RU2242919C2 - Method for studying functional state of cardio-vascular system - Google Patents

Abstract

FIELD: medicine, cardiology.

SUBSTANCE: the present innovation deals with contact-free surveying functional state of cardio-vascular system in electro-magnetic field being harmless for people. Patient's survey should be carried out with the help of a screen with a matrix of pickup units of radio-capacitive type which should be successively installed into vascular areas of different regions at the distance of 15-35 mm against body surface. Electro-magnetic field should be created with the help of high-frequency generator with an emitter of 0.5-20 mW power and 6-24 MHz frequency. Signals of pickup units after detecting, filtration, enhancing and analog-digital transformation should be introduced as pulsograms of corresponding vascular areas. The data obtained are necessary to calculate and analyze the values of central and regional hemodynamics. The method is of broadened functional possibilities.

EFFECT: higher efficiency of surveying.

1 cl, 6 dwg

Description

The invention relates to the field of medical equipment, in particular to non-contact (remote) research of central and regional blood circulation in an electromagnetic field.

It is known that contact methods, in particular rheography, rheoplethysmography (RPG) and impedance RPG, are widely used to study circulatory disorders and evaluate the main indicators of cardio and hemodynamics. The disadvantage is that it is necessary to pass a probing current with a frequency of 20-200 kHz through the studied areas of the patient’s body [L1, 2].

The closest in technical essence is the method of non-contact (remote) study of the functions of the body systems, in particular the respiratory function, which allows you to remotely record volumes of breathing cycles, evaluate the condition of the right and left lungs, compare the parameters of the upper, middle, lower sections of each lung, and build visualization maps of ventilation lungs. Examinations are carried out in the space of the electromagnetic field using the screen of the matrix of sensors (MD) of the radio-capacitive type, which is installed in the projection area of the lungs and diaphragm. An electromagnetic field is created by a high-frequency generator mounted in a chair with an emitter [L3]

The known method does not allow to investigate the functional state of the cardiovascular system of a person, to calculate and analyze the main indicators of hemodynamics, to conduct a sequential examination of the vascular zones of various areas (sections) of the body surface.

The present invention is directed to the creation of a method with advanced functions, carrying out the study of both central and regional (peripheral) blood circulation.

The technical result of the invention is to expand the functionality of the method due to non-contact (remote) registration of pulse signals (pulsograms) of the right and left parts of the heart, symmetrical areas of the main vessels of the trunk regions, limb sections, and study of cerebral vessels.

This is achieved by the fact that in the claimed method, studies of the subject are placed in the space of an electromagnetic field with a power of 0.5-20 mW and a frequency of 6-24 MHz (in a sitting or lying position, in clothes). Measurements are carried out using a MD capacitive screen, which is sequentially installed in the vascular zones of various areas of the body surface at a distance of 15-35 mm from the surface. The signals of the sensors after detection, filtering, amplification and analog-to-digital conversion are presented in the form of pulsograms of the corresponding vascular zones of the heart, the main vessels of the trunk, limb, and cerebral hemispheres. Indicators of central hemodynamics, such as heart rate (HR), stroke volume (UO), minute volume of blood circulation (MO), cardiac index (SI), pulse wave propagation velocity (SRWP), cardiac cycle duration (C), electric systole, are calculated. (Ce), total peripheral resistance (OPS), total systole (Co); indicators of regional blood flow: peripheral resistance index (IPS), outflow index (IN) measuring index (II), elasticity index (IE), pulse wave propagation velocity of the department (SRPVo), mechanical systole duration (cm), stress period (PN), phase of asynchronous contraction (Fas), phase of isometric contraction (Fis), period of exile (PI), phase of rapid expulsion (Phby), phase of delayed exile (Fsey), etc. asymmetry indicators of the left and right parts of the heart; indicators of the state of cerebral hemodynamics.

The method also allows you to study the hemodynamics of the vascular zones of various areas of the body surface using two, three or more MD screens. The essence of the method is illustrated by drawings.

Figa - the location of the screens MD1, MD2, MD3 in a sitting position, the mode of simultaneous examination of the chest area, symmetrical sections of the right and left lower leg and cerebral circulation. At the same time, the MD1 screen for studying cerebral circulation is structurally made in the form of a helmet.

Figb is a block diagram of a device that implements the claimed method.

A radio frequency generator 1 with a radiator creates an electromagnetic field with a power of 0.5-20 mW and a radiation frequency of 6-24 MHz in which patient 2 is placed in a sitting position or lying on a medical couch. The device consists of screens with a matrix of sensors 3 (Mdi), a communication channel 7, a synchronization unit 8, a power supply 9, an ADC converter 10 built into the computer 11, and a guidance mechanism. An array of sensors 4, a block of detectors 5, a multi-channel amplifier 6 are located in the housing of the MDi 3 screen. The power supply unit and the synchronization unit are designed to power, synchronize the operation of electronic circuits (i-1,., 3).

The guidance mechanism 12 performs the installation of MDi screens in the vascular zones of various areas of the body surface in accordance with the computer program for examining the patient. The guidance mechanism consists of a control unit 13, lifts 14i, displacement units 15i, rotation units 16i and control sensors 17. Calibration mode is provided [L3]

The examination is carried out with a half-breath holding breath, the recording should provide at least 6-9 cycles suitable for analysis, the ECG is recorded in the II standard lead. Fluctuations in the patient’s pulse modulate the parameters of the electromagnetic field, a multidimensional, distributed space of this field is formed, the parameters of each section of which are proportional to the amplitude of the oscillation of the wall of the organ or vessel department and can reflect the regional hemodynamics of the studied area. High sensitivity, selectivity of the device and the security of the reception from external interference depends on the correct choice of screen design, matrix circuit and device.

The signals from the sensors after detection, filtering, amplification, and analog-to-digital conversion are proportional to the amplitudes of the pulse wave and reflect the regional hemodynamics of the study areas.

Figv, 1d - examination with the aid of the MD 44 screen. Dimension of typical measuring matrices of the screen Мdi 2 × 2, 4 × 2, 4 × 4 (3 × 2, 3 × 4, 4 × 6, 6 × 6), dimension specialized matrices arbitrary - 33, 45.

Figure 2 - study of the heart region, 4-channel remote pulsograms (DPG) of the symmetric zones of the heart region, indicators of central hemodynamics.

When examining the heart, the MD screen is installed in the area of the projection of the departments of the heart onto the chest wall, and the upper sensors of the MDi screen should be located at the level of the second intercostal space symmetrically to the middle of the sternum on the left and right. Accordingly, the sensors located in the second, third and fourth lines of the screen should overlap the measuring zones of the fourth, sixth intercostal space, the region of the costal arch. The distance from the MD screen to the anterior body wall (L) during examination of the chest wall is determined by the pulse measurement mode and is selected in the range of 15-45 mm. Diagnostic techniques were tested on test phantoms. Using a group of volunteers, the ability to test the applicability of the proposed method, to develop a program for assessing the state of the cardiovascular system. Below are examples of printouts of survey data obtained using the proposed demand (curves and digital values).

Figa - studies of the symmetrical zones of the chest and the symmetrical sections of the left - right lower leg in a sitting position. Screens MD1, MD2 are installed in the corresponding vascular zones. Files a4, s2 allow you to calculate the magnitude of PWR by the marked time delay.

Fig.3b - study of the lower extremities, examination of the symmetrical zones of the left and right lower leg, DPG curves for breath holding (7), calm breathing (8), normal (A4) and pathology, atherosclerosis of the right lower leg (AB1).

Figa - study of the region of the heart, impaired hemodynamics of the right (ki5) and left (br12) parts of the heart. File ki5 - pulmonary heart, file br12 - latent aortic insufficiency.

The right sections correspond to the left zones of the projection of the heart onto the chest wall (pulmonary trunk), and the left sections correspond to the right (the aortic arch).

The software of the proposed method allows for the DPG k-zone to build a differentiated pulsogram (DDG) and a table of hemodynamic parameters consisting of: AI, IE, IPS, VO, Sm, PN, Fas, Fis, PI, Phbi, Fairy, AI - the measurement index of the remote pulsography, (k-1, .16).

Figb - analysis of DPG zones 15 and 14 - the second intercostal space on the left and right. To calculate the stroke volume, symmetric DPG- are used.

- curves of the left and right zones of the second and fourth intercostal space, the amplitude of which is proportional to the ejection of blood into the aorta and into the pulmonary artery.

UO-2/3-QmlT1 = 2 / 3Qr Tr

Tr, Tl - time of exile,

Qml, Qr - maximum flow during systole,

dV / dt - Qm, V - chest volume.

Qm = K pr · Um, Um = (U1m + U2m + U3m + U4m) / 4,

Uim - maximum amplitude of DPGi - projection zones of the heart,

CRC - coefficient depends on body weight, chest circumference, L, height, gender, age, etc.

Figa - eight-channel DPG of the heart region, ECG. According to the data of the zones of the second and fourth intercostal space (curves 1, .., 4), we calculate PI, UO, heart rate, MO, using the patient’s height and mass data, calculate the parameters of the central hemodynamics SI, OPS, A, .., C, Co [ l.4]. At the user's request, for each zone, the indicators IE, AI, IPS, VO, Sm, PN, Fas, Fis, PI, Fbi, Fzi, etc. are calculated, compared with the proper values. The ratio of the values of the indicators of the left Vl and the right Vp departments is calculated (Vl / Vp - asymmetry indicators). The method can work in various modes and can be equipped with one, two, three or more MD screens, which are installed in the vascular zones of various areas of the body surface, to study the state of the heart chambers and hemodynamics of the trunk, extremities and hemispheres of the brain. The basic complex N 1 contains one MD screen (4 × 4), which allows, in a sequential mode, in the supine position, to study the vascular zones of the chest and abdomen, pelvis, back, neck, symmetrical sections of both thighs, right and left lower leg .

Fig.5b - the study of the vascular zones of the chest (V73), abdominal cavity (V75), pelvis (V77) and hips (V712). The study was conducted by the base complex n 1 in the supine position in the mode of sequential movement (scanning). The shape of the curves allows you to analyze the hemodynamics of the great vessels in the direction from the center to the periphery. Specialized complexes of the proposed method can be equipped with two, three and four MD screens. To study cerebral circulation, the curved design of the MD screen (in the form of a helmet) is used.

Figa - study of cerebral hemodynamics. DPG - curves in the symmetrical zones of the cerebral hemispheres.

The method is as follows. In the space of the electromagnetic field, the generator with the emitter of which is mounted on the inner surface of the seat of the chair (couch), a patient is examined in clothes, in a sitting or lying position. When holding the breath, pulse fluctuations modulate the parameters of the electromagnetic field.

Installation of MD1-MD4 screens is done by a computer program in automatic mode using the guidance mechanism. The measuring signals are fed to the inputs of the sensor matrix 4, after which they are detected using detectors 5, amplified in an amplifier 6, and digitized using an ADC converter 10 built into the computer 11. The distance from the MDi screen to the front wall of the body is monitored at the level of upper and lower zones with the help of measuring probes, the distance depends on the equipment settings, measuring mode and is selected in the range of 15-35 mm. Manual mode of guidance mechanism 12 is provided. The calibration procedure is performed by a single movement of the MDi screen, the step is selected in the range of 0.1-0.6 mm.

Fig.6b - a portable device that implements the claimed method, consists of a trolley, telescopic lift, screen MD1, it is possible to install a second screen MD2 on a portable stand. In the stationary version, the complexes can be presented in the form of a system (multi-purpose) equipped with two, three or more MD screens.

One of the options is designed in the form of a capsule with measuring sensors in the amount of 64-128.

The advantages of the claimed method

1. Contactlessness, the absence of a stimulating effect on the studied organ or main vessel.

2. Speed, the possibility of rapid diagnosis and monitoring.

3. The mode of simultaneous examination of areas of the body. Multi-channel, the number of channels from 8 to 128.

4. Inspection in clothes or underwear.

5. Contactless study of cerebral circulation.

6. Availability. Lack of consumables.

7. Opening directions for new medical developments.

The simplicity of the examination procedure allows you to investigate functional disorders after physical exertion, with emotional overstrain, stress and against the background of pharmacological tests.

The application of the proposed method for

- diagnosis of diseases of the heart and vascular system;

- functional assessment of cardiac and hemodynamic parameters;

- express diagnostics, preventive examinations and monitoring;

- conducting functional tests and auto-training;

- the choice of medicines for the patient;

- studies of psychological state and stress;

in functional diagnostics rooms, in cardiology departments, in recovery centers and at home.

Sources of information

1. Impedance reoplethysmography. M.I. Gurevich, A.I. Soloviev. Kiev: Naukova Dumka, 1982, pp. 25-27, 112-133.

2. Technique and technique of rheography and rheoplethysmography. V.I. Polishchuk, L.G. Terekhova. Moscow: Medicine, 1983, p. 84-114

3. Patent for the invention N 2122344. V. F. Zhuravlev. Moscow, November 27, 1998

4. Kubicek WC. Impedance pletismography. Patent 3,340,867 US.

Claims (2)

1. A method for studying the functional state of the cardiovascular system, namely, that the subject is placed in the space of an electromagnetic field created by a high-frequency generator with an emitter, and a screen with a sensor matrix is installed for investigation, characterized in that the screen with the sensor matrix is sequentially installed in vascular zones of various areas at a distance of 15-35 mm from the body surface, sensor signals after detection, filtering, amplification and analog-to-digital conversion ulation as pulsograms vascular zones and corresponding calculation produce hemodynamic indicators such as heart rate, stroke volume, minute volume of blood circulation, cardiac index, the propagation velocity of the pulse wave, the cardiac cycle length and the electrical systole, total peripheral resistance; indicators of regional blood flow: peripheral resistance index, outflow index of the measuring index, elasticity index, mechanical systole duration, stress period, asynchronous contraction phase, isometric contraction phase, expulsion period, fast expulsion phase, delayed expulsion phase, asymmetry indicators of the left and right heart, indicators of the state of cerebral hemodynamics; moreover, a high-frequency generator with a power of 0.5-20 mW and a frequency of 6-24 MHz is used. 2. The method according to claim 1, characterized in that during the simultaneous examination of the vascular zones of various regions, two, three or more screens with a sensor matrix are used.

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