case where the similarity is calculated by using the correlation coefficient and the amplitude ratio and the similarity is displayed has been described. Instead of or in addition to this, the correlation coefficient is displayed. And the amplitude ratio may be displayed. In this way, a medical worker such as a doctor can determine an abnormal part of the heart based on two indicators such as a correlation coefficient and an amplitude ratio, so that the abnormal part of the heart can be determined more accurately than before. It becomes possible to identify. Further, for example, only the amplitude ratio closest to “1” may be displayed among the amplitude ratios between the template waveform and the electrocardiogram waveforms of a plurality of electrical stimulation sites.

  In the above-described embodiment, the case where the electrocardiogram inspection method of the present invention is applied to the polygraph 100 has been described. However, the electrocardiogram inspection system other than the polygraph 100 can be widely applied.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or main features thereof.

  The present invention can be applied to an electrocardiogram inspection method and an electrocardiogram inspection system that calculate the similarity between a template waveform and a pacing waveform.

DESCRIPTION OF SYMBOLS 10 Input apparatus 20 Display 100 Polygraph 200 Main body unit 201 Template waveform memory | storage part 202 Pacing waveform memory | storage part 203 Similarity calculation part 300 Interface unit 400 EPS (Electrophysiological Study: Electrophysiological examination) unit 500, 510, 520, 530 Relay box

Claims (8)

An operation method of an electrocardiogram examination apparatus having a similarity calculation unit,
In the similarity calculation unit, obtaining an electrocardiogram corresponding to the examination site that appears when an electrical stimulus is applied to the examination site of the heart;
In the similarity calculation unit, calculating a correlation coefficient between a pre-stored template waveform at the time of abnormal heart and an electrocardiogram waveform corresponding to the examination site;
In the similarity calculation unit, calculating an amplitude ratio between the template waveform and an electrocardiogram waveform corresponding to the examination site;
In the similarity calculation unit, using the correlation coefficient and the amplitude ratio, obtaining a similarity between the template waveform at the time of the heart abnormality and the electrocardiogram waveform corresponding to the examination site;
including,
The operation method of the electrocardiogram examination apparatus . The similarity is obtained by calculation including an expression of the correlation coefficient × the amplitude ratio.
The operation method of the electrocardiogram examination apparatus according to claim 1. The amplitude ratio is
Of the amplitude value of the template waveform and the amplitude value of the electrocardiographic waveform corresponding to the examination site, the larger amplitude value is used as the denominator, and the smaller amplitude value is obtained as the numerator. is there,
The operation method of the electrocardiogram examination apparatus according to claim 1. The electrocardiogram waveform corresponding to the template waveform and the examination site for determining the similarity is a ventricular extrasystole waveform,
The operation method of the electrocardiogram examination apparatus according to claim 2. The template waveform is an electrocardiographic waveform acquired in advance without applying electrical stimulation from the same subject as the subject who obtained the electrocardiographic waveform by the electrical stimulation.
The operation method of the electrocardiogram examination apparatus according to any one of claims 1 to 4. An electrical stimulation device for applying electrical stimulation to the examination site of the heart;
An electrocardiogram measuring device;
An electrocardiogram examination apparatus having a display unit for displaying an electrocardiogram waveform obtained by the electrocardiogram measurement apparatus;
An electrocardiogram examination system comprising:
The electrocardiogram inspection apparatus comprises:
Correlation between pre-stored template waveform at the time of abnormal heart and electrocardiogram waveform corresponding to the examination site obtained by the electrocardiogram measurement device when electrical stimulation is given to the examination site of the heart by the electrical stimulation device Obtaining a number and an amplitude ratio, and further using the correlation coefficient and the amplitude ratio to obtain a similarity between the template waveform at the time of the cardiac abnormality and an electrocardiographic waveform corresponding to the examination site.
ECG inspection system. The electrocardiogram inspection apparatus comprises:
The similarity is obtained by calculation including an expression of the correlation coefficient × the amplitude ratio.
The electrocardiogram inspection system according to claim 6. The amplitude ratio is
Of the amplitude value of the template waveform and the amplitude value of the electrocardiographic waveform corresponding to the examination site, the larger amplitude value is used as the denominator, and the smaller amplitude value is obtained as the numerator. is there,
The electrocardiogram inspection system according to claim 6 or 7.

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