RU2383297C1 - Device for control over cardiac activity of people - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: device contains analogue unit, information storage unit, interface unit, display unit and diagnostics unit. Analogue unit consists of successively switched unit of electrodes, selector of leads, differential amplifier, suppression filter and low-frequency filter. Information storage unit includes analogue-digital transformer, generator of recording and reading, counter and memory unit. Interface unit includes digital-analogue transformer, videosignal displacer, generator of tact pulses and generator of frame and line pulses. Diagnostics unit consists of comparator, support voltage source, univibrator, microcontroller and light-emitting diode matrix. Output of low-frequency filter is connected with input of analogue-digital transformer and first input of generator of recording and reading, whose output via counter is connected with first input of memory unit. Second input of memory unit is connected to output of analogue-digital transformer, and counter output is connected with second input of generator of recording and reading. Output of memory unit via digital-analogue transformer is connected to first input of videosignal displacer, whose output is connected with display unit. Tact pulse generator via generator of frame and line pulses is connected with second input of videosignal displacer. Low-frequency filter output is connected to first input of comparator, whose second input is connected with support voltage source. Comparator output is connected with successively connected univibrator, microcontroller and light-emitting diode matrix.

EFFECT: application of device will allow to display person's electrocardiogram visually and perform analysis of its R-complex, determining main types of arrhythmia.

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Description

The invention relates to medical equipment and is intended for continuous monitoring and control of a person’s electrocardiogram in both inpatient and in-patient settings.

At present, cardiovascular diseases occupy one of the main causes of population mortality both in Russia and around the world. In this regard, the early diagnosis of heart disease, in particular arrhythmias, is an urgent problem. To solve it, the creation of effective diagnostic devices is required, which allows promptly and objectively assessing a person’s condition and taking measures for timely treatment.

The Individual Indicator of the Heart [A.S. No. 1725828, MKI А61В 5/04], which contains two electrodes, a differential amplifier, a bandpass filter, an amplitude R-pulse selector, a pulse generator, an adder and an alarm block.

The electrodes are connected to the inputs of a differential amplifier, the output of which through a band-pass filter is connected to the input of the amplitude selector of R-pulses. The output of the amplitude selector of R-pulses is connected to the inputs of the pulse generator and the alarm block, the outputs of which are connected to the inputs of the adder.

The indicator works as follows. Through two electrodes mounted on the patient’s wrists, the electrocardiogram signal is fed to a differential amplifier, where it is amplified to the required value. After passing through a band-pass filter, the signal is cleaned of network noise and interference created at the points of contact of the electrodes with the patient’s body. Next, the signal is fed to the input of the amplitude selector of R-pulses, where R-pulses are extracted from the entire complex of the cardiogram. These pulses start the pulse generator, which through the adder provides a sound signal with a frequency of 1 kHz. In case of cardiac arrest, the R-complex signals cease to enter the alarm block, which at the same time gives a continuous sound signal with a frequency of 2 kHz and an alarm signal to the external circuit.

The advantage of the known device lies in the fact that it allows you to give a sound signal and an alarm signal to the clinic staff when the patient’s heart stops. Timely help to the patient is able to maintain his health and restore heart function.

However, the design of the device makes it possible to give an alarm only after cardiac arrest, without reacting at all to the deterioration of the patient's condition. It is known that taking timely measures to worsen heart function is much more effective than emergency methods after it stops. Therefore, it is desirable that the device displays a cardiogram and, if necessary, gives an alarm signal already at the stage of deviation of the R-complex parameters from the permissible norm, which can be observed by a change in the shape of the cardiogram or deviations of the R-complex parameters caused by arrhythmia in the heart.

Closest to the claimed solution for the combination of essential features and the achieved result is a device for monitoring cardiac activity of a person [A.S. No. 2089097, MKI 6 A61B 5/04], which consists of an analog unit, an information storage unit, an interface unit and a display unit.

The analog block includes a series of electrodes, a lead selector, a differential amplifier, a blocking filter, and a low-pass filter. The information storage unit consists of an analog-to-digital converter, a recording and reading generator, a counter and a memory unit. The interface unit includes a digital-to-analog converter, a video signal mixer, a clock pulse generator, and a frame and line pulse generator.

The output of the low-pass filter is connected to the input of the analog-to-digital converter and the first input of the write and read generator, the output of which is connected through the counter to the first input of the memory block. The second input of the memory unit is connected to the output of the analog-to-digital converter, and the counter output is connected to the second input of the write and read generator. The output of the memory unit through a digital-to-analog converter is connected to the first input of the video signal mixer, the output of which is connected to the display unit. The clock generator through the shaper of personnel and horizontal pulses is connected to the second input of the video signal mixer.

The device operates as follows. The electrocardiogram signal is removed from the electrodes mounted on the patient’s body, which make up the electrode block. Then the signal is fed to the input of the lead selector, with which the signal of one of the three leads of the electrocardiogram is selected. Next, the signal is amplified by a differential amplifier and fed to the input of the blocking filter, with the help of which the suppression of mains voltage pickups occurs. After that, high-frequency interference is smoothed out by a low-pass filter. The filtered electrocardiogram signal is fed to the input of an analog-to-digital converter designed to convert the signal to digital form for recording it in a memory unit. Information is recorded and read from the memory block under the action of a signal from a write and read generator, which acts on the memory block through a counter. Upon receipt of a signal from the output of the analog block to the first input of the write and read generator, a generation of write pulses occurs at the clock input of the counter. At the output of the counter, a binary code is generated that controls the address input of the memory block. In this case, information is recorded in the trigger cells of the memory block. After the end of the recording process, a signal is supplied from the counter output to the second input of the recording and reading generator, which transfers it to the reading mode. At the same time, the information recorded in it is read from the output of the memory block and fed to the input of the digital-to-analog converter, which performs the inverse conversion of the signal into analog form. From the output of the digital-to-analog converter, the signal is fed to the first input of the video signal mixer. At its second input, a synchronized mixture of frame and line scan signals is generated by the frame and line pulse generation unit, which is controlled by the clock generator. The signal generated at the output of the video signal mixer is fed to the antenna input of the information display unit. As a display device, a household TV is used.

Thus, as a result of such signal conversion, a person’s electrocardiogram can be observed on a TV screen.

The advantage of the known device lies in the fact that the dimensions of the electrocardiogram on the TV screen significantly exceed its sizes, taken on a paper tape with a graphical recorder. This greatly improves the accuracy of transmission of the image of the electrocardiogram and diagnosis.

Another advantage of the device is that with the electron beam image transmission method, the electrocardiogram is transmitted without distortion, which allows for a detailed analysis of it.

However, the device lacks the ability to analyze an electrocardiogram and to provide a timely signal in case of heart rhythm disturbance. With daily, for example, monitoring of the heart, the identification of short-term arrhythmias in his work becomes quite difficult. This reduces the reliability of the diagnosis of the heart and making the right decisions of the course of treatment.

The problem solved by the invention is to develop a device for real-time real-time monitoring of cardiac activity, which allows you to visually display a person’s electrocardiogram and determine the main types of arrhythmia by analyzing its R-complex.

To solve this problem, in the known device for monitoring cardiac activity of a person, containing an analog unit, an information storage unit, an interface unit and a display unit, an additional diagnostic unit is introduced.

The analog block consists of a series-connected electrode block, a lead selector, a differential amplifier, a blocking filter and a low-pass filter. The information storage unit includes an analog-to-digital converter, a recording and reading generator, a counter and a memory unit. The interface unit includes a digital-to-analog converter, a video signal mixer, a clock pulse generator, and a frame and line pulse generator.

The diagnostic unit consists of a comparator, a voltage reference source, a single vibrator, a microcontroller and an LED matrix.

The output of the low-pass filter is connected to the input of the analog-to-digital converter and the first input of the write and read generator, the output of which is connected through the counter to the first input of the memory block. The second input of the memory unit is connected to the output of the analog-to-digital converter, and the counter output is connected to the second input of the write and read generator. The output of the memory unit through a digital-to-analog converter is connected to the first input of the video signal mixer, the output of which is connected to the display unit. The clock generator through the shaper of personnel and horizontal pulses is connected to the second input of the video signal mixer. The output of the low-pass filter is connected to the first input of the comparator, the second input of which is connected to a reference voltage source. The output of the comparator is connected to a series-connected single-shot, microcontroller and LED matrix.

Thanks to the introduction of a comparator, a reference voltage source, a single vibrator, a microcontroller and an LED matrix and a new interaction of elements in the device, real-time monitoring of human heart activity is ensured. This is due to the fact that with the help of the newly introduced comparator, a reference voltage source, a single vibrator and a microcontroller, it became possible to analyze the R-complex of the electrocardiogram and recognize on its basis the main types of arrhythmias in the work of the heart. Identified types of arrhythmias are displayed using an LED matrix by lighting one of its LEDs. Each of the LEDs corresponds to one type of arrhythmia. At the same time, the use of a microcontroller allows you to more flexibly analyze the appearance of the R-complex and constantly improve the algorithm for detecting arrhythmia. All this allows you to significantly improve the accuracy and reliability of the display and analysis of the cardiogram. The use of a microcontroller opens up new possibilities for a detailed analysis of a cardiogram and for real-time real-time detection of the main types of arrhythmia.

Figure 1 presents a block diagram of a device for monitoring cardiac activity of a person.

Figure 2 shows the electrocardiogram obtained at the output of the analog block.

A device for monitoring human cardiac activity includes an analog unit 1, an information storage unit 2, an interface unit 3, a display unit 4, and a diagnostic unit 5. In turn, an analog unit 1 includes sequentially connected electrode unit 6, lead selector 7, differential amplifier 8 , a blocking filter 9 and a low-pass filter 10. The information storage unit 2 includes an analog-to-digital converter 11, a write and read generator 12, a counter 13, and a memory unit 14. The interface unit 3 includes a digital-to-analog converter Tel 15, shifter 16, video signals, a clock generator 17 and the generator frame and line 18. The pulse diagnosis unit 5 is composed of a comparator 19, reference voltage source 20, monostable multivibrator 21, the microcontroller 22 and the LED array 23.

The output of the low-pass filter 10 is connected to the input of the analog-to-digital converter 11 and the first input of the write and read generator 12, the output of which through the counter 13 is connected to the first input of the memory unit 14. The second input of the memory unit 14 is connected to the output of the analog-to-digital converter 11, and the output of the counter 13 is connected to the second input of the write and read generator 12. The output of the memory unit 14 is connected via a digital-to-analog converter 15 to the first input of the video signal mixer 16, the output of which is connected to the display unit 4. Clock generator RS 17 through a frame and line pulse generator 18 is connected to the second input of the video signal mixer 16. The output of the low-pass filter 10 is connected to the first input of the comparator 19, the second input of which is connected to the voltage reference 20. The output of the comparator 19 is connected to the single-shot 21, the microcontroller, connected in series 22 and LED matrix 23.

In the inventive device for monitoring cardiac activity of a person, the differential amplifier 8 is made on the basis of the assembly of operational amplifiers TL 064. The blocking filter 9 is assembled according to a double T-shaped bridge configured to suppress network interference with a frequency of 50 Hz. As a storage device, a KR537RU10 memory chip with a memory capacity of 16 kB is used. As microprocessor 22, a 16F84 series PIC controller is used. The remaining elements of the device are chips of medium degree of integration. As the display unit 4, a household TV is used.

A device for monitoring cardiac activity of a person works as follows.

The signal of the electrocardiogram is removed from the electrodes mounted on the patient’s body, which make up the block of electrodes 6. Then the signal is fed to the input of the lead selector 7, with which the signal of one of the three leads of the electrocardiogram is selected. Next, the signal is amplified by a differential amplifier 8 and fed to the input of the blocking filter 9, with the help of which the suppression of mains voltage pickups occurs. After that, the high-frequency interference is smoothed out by a low-pass filter 10. The filtered electrocardiogram signal is fed to the input of an analog-to-digital converter 11, which is designed to convert the signal into digital form for writing it to the memory unit 14. Information is recorded and read from the memory unit 14 by the action of the signal a write and read generator 12, acting on the memory unit 14 through the counter 13. When a signal is received from the output of the analog block 1 to the first input of the write and read generator 12, t is the generation of recording pulses arriving at the clock input of the counter 13. At the output of the counter 13, a binary code is generated that controls the address input of the memory block 14. At the same time, information is recorded in the trigger cells of the memory block 14. After the recording process is finished, the signal is output from the output of the counter 13 the second input of the write and read generator 12, translating it into read mode. At the same time, the information recorded in it is read from the output of the memory unit 14 and fed to the input of the digital-to-analog converter 15, which performs the inverse conversion of the signal into analog form. From the output of the digital-to-analog converter 15, the signal is supplied to the first input of the video signal mixer 16. A second mixture of frame and line scanning signals generated by the frame and line pulse generation unit 18, which is controlled by the clock generator 17, is fed to its second input 17. The signal generated at the output of the video signal mixer 16 is fed to the antenna input of the display unit 4. The filtered electrocardiogram signal from the output of the low-pass filter 10 is fed to the first input of the comparator 19, where it compares is connected with the reference voltage U _op generated by the reference voltage source 20. When the signal of the electrocardiogram of the reference voltage U _{op is} exceeded, a high level voltage corresponding to log 1 is generated at the output of the comparator 19. Pulses log. 1 at the output of the comparator 19 are formed during the passage of the R-complex (R wave of the electrocardiogram). On the front of these pulses, the single-shot 21 generates a voltage pulse of 15 μs duration, which is fed to the input of the microcontroller 22. The microcontroller 22 analyzes the duration of the time intervals between the arrivals of the R-complex and determines the types of arrhythmia according to the algorithm laid down in it. If arrhythmia is detected, this signal ignites one of the LEDs of the LED matrix 23. For example, if the average (over 8 cycles) time between the arrival of the R-complex is less than 0.5 s, the microprocessor 22 signals tachycardia in the heart. If the same indicator exceeds 1.2 s, the microprocessor 22 sends a signal to the corresponding bradycardia LED of the LED matrix 23. Similarly, the diagnosis of other types of arrhythmia is carried out.

Thus, the patient’s electrocardiogram is monitored and the patient’s condition is monitored in real time. When one of the types of arrhythmias appears, the device sends a light signal to one of the diodes of the LED matrix 23. When the normal rhythm is restored, the LED glow remains until it is forcedly extinguished by medical personnel. Due to this logic of the device, a more reliable identification of arrhythmias in the work of the heart is ensured, which allows you to correctly assign the patient a course of further treatment.

Presented in figure 2 an electrocardiogram obtained at the output of the analog block 1 of the inventive device. The location of the electrodes corresponds to the removal of the chest leads of the electrocardiogram. A comparative analysis of figure 2 with a similar electrocardiogram obtained in the hospital of the city of Khabarovsk, indicates its high reliability of the data and, as a result, the correctness of the circuit decisions adopted in the inventive device.

Claims (1)

A device for monitoring human cardiac activity, comprising an analog block including a series of electrodes, a lead selector, a differential amplifier, a blocking filter and a low-pass filter, an information storage unit consisting of an analog-to-digital converter, a recording and reading generator, a counter, and a memory unit, an interface unit including a digital-to-analog converter, a video signal mixer, a clock pulse generator, and a frame and line pulse generator a display unit, while the output of the low-pass filter is connected to the input of the analog-to-digital converter and the first input of the write and read generator, the output of which through the counter is connected to the first input of the memory block, the second input of the memory block is connected to the output of the analog-to-digital converter, and the output of the counter connected to the second input of the write and read generator, the output of the memory unit through a digital-to-analog converter is connected to the first input of the video signal mixer, the output of which is connected to the display unit, the clock generator x pulses through the shaper of personnel and horizontal pulses is connected to the second input of the video signal mixer, characterized in that it additionally includes a comparator, a reference voltage source, a single vibrator, a microcontroller and an LED matrix, while the low-pass filter output is connected to the first input of the comparator, the second input which is connected to a reference voltage source, the comparator output is connected to a single-shot, a microcontroller and an LED matrix connected in series.

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