TWI818264B - Myocardial ischemia detection device and myocardial ischemia detection method - Google Patents

Abstract

A myocardial ischemia detection device includes a measurement unit and a processing unit. A myocardial ischemia detection method includes a measurement step, a feature extraction step and a first analysis step. The measuring step obtains several ECG signals of a human body through the measuring unit. The measurement locations of at least part of the ECG signals correspond to the left chest of the human body. The feature extraction step uses the processing unit to capture the QT interval of each ECG signal, and calculates several feature values corresponding to several points on the human body based on this. The first analysis step is to compare the point position corresponding to at least one of the lowest feature values to detect the position of myocardial ischemia. Compared with the existing analysis method of waveform changes in the ST segment, these QT intervals are less affected by noise and baseline deviation, and can avoid evaluation errors.

Description

Myocardial ischemia detection device and myocardial ischemia detection method

The present invention relates to an analysis of electrocardiogram signals, and in particular, to a myocardial ischemia detection device and a myocardial ischemia detection method.

The three coronary arteries that maintain blood supply to the heart are the right coronary artery (RCA), the left anterior descending coronary artery (LAD), and the left recurrent coronary artery (LCX). Different medical treatments are required for different arterial blood vessel obstructions. The American Heart Association stipulates that patients with myocardial infarction should receive cardiac catheterization within 90 minutes after arriving at the hospital to reduce the patient's myocardial ischemia time and mortality. Therefore, how to evaluate whether there is myocardial ischemia and myocardial ischemia in the shortest possible time? Location is quite important.

Generally, when assessing the location of acute myocardial ischemia, a twelve-lead electrocardiogram is used. During assessment, medical personnel need to conduct guidance based on different groups such as anterior chest leads (V1-V6), inferior wall leads (II, III, aVF), and lateral wall/apical leads (I, aVL, V5, V6). Comprehensive assessment of the rising or falling waveform changes of the ST segment in the course of the process. Since the changes in the ST segment are often not obvious in the early stage of myocardial ischemia, it is actually difficult to shorten the assessment time in practice.

In addition, the waveform changes of the ST segment of the electrocardiogram are easily affected by chest wall impedance, noise and baseline deviation, so it is also easy to produce evaluation errors.

Therefore, it is an object of the present invention to provide a myocardial ischemia detection device that overcomes at least one of the shortcomings of the prior art.

Another object of the present invention is to provide a myocardial ischemia detection method that can overcome at least one of the shortcomings of the prior art.

Therefore, the myocardial ischemia detection device of the present invention is suitable for a human body. The myocardial ischemia detection device includes a measurement unit and a processing unit.

The measurement unit includes four limb electrodes and several chest electrodes. The limb conduction electrodes and the chest electrodes are suitable for obtaining several ECG signals of the human body. The measurement positions of at least part of the chest electrodes correspond to the left chest of the human body.

The processing unit signal is connected to the measurement unit and can receive the ECG signals. The processing unit can capture the QT intervals of the ECG signals, and use the QT intervals to calculate a number of characteristic values corresponding to several points on the left chest of the human body, and then based on the characteristic values The ECG signal measurement position corresponding to at least one of the lowest ones is used to detect the myocardial ischemia position of the human body.

The myocardial ischemia detection method of the present invention includes a measurement step, a feature extraction step, and a first analysis step.

The measurement step is to obtain several ECG signals of a human body. The measurement locations of at least part of the ECG signals correspond to the left chest of the human body.

The feature extraction step uses a processing unit to capture the QT interval of each ECG signal, and calculates several feature values corresponding to several points on the left chest of the human body based on the QT intervals.

The first analysis step is to compare the point corresponding to at least one of the lowest feature values with the position of the left chest of the human body to detect the position of myocardial ischemia.

The effect of the present invention is to detect the myocardial ischemia position of the human body by calculating the characteristic values based on the QT intervals. Compared with the existing analysis method based on the waveform changes of the ST segment, the QT intervals are shorter. It will not be affected by chest wall impedance, noise and baseline deviation, so it can avoid evaluation errors.

Referring to Figures 1 to 4, an embodiment of the myocardial ischemia detection device of the present invention is suitable for a human body 1. The human body includes a reference surface 100 corresponding to the left chest. The reference plane 100 is composed of a right sternal edge 11 of the human body 1, a first intercostal horizontal line 12 corresponding to the height of the right sternal edge 11, a left axillary midline 13, and an eighth rib corresponding to the right sternum. The height of the edge 11 is defined by a horizontal line 14.

The myocardial ischemia detection device includes a measurement unit 2, a processing unit 3, a database unit 4, an input unit 5, an output unit 6, and a wearable unit 7. The processing unit 3 is connected with signals to the measurement unit 2 , the processing unit 3 , the database unit 4 , the input unit 5 , and the output unit 6 .

The input unit 5 can be input with an operation command, a mode selection command, and an output command.

The measurement unit 2 includes four limb conductive electrodes 26 and a plurality of chest electrodes 21 that are suitable for being arranged on the reference surface 100 and spaced apart from each other. The measurement unit 2 can cause the limb conductive electrodes 26 and the chest electrodes 21 to obtain several ECG signals of the human body 1 according to the operation instruction. At least part of the measurement positions of the chest electrodes 21 correspond to the left chest of the human body 1 . Each ECG signal consists of P wave, Q wave, R wave, S wave and T wave.

Among them, it should be noted that in order to clearly reveal the placement positions of the chest electrodes 21 and the wearing unit 7 corresponding to the human body 1, in Figure 3 and subsequent Figures 10, 15 and 16, the chest electrodes 21 and the wearing unit 7 are The front electrode 21 is drawn with an imaginary line, while the wearable unit 7 in Figure 2 is drawn with a dotted line.

The number of the chest electrodes 21 can be more than 16, and a corresponding number of ECG signals of the reference surface 100 of the human body 1 are obtained through the chest electrodes 21 , and the ECG signals correspond to the measurement positions. arranged on the reference plane 100 .

In terms of the lateral positions of the chest electrodes 21 corresponding to the human body 1, at least 2 of the chest electrodes 21 correspond to the right sternal edge 11, and at least 3 of the chest electrodes 21 correspond to the left side. Sternal border 111, at least 3 chest electrodes 21 corresponding to the midline 113 between the left sternal border 111 and a left clavicle midline 112, at least 4 chest electrodes 21 corresponding to the left clavicle midline 112, at least 2 The chest electrode 21 corresponds to a left axillary front edge line 114, and at least two chest electrodes 21 correspond to the left axillary midline 13.

In terms of the longitudinal position of the chest electrodes 21 corresponding to the human body 1, at least 3 of the chest electrodes 21 correspond to a third intercostal space, corresponding to the height of the right sternal edge 11, and at least 5 chest electrodes 21. The front electrode 21 corresponds to a fourth intercostal space corresponding to the height of the right sternal edge 11 , at least four chest electrodes 21 correspond to a fifth intercostal space corresponding to the height of the right sternal border 11 , and at least one chest electrode 21 corresponds to a sixth intercostal space. The heights of at least three of the chest electrodes 21 corresponding to the height of the right sternal edge 11 and corresponding to the midline 113 between the left sternal edge 111 and the left clavicle midline 112 are between the third intercostal space and between the sixth ribs.

In this embodiment, the number of the chest electrodes 21 is 16. In terms of the lateral position of the chest electrodes 21 corresponding to the human body 1, 2 of the chest electrodes 21 Corresponding to the right sternal edge 11, three prethoracic electrodes 21 correspond to the left sternal edge 111, and three prethoracic electrodes 21 correspond to the midline 113 between the left sternal edge 111 and the left clavicle midline 112, and four thoracic electrodes 21. The front electrode 21 corresponds to the left clavicle midline 112, the two chest electrodes 21 correspond to the left axillary front edge line 114, and the two chest electrodes 21 correspond to the left axillary midline 13; Corresponding to the longitudinal position of the human body 1, three of the chest electrodes 21 correspond to the third intercostal space corresponding to the height of the right sternal edge 11, and five of the chest electrodes 21 correspond to the fourth intercostal space. At the height of the right sternal margin 11 , four chest electrodes 21 correspond to the fifth intercostal space, correspond to the height of the right sternal margin 11 , four chest electrodes 21 correspond to the sixth intercostal space, correspond to the height of the right sternal border 11 , and correspond to The three chest electrodes 21 located on the midline 113 between the left sternal edge 111 and the left clavicle midline 112 respectively correspond to the heights of a fourth rib, a fifth rib and a sixth rib.

In this embodiment, the measurement unit 2 further includes a signal buffer 22 electrically connected to the chest electrodes 21 , a signal amplifier 23 electrically connected to the signal buffer 22 , and a filter electrically connected to the signal amplifier 23 filter 24, and a signal converter 25 electrically connected to the filter 24. The signal buffer 22 can provide a large enough input impedance to couple the ECG signals to the signal amplifier 23. The signal amplifier 23 further amplifies the ECG signals and inputs them into the filter 24. The filter 24 can The noise of the ECG signals and the interference of the power signal are removed, and the signal converter 25 can convert the ECG signals into analog signals for subsequent analysis by the processing unit 3 .

The database unit 4 stores a comparison information 41 . The comparison information 41 is divided into three comparison areas 411 from the upper right to the lower left. The comparison areas 411 represent the left recurrent coronary artery (LCX), the left anterior descending coronary artery (LAD), and Right branch of coronary artery (RCA).

The processing unit 3 is connected to the measurement unit 2 and can receive the ECG signals. The processing unit 3 can capture the QT intervals and RR intervals of the ECG signals, and calculate several reference planes corresponding to the left chest of the human body 1 through the QT intervals and the RR intervals. Eigenvalues of several points of 100. The characteristic values are the QTc intervals corresponding to the points calculated based on the ECG signals.

The calculation method of the characteristic values is to calculate the QTc interval of the ECG signals through the QT interval and the RR interval, and then determine whether to use the two-dimensional method based on the number and demand of the chest electrodes 21 The interpolation calculation expands and calculates the QTc interval at more points, and uses the QTc interval calculated from the ECG signals and the expanded QTc interval as the characteristic values respectively.

In this embodiment, the processing unit 3 captures the QT intervals and RR intervals of the above 16 ECG signals, and calculates 16 QTc intervals respectively based on the QT intervals and the RR intervals, and then The QTc interval is expanded to 24 points through two-dimensional interpolation calculation. Among them, the calculation formula for calculating the QTc interval of the ECG signals based on the QT interval and the RR interval is:

Among them, QTc is the QTc interval, QT is the QT interval (in milliseconds), and RR is the RR interval (in seconds).

The processing unit 3 can detect the myocardial ischemia position of the human body 1 based on the ECG signal measurement position corresponding to at least one of the lowest characteristic values, and can detect the myocardial ischemia position of the human body 1 based on the high and low distribution status of the characteristic values. The comparison information 41 is compared to detect the range of myocardial ischemia, and the detection results of the myocardial ischemia position and the range of myocardial ischemia can be output to the output unit 6 according to the output command.

The processing unit 3 can also display the feature values on the output unit 6 according to the output command, and can also image the numerical differences and corresponding distribution positions of the feature values on the output unit 6 with different color levels. . Among them, the processing unit 3 uses different color levels to image the numerical differences of the feature values and the corresponding distribution positions, which is similar to the layered coloring method and the landform color shading method used in cartography, that is, Different colors or shades are used to represent different levels of feature values, allowing a user to easily and conveniently understand the distribution of levels of these feature values, thereby facilitating the assessment of the location and extent of myocardial ischemia.

In addition, the processing unit 3 can calculate and evaluate the severity of overall myocardial ischemia in at least one of a first evaluation mode and a second evaluation mode according to the mode selection instruction of the input unit 5, and according to the output The instruction is to output the evaluation result to the output unit 6 .

The first evaluation mode uses an evaluation parameter algorithm to calculate a discrete parameter ( ), and evaluate the severity of the overall myocardial ischemia of the human body 1 based on the discrete parameters. The evaluation parameter algorithm is:

in, is the discrete parameter, S is the total number of points, is the QTc interval of a specific point, n is the number of points closest to the specific point corresponding to position 1 of the human body, It is the QTc interval of one of the points closest to the specific point corresponding to the 1 position of the human body. when The larger the value, the more serious the overall myocardial ischemia of the human body 1 is.

The second evaluation mode is to calculate the difference value QTcD between the maximum value and the minimum value of the QTc intervals at the points, and evaluate the human body 1 based on the difference value QTcD between the maximum value and the minimum value of the QTc intervals. The severity of overall myocardial ischemia. When the difference value QTcD between the maximum value and the minimum value of the QTc interval is larger, it means that the severity of the overall myocardial ischemia of the human body 1 is more serious.

The wearable unit 7 can be worn by the human body 1 , and the chest electrodes 21 of the measurement unit 2 are arranged on the wearable unit 7 . When the human body 1 wears the wearing unit 7 , the chest electrodes 21 respectively correspond to predetermined positions of the reference surface 100 . In this embodiment, the wearing unit 7 is a vest-type outer garment.

Referring to Figures 1 to 4, in actual application, a myocardial ischemia detection method can be used for detection. The myocardial ischemia detection method includes the following steps S1 to step S5.

Step S1, input command step: input the operation command, the mode selection command, and the output command into the input unit 5 .

Step S2, measurement step: obtain the ECG signals of the human body 1.

Among them, the measurement positions of at least part of the ECG signals correspond to the left chest of the human body 1.

The measurement step is to obtain the ECG signals of a reference surface 100 of the human body 1 . The reference plane 100 is composed of the right sternal edge 11 of the human body 1, the horizontal line 12 of the first intercostal space corresponding to the height of the right sternal edge 11, the left axillary midline 13, and the eighth rib corresponding to the right sternum. The height of the edge 11 is defined by a horizontal line 14.

Step S3, feature extraction step: the processing unit 3 captures the QT interval and RR interval of each ECG signal, and calculates several corresponding to the human body 1 based on the QT intervals and the RR intervals. The characteristic values of several points on the left chest.

In this embodiment, the feature values calculated in the step of retrieving features are calculated based on the ECG signals and the QTc intervals corresponding to the points.

Step S4, first analysis step: compare the point corresponding to at least one of the lowest feature values with the position of the left chest of the human body to detect the position of myocardial ischemia, and compare the points of the feature values The high and low distribution status is compared with the comparison information 41 to detect the range of myocardial ischemia.

The first analysis step can be automatically processed by the processing unit 3 to detect the myocardial ischemia position and myocardial ischemia range of the human body 1, and then output the detection results to the output unit 6 according to the output command. The first analysis step can also be performed by the processing unit 3 first according to the output command, according to the position of the left chest of the human body 1 and using different color levels to represent the level of the characteristic values. After the output unit 6 generates the corresponding image, the user visually evaluates the high and low distribution of the feature values, and the user detects the location of myocardial ischemia and myocardial insufficiency by comparing the image with the comparison information 41. range of blood.

Step S5, second analysis step: The processing unit 3 calculates and evaluates the overall myocardial defect of the human body 1 in at least one of the first evaluation mode and the second evaluation mode according to the mode selection instruction of the input unit 5. The severity of blood loss is determined, and the evaluation result is output to the output unit 6 according to the output instruction.

Through the above steps S1 to S5, the myocardial ischemia location, myocardial ischemia range, and the overall myocardial ischemia severity of the human body 1 can be evaluated.

Refer to Table 1 below and Figures 4 and 6. For example, Table 1 is a QTc interval distribution table, which uses the myocardial ischemia detection device and the myocardial ischemia detection method to measure 16 chest The electrode 21 acquires 16 ECG signals from the left chest of a patient with left recurrent coronary artery (LCX) stenosis. After calculating the QTc interval of these ECG signals, the calculation is then performed through two-dimensional interpolation. A QTc interval distribution table of a total of 24 points is obtained (including the aforementioned 16 QTc intervals calculated from the ECG signal). The values in the table represent the QTc interval of each point, and are based on the corresponding ECG signal. The measurement positions and the corresponding point positions of the two-dimensional interpolation are arranged, and Figure 6 is an image output to the output unit 6 using different color levels to represent the levels of the feature values.

It can be seen from Table 1 and Figure 6 that the lowest one among the QTc intervals corresponds to the upper right part of the figure. By referring to the comparison information 41 in Figure 4, the patient's myocardial ischemia location can be evaluated. It is located in the blood supply area of the left recurrent coronary artery (LCX).

It should be noted that the QTc intervals of the above 24 points can also be obtained through 17, 18 or other numbers of the chest electrodes 21 to obtain the ECG signals, and then obtain the 24 points through a two-dimensional interpolation calculation program. The QTc interval of the position can also be calculated directly through the ECG signals obtained by the 24 chest electrodes 21 without going through a two-dimensional interpolation calculation process, and the points of the QTc interval distribution table The number of bits can also be other. For example, the ECG signals obtained through 24 chest electrodes 21 can be expanded into a QTc interval distribution table of 36 points by two-dimensional interpolation calculation.

Table 1 Examples of QTc intervals in patients with left recurrent coronary artery (LCX) stenosis 426 409 400 392 377 368 426 405 396 383 362 358 411 396 388 366 451 451 411 404 386 366 409 430

Refer to Table 2 below and Figures 4 and 7. Table 2 shows the use of the myocardial ischemia detection device and the myocardial ischemia detection method to detect a patient with right coronary artery (RCA) stenosis using 16 of these chest electrodes 21. After calculating the QTc intervals of 16 ECG signals obtained from the left chest of the patient, a total of 24 points of QTc interval distribution table (including the aforementioned 16 QTc intervals calculated from the ECG signal), and Figure 7 is the corresponding image displayed on the output unit 6.

It can be seen from Table 2 and Figure 7 that the lowest one of the QTc intervals corresponds to the left side of the figure. Together with the comparison information 41 in Figure 4, it can be estimated that the patient's myocardial ischemia location is Located in the territory supplied by the right branch of the coronary artery (RCA).

Table 2 Examples of QTc intervals in patients with right coronary artery (RCA) stenosis 417 428 356 390 400 404 428 348 390 394 409 409 394 360 398 394 409 413 394 377 392 402 405 409

Refer to Table 3 and Figures 4 and 8 below. Table 3 uses the myocardial ischemia detection device and the myocardial ischemia detection method to detect stenosis of a left anterior descending coronary artery (LAD) with 16 of these chest electrodes 21. After calculating the QTc intervals of 16 ECG signals obtained from the patient's left chest, a QTc interval distribution table of a total of 24 points (including The aforementioned 16 QTc intervals calculated from the ECG signal), and FIG. 8 is the corresponding image displayed on the output unit 6 .

It can be seen from Table 3 and Figure 8 that the lowest one of the QTc intervals corresponds to the upper middle area in the figure. By referring to the comparison information 41 in Figure 4, the patient's myocardium can be evaluated. The ischemic site is located in the blood supply area of the left anterior descending branch of the LAD coronary artery (LAD).

Table 3 Examples of QTc intervals in patients with left anterior descending coronary artery (LAD) stenosis 415 374 378 378 388 393 415 399 382 382 399 399 403 390 403 403 403 399 403 397 402 407 405 402

Refer to Table 4 and Figures 4 and 9 below. Table 4 uses the myocardial ischemia detection device and the myocardial ischemia detection method to detect one or three coronary arteries with stenosis (3VD) using 16 of these chest electrodes 21. After calculating the QTc intervals of 16 ECG signals obtained from the patient's left chest, a QTc interval distribution table of a total of 24 points (including The aforementioned 16 QTc intervals calculated from the ECG signal), and FIG. 9 is the corresponding image displayed on the output unit 6 .

It can be seen from Table 4 and Figure 9 that the lowest one among the QTc intervals corresponds to the upper left area in the figure. However, Figure 9 shows that the areas with low QTc intervals include the upper left area and the middle area in the figure. In the upper right corner of , and referring to the comparison information 41 in Figure 4 , the area with low QTc interval covers the three comparison areas 411 of the comparison information 41 , so the extent of myocardial ischemia of the patient can be assessed. Covers the territory supplied by three coronary arteries (3VD).

Table 4 Examples of QTc intervals in patients with stenosis of all three coronary arteries (3VD) 376 364 442 417 411 400 364 458 430 417 405 389 401 438 422 417 422 422 401 419 423 430 426 424

The above-mentioned Tables 1 to 4 and Figures 6 to 9 use 16 ECG signals to detect myocardial ischemia, but are not limited thereto. The myocardial ischemia detection device and the myocardial ischemia detection method can also be applied to different numbers of The chest electrodes 21 and different numbers of ECG signals can also be evaluated using QTc interval distribution tables with different numbers of points. For example, the following Tables 5 to 8 and Figures 11 to 14 are in sequence respectively. For the patients in the above Tables 1 to 4 and the above Figures 6 to 9, 24 ECG signals are obtained with the 24 chest electrodes 21 shown in Figure 10. After calculating the QTc interval of the ECG signals , and then obtain a QTc interval distribution table of a total of 36 points (including the aforementioned 24 QTc intervals calculated from the ECG signals) through two-dimensional interpolation calculations and the corresponding images displayed on the output unit 6 .

Among them, in terms of the lateral positions of the chest electrodes 21 corresponding to the human body 1, 4 of the chest electrodes 21 correspond to the right sternal edge 11, and 5 of the chest electrodes 21 correspond to the left The sternal border 111 and the four chest electrodes 21 correspond to the midline 113 between the left sternal border 111 and the left clavicle midline 112. The four chest electrodes 21 correspond to the left clavicle midline 112 and the four chest electrodes. 21 corresponds to the left axillary front edge line 114, and three chest electrodes 21 correspond to the left axillary midline 13; in terms of the longitudinal position of the chest electrodes 21 corresponding to the human body 1, the chest electrodes 21 Two of the chest electrodes 21 correspond to the first intercostal space corresponding to the height of the right sternal edge 11, three chest electrodes 21 correspond to a second intercostal space corresponding to the height of the right sternal edge 11, and five chest electrodes 21 correspond to the The third intercostal space corresponds to the height of the right sternal edge 11 , the six prethoracic electrodes 21 correspond to the fourth intercostal space corresponds to the height of the right sternal edge 11 , and the five prethoracic electrodes 21 correspond to the fifth intercostal space corresponding to the right sternal edge 11 The height of the three chest electrodes 21 corresponds to the sixth intercostal space and the height of the right sternal edge 11 .

By comparing the above Tables 1 to 4 and the above Figures 6 to 9, and the following Tables 5 to 8 and Figures 11 to 14, it can be found that for the same patient, regardless of the 16 ECG signals (see Figure 3; QTc interval distribution table at 24 points) or 24 ECG signals (see Figure 10; QTc interval distribution table at 36 points) for calculation and analysis, which can be obtained when analyzing the location and extent of myocardial ischemia. Consistent analysis results, and in some cases, analysis with 24 ECG signals (36-point QTc interval distribution table) can also more clearly see areas with low QTc intervals (for example: Figure 14 Compared with Figure 9, it can be clearly seen that the area with low QTc interval covers the three comparison areas 411 of the comparison information 41). In this embodiment, 24 ECG signals are analyzed (and then the QTc interval distribution table of a total of 36 points is obtained through two-dimensional interpolation calculation), if When it is greater than 9.4 milliseconds (msec) or QTcD is greater than 66 milliseconds (msec), it means there is significant myocardial ischemia, and more aggressive treatment may be required.

Table 5 Examples of QTc intervals in patients with left recurrent coronary artery (LCX) stenosis 426 422 413 413 413 413 426 413 405 403 401 407 426 409 400 392 388 384 426 405 396 383 362 358 411 396 388 366 451 451 411 404 386 366 447 449

Table 6 Examples of QTc intervals in patients with right coronary artery (RCA) stenosis 398 398 411 411 411 411 413 417 425 409 408 410 417 428 356 390 405 408 428 348 390 394 409 409 394 360 398 394 409 413 394 377 392 402 398 405

Table 7 Examples of QTc intervals in patients with left anterior descending coronary artery (LAD) stenosis 395 370 372 372 372 372 395 336 374 374 380 376 415 374 378 378 395 390 415 399 382 382 399 399 403 390 403 403 403 399 403 397 402 407 403 401

Table 8 Examples of QTc intervals in patients with stenosis of all three coronary arteries (3VD) 413 422 391 391 391 391 385 372 360 389 394 392 376 364 442 417 401 394 364 458 430 417 405 389 401 438 422 417 422 422 401 419 424 430 430 426

When assessing the severity of overall myocardial ischemia, whether the first assessment mode or the second assessment mode is used, the main principle is to calculate the degree of dispersion of the QTc intervals. When The greater the QTcD value or the difference between the maximum value and the minimum value of the QTc interval, the more serious the overall myocardial ischemia of the human body 1 is.

For example, taking the analysis results of 16 ECG signals, Table 1 The value is 17.96, the difference between the maximum value and the minimum value of the QTc interval is 93, and the QTcD in Table 3 The value is 7.58, and the difference between the maximum value and the minimum value of the QTc interval, QTcD, is 41. Therefore, whether the first evaluation mode or the second evaluation mode is used, the patients in Table 1 can be estimated The overall severity of myocardial ischemia is more serious than that of the patients in Table 3, and the patients in Table 1 Both values and QTcD indicate that the patients in Table 1 may require more aggressive treatment and therefore have consistent assessment results.

In addition, taking the analysis results of 24 ECG signals as an example, taking Tables 5 and 7 of the same patients as Table 1 and Table 3 respectively, the The value is 13.35, the difference between the maximum value and the minimum value of the QTc interval is 93, and the QTcD in Table 7 The value is 9.11, and the difference between the maximum value and the minimum value of the QTc interval is QTcD 79. Therefore, it can also be inferred that the severity of the overall myocardial ischemia of the patients in Table 5 (that is, the patients in Table 1) is greater than that in Table 5. 7 patients (i.e., patients in Table 3) are serious, which means that consistent analysis results can be achieved regardless of whether 16 ECG signals or 24 ECG signals are used for analysis.

In addition, the arrangement of the chest electrodes 21 may not be limited to the arrangement of FIG. 3 and FIG. 10 . Take FIG. 15 as an example. FIG. 15 shows another arrangement of 24 chest electrodes 21 . In terms of the lateral position of the chest electrodes 21 corresponding to the human body 1, three of the chest electrodes 21 correspond to the right sternal edge 11, and five of the chest electrodes 21 correspond to the left sternal edge 111, The five chest electrodes 21 correspond to the midline 113 between the left sternal edge 111 and the left clavicle midline 112, the four chest electrodes 21 correspond to the left clavicle midline 112, and the four chest electrodes 21 correspond to the left The front edge line 114 of the armpit and the three chest electrodes 21 correspond to the left axillary midline 13; in terms of the longitudinal position of the chest electrodes 21 corresponding to the human body 1, one of the chest electrodes 21 The chest electrode 21 corresponds to a second intercostal space corresponding to the height of the right sternal edge 11 , four chest electrodes 21 correspond to the third intercostal space corresponding to the height of the right sternal border 11 , and five chest electrodes 21 correspond to the fourth intercostal space. At the height of the right sternal margin 11 , five chest electrodes 21 correspond to the fifth intercostal space, four chest electrodes 21 correspond to the sixth intercostal space, correspond to the height of the right sternal border 11 , and correspond to The five chest electrodes 21 located on the midline 113 between the left sternal edge 111 and the left clavicle midline 112 respectively correspond to a third rib, the fourth rib, the fifth rib, and the sixth rib. and the height of the seventh rib.

After actual measurement and analysis, according to the arrangement of the chest electrodes 21 disclosed in Figure 15, when analyzing the location and range of myocardial ischemia, as well as the severity of the patient's overall myocardial ischemia, it can be obtained that the same results as shown in Figure 3 and Figure 10 The analysis results are consistent with the arrangement of the chest electrodes 21.

In addition, referring to Figure 16, the number of the chest electrodes 21 can also be 36. In terms of the lateral position of the chest electrodes 21 corresponding to the human body 1, 7 of the chest electrodes 21 The electrode 21 corresponds to the right sternal edge 11, the seven chest electrodes 21 correspond to the left sternal edge 111, and the seven chest electrodes 21 correspond to the midline 113, 6 between the left sternal edge 111 and the left clavicle midline 112. One chest electrode 21 corresponds to the left clavicle midline 112, five chest electrodes 21 corresponds to the left axillary anterior edge line 114, and four chest electrodes 21 corresponds to the left axillary midline 13; with these chest electrodes 21 corresponds to the longitudinal position of the human body 1, two of the chest electrodes 21 correspond to the first intercostal space, correspond to the height of the right sternal edge 11, and three chest electrodes 21 correspond to the second The intercostal space corresponds to the height of the right sternal border 11 , the four chest electrodes 21 correspond to the third intercostal space and the five chest electrodes 21 correspond to the fourth intercostal space and the height of the right sternal border 11 , Five chest electrodes 21 correspond to the fifth intercostal space corresponding to the height of the right sternal border 11, five chest electrodes 21 correspond to the sixth intercostal space corresponding to the height of the right sternal border 11, and five chest electrodes 21 correspond to a seventh The intercostal space corresponds to the height of the right sternal edge 11 and corresponds to the midline 113 between the left sternal edge 111 and the left clavicle midline 112. The seven chest electrodes 21 respectively correspond to a second rib and the third rib. The height of the third rib, the fourth rib, the fifth rib, the sixth rib, the seventh rib and the eighth rib.

After actual measurement and analysis, according to the arrangement of the chest electrodes 21 disclosed in Figure 16, when analyzing the location and range of myocardial ischemia, as well as the severity of the patient's overall myocardial ischemia, it can also be obtained according to Figures 3 and 3. The analysis results are consistent with the arrangement of the chest electrodes 21 in Figure 10 and Figure 15 .

According to the above description, the advantages of the myocardial ischemia detection device and myocardial ischemia detection method of the present invention include:

1. The present invention calculates the characteristic values based on the QT intervals and the RR intervals to detect the myocardial ischemia position of the human body 1. Compared with the existing analysis method that uses the waveform changes of the ST segment, the QT The intervals and these RR intervals are less affected by chest wall impedance, noise, and baseline shifts, thus avoiding estimation errors.

2. The present invention uses the ECG signal measurement position corresponding to at least one of the lowest characteristic values to detect the position of myocardial ischemia. Compared with the existing ST segment rise or rise of most leads of the same group, Using the falling waveform change as the basis for evaluation, the detection method of the present invention is relatively easy and can effectively improve its sensitivity.

3. The numerical differences and corresponding distribution positions of the characteristic values are imaged on the output unit 6 with different color levels, so that the user can easily and conveniently understand the high and low distribution of the characteristic values to facilitate the assessment of myocardium. The location of ischemia and the extent of myocardial ischemia can effectively shorten the evaluation time.

4. Using a single indicator (i.e. It is very simple to evaluate the severity of overall myocardial ischemia using the QTcD value or the difference between the maximum value and the minimum value of the QTc interval.

5. By arranging at least 16 chest electrodes 21, the chest electrodes 21 are arranged at special layout positions of the reference surface 100, and the processing unit 3 calculates the ECG signal based on the ECG signals. Equivalent eigenvalues can completely provide the characteristics of the ECG signal of the reference surface 100. Therefore, even when applied to an unstressed human body 1, the location and range of chronic and acute myocardial ischemia of the human body 1 can be estimated. Moreover, due to the The number of chest electrodes 21 is only at least 16, so there is no need to increase too much manufacturing cost and the use is very convenient.

6. Since the chest electrodes 21 are arranged on the reference plane 100, the characteristics calculated from the ECG signals measured by the 16 chest electrodes 21 can be calculated through two-dimensional interpolation calculations. Values, expanded to 24 point characteristic values, can improve the accuracy of judgment compared to traditional twelve-lead electrocardiograms, and can reduce the number of chest pains compared to the existing method of obtaining electrocardiograms with more than a hundred electrodes. The number of front electrodes 21 is reduced to reduce costs and simplify the positioning steps when attaching the electrodes to the human body 1 .

7. By arranging the wearing unit 7, when the human body 1 wears the wearing unit 7, the chest electrodes 21 respectively correspond to the predetermined positions of the reference surface 100, thus simplifying the setting of the chest electrodes 21. The positioning and operating steps of the human body can speed up the work process and ensure the correct placement of the chest electrodes 21 .

In addition, it should be noted that in this embodiment, each characteristic value is the QTc interval of a respective ECG signal. However, in other implementations, each characteristic value can also be a respective QTc interval of the ECG signal. The QT interval of the signal (that is, it is not corrected by the RR interval, so there is no need to capture the RR interval of each ECG signal), and the same effect can be achieved according to the above detection steps.

In summary, the myocardial ischemia detection device and myocardial ischemia detection method of the present invention detect the myocardial ischemia position of the human body 1 by calculating the characteristic values based on the QT intervals and the RR intervals, Compared with the existing analysis method based on ST segment waveform changes, the QT intervals and the RR intervals are less affected by chest wall impedance, noise and baseline deviation, so evaluation errors can be avoided, so it is indeed The purpose of the present invention can be achieved.

However, the above are only examples of the present invention and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made based on the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. within the scope covered by the patent of this invention.

1: human body 100:Reference surface 11: Right sternal edge 111: Left sternal edge 112: Midline of left clavicle 113: Center line 114: Front edge line of left armpit 12: Horizontal line 13: Midline of left armpit 14: Horizontal line 2:Measurement unit 21: Chest electrode 22: Signal buffer 23: Signal amplifier 24:Filter 25:Signal converter 26:limb electrode 3: Processing unit 4: Database unit 41:Comparison information 411:Comparison area 5:Input unit 6:Output unit 7: Wearing unit

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a system block diagram of an embodiment of the myocardial ischemia detection device of the present invention; Figure 2 is a schematic diagram illustrating that a reference plane of a human body corresponding to several ECG signals obtained in this embodiment is a horizontal line corresponding to the height of the right sternal edge and a first intercostal space of the human body. , a left axillary midline, and a horizontal line of the eighth rib corresponding to the height of the right sternal border; Figure 3 is a schematic diagram illustrating the placement locations of 16 chest electrodes in this embodiment; Figure 4 is a schematic diagram of comparison information stored in a database unit in this embodiment; Figure 5 is a flow chart illustrating the flow of a myocardial ischemia detection method using this embodiment; Figure 6 is a schematic diagram illustrating the acquisition of 16 ECG signals from the left chest of a patient with left return coronary artery (LCX) stenosis, and after obtaining the characteristic values of 24 points through two-dimensional interpolation calculation, An image output to an output unit using different color levels to represent the levels of the characteristic values of the ECG signals; Figure 7 is another schematic diagram illustrating that 16 ECG signals are obtained from the left chest of a patient with right coronary artery (RCA) stenosis, and after two-dimensional interpolation calculation is used to obtain the characteristic values of 24 points, The image output to the output unit uses different color levels to represent the levels of the characteristic values of the ECG signals; Figure 8 is another schematic diagram illustrating the acquisition of 16 ECG signals from the left chest of a patient with left anterior descending coronary artery (LAD) stenosis, and the use of two-dimensional interpolation to calculate the characteristic values of 24 points. Then, different color levels are used to represent the levels of the characteristic values of the ECG signals and the images are output to the output unit; Figure 9 is another schematic diagram illustrating the acquisition of 16 ECG signals from the left chest of a patient with three coronary artery stenosis (3VD), and the two-dimensional interpolation calculation to obtain the characteristic values of 24 points. , using different color levels to represent the level of the characteristic values of the ECG signals and outputting the image to the output unit; Figure 10 is a schematic diagram similar to Figure 3, illustrating a modified arrangement in which the number of chest electrodes in this embodiment is changed to 24; Figure 11 is a diagram similar to Figure 6, illustrating that 24 ECG signals were obtained from the left chest of the patient with left return coronary artery (LCX) stenosis, and 36 points were obtained using two-dimensional interpolation calculations. After the characteristic value is determined, different color levels are used to represent the level of the characteristic value of the ECG signal and the image is output to the output unit; Figure 12 is a diagram similar to Figure 7, illustrating that 24 ECG signals were obtained from the left chest of the patient with right coronary artery (RCA) stenosis, and the characteristics of 36 points were obtained through two-dimensional interpolation calculations. After the value is obtained, different color levels are used to represent the level of the characteristic values of the ECG signals and the image is output to the output unit; Figure 13 is a diagram similar to Figure 8, illustrating that 24 ECG signals were obtained from the left chest of the patient with left anterior descending coronary artery (LAD) stenosis, and 36 points were obtained by two-dimensional interpolation calculation. After the characteristic value is determined, different color levels are used to represent the level of the characteristic value of the ECG signal and the image is output to the output unit; Figure 14 is a diagram similar to Figure 9, illustrating that 24 ECG signals were obtained from the left chest of the patient with all three coronary arteries stenosis (3VD), and the characteristics of 36 points were obtained by two-dimensional interpolation calculation. After the value is obtained, different color levels are used to represent the level of the characteristic values of the ECG signals and the image is output to the output unit; Figure 15 is another schematic diagram similar to Figure 3, illustrating another variation of the arrangement in which the number of chest electrodes in this embodiment is changed to 24; and FIG. 16 is another schematic diagram similar to FIG. 3 , illustrating a modified arrangement in which the number of chest electrodes in this embodiment is changed to 36.

2:Measurement unit

21: Chest electrode

22: Signal buffer

23: Signal amplifier

24:Filter

25:Signal converter

26:limb electrode

3: Processing unit

4: Database unit

5:Input unit

6:Output unit

Claims (7)

A myocardial ischemia detection device, suitable for a human body, the myocardial ischemia detection device includes: a measurement unit, including four limb conduction electrodes, and several chest electrodes, the limb conduction electrodes and the chest electrodes It is suitable for obtaining several ECG signals of the human body, and at least part of the measurement positions of the chest electrodes correspond to the left chest of the human body; a processing unit, the signal is connected to the measurement unit and can receive the ECG signals, The processing unit can capture the QT intervals and RR intervals of the ECG signals, and use the QT intervals and the RR intervals to calculate a number of points corresponding to several points on the left chest of the human body. The characteristic value of the QTc interval is used to detect the myocardial ischemia position of the human body based on the ECG signal measurement position corresponding to at least one of the lowest characteristic values; and an output unit is connected to the measurement signal. Unit; wherein, the processing unit can image the numerical difference of the feature values and the corresponding distribution position in the output unit with different color levels, and the processing unit can also calculate a discrete parameter with an evaluation parameter algorithm, and use This discrete parameter evaluates the severity of the human body's overall myocardial ischemia. The evaluation parameter algorithm is:

, SI _QTc is the discrete parameter, S is the total number of such points, (QTc) _k is the QTc interval of a specific point, n is the number of points closest to the specific point corresponding to the human body position, (QTc) _i is the QTc interval of one of the points closest to the point corresponding to the position of the human body. The myocardial ischemia detection device as claimed in claim 1, further comprising a database list Yuan, the database unit stores a comparison information, and the processing unit can compare the comparison information with the comparison information according to the high and low distribution status of the characteristic values to detect the range of myocardial ischemia. The myocardial ischemia detection device as described in claim 2, wherein the chest electrodes of the measurement unit and the chest electrodes are adapted to obtain at least 16 of the ECG signals from a reference surface of the human body, The reference plane is defined by a right sternal border of the human body, a horizontal line of the first intercostal space corresponding to the height of the right sternal border, a left axillary midline, and a horizontal line of the eighth rib corresponding to the height of the right sternal border. out. The myocardial ischemia detection device according to claim 2, wherein the processing unit can also calculate the difference value QTcD between the maximum value and the minimum value of the QTc intervals at the points, and calculate the difference value QTcD based on the QTc intervals. The difference between the maximum value and the minimum value evaluates the severity of the human body's overall myocardial ischemia. A myocardial ischemia detection method includes: a measurement step to obtain several ECG signals of a human body, and the measurement positions of at least part of the ECG signals correspond to the left chest of the human body; and a feature acquisition step to obtain A processing unit captures the QT interval and RR interval of each ECG signal, and calculates several QTc intervals corresponding to several points on the left chest of the human body based on the QT intervals and the RR intervals. characteristic values of the period; a first analysis step, comparing the point corresponding to at least one of the lowest of the characteristic values to the position of the left chest of the human body, wherein the high and low distribution status of the characteristic values is calculated according to Corresponding to the position of the left chest of the human body, an image is generated using different color levels to represent the levels of the characteristic values, and the range of myocardial ischemia is detected by comparing the image with the comparison information; and The second analysis step uses an evaluation parameter algorithm to calculate a discrete parameter, and uses the discrete parameter to evaluate the severity of the human body's overall myocardial ischemia. The evaluation parameter algorithm is:

(QTc) _i |}, SI _QTc is the discrete parameter, S is the total number of points, (QTc) _k is the QTc interval of a specific point, n is the position closest to the point corresponding to the human body The number of points, (QTc) _i is the QTc interval of one of the points closest to the point corresponding to the human body position. The myocardial ischemia detection method as described in claim 5, wherein the measurement step is to obtain the ECG signals from a reference plane of the human body, the reference plane being composed of a right sternal edge of the human body and a first The intercostal space is defined by a horizontal line corresponding to the height of the right sternal border, a left axillary midline, and a horizontal line of the eighth rib corresponding to the height of the right sternal border. The myocardial ischemia detection method as described in claim 5, wherein the characteristic values calculated in the feature extraction step are the QTc intervals corresponding to the points calculated based on the ECG signals, and the myocardial ischemia detection method The method also includes a second analysis step. The second analysis step is to calculate the difference between the maximum value and the minimum value of the QTc intervals at the points, and based on the difference between the maximum value and the minimum value of the QTc intervals. The gap value QTcD evaluates the severity of the person's overall myocardial ischemia.

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