RU2552876C2 - Electrocardiograph for non-invasive real-time micropotential recording on electrocardiogram - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to devices for measuring bioelectric potentials of the heart. An electrocardiograph comprises a supply unit, electrodes, a microcontroller, a computer, an analogue-to-digital converter, and a digital-to-analogue converter. The electrocardiograph has a multi-channel structure and comprises several identical channels. The electrodes are medical nanoelectrodes for the chest EEG recording. Outputs of the nanoelectrodes are connected to inputs of measuring amplifiers; outputs of the measuring amplifiers are connected to the first inputs of operational amplifiers outputs of which are connected to inputs of the analogue-to-digital converter; outputs of the analogue-to-digital converter are connected to inputs of microcontrollers, outputs of which are connected to the computer and to the second inputs of the operational amplifiers through the digital-to-analogue converter.

EFFECT: invention aims at the higher resolution of electrocardiographic equipment for non-invasive real-time micropotential recording on the electrocardiogram without applying any analogue and program filters, collecting cardiac pulses which lead to the distortion of true bioelectric activity of the heart for the purpose of early diagnostic of the heart diseases and eliminating the episodes of sudden cardiac death.

20 dwg

Description

The invention relates to medical equipment, namely to devices for measuring bioelectric potentials, used mainly in medical diagnostic devices.

A device is known [Kurikov S.F., Prilutsky D.A., Selishchev S.V. The use of sigma-delta-analog-to-digital conversion in multi-channel electrocardiographs uran.donetsk.ua> ~ masters ... fkita / pichka / librar], which use delta-sigma analog-to-digital filters (ADCs), while traditional input circuits do not use Filters - 50 Hz blocking, anti-tremor, high-pass filter and low-pass filter. The constant component at the input of the ECG is compensated by 5-6 additional bits of sigma-delta-ADC. The disadvantage of this device is the use of software filters made on a computer to improve the signal-to-noise ratio in order to increase the resolution of the measuring channels, which lead to distortion of the fine structure of the biopotential. The following technical parameters have been achieved:

- input voltage range from 1.2 μV; 5 uV; 10 μV to 10 mV;

- frequency ranges - (0-40) / (0-146) Hz;

- quantization frequency - 2000 Hz.

Known electrode device [SU 2469642, IPC A61B, publ. December 20, 2012 Bull. No. 35], containing a dielectric body in which a dielectric porous contact element is located, on the non-working side of which a recess is made with a silver layer applied to its surface and connected to a discharge element, and an electrolyte is used to saturate the dielectric porous contact element, characterized in that the entire pore volume of the dielectric porous contact element is filled with silver nanoparticles coated with silver chloride and impregnated with an electrolyte, while the silver layer through the current-conducting silver element by means of a junction is electrically connected to a conductor connected to the input of the electrographic device, and a sealant is applied to the non-working side of the contact element, covering the recess and the junction.

The electrode device according to claim 1, characterized in that the composition, wt.%:

water 31-35 potassium chloride 10-13 agar agar 2-3 polyacrylamide 0.5-0.8 glycerol rest

The metrological and operational parameters of medical nanoelectrodes exceed the parameters of all medical electrodes known in the world.

A device is known [SU 2240720, IPC A61B 5/04, publ. November 27, 2004 Bull. No. 48], selected as a prototype, containing a power supply, two electrodes and a series-connected processor, an optocoupler isolation unit and a computer, it additionally contains two more electrodes, a power converter, a switch (an offset potential compensation unit between the electrodes) and an analog-to-digital converter (ADC), the output of which is connected to the first input of the processor, the second input of which is connected to the second output of the optocoupler isolation unit. The outputs of the power supply through the power converter are connected to the power inputs of the switch, the offset potential compensation block between the electrodes, the ADC, the processor, the optocoupler isolation unit and the computer, the output of which is connected through the optocoupler isolation unit to the second input of the processor, the third output of which is connected to the third input of the compensation unit bias potential between the electrodes, and the fourth output is connected to the fifth input of the switch, the first, second, third and fourth inputs of which are connected to one of the four electrodes, and each th output is connected to the corresponding input of the bias potential compensation between the electrodes.

Serially manufactured glass electrodes, for example EVL-1MZ, were used as electrodes in this device. Most effectively, the present invention can be used to conduct an examination (screening) of the population in order to identify pathology of the internal organs in the early stages of the disease.

The measurement range of the biopotential potential provided by the device is in the range from 0.1 mV to 200 mV.

The disadvantages of this device are the low resolution (0.1 mV), the device uses glass reference electrodes of comparison EVL-1M3, which are not adapted for mounting on the human body and are shockproof, the presence of software filters on the processor, which lead to distortion of the recorded biopotential, that is, they distort its fine structure.

The objective of the invention is to increase the resolution of a high-resolution electrocardiograph for non-invasive recording of micropotentials on an electrocardiogram in real time without the use of both analog and software filters, without the accumulation of cardio pulses that lead to distortions of the true bioelectric activity of the heart, with the aim of early diagnosis of heart diseases and exceptions for sudden cardiac mortality (BCC).

The problem is solved due to the fact that the device, as in the prototype, contains a power supply, electrodes, a microcontroller, a computer, an analog-to-digital converter, a digital-to-analog converter, a DC component compensation unit.

According to the invention, the device has a multi-channel structure and contains several identical channels, the device uses medical nanoelectrodes as electrodes for ECG removal from the chest, the outputs of nanoelectrodes are connected to the inputs of the measuring amplifiers, the outputs of the measuring amplifiers are connected to the first inputs of the operational amplifiers, the outputs of which are connected to the inputs ADC, ADC outputs are connected to the inputs of the microcontroller, the outputs of which are connected to the computer and through the DAC with the second inputs of the operating preamplifier.

Due to the high metrological parameters and the special structure of the internal structure, medical nanoelectrodes make it possible to record non-invasively micropotentials on an electrocardiogram in real time without the use of standard analog or software filters, the accumulation of cardio pulses that lead to distortions of the true bioelectric activity of the heart in order to diagnose heart diseases and exceptions for sudden cardiac mortality (BCC).

The proposed structure of the device provides high quality transfer of biopotentials from nanoelectrodes to a computer:

1. In the structure of the device there is no switch that introduces switching interference in the known device.

2. The device uses high-performance ADCs and DACs.

3. The low-noise sigma-delta-ADC (at least 24 bits) is used as an ADC.

4. The microcontroller organizes the exchange with the computer and controls the DAC to compensate for the DC component at the input.

5. The signal isolation device provides protection against electric shock.

6. The registered electrocardiograms are stored in a computer, the amplitude-time parameters of the ECG teeth and peaks on the teeth are calculated, a recommendation on the state of the cardiovascular system for the doctor who sets the final diagnosis is automatically issued.

7. The device is powered by rechargeable batteries.

This device made it possible to register non-invasively low-amplitude teeth of the electrocardiographic signal and peaks at them at a level of 1 μV, units and tens of microvolts without the use of both traditional analog and software filters that introduce amplitude and phase distortions, that is, register non-invasively true bioelectric activity of the heart without distortions in the shape of low-amplitude teeth.

In FIG. 1 shows the structure of the device.

In FIG. 2 shows ECG fragments recorded simultaneously: a, c - in the frequency range 0-1000 Hz; b, d - in the frequency range 0-150 Hz; a, b - region of teeth P, Q; c, d - R-wave.

In FIG. 3 presents ECG fragments recorded simultaneously: a, c - in the frequency range 0-1000 Hz; b, d - in the frequency range 0-150 Hz; a, b - tooth P; c, d - teeth P, Q, S, T, U.

In FIG. 4 shows an ECG fragment of patient 44, 2 — Holter lead.

In FIG. 5 shows an ECG fragment of patient 45, 3 - Holter lead.

In FIG. 6 shows an ECG fragment of patient 47, 2 — Holter lead.

In FIG. 7 shows an ECG fragment of patient 48, 2 — Holter abduction.

In FIG. Figure 8 shows ECG fragments according to patient's Holter 50: a - 1 lead; b, c - 3 leads; g - general view, 1 lead.

In FIG. 9 shows an ECG fragment of patient 51, 2 Holter lead.

In FIG. 10 shows ECG fragments according to Holter of patient 52: a - 1 lead; 6-2 assignment.

In FIG. 11 presents ECG fragments according to Holter of patient 53: a - 1 lead; 6-2 assignment; in - 3 assignment.

On Fig presents ECG fragments according to the Holter of the patient 54: a - 1 lead; b - 2 assignment; in - 3 assignment.

On Fig presents ECG fragments according to the Holter of the patient 55: a - 1 lead; b - 2 assignment.

On Fig presents a fragment of the ECG of the patient 56, 1 lead.

On Fig presents ECG fragments according to the patient's Holter 57: a - 1 lead; b - 2 assignment; in - 3 assignment.

On Fig presents ECG fragments according to the patient's Holter 58: a - 1 lead; b - 2 assignment; in - 3 assignment.

On Fig presents a fragment of the ECG of the patient 59, 1 lead according to Holter.

On Fig presents a fragment of the ECG of the patient 60, 1 lead according to Holter.

On Fig presents ECG fragments according to the Holter of the patient 61: a - 1 lead; b - 2 assignment; in - 3 assignment.

On Fig presents ECG fragments according to the Holter of the patient 62: a - 1 lead; b - 2 assignment.

A high-resolution electrocardiograph for non-invasive recording of micropotentials on a real-time electrocardiogram (Fig. 1) contains medical nanoelectrodes 1 _1i and 1 _2i , measuring amplifiers 2 _i , operational amplifiers 3 _i , analog-to-digital converters 4 _i , microcontroller 5, digital-to-analog converter 6 _i , isolator 7, personal computer 8.

The principle of operation of the device is as follows.

Medical nanoelectrodes 1 _1i and 1 _2i are mounted on the chest of the patient. Electrocardiographic signals from the nanoelectrodes are fed to the inverting and non-inverting inputs of the measuring amplifiers 2 _i , from the output of the measuring amplifiers the signals are fed to the non-inverting input of the operational amplifier 3 _i , the signals from the output of the operational amplifiers are fed to the input of the analog-to-digital converter 4 _i and, after digitization, are fed to the input of the microcontroller 5, which evaluates the input signal and in the presence of a constant component provides a signal to the DAC 6 _i to eliminate a constant signal at the input by applying compensating voltage to the inverting input of operational amplifiers 3 _i . Isolator 7 isolates the patient from computer 8. Signals to the computer input are received through the USB port.

Clinical studies have been conducted on a high-resolution electrocardiograph for non-invasive recording of micro-potentials on a real-time electrocardiogram.

The results of clinical studies were obtained at the Tomsk Research Institute of Cardiology. The electrocardiograms of patient P1 were recorded simultaneously in the frequency range from 0 to 1000 Hz, FIG. 2 a, b, and in the frequency range from 0 to 150 Hz, FIG. 2 b, d, a, b - region of teeth P, Q; c, d - R-wave. There are no filters in the registration devices; removal is carried out from the chest according to Holter. The devices were not synchronized and therefore there is a slight time delay. A device with a bandwidth from 0 to 150 Hz smooths the peaks in contrast to a high-frequency device.

The electrocardiograms of patient 2 recorded simultaneously by the same devices are shown in FIG. 3 a, b, c, d, a, c - frequency range 0-1000 Hz; b, d - frequency range 0-150 Hz; a, b - tooth P; c, d - teeth P, Q, S, T, U.

On electrocardiograms, FIG. 2 a, b and FIG. 3a, c, recorded in the frequency band from 0 to 1000 Hz, the peaks of the microvolt level on standard teeth and their position on the ECG time axis are more clearly recorded.

To assess the possibility of recording micropotentials on an electrocardiogram level of 1 μV, units and tens of microvolts using equipment on nanoelectrodes in the frequency range from 0 to 150 Hz without analog and software filters and the accumulation of cardio pulses, the results of clinical trials are presented, FIG. 4 - 20. All patients had myocardial infarction and were observed in the emergency cardiology department of the Tomsk Scientific Research Institute of Cardiology.

In FIG. 4, in patient 44, in 2 Holter leads, the amplitude of the P-wave is 60 μV, and the peaks are from 3 μV to 30 μV.

In FIG. 5, the patient has 45 in 3 leads according to Holter, the amplitude of the P-wave is 30 μV, and the peaks are from 5 μV to 20 μV.

In FIG. 6 in patient 47 in 2 Holter leads, the amplitude of the P-wave is 50 μV, peaks from 10 μV to 70 μV.

In FIG. 7 the patient has 48, 2 leads, the amplitude of the P-wave is 25 μV, peaks - from 8 μV to 15 μV.

In FIG. 8, in patient 50, in a Holter study in 1 lead, the amplitude of the P-wave is 25 μV, peaks from 4 to 5 μV, FIG. 8a; in 3 leads, the amplitude of the P wave from 7 μV to 15 μV, peaks from 7 μV to 15 μV, FIG. 8b, c; a general view of the ECG in 1 lead is shown in FIG. 8 g

In FIG. 9 in patient 51, in 2 Holter leads, the amplitude of the P-wave is 55 μV, peaks from 3 μV to 33 μV.

In FIG. 10, in patient 52, in a Holter study in 1 lead, a change in the polarity of the P-wave before the extrasystole is observed, the tooth is bipolar, the amplitude of the P-wave is 20 μV, peaks from 5 μV to 10 μV; in the 2nd lead, the amplitude of the P wave is 15 μV, the bipolar wave, peaks from 5 μV to 10 μV.

In FIG. 11 in patient 53 during the Holter study in 1 lead, the amplitude of the P-wave is 35 μV, peaks from 3 to 10 μV; in 2 leads, the amplitude of the P-wave is 45 μV, peaks from 3 to 5 μV; in 3 leads, the amplitude of the P-wave is 15 μV, peaks from 2 to 7 μV.

In FIG. 12 in patient 54 during a Holter study in 1 lead, the amplitude of the P-wave is 5 μV, peaks from 5 to 10 μV; in 2 leads, the amplitude of the P-wave is 8 μV, of the peaks ± 4 μV; in 3 leads the amplitude of the P-wave is 7-8 μV, peaks - from 2.5 to 5 μV.

In FIG. 13 in patient 55, in a Holter study in 1 lead, the amplitude of the P-wave is 100 μV, peaks from 8 to 70 μV; in the 2nd lead, the amplitude of the P-wave is 40 μV, the bipolar wave, peak amplitudes from 20 μV to ± 40 μV.

In FIG. 14, the patient has 56 in 1 Holter lead, the amplitude of the P-wave is 180 μV, the peak is 80 μV.

In FIG. 15 in patient 57 during the Holter study in 1 lead, the amplitude of the P-wave is 100 μV, peaks from 8 μV to 60 μV; in 2 leads, the amplitude of the P-wave is 70 μV, the peak amplitudes are from 10 μV to 25 μV; in 3 leads, the amplitude of the P-wave is 50 μV, peaks from 10 μV to 15 μV.

In FIG. 16 in patient 58, when examining the heart according to Holter in 1 lead, the amplitude of the P-wave is 170 μV, peaks from 10 μV to 25 μV; in 2 leads, the amplitude of the P-wave is 110 μV, the peak amplitudes are from 10 μV to 20 μV; in 3 leads, the amplitude of the P-wave is 80 μV, peaks from 10 μV to 25 μV.

In FIG. 17, the patient has 59 in 1 Holter lead, the amplitude of the P-wave is 120 μV, and the peaks are from 6 μV to 40 μV.

In FIG. 18, the patient has 60 in 1 Holter lead, the amplitude of the P-wave is 175 μV, peaks from 6 μV to 75 μV.

In FIG. 19 in patient 61, in a Holter study in 1 lead, the amplitude of the P-wave is 150 μV, peaks from 10 μV to 20 μV; in 2 leads, the amplitude of the P-wave is 75 μV, peak amplitudes are from 5 μV to 45 μV; in 3 leads, the amplitude of the P-wave is 45 μV, peaks - from 7 μV to 35 μV.

 In Fig.20, the patient 62 in the study according to Holter in 1 lead amplitude of the R-wave 175 μV, peaks from 5 μV to 50 μV; in 2 leads, the amplitude of the P-wave is 100 μV, the peak amplitudes are from 5 μV to 50 μV.

Based on the studies, the following conclusions can be drawn:

1. The developed equipment allows you to measure the amplitude and moment of appearance of low-amplitude teeth and peaks on them on a normal ECG.

2. The amplitudes of the teeth and peaks vary from units to hundreds of microvolts.

3. With the expansion of the equipment frequency band to 1000 Hz, the quality of recording signals of units and tens of microvolts improves.

Low-amplitude biopotentials of the microvolt level heart were recorded in real time without distortion from the chest of patients from standard Holter leads without filters, both analog and software.

This approach will complement the existing ECG diagnostics, which are widely used in clinics, with diagnostic parameters that are used to make an accurate diagnosis using high-resolution electrocardiographs, for example, according to the Simson method. Simson's method is based on the accumulation of 100-300 cardiac complexes, with further filtering of the total pulse.

In certain pathologies, late atrial potentials (APS) of less than 5 μV, which occur at the end of the P-wave or late ventricular potentials (VCA) of less than 20 μV, which occur after the S-wave at the beginning of the S-T complex, are detected in the total cardio pulse for certain pathologies. Detection of cardiac impulse of PPP and PPS is a harbinger of sudden cardiac death according to clinical studies by the Simson method.

The disadvantages of the Simson method are the impossibility of analyzing the ECG signal in real time and the inclusion in the decision rule of parameters that are remotely related to the nature of the studied low-amplitude ECG components.

Our clinical studies on the proposed device showed that the device is capable of measuring low-amplitude fluctuations on a cardio pulse of 1 μV, units of microvolts, tens of microvolts in real time without the use of filters, which lead to amplitude and phase distortions of the ECG signal. The graphs clearly show the instability of the heart. Evidence of the absence of electromyographic interference is the fact that the low-amplitude fluctuations observed in the horizontal sections of the ECG, that is, during cardiac rest, are absent at the P-waves at the time of excitation, which indicates a change in the physiological state of the heart muscle fiber in the transition from the resting phase to the phase excitement.

This device opens up new prospects for a more accurate and early diagnosis of heart disease in mass studies in outpatient settings to exclude sudden cardiac mortality (SCD).

Claims (1)

An electrocardiograph for non-invasively recording micropotentials on a real-time electrocardiogram containing a power supply, electrodes, a microcontroller, a computer, an analog-to-digital converter, a digital-to-analog converter, characterized in that it has a multi-channel structure and contains several identical channels, medical nanoelectrodes are used as electrodes for ECG removal from the chest, the outputs of the nanoelectrodes are connected to the inputs of the measuring amplifiers, the outputs of the measuring amplifiers They are connected to the first inputs of operational amplifiers, the outputs of which are connected to the inputs of the ADC, the outputs of the ADC are connected to the inputs of the microcontroller, the outputs of which are connected to a computer and, through the DAC, to the second inputs of the operational amplifiers.

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