RU2268641C2 - Differential vector-cardiograph - Google Patents

Abstract

FIELD: medical radio electronics.

SUBSTANCE: device can be used for testing cardio-vascular system of patient. Differential vector-cardiograph has high frequency oscillator, common electrode, unit for reading electrocardiogram and radio cardiogram provided with amplification channels and filtration channels, multiplexer, microprocessor unit with common bus, analog-to-digital converter, keyboard, mouse and indication unit. Device provides higher precision of measurements due to usage of electric component heart activity and truth of diagnostics due to ability of representation of results of testing in form of variety of vector-cardiograms in real time-scale.

EFFECT: improved precision.

1 dwg

Description

The invention relates to medical electronics and can be used to study the human cardiovascular system.

A known method for diagnosing the condition of the myocardium [1], which consists in the establishment of two electrodes on the chest and removal of the ECG at two locations with subsequent analysis of the ECG. The disadvantage of this method is the limited accuracy of the measurements.

A known method of differential vector cardiography [2], which consists in recording the potentials of the heart using a matrix of electrodes located on the surface of the chest, and constructing vector cardiograms of linear combinations of the amplitudes of the teeth Q, R, S, T, segments ST and QR on the background of the corresponding vector cardiograms norms. The disadvantage of this method is the complexity of technical implementation with a large number of leads and limited measurement accuracy, since it is not provided for the allocation of the electrical component of the activity of the heart.

The closest in technical essence is the method of separation of the electrical component of the activity of the heart [3], which consists in removing the electrocardiogram and rheoelectrogram from the same electrodes, obtaining the difference of their Fourier spectra and converting the difference into a time function, which is considered the electrical component of the activity of the heart. The disadvantage of this method is the difficulty of technical implementation with a large number of electrodes and the limited reliability of visual diagnostics.

The technical result of the proposed device is to increase the accuracy of measurements by using the electrical component of the activity of the heart and the reliability of diagnosis due to the possibility of presenting the results of the study in the form of a wide variety of vector cardiograms in real time.

The technical result is ensured by the fact that in the differential vector cardiograph containing a serially connected RF generator and a common electrode, electrodes mounted on the human body, and a calculator of the electrical component of heart activity, an electrocardiogram (ECG) and rheoelectrogram (REG) block containing channels is introduced amplification and filtration, the inputs of which are connected to the corresponding electrodes located on the surface of the chest in the form of a flat matrix, and the outputs are the outputs of the ECG and P EG, connected in series to a multiplexer, the input of which is connected to the output of an ECG and REG block, and an ADC, and the calculator of the electrical component of heart activity is made in the form of a microprocessor unit with a common bus, to which a multiplexer control input, an ADC output, a keyboard output, and a mouse output are connected and the input of the display unit.

A block diagram of a differential vector cardiograph is shown in the drawing.

The differential vector cardiograph contains an RF generator 1, a common electrode 2, an ECG and REG block 3, a multiplexer 4, a microprocessor (MP) unit 5 with a common bus 6, ADC 7, a keyboard 8, a mouse 9, an indication unit 10.

Differential vector cardiograph works as follows. At the output of each channel of the ECG and REG block 3, a signal is formed consisting of a composition of the following three types of signals. The RF generator 1 by means of a common electrode 2 ensures microcurrents flowing through the body of the test block to the electrodes 3, the values of which depend on the pulse oscillations of the vessels and form REG signals (RF signals) at the output of the block 3. The ECG potentials are simultaneously taken from the same electrodes, forming ECG signals (LF signals) at the output of block 3, which are the composition of the electrical component of the activity of the heart (useful component) and the component of the pulse oscillations of the vessels (interfering component). Channel signals from the output of unit 3 in series by means of a multiplexer 4 operating under control of the 5 MP unit via bus 6 are fed through the ADC 7 to bus 6. Using the keyboard 8, the necessary software configuration of the 5 MP unit is installed, which allows compensation of ECG and REG functions interfering component in the spectral region, and then by inverse transformation to obtain in the time domain the function of the electrical component of the activity of the heart (useful ECG component) and then use it is for constructing on the screen of block 10 indications of differential vector cardiograms. Using the mouse 9 on the screen of the display unit 10, the real-time indications are controlled using the cursor, the number and scale of the vector cardiograms, the number and location of active electrodes on which each (possibly the only common) vector cardiogram is built, in particular, in the calculated energy center of the signal using the matrix of electrodes, and they also call from the data bank, indicate and combine the vector cardiograms of the norm.

A differential vector cardiograph can be made of standard modules and on an accessible element base. The constructive implementation of the blocks may coincide or include structures of the same purpose of the prototype and analogues. The execution of the remaining blocks is determined by their functional purpose in the device and is known or obvious from the prior art in the applicable time and frequency ranges. Typical software, in particular, that implements the algorithms given in the prototype [3], as well as standard cluster analysis programs, is used as software.

Bibliographic list

1. A.S. No. 768392. A method for diagnosing the condition of the myocardium / L.A. Dmitrievskaya // BI No. 37, 1980.

2. Patent No. 2136206 (RU). The method of differential vector cardiography / Sh.Z. Zagidullin and others // BI No. 25, 1999.

3. Patent No. 2138193 (RU). The method of separation of the electrical component of the activity of the heart / A.V. Agranovsky and others // BI No. 27, 1999.

Claims (1)

A differential vector cardiograph containing a serially connected RF generator and a common electrode, electrodes mounted on the human body, and a calculator of the electrical component of the activity of the heart, characterized in that a block for recording electrocardiograms and rheoelectrograms containing amplification and filtering channels, the inputs of which are connected with the corresponding electrodes located on the surface of the chest in the form of a flat matrix, and the outputs are the outputs of the electrocardiogram block and rheoelectrograph m, a multiplexer connected in series, the input of which is connected to the output of the electrocardiogram and rheoelectrogram recording unit, and the ADC, and the calculator of the electrical component of the activity of the heart is made in the form of a microprocessor unit with a common bus to which the multiplexer control input, the ADC output, the keyboard output, the mouse output are connected and the input of the display unit.