RU2107458C1 - Method to predict the flow of ischemic cardiac disease - Google Patents

Abstract

FIELD: medicine, cardiology, diagnostics. SUBSTANCE: according to the values of the upper arterial pressure it is necessary to deduct the values of lower arterial pressure to determine an empirical coefficient of linear correlation (CLC) between this difference and the upper arterial pressure as dependent on the days of disease flow. Moreover, the first CLC estimation is conducted in that day of a disease when at least three or more different pairs of the upper and lower pressures are available. During another days of estimations new data concerning pressure are added to the obtained statistical sums and new CLC is detected. For normal organism these successive CLC values must be 0.9 not less. Pathology measure of a sick organism is a difference between 0.9 and CLC value determined. EFFECT: higher accuracy of diagnostics due to more complete usage of available information obtained at measuring lower arterial pressure and excluding subjective errors at estimating data according to lower and upper arterial pressure. 2 dwg

Description

 The invention relates to medicine, in particular to cardiology, and is intended for the diagnosis of coronary heart disease in the post-infarction period.

 There is a method of measuring blood pressure, which consists in applying a rubber cuff to the patient’s shoulder with an arterial pulsation sensor mounted in it, injecting air into the cuff and then bleeding it off and measuring the air pressure in the cuff using a pressure gauge, with the recorder’s tape moving in time with its readings . The pen of the recorder is set in motion by an arterial pulsation sensor mounted in the cuff; at the same time, several teeth are written out on the tape of the recorder. The position of the tape at the time of the appearance of the first of the teeth determines the upper blood pressure, the last - the lower. This method has low accuracy, because It contains a source of subjective errors related to the assessment of the values of upper and lower blood pressure, which depends on the qualifications of the doctor [1].

A known method for diagnosing the course of coronary heart disease [2], which consists in applying a rubber cuff to the patient’s shoulder connected to a manometer, injecting air into it and simultaneously listening with a stethoscope to the artery below the cuff application site. Pitting air gradually from the cuff, is determined by means sfignomanometra its pressure at the time of occurrence of noise in headphones stethoscope (high blood pressure _{in the} blood pressure) and the air pressure in the moment of disappearance of the noise (lower blood pressure BP _n). By the constancy of these pressures in the treatment of coronary heart disease, as well as by their presence within certain limits (for blood pressure _, this limit is usually determined by the patient’s well-being), the patient’s condition is judged.

 This method of diagnosing the course of coronary heart disease is taken as a prototype.

However, the known method adopted for the prototype has the disadvantage that it does not exclude subjective errors associated with determining the moments of measuring BP _in and BP _n (fixing these moments depends on the hearing acuity of the operator) and with the analysis of the values of BP _in and BP _n , the accuracy of which depends from the qualifications of a doctor.

The technical result of the invention is to improve accuracy of diagnosis by making fuller use of the lower blood pressure data and subjective error exception when assessing _blood pressure and blood pressure _BC.

This result is achieved thanks to the fact that according to _a daily measurement of blood pressure and a BP _n determined empirical coefficient of linear correlation (CLA) [3] between the upper blood pressure and the difference between the upper and lower blood pressure (pulse pressure). The first determination of CLK is made when, as a result of daily measurements of blood pressure _in blood pressure and blood pressure _n , at least three pairs of these values are distinct from each other. Subsequently, a new pair of measurements is added to the statistical sums by which the CLK is determined, and taking into account the increase in the number of measurement pairs per unit, a new CLK is calculated for the next day of illness. Thus, it is possible to obtain the dependence of consecutive CLA on the days of the disease, during which, as well as on the basis of CLA, it is possible to judge the course of coronary heart disease. Since CLA is calculated according to a formula, on the basis of indications sfignomanometra by its definition is completely excluded subjective error associated with the analysis of blood pressure _values BP and _n in the known method. In contrast to the known method, CLA is a completely objective characteristic of the patient's condition.

The inventive level of the proposed AD data processing _method and AD _n is determined by that of the known information about the blood pressure of the nature and methods of measuring it [2] for medical professionals clearly implies the possibility to characterize closeness of the relationship of the internal organs (in this case the heart and circulatory system) The linear correlation coefficient between parameters determining the operation of these bodies (in this case, _blood pressure and pulse pressure). Normally, this relationship should be strong, then KLK will be close to unity. But since the hardware error of the sphygnomanometer, associated with subjective errors in determining the moments of noise appearing in the headphones and its disappearance, is about 10%, the CLK value of its unit corresponds to the norm, and not less than 0.9. In pathology, the work of the heart and circulatory system is inconsistent, which leads to the appearance of a difference between 0.9 and the found CLA value, which can serve as a measure of pathology. Magnetic storms, upsetting the work of the circulatory system, cause CLA fluctuations the more, the higher the deviation of the body from the norm.

The method is as follows. With daily sfignomanometra measured upper and lower blood pressure _{in the} blood pressure BP _n. After each measurement, the difference in blood pressure is determined _{in the} -AD _n . Determine the day when, as a result of daily measurements, three distinct pairs of AD _in and AD _{n are} accumulated. The three pairs of AD _in and AD _in - AD _n determine the statistical sums and the empirical coefficient of linear correlation of CLK, corresponding to the day of accumulation of three pairs of different AD _in and AD _n . On the following measurement days, new statistical sums and a new CLK corresponding to these measurement days are calculated. The course of coronary heart disease is judged by the value of successive linear correlation coefficients (CLA), which for a normal body should not fall below 0.9, and for a patient, the degree of pathology is determined by the difference between 0.9 and the found CLA.

 In FIG. 1 shows data on the dependence of CLA on the day of measurement during a 24-day rehabilitation after a heart attack; in FIG. 2 shows an example implementation of the method.

 In FIG. 1 curve 1 refers to a patient with angina pectoris after a heart attack 25 years ago, curve 2 - to the case of rehabilitation after the first heart attack, curve 3 - to rehabilitation after the second heart attack. Vertical dashed lines show the days of magnetic storms. The CLA corresponding to curve 1 (patient 1) is kept at 0.9 and remains virtually unchanged during magnetic storm days. Curve 2 (patient 2) is characterized by small fluctuations associated with magnetic storms, CLK at the end of rehabilitation is set at 0.8. Curve 3 (patient 3) is characterized by significantly larger fluctuations near the days of magnetic storms, and by the end of rehabilitation it is set at 0.6. All this is consistent with the above information about the pathology.

где
P_iВ - верхнее артериальное давление в i-ый день измерения;
P_iН - нижнее артериальное давление в i-ый день измерения;
n - общее число дней измерений давления, включая день определения r_n;

- статистические суммы.In FIG. 2: 1 - data input unit, 2 - computing unit, 3 - memory units, the number of which corresponds to the number of patients, 4 - display, 5 - printer. The nature of the connection of the blocks is given in figure 2. The scheme works as follows. In block 1, data on upper and lower blood pressure, date of measurement and patient number are entered. In this block, the lower blood pressure is subtracted from the upper and a logical operation is carried out to determine the measurement date when three distinct pairs of upper and lower pressures are accumulated in the memory of block 1 (usually the third or fifth day of measurement). After that, all accumulated pairs of values together with their number are transferred to block 2, in which, according to the well-known formula [1], the statistical sums are determined and the empirical linear correlation coefficient r _{n is} calculated for the n-th day of observations:

Where
P _iB - upper blood pressure on the i-th day of measurement;
P _iН - lower blood pressure on the i-th day of measurement;
n - the total number of days pressure measurements, including the day of determination r _n;

- statistical amounts.

 The measurement date, when in block 1 three different pairs of upper and lower pressures are accumulated, as well as the values of the statistical sums and CLK defined in block 2, are transferred to the first memory element of that of blocks 3, whose address is determined by the patient number. When you enter the following values of the upper and lower pressures in block 1, the difference between the upper and lower pressures is determined again, and the number of measurements increases by one. The measurement date arrives at the next element of memory block 3, determined by the patient number (the number of elements in each of memory blocks 3 should be equal to the number of treatment days minus two). The difference between the upper and lower pressures defined in block 1 and a new number of measurements are sent to block 2, which simultaneously sums up the statistical sums from the previous memory element of block 3. In block 2, new statistical sums are calculated, and together with the new number of measurements, the CLK for next day of measurements. These new statistical sums, together with the new CLK, are entered into the element of memory block 3, in which there is already a new measurement date. Such operations are performed before the end of the treatment period, which allows you to record in each of the elements of the memory blocks 3 that relates to this patient, the measurement date and the corresponding CLK value. When you press the button with the number of this patient, all accumulated data on the KLK dependence on the days of pressure measurement are displayed on display 4, forming a graph, the abscissas of which correspond to the days of measurements preceding the day of the survey, and the ordinates correspond to KLK values related to these days. The display also shows a table of CLK values for each day of measurement. Thus, a portion of the graph of FIG. 1, up to the day of the survey, which allows you to monitor the progress of CLA in the treatment of coronary heart disease, i.e. diagnose its course. At the end of treatment, all the data on the dependence of CLA on the day of measurement, as well as a graph of this dependence are displayed on printer 5, which makes it possible to obtain a document attached to the medical history. After that, the corresponding memory block is cleared and ready to receive data from the next patient.

 Using the operation to determine successive empirical correlation coefficients between upper blood pressure and the difference between upper and lower pressure depending on the day of measurement allows you to more accurately monitor the progress of treatment of coronary heart disease, as well as make predictions for the future based on the final value of CLK.

Sources of information
1. Brief medical encyclopedia. - M .: Soviet Encyclopedia, 1973, v. 2, p. 305 (Oscillography).

 2. Brief medical encyclopedia. - M .: Soviet Encyclopedia, 1973, v. 2, p. 32-33 ("Blood Pressure") is a prototype.

 Shelest A.E. Microcalculators in physics. - M .: Nauka, 1988, p. 56-57.

Claims (1)

A method of diagnosis of coronary artery disease, comprising: daily measurement via ofignomanometra upper _blood pressure and lower BP _n arterial pressure, characterized by determining the day as a result of daily measurements accumulated three different from each other either _BP or by HELL _n , or both pairs of HELL _in and HELL _n together, determine the difference between HELL _in and HELL _n for these three pairs, summarize HELL _in , HELL _in ² , HELL _in -AD _n , (HELL _in -AD _n ) ² and HELL _in • (HELL _{in -} HELL _n ) for all three pairs of measurements and determine the linear correlation coefficient p about the formula

where n is the number of measurement pairs,
in the following days, summation of blood pressure _in , blood pressure _in ² , blood pressure _in -PH _n , (blood pressure _in -PH _n ) ² and blood pressure _in • (blood pressure _in -PH _n ) for all days of measurements and taking into account the number of measurements n is determined by the above the formula r _n corresponding to these measurement days, and by decreasing r _n below 0.9, the disease progression is judged, when r _n approaches 0.9, it is about recovery.

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