RU2204319C2 - Method and device for detecting myocardial infarction and determining its localization - Google Patents

Abstract

FIELD: medicine; medical engineering. SUBSTANCE: method involves comparing electric mobility of two neighboring myocardium areas in two leads. Sharp drop in tangent inclination with respect to harmonic spectrum envelope in the cases of various signs of tangent slope being found, infarction is considered to be available. The lead number showing negative tangent slope value is interpreted in terms of infarction lesion position. The device has movable body, two contact plates, two conductors connecting the plates to the receiving devices, two identical units for measuring heart beat periods, two analog-to- digital converter and two computation units for calculating tangent inclination angles to harmonic spectrum envelopes of QRS- complex biopotentials taken at the places the contact plates are positioned. The device has unit for measuring output signals ratio of both computation units connected to acoustic or luminous level signalization unit. EFFECT: high accuracy and reliability of measurements. 2 cl, 1 dwg, 1 tbl

Description

 The invention relates to cardiology and is intended to detect myocardial changes associated with a heart attack.

 There is a known [1] method for detecting myocardial infarction and determining its location, which consists in determining, using standard leads, the biopotentials of the heart and recording their changes in time on a recorder (electrocardiogram - ECG). Examining this record, a cardiologist can identify dangerous changes in the heart (including heart attack), and determine the location of the pathology by the number of the lead in which the ECG abnormality is detected. This method is similar to the invention.

 However, the known method has the disadvantage that it is necessary to record the ECG on a paper tape, as well as the fact that great demands are placed on the qualifications of a cardiologist for the correct interpretation of the ECG. In addition, it is practically impossible to distinguish between severe lung myocardial injuries (necrosis, i.e. heart attack) and relatively mild (microinfarction, angina pectoris, tachycardia, etc.) by ECG.

 There is a known [2] method for determining the electrical mobility of the heart, which consists in determining the biopotential of the heart in one of the chest leads closest to the heart (for example, in lead V2), measuring the period of heartbeats and analog-to-digital conversion (ADC) of the QRS complex of biopotential and determining its duration, the introduction of all these data into a computer and the calculation of the slope of the tangent to the envelope of the harmonic spectrum. With a negative inclination of the tangent, they say about the pathology of the heart, with a positive slope, about its normal state. This method is adopted as a prototype of the invention.

 However, the known method, although it does not require ECG recording and its decoding, has the disadvantage that it does not distinguish between severe (heart attack) and light (angina pectoris, etc.) cardiac pathology, and also does not provide information about the location of the heart attack.

 The proposed method for detecting myocardial infarction and determining its location allows to obtain a technical result, which consists in the fact that through the use of six pectoral leads (V1-V6), covering the entire surface of the heart, and comparing the slopes of the tangents to the envelope spectra of harmonics in neighboring leads, it becomes possible to identify myocardial infarction and determining its location.

 The invention consists in the following. The author found that in case of serious damage to any part of the myocardium (such as a heart attack), neighboring sections of the heart muscle take over the work of the affected area (like the formation of a parapet), and their electrical mobility increases dramatically. By comparing the electrical mobilities of two neighboring sections of the myocardium, in two adjacent leads, and finding a sharp difference in the slopes of the tangents to the envelope of the harmonic spectrum at different signs of the tangent slope, one can judge the presence of a heart attack, and by the number of the lead in which the tangent is negative is the location of the heart attack .

 The claimed method differs from the closest analogue in that the measurement of biopotentials and their processing in order to obtain a slope of the tangent to the spectral envelope are performed not in one, but in all chest leads and in that the output signals are compared in neighboring leads.

 The inventive step of this method is determined by the fact that the author first discovered and used the “parapet” phenomenon, which consists in the fact that in the case of serious lesions of any part of the heart muscle (such as a heart attack), neighboring areas of the myocardium take over the work of the affected area, and their electrical mobility rises sharply.

 The method is as follows.

 The biopotentials of the heart obtained in all standard pectoral leads are processed in turn to measure the period of heartbeats and determine the duration and results of the analog-to-digital conversion of the QRS complex obtained in this lead. All data are entered in turn into a computer in order to calculate the slope of the tangent to the envelope of the harmonic spectrum. Calculation results are printed for all pectoral leads. This makes it possible to print out whether there are adjacent leads with a large difference in the slope of the tangent with different signs (whether there is a heart attack), and if there is such a difference, determine the location of the heart attack from the neighboring leads in which the slope of the tangent is negative (table) .

 A device [1] is known for detecting myocardial infarction and determining its location, consisting of a body fixed at certain points of the body (standard leads), a contact plate and a conductor connecting it with a galvanometer and a recorder. Studying the time-recorded biopotentials of various points of the heart (ECG) recorded on the recorder enables a cardiologist to find out the presence of a heart attack and determine its location. This device is taken as a prototype.

 However, the known device has the disadvantage that it is equipped with rather bulky blocks in the form of a galvanometer and a recorder, and working with it when decoding the ECG requires a highly qualified cardiologist.

 The proposed device for detecting myocardial infarction and determining its location allows to obtain a technical result, namely, that the galvanometer and recorder are replaced by much more compact electronic units, two analog-to-digital converters and two computing units, and when working with it, you do not need high qualification of the attendant staff.

 The invention consists in the following. A device for detecting myocardial infarction and determining its location, containing a mobile housing, two contact plates, two conductors connecting these plates to receiving devices, two identical heart rate meters and an analog-to-digital converter, and two computing units for calculating the slopes of the tangents to the envelope of the harmonic spectrum The QRS complex of biopotentials obtained at the location of the contact plates is equipped with a meter for the ratio of the outputs of both computing units connected with a sound or light alarm level.

 From the closest analogue, the claimed device is distinguished by the presence of a movable housing, two contact plates, analog-to-digital converters and computing units, as well as a ratio meter equipped with sound or light level signaling.

 The inventive step of this device is determined by the fact that when constructing it, the “parapet” phenomenon established by the author is used, which consists in the fact that in the presence of a significant lesion (such as a heart attack) in some part of the heart muscle, the neighboring areas of the myocardium take over the work of the affected area, which expressed in a sharp change in the electrical mobility of the heart during the transition from the affected area to the neighboring.

 The invention is illustrated in the drawing, which shows a diagram of the proposed device. The device contains a movable housing 1, contact plates 2 and 2 ', heart rate meters and analog-to-digital converters 3 and 3' [2], computing units for calculating the slope of the tangents to the envelopes of the harmonic spectrum 4 and 4 '[2], ratio meter 5 (triggered only when its negative value) and block 6 light or sound level alarm.

 In the process, the mobile body 1 scans the heart region so that both contact plates 2 are pressed against the surface of the body. At each scan point, a delay of 3-4 seconds is required until the relationship meter is triggered. Contact plates capture the biopotentials of two adjacent points of the heart muscle. These biopotentials are processed in blocks 3 and 3 'in order to determine the period of heartbeats, the duration of the QRS complex and its analog-to-digital conversion. The data obtained in blocks 3 and 3 'are transmitted to blocks 4 and 4', where the slope of the tangent to the envelope of the harmonic spectrum is calculated. The output signals of blocks 4 and 4 'are supplied to the ratio meter 5, which is triggered when the ratio is negative. At a certain level of negative attitude, a command is sent to block 6, and a sound or light alarm is triggered, which indicates the presence of myocardial infarction; the position of the movable housing at this moment indicates its place.

 Using a device consisting of a movable housing, two contact plates, two analog-to-digital converters, two computing units and a ratio meter equipped with a sound level alarm allows detecting myocardial infarction and determining its location without removing an ECG and deciphering it by a cardiologist.

SOURCES OF INFORMATION
1. V.N. Orlov. Guide to electrocardiography. "Medicine", M., 1983, p. 256.

 2. R.E. Ershov, A.G. Ivanov. A method for determining the electrical mobility of the heart. Application for invention 940322299/14 (032127).

Claims (2)

 1. A method for detecting myocardial infarction and determining its location, which consists in determining the biopotentials of the heart, measuring the period of heartbeats, analog-to-digital conversion (ADC) of the QRS complex of the biopotential and determining its duration by the number of clock cycles of the ADC, entering all these data into the computer and calculating the tangent to the envelope of the harmonic spectrum, characterized in that the biopotentials are determined for all chest leads V1-V6, for each of these leads the slope of the tangent to the envelope of the harmonic spectrum is determined, and the presence A heart attack is judged by the existence of two adjacent leads, in which the slopes of the tangents have different signs and differ sharply in absolute value, and the location of the myocardial infarction is determined by the found two chest leads for which the slope of the tangent to the envelope of the harmonic spectrum will be negative.  2. Device for detecting myocardial infarction and determining its location, comprising a housing, a contact plate and a conductor connecting the contact plate to the receiving device, characterized in that it is provided with a second contact plate, a second conductor connecting it to the receiving device, two identical period meters heartbeats, analog-to-digital converters and computational units, as well as a meter for the ratio of the output signals of computational units that are triggered when negative and this relationship, and sound or light signaling the magnitude of the relationship.

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