RU2154980C2 - Method for determining arterial blood pressure values based on cardiointervalometric indices(cardiac rhythm variability estimation) - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves applying cardiointervalography. Cardiointervalography values are analyzed. The values are treated to build an image of their combinations. The so built image is compared to reference one having some arterial blood pressure value set in correspondence. The arterial blood pressure is determined by most close approaching of the built image to a reference object. EFFECT: arterial blood pressure measurements under conditions where traditional methods are not applied. 3 dwg, 1 tbl

Description

 A known method for determining the functional state of the cardiovascular and autonomic nervous systems, determining hemodynamic disorders, including in hypertensive and hypotonic diseases, including the allocation of RR-intervals, statistical, spectral and other analysis of RR-intervals (see. Heart rate variability. Standards measurement, physiological interpretation and clinical use developed by the working group of the European Association of Cardiology and the North American Association of Electrophysiology and pacing, European Journal of Cardiology, March 1996, pp. 344-381. Heart rate variability. Standards of measurement, physiological interpretation and clinical use. The European Society of Cardiology and the North American Society of Pacing and Electrophysiology. European Heart Journal Vol 17, 354-381, March 1996).

 However, this method involves the calculation of only statistical and spectral indicators of heart rate variability in hemodynamic disorders, including hypertension and hypotension; a description of typical changes in some statistical and spectral indicators of heart rate variability in hypertensive and hypotonic diseases; without revealing the relationship between the violation of the regulation of blood pressure and the way of interrelations of indicators of heart rate variability. This leads to a narrowing of the diagnostic capabilities of the method of cardiointervalometry (assessment of heart rate variability) and the inability to solve the inverse problem of reliable determination of blood pressure based on an analysis of cardiointervalometry (assessment of heart rate variability).

 The objective of the invention is to develop a new concept for determining blood pressure based on the analysis of the image of the interdependence of indicators of cardiointervalometry (assessment of heart rate variability).

 To do this, in the known method for determining the functional state of the cardiovascular and autonomic nervous systems, determining hemodynamic disorders, including in hypertensive and hypotonic diseases, including the allocation of RR-intervals, statistical, spectral and other analysis of RR-intervals, indicators of analysis of cardiac variability rhythms are processed using a mathematical apparatus or other method, so as to compile the image of the inter-combinations of indicators for analyzing heart rate variability, reliably corresponding to blood pressure, determined both by the Korotkov method, the oscillometric method, and other standardized methods, according to the following structural formula, presented at the end of the text.

 A particular case of this structural formula is a method for directly calculating blood pressure indicators from cardiointervalometry indicators. In this case, the calculation formulas are based on the understanding by the expert making up these formulas of the image of the cardiointervalometry metrics, based on his experience.

 In FIG. 1 shows a block diagram of a device for recording a cardiointervalogram, where 1 is a cardioanalyzer designed to register an electrocardiogram and transfer it to a recording device (PC), 2 is an ECG electrode applied to a patient, 3 is a recording device (PC).

 Figure 2 shows the software interface, where 1 is the cardiointervalogram (the ordinal number of the RR interval is plotted along the abscissa axis, the value of the RR interval is plotted along the ordinate axis, 2 are some of the cardiointervalometry indicators shown in the table.

 In FIG. 3 shows the results of the structural formula. In this example, the image of the cardiointervalogram indicators correlations corresponding to certain blood pressure values was calculated using neural network technologies.

The method is as follows:
After registering the patient’s cardiointervalogram using one of the known methods, a certain number of RR-interval values are necessary for PCR, which is necessary for calculating the statistical, spectral and other indicators of the cardiointervalogram (Fig. 1). Calculate the statistical, spectral and other indicators of the cardiointervalogram (Fig. 2). The image of the cardiointervalogram indicators interconnections is revealed, both with the help of the corresponding mathematical apparatus for pattern recognition, expert systems, and at the intuitive-practical level in the form of formulas, etc. Find a reference image that reliably matches the parameters of blood pressure, determined both by the Korotkov method, the oscillometric method, and other standardized methods, as close as possible to the revealed image of the cardiointervalogram indicators interconnections (finding the reference image can be carried out either using the appropriate mathematical apparatus or intuitively -practical level, etc.). The parameters of blood pressure are determined based on the correspondence of the detected and reference images (Fig. 3).

 A modified scheme for determining blood pressure values is possible based on an analysis of cardiointervalometry (assessing heart rate variability), in which some steps, such as finding a reference image, are reduced or, conversely, expanded.

 A special case of this scheme is a scheme in which blood pressure parameters are directly determined after statistical, spectral and other indicators of the cardiointervalogram are calculated, based on formulas based on the understanding by the expert who composes these formulas of the image of the interrelation of cardiointervalometry indicators.

 Example.

 A study was conducted on a certain number of patients with hypertension who recorded cardiointervalogram and systolic and diastolic blood pressure by the Korotkov method. The resulting database was processed by a neural network software product such as BrainMaker. To train the neural network, the patient’s cardiointervalogram data were supplied to its “input neurons”, and the known values of systolic and diastolic blood pressure determined by the Korotkov method were assigned to the outputs of the neural network. After the “training” (reference image), the neural network formed a set of weighting factors, etc. for "recognizing" the values of systolic and diastolic blood pressure, determined by the Korotkov method, without its direct measurement, on the basis of the image of the interrelations of cardiointervalometry indicators (detected image). Verification of the accuracy of prediction of systolic and diastolic blood pressure values in a priori unexplored patients by comparing the predicted blood pressure and control measurement of blood pressure by the Korotkov method revealed an acceptable prediction accuracy.

 The described method allows you to determine blood pressure in conditions where it is impossible or difficult to use traditional methods of measuring blood pressure using a cuff (in a pressure chamber, during certain medical procedures, if necessary, continuous daily monitoring of blood pressure, etc.).

Literature
A working group of the European Association of Cardiology and the North American Association of Electrophysiology and Cardiac Stimulation, chaired by AJ Camm and M. Malik.

 Heart rate variability. Standards for Measurement, Physiological Interpretation, and Clinical Use, European Journal of Cardiology, March 1996, p. 354-381. Heart rate variability. Standards of measurement, physiological interpretation and clinical use. The European Society of Cardiology and the North American Society of Pacing and Electrophysiology. European Heart Journal Vol. 17, 354-381, March 1996.

Claims (1)

 A method for determining blood pressure values, characterized in that a cardiointervalogram (CIG) is recorded, an analysis of its indicators is carried out, an image of CIG indicators is made up of correlations, and blood pressure is determined by the maximum approximation of this image to the reference CIG image, which corresponds to certain blood pressure values.

Images