KR100980331B1 - Myocardial Infarction Diagnostics using Parameters of Magnetocardiography - Google Patents

Abstract

The present invention relates to a method for diagnosing myocardial infarction using a combination of parameters of the cardiac diagram. More specifically, the peak and the T wave of the T wave, which is a repolarization section that is significantly affected by cardiac disease, are measured in the cardiac diagram signal measured by the cardiac diagram measuring apparatus. After extracting parameters such as magnetic map angle and current angle, the representative parameters that can be used for ischemic diagnosis are selected from the extracted parameters. By checking the status of normal or patient in each parameter, the final check-sum determines the presence of myocardial infarction, especially in ECG, which is not present in ECG, enabling easy measurement by non-contact, and within 10 minutes of measurement. Method for diagnosing myocardial infarction caused by ischemia will be.

Myocardial infarction diagnostic method according to the ischemia of the present invention is a myocardial infarction diagnostic method using a cardiac diagram measuring device, the process of measuring the cardiac in the shield room; Extracting a parameter using the measured core figure; Assigning a score to the extracted parameter against a reference value; And determining the presence or absence of the patient by the sum of the assigned scores.

In addition, the parameters used in the present invention consists of T-CA, T-FMA, T-MMR, TT-MAMx, TT-MAMn, TT-MAD, TT-DD, TT-CAMx, TT-CAMn, TT-CAD .

Core, parameter, ischemia, myocardial infarction, magnetic map angle, current angle

Description

Myocardial Infarction Diagnostics using Parameters of Magnetocardiography

The present invention relates to a method for diagnosing myocardial infarction using a combination of parameters of the cardiac diagram. More specifically, the peak and the T wave of the T wave, which is a repolarization period that is significantly affected by cardiac disease, are measured in the cardiac diagram signal measured by the cardiac diagram measuring apparatus. After extracting parameters such as magnetic map angle and current angle, the representative parameters that can be used for ischemic diagnosis are selected from the extracted parameters. By checking the status of normal or patient in each parameter to determine whether myocardial infarction is not present in ischemic patients, especially in ECG, by the final check-sum, it is possible to easily measure non-contact, and within 10 minutes after measurement Ischemia-induced myocardial infarction method that can diagnose and enable rapid prescription A.

In Korea, cardiovascular disease is the leading cause of death following cancer disease. In particular, coronary artery disease of the heart causes acute myocardial infarction or myocardial necrosis when the disease is diverse and late detection, and furthermore, stroke is associated with early detection of coronary artery disease.

Many medical devices are used for the diagnosis of coronary artery disease, but there are not many non-invasive diagnostic methods. Typical non-invasive and non-hazardous equipment used is electrocardiogram (ECG). The ECG provides a basic cardiac condition, but the sensitivity and specificity of the diagnosis of some diseases such as myocardial infarction are not high. Therefore, other test methods should be performed to measure this.

Another noninvasive method is ultrasonography, which is relatively well known for severe calcification of coronary arteries, but is reported to have low sensitivity to microcalcifications (GJ Friedrich, NY Moes). , and VA Muhlberger, “Detection of intralesional calcium in coronary arteries,” Circulation, vol. 94, no. 3, pp. 588, 1996.)

Blood tests are used to determine whether myocardial infarction is present. However, in order to know if there is an infarction by this method, it is reported that a continuous blood sampling for 8 to 12 hours can increase the sensitivity. It is pointed out that the patient has to wait 12 hours or more for examination even if the patient's condition changes rapidly. (R. H. Christenson, H. M. Azzazy, "Biochemical markers of the acute coronary syndromes," Clin Chem. Vol. 44, no. 8, pp. 1855-1864, 1998)

In addition, anatomical information, MRI, is used for diagnosing the coronary artery of the heart. This method shows better resolution than 50% of stenosis than the conventional invasive coronary angiogram, but it is not suitable for early diagnosis.

Next, there are magnetograms (MCGs) that measure the magnetic field of the heart in a similar way to ECG, which measures the current signal of the heart. The cardiac diagram is a device that measures the magnetic field that generates the current source of the heart and recalculates the current source or directly analyzes the magnetic field distribution.It is not only harmless to the human body like ECG, but also a non-contact method that does not require the adhesion of electrodes. It's suddenly rising.

The MCG was evaluated to be very effective and highly useful for the diagnosis of ischemia, arrhythmia and fetal heart. In addition, the MCG, a non-contact diagnostic device, needs to study various diseases in the measurement data so that the diagnosis time can be shortened and the disease management can be performed quickly.

Myocardial infarction diagnostic method using a combination of parameters of the core diagram of the present invention for solving the above problems,

A method for diagnosing myocardial infarction using a core measuring apparatus, the method comprising: measuring a core scale in a shielded room; Extracting a parameter using the measured core figure; Assigning a score to the extracted parameter against a reference value; And determining the presence or absence of the patient by the sum of the assigned scores.

In addition, the parameters extracted in the parameter extraction process is T-CA, T-FMA, T-MMR, TT-MAMx, TT-MAMn, TT-MAD, TT-DD, TT-CAMx, TT-CAMn, TT-CAD In case of deviation from the standard value of each parameter, 1 point is given to the patient if the total score is 4 points or more.

As described in detail above, myocardial infarction diagnostic method using a combination of parameters of the cardiac diagram of the present invention,

The parameters of magnetic map angle and current angle are extracted from the peak of T wave, which is a repolarization section that is greatly influenced by heart disease, and the specific values of T wave from the core figure signal measured by the core figure measuring device. From the extracted parameters, we select representative parameters that can be used for ischemia diagnosis, set the distribution of normal people and patients in each of these parameters, and then check the normal or non-patient status in each parameter to determine the presence of ischemia patients by the final check-sum. This enables easy measurement by non-contact, and can diagnose the presence of patients within 10 minutes after the measurement.

That is, the myocardial infarction diagnostic method of the present invention is better looking for myocardial infarction due to ischemia than general ischemia. Ischemia-related diseases can be divided into stable angina, unstable angina, myocardial infarction without ST-segment elevation (STEMI), and myocardial infarction (NSTEMI) with ST-segment elevation, among which angina is a pre-infarction symptom. Segment elevation is immediately observed because ECG records are observed, but in case of NSTEMI, it is very difficult to confirm immediately because it cannot be observed in ECG.

Therefore, myocardial infarction without elevation of ST-segment could not be confirmed by ECG, so immediate emergency treatment was difficult. However, the result of the 10-variable check sum proposed by the diagnostic method of the present invention confirmed 96% of myocardial infarction without elevation of ST-segment. By allowing the procedure to be performed, the diagnosis time of myocardial infarction due to ischemia can be greatly shortened and a useful method for improving the accuracy of the diagnosis can be provided.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Myocardial infarction diagnostic method using a combination of parameters of the cardiac diagram according to the present invention uses the data of the cardiac diagram measuring apparatus, and as shown in Figure 1, the cardiac diagram measurement process, the parameter extraction process, the scoring process, the determination process.

In the magnetic field measurement process (P1), measurements are made in a magnetic shield room, which is activated by minute electrical signals to the human body, and these microelectric signals correspond to one tenths of thousands of the earth's magnetic fields. In order to do this, measurements must be made with the earth magnetic field blocked. For example, the brain has one billionth century of the earth's magnetic field, and the heart transmits signals to one millionth of the earth's magnetic field. To measure this, the core is also measured in a shielded room. The instrument is installed so that measurements can be made.

As shown in FIG. 2, the magnetic field measurement device 10 is installed in the magnetic shield room 20. The core measurement device is a 64-channel superconducting quantum interference device (SQUID) element is arranged to measure the minute current and magnetic body of the body. Such a squid 11 is installed in a cooling means for maintaining the cryogenic temperature to maintain it by operating in a cryogenic state below minus 250 degrees to be measured.

When the core figure is measured in the magnetic shield room, a parameter extraction process P2 is performed. For example, as shown in FIG. 3A, a core diagram signal having a pattern similar to the ECG signal of the ECG appears. As shown, the core diagram signal sequentially shows P, Q, R, S, and T peaks. The abnormal signs of a heart attack patient are found in the T peak section, and early diagnosis of ischemia, which is one of the main causes of cardiac abnormalities, may be possible.

Therefore, various variables extracted from the T-peak and the 1/3 point of the T-peak to the T-peak (Fig. 3b) (JW Park, F. Jung, "Qualitative and quantitative description of myocardial ischemia by means of magnetocardiography," Biomed Tech (Berl), vol. 49, pp. 267? 73, 2004.), provides early diagnosis of myocardial infarction due to ischemia and combination of parameters that can improve the accuracy to provide diagnostic methods that improve sensitivity and specificity. do.

First, various variables are shown in Figure 3a is a core diagram signal graph measured by the core measurement device, Figure 3b is a graph showing only the T wave in the core diagram signal, Figure 4a is a figure showing the core diagram as a magnetic field map 4B is a diagram showing a core diagram as a current map, and FIG. 4C is set with reference to a graph in which a magnetic field map anode and a cathode in a horizontal state are displayed in a vertical state.

The variable extraction is referred to as the maximum current moment (MCM) when the T peak is peaked as shown in FIG. 3B, and the line where the two peaks of the body form the maximum current source as shown in FIG. 4B (“body horizontal plane”). Angle of the maximum current (CA) represented by θc in the drawing, and a magnetic map represented by θm in the drawing as an angle formed by the line connecting the cathode and the anode with the body horizontal plane as shown in FIG. 4A. Field map angle (FMA), the distance between the center of the cathode and anode, the pole distance (PD) in the drawing, the maximum / minimum pole size ratio at the cathode and anode as shown in FIG. Maximum to minimum ratio (MMR) can be extracted.

In addition, as shown in FIG. 3b, a specific time in the T _{max / 3} to T _max intervals that are frequently used for myocardial ischemia, that is, a point starting from one-third of the maximum T wave size and reaching the peak of the T wave (TT-). Map angle maximum (MAMx), which is the maximum angle formed by the cathode and anode in the section, map angle minimum (MAMn), which is the minimum angle formed by the cathode and anode in the specific time section of the TT section, Map angle dynamics (MAD), which is the maximum change angle of a magnetic map in a specific time section of the TT section, and distance dynamics, which is a maximum change in the distance between a cathode and an anode in a specific time section of the TT section. DD), a maximum current angle (CAMx) that is the maximum angle formed by the maximum current source in a specific time section of the TT section, and a minimum current angle that is the minimum angle formed by the maximum current source in a specific time section of the TT section. angle min imum; CAMn), and variables of current angle dynamics (CAD) were extracted in a specific time interval of the TT interval.

Combination of ten parameters such as T-CA, T-FMA, T-MMR, TT-MAMx, TT-MAMn, TT-MAD, TT-DD, TT-CAMx, TT-CAMn and TT-CAD extracted as described above Ischemia was diagnosed. Of course, the Applicant further increased the number of parameters to derive the results by various combinations, but the same use of the ten was similar, so that only ten were extracted for quick diagnosis.

When applied to patients using the above 10 parameters, patients with myocardial infarction can be distinguished with accuracy from at least 85% to up to 96%. Doing so could lead to more accurate and faster results.

When the extraction of the parameter is completed, a process of assigning a score to a reference value (P3) is performed. Here, the reference value was measured by the degree of the cardiac for the normal person and the patient to check each of the above parameters, and set a range for distinguishing the normal person and the patient. (At this time, the reference line of the display angle is on the right, the bottom is embossed in the clockwise direction, and the top is intaglio in the counterclockwise direction, and the specific time is 30 ms.)

* TT-CAMx is within the range of -10 ~ 80 within the normal range.

* TT-CAMn is within the range of -20 to 56 within the normal range.

* TT-CAD is within the range of 0 to 19 degrees.

* TT-MAMx sets the angle within -98 ~ -33 to the range of normal person.

* TT-MAMn is within the range of -85 ~ -50 within the range of normal people.

* TT-MAD is within the range of 0 to 18 degrees.

* TT-DD is within the range of 0 ~ 26 mm within the normal range.

* T-CA ranges from -5 to 77 within the normal range.

* T-FMA is within the range of -86 ~ -45 within the normal range.

* T-MMR is within the range of 0.5 to 1 within the normal range.

Each variable was calculated by the following procedure.

Normal group 1-165 young people in their 20s (27.2 ± 9.0 years) who had no history of heart disease and who had no heart problems today, had no abnormalities on the electrocardiogram.

Those with a similar age to those in normal group 2 to 57 ischemic myocardial infarction who have no history of heart disease and who have recently been determined to have no abnormalities on electrocardiogram, echocardiography, and coronary angiography at the hospital. The mean age was 55.9 years (± 10.5 years).

Patients-83 people who were finally found to have ischemic myocardial infarction with an average age of 59.7 years (± 11.1 years). They were found to have no abnormalities on the electrocardiogram, but had an average of 85.5 (± 19.2)% of coronary artery stenosis.

The cardiacity was measured in both normal group 1, normal group 2, and patient group. The receiver operating characteristic curves (ROC) were used to determine the boundary between the patient group and the normal group.

For example, in the case of T-CA, as shown in FIG. 5, the area of the ROC curve in which the normal group 1 and the patient group are divided is very high as 0.927. Most of the variables showed high discrimination from at least 0.7 to 0.93 (note that an area of ROC curve of 1.0 means that the two groups are completely separated).

Next, in the determination method, one point is given only when the parameter measurement value of the diagnosis subject is out of the normal range compared with the above items.

If a score is given against the reference value, a determination process (P4) is performed to determine whether the patient is given the score.

In other words, when the total of points awarded in each of the ten items is 4 or more points, that is, when the four parameters deviate from the normal range, the patient is diagnosed with myocardial infarction due to ischemia.

The total score, which is a criterion for determining the presence or absence of the patient, was set by Table 1 below and FIG. As noted, the scores of 203 normal and 83 patients with myocardial infarction showed that the percentage of the normal population decreased significantly below 2 points, and that of the patient rapidly increased from 4 points. Therefore, up to 3 points were determined to be normal and from 4 points to patients.

As can be seen from the table, 84% (sensitivity) of normal subjects below 3 points and 96% (specificity) of patients above 4 points. Therefore, when the boundary between the normal person and the patient is set to a different score, for example, 2 points or less, the normal is 75% (sensitivity) and the patient is 98% (specificity). That is, the sensitivity and specificity are complementary to each other, so that under the same conditions, when one side becomes higher, the other side becomes lower. Therefore, in general, the case where the sum or average of these two values is the largest is considered to be the most optimal. When the mean value of these two values is the largest, the case where the boundary between the normal and the patient is set to 3 points is decided.

As described above, 146 people in their 20s, 57 people in their 50s, and 83 patients in their 50s were measured. The parameter data values of each group according to the measurement are shown in Table 2 below.

Here, TT- is a section from the one-third point of the T wave to the peak of the T wave, and T- means a variable derived from the T-wave peak (see FIG. 3B).

Statistical significance was marked with a star (**: p <0.01).

No statistical significance was found among the normals, but significance was found in myocardial dysplasia, which is different from both normal groups.

Table 3 shows the results of diagnosis by the different diagnostic methods for the two normal group and the patient (myocardial infarction) group.

All 83 patients measured in the ECG diagnosis were those without ST-segment elevation, which is characteristic of myocardial infarction on ECG.

The C-Angio (coronary angiogram) method is an invasive method that is used as a key technique for understanding myocardial infarction in hospitals. Therefore, the normal 20s cannot be inspected, so there is no data.

The C-Angio is used as the gold standard for detecting the presence of myocardial ischemia and coronary heart disease. However, this method takes about 30 minutes to 3 hours, has to be administered a contrast agent, the behavior is limited for hemostasis for 24 hours after the procedure. Excessive X-ray exposure is also a problem. This method has a high risk of test because there is a possibility that about 1 person dies every 100,000 people who are tested. However, it can be seen that the probability of patient diagnosis is somewhat lower than that of the present invention.

Therefore, the diagnostic method of the present invention is a non-contact, low risk of inspection, it can be seen that faster and more accurate diagnosis than existing inspection methods.

In addition, the above-mentioned example is only an example to demonstrate this invention. Therefore, it is obvious that the ordinary skilled in the art to which the present invention pertains uses the partial change with reference to the detailed description.

1 is a process diagram showing a diagnostic process of the ischemic diagnostic method according to the present invention.

Figure 2 is a schematic diagram showing an apparatus for measuring the core figure of the present invention.

Figure 3a is a core diagram signal graph measured by the core measurement device according to the present invention.

3b is an enlarged graph illustrating only a T wave in a core diagram signal;

Figure 4a is a diagram showing the core diagram of the magnetic field map.

4b is a diagram showing the core diagram as a current map;

Figure 4c is a graph showing the magnetic field map anode and cathode in a vertical state in a horizontal state.

5 is a graph showing a receiver response characteristic curve (ROC) of T-CA among parameters according to an embodiment of the present invention.

Figure 6 is a graph showing the score distribution of the normal group and the patient group diagnosed by the diagnostic method of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: core measurement device

11: Squid

20: magnetic shield room

Claims (4)

In myocardial infarction diagnostic method using a core measurement device, Measuring core size in a shielded room (P1); Using the measured core diagram, parameters consisting of T-CA, T-FMA, T-MMR, TT-MAMx, TT-MAMn, TT-MAD, TT-DD, TT-CAMx, TT-CAMn, and TT-CAD are measured. Extraction process (P2); Giving a score to the extracted parameter against a reference value (P3); Myocardial infarction diagnostic method using a combination of parameters and the cardiac parameters, characterized in that comprises; step (P4) to determine the presence of a patient by the sum of the points given. delete The method of claim 1, The reference values for the parameters are -10 to 80 degrees for TT-CAMx, -20 to 56 degrees for TT-CAMn, 0 to 19 degrees for TT-CAD, -98 to -33 degrees for TT-MAMx, and -TT for -TT-MAMn. 85 to -50 degrees, 0 to 18 degrees for TT-MAD, 0 to 26 mm for TT-DD, -5 to 77 degrees for T-CA, -86 to -45 degrees for T-FMA, 0.5 for T-MMR Myocardial infarction diagnostic method using a combination of parameters of the heart diagram, characterized in that the ratio within ~ 1 to the normal range. The method of claim 1, The determination process is a cardiomyocardial diagnosis method using a combination of cardiac parameters, characterized in that the diagnosis of the patient when the total score given by one point is more than four points if the deviation from the reference value of each parameter in the previous process.

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