KR20060078207A - The system and method for a cardiovascular diagnosis monitoring - Google Patents

Abstract

The present invention relates to a system and method for monitoring cardiovascular diagnostics, and more particularly, to calculating simple and comprehensive diagnostic information by executing tests which had to be performed in the past at one time.

System for cardiovascular diagnostic monitoring of the present invention comprises an analog circuit unit for directly receiving a signal from the human body; A digital circuit unit which receives the signal obtained from the analog circuit unit and performs A / D conversion to interface with a PC; And a program unit configured to process a signal by applying an algorithm to the obtained signal and a monitoring program part indicating a result of processing the signal.

Accordingly, the system and method for cardiovascular diagnostic monitoring according to the present invention calculate various data for diagnosing cardiovascular diseases, and execute the tests that had to be performed in the past as a system and method that can be continuously monitored at a time. By doing so, simple and comprehensive diagnostic information can be calculated.

Cardiovascular, diagnostic, monitoring

Description

The system and method for a cardiovascular diagnosis monitoring

1 is a perspective view showing an ultrasound diagnostic apparatus having a conventional patient monitor.

Figure 2 shows a side view of the ultrasonic diagnostic apparatus having a conventional patient monitor.

3 shows an ultrasonic wave propagation model in a living tissue according to the present invention.

Figure 4 shows the definition of the pulse propagation time according to the present invention.

5 shows an electrocardiogram waveform according to the present invention.

6 shows a schematic diagram of an overall system according to the invention.

7 is a block diagram illustrating a signal detection procedure of an electrocardiogram circuit according to the present invention.

8 is a block diagram of a program unit of the cardiovascular diagnostic monitoring system according to the present invention.

9 illustrates a process of extracting flow rate information from data acquired by the Doppler sensor according to the present invention.

10 shows a display configuration according to the present invention.

The present invention relates to a system and method for monitoring cardiovascular diagnostics, and more particularly, to calculating simple and comprehensive diagnostic information by executing tests which had to be performed in the past at one time.

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the embodiment of the conventional invention will be described in detail.

1 is a perspective view of an ultrasound diagnostic apparatus having a conventional patient monitor, and FIG. 2 is a side view of an ultrasound diagnostic apparatus having a conventional patient monitor. The conventional ultrasonic diagnostic apparatus includes a main body 10 incorporating a device for converting a frequency signal applied through a transducer (not shown) into an image signal for display and a main monitor 20 for displaying the image signal. Equipped. The main monitor 20 is connected to the main body 10 so that the operator can rotate to see the diagnostic data in various directions. And, in the upper portion of the front of the main body 10, the key operating panel 30 is provided so that the operator can operate the key required for diagnosis.

Most patients are located on the side of the ultrasound diagnostic apparatus. Therefore, the conventional ultrasonic diagnostic apparatus is provided with a support groove 12 that can support the monitor for the patient on the side of the ultrasonic diagnostic apparatus main body 10.

On the other hand, the patient monitor 40, as shown in Figure 2, has a support shaft 44 in the form of a rod configured to be plugged into the support groove 12 located on the side of the main body 10. Above the support shaft 44, a display unit 42 for displaying an image signal applied from the main body 10 of the ultrasonic diagnostic apparatus is configured. Here, the display unit 42 uses a small liquid crystal monitor. The display unit 42 includes an image signal input terminal for receiving an image signal applied from the main body 10 of the ultrasound diagnosis apparatus. The main body 10 and the video signal input terminal are connected by a predetermined cable. In addition, the display unit 42 is provided with a power source can be supplied with power from the main body 10, it is possible to supply power from the outside through the adapter. In addition, the display unit 42 may rotate based on the support shaft 44.

In addition, the patient monitor 40 is compatible to be detachable from other types of ultrasonic diagnostic apparatus having the above-described support groove, so that it is possible to display an image signal applied from another type of ultrasonic diagnostic apparatus.

However, the conventional ultrasonic diagnostic apparatus having a patient monitor as described above is unable to calculate simple and comprehensive diagnostic information by performing one-time execution of various data calculations, continuous monitoring, and tests for diagnosing cardiovascular diseases. There is this.

Accordingly, the present invention is to solve the above problems, the present invention is to obtain the information of the blood vessels through the Doppler sensor, to calculate various values to extract parameters useful for diagnosis, ECG and pulse wave using the state of the blood vessels The present invention provides a system and method for monitoring cardiovascular diagnosis that can produce comprehensive test results for cardiovascular diagnosis such as diagnosis.

The present invention relates to a system and method for monitoring cardiovascular diagnostics, and more particularly, to calculating simple and comprehensive diagnostic information by executing tests which had to be performed in the past at one time.

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the embodiment of the present invention will be described in detail.

First, looking at the parameters measured for the cardiovascular diagnostic monitoring in the present invention are as follows.

First is blood flow rate. Doppler effects currently used in the vascular system include blood vessel and cerebrovascular examination of extremities. The method injects sound into a blood vessel at an angle (θ) with respect to the direction of blood flow. The movement speed of blood cells is called V [m / s], and the incident frequency f ₀ [Hz] and the reflection frequency f _r [Hz] If the sound velocity is C [m / sec], the Doppler frequency shift Δf is expressed by Equation 1.

The Doppler frequency shift equation can be used to calculate the velocity of the moving boundary. By using Equation 1 for the Doppler frequency shift Δf, blood flow velocity V may be calculated as Equation 2.

Second is the flow rate. Since the flow rate is affected by the unit area when the velocity is constant as the volume of the liquid passing through the cross section per unit time, it can be expressed as Equation 3, which is a value obtained by multiplying the unit area by the measured velocity. Therefore, by measuring the blood flow rate ΔV and multiplying the blood flow rate by the cross-sectional area, the blood flow rate ΔQ can be obtained.

Where ΔQ is the blood flow [m 3 / sec] A is the cross-sectional area of the blood vessel [m 2]

    ΔV: mean velocity of blood passing through the cross-sectional area [m / sec]

Blood flow information can be obtained by using an electronic flowmeter or a thermal dilution method, and since both are invasive, blood flow measurement by the ultrasonic Doppler method has an advantage in this regard. However, there is an error coming from the limitation of ultrasound in exchange for the advantage of non-vascular. As shown in Equation 3, in order to measure the blood flow volume by ultrasound, the average flow rate and the cross-sectional area of the tube should be measured. When measuring the two factors, various error factors are included. Therefore, in order to measure blood flow more accurately, it is essential to accurately measure the variable blood flow rate (ΔV), which is a basic factor, to reduce the error factor.

Third, blood vessel thickness. The ultrasonic parameters used to measure the thickness in the soft tissue of the living body are ultrasonic propagation speed (sonic speed). pulse echo overlap method, singaround method, phase interference method and spectrum analysis method. The most widely used ultrasonic thickness measurement method is the ultrasonic pulse-echo method, and standards for measuring the thickness by the ultrasonic pulse-echo method are provided in each country. In the system of the present invention, since the measurement point of the Doppler signal is the radial artery, the thickness of the radial artery and the resolution of the ultrasonic sensor are considered, and the information on the thickness and the blood flow are simultaneously obtained using one pulse Doppler sensor. Blood vessel thickness was measured using the ultrasonic pulse-echo method which can be simply calculated. The ultrasonic pulse-echo method is a method in which a transmitted pulse receives a signal reflected back from a boundary of a tissue and uses the time difference thereof.

3 shows an ultrasonic wave propagation model in a living tissue according to the present invention. V represents the speed of sound in each tissue. The speed of sound in the human body or medium is determined by its type and is independent of frequency. t represents the ultrasonic propagation time from the ultrasonic sensor to each tissue. Transmitting waves incident toward the tissue are reflected at the boundary of each tissue and returned with information about the tissue. In this case, the time when the received wave passes back through each tissue may be represented as 2 (t ₂ -t ₁ ) in tissue 1. Therefore, when the thicknesses of the tissues 1 and 2 are represented by the relationship between time, distance, and sound velocity, they are represented by Equations 5 and 6, which is a modification of Equation 4.

T: time, x: distance, v: sound velocity

X: thickness of each tissue

X: thickness of each tissue

Here, since the sound velocity v is the soft tissue of the human body, the average value thereof is about 1,540 (m / sec), so that the thickness x can be measured by knowing the reciprocating propagation time t of the ultrasonic waves.

Fourth, it is a pulse wave. Pulse waves are the transmission of arterial pressure waves caused by a heartbeat. When the left ventricular pressure is delivered to the aortic pressure by the heartbeat, the aortic valve opens and at the same time blood flows out. As the blood flows out, the internal pressure of the aortic root increases and the arteries expand. Thereafter, when the contraction of the heart is completed and the intracardiac pressure is lower than the intraaortic pressure, the aortic valve is closed and the internal pressure drops at the same time, causing the aortic wall to contract. As the intraaortic pressure rises or falls, changes in the arterial wall, in which the wall of the vessel contracts and expands, continuously occur. This pressure wave propagates peripherally along the vessel wall, which propagates at the wavelength to form a pulse wave.

Pulse wave includes a pressure pulse wave that detects a change in pressure of a blood vessel and a volume pulse wave that measures a volume change of a blood vessel according to a physical characteristic of a measurement object. The meaning of pulse wave in diagnostic medicine is used as an important indicator in determining changes in mechanical phenomena (pulsation, myocardial contraction and valve disorders), and hemodynamic abnormalities (pressure, volume change). In particular, the rate of pulse wave delivery is greatly influenced by the elasticity of the blood vessel and the thickness of the blood vessel wall, and increases when the vessel is hard or the vessel wall is thick, and the smaller the radius of the vessel, the faster. Therefore, the rate of pulse wave reflects the elasticity of the vascular system well. Acceleration pulse wave is the second derivative of photopl ethysmogram (PTG). It is used to make the inflection point of the fingertip red pulse wave more clear, and it is currently established as an independent test of the acceleration pulse wave. Acceleration pulse wave test equipment is simple and time-consuming to record, painless to the subject, and fully applicable to the analysis of waveforms. In this system, a pulse wave detector was constructed using a pressure sensor to obtain pulse transit time (PTT) from the heart to the radial artery. Vascular condition can be diagnosed by checking the trend of PTT.

The system for cardiovascular diagnostic monitoring of the present invention can be largely divided into three parts: the analog circuit unit 100, the digital circuit unit 200, and the PC program unit 300. The analog circuit unit 100 is manufactured to acquire various cardiovascular diagnostic parameters, the Doppler sensor circuit unit 100a using a pulsed Doppler sensor of 5 MHz frequency, the ECG sensor circuit unit 100b for detecting ECG data, and the pulse pressure for detecting pulse waves. It consists of the sensor circuit part 100c. The digital circuit unit 200 performs interface and data processing of the detected circuit, and the PC program unit 300 performs signal processing and data display. 6 shows a schematic diagram of an overall system according to the invention.

First, the analog circuit unit 100 will be described. The analog circuit unit 100 is a part that directly receives a signal from the human body in the cardiovascular diagnostic system and uses the Doppler sensor circuit unit 100a, the ECG sensor circuit unit 100b, and the pulse pressure sensor circuit unit 100c to acquire data necessary for cardiovascular diagnosis. It is composed.

The Doppler sensor circuit unit 100a is composed of a Doppler sensor, a transmission wave generator, and a reception wave receiver. The Doppler sensor uses a manufactured 5MHz sensor, and the transmit wave generator uses a high-speed ADC (Analogue / Digital Converter) board to drive the transmit pulse. In addition, the sensor having a single vibrator having a transmitter and a receiver manufactured separately has a center frequency of 5 MHz. Since the vibrator of the sensor is manufactured to have a constant angle, there is no need to tilt the sensor separately when measuring the blood flow signal.

The ECG sensor circuit unit 100b includes a differential amplifier for amplifying blood flow signals and a filter for obtaining a clean signal. The amplification part was designed to amplify the signal with high input impedance at the input part to match the impedance with the body. The filter unit produces a lowpass filter and a notch filter to remove noise from the received signal and acquire only a desired ECG signal, and amplifies the signal to have sufficient resolution before A / D conversion by the ADC chip. The amplification ratio of the fabricated circuit is about 1000 times and has a narrow bandwidth of 1 ~ 25Hz. 7 is a block diagram illustrating a signal detection procedure of an electrocardiogram circuit according to the present invention.

The pulse pressure sensor circuit part 100c is a part for receiving the time that an artery runs by blood pressure in a wrist. The signal was amplified for accurate acquisition and noise was removed using a filter.

Second, the digital circuit unit 200 will be described. The digital circuit unit 200 receives a signal obtained from the analog circuit unit 100 and performs A / D conversion to perform an interface with a PC. Conventional equipment obtains Doppler frequency shift in hardware and sends it to a DSP or PC to measure blood flow rate. However, the cardiovascular diagnosis system manufactured by the system of the present invention is not a method of implementing a frequency shift signal in hardware, but a method of directly receiving a reflected signal into a computer and processing the same in software, thereby avoiding a desired resolution and signal distortion. A high speed A / D board was used to display in real time. Using the high-speed A / D board, the received wave received from the Doppler sensor was transmitted to the PC and the signal processing was processed by the program on the PC.

Third, the program unit 300 will be described. The program unit 300 includes a portion for processing a signal by applying an algorithm to the acquired signal and a monitoring program portion for indicating a result of processing the signal. The former displays the results by measuring the Doppler frequency variation, and the program displays the results by the program which can monitor the cardiovascular diagnosis state of the subject. The ECG and pulse circuits are relatively simple in hardware, and the signal is input to the computer through the amplifying stage and the filter, and the signal is input to the signal processing for waveform output, blood pressure calculation, etc. On the other hand, when the Doppler signal is input, a wall filter (300 to 600 Hz) for removing the slow movement of the blood vessel through the amplification stage and a low pass filter for removing noise, etc. are passed through. In addition, the software is divided into three parts by a time controller, and a process of calculating blood vessel thickness, vessel diameter, and Doppler frequency shift is performed. This series of processes is done in software, making it easy to calibrate according to input conditions and modify algorithms. Therefore, the system according to the present invention can be said to have a good basic scalability. 8 is a block diagram showing the program unit 300 of the cardiovascular diagnostic monitoring system according to the present invention.

In the signal processing method of the system for cardiovascular diagnostic monitoring according to the present invention, a process in which data obtained from a Doppler sensor is input into a PC is divided into two processes.

In the first process, the FFT (Fast Fourier Transformation) finds the center frequency of the Doppler sensor and compares it with the center frequency value of the previously input sensor to measure the degree of Doppler frequency deflection.

In the second process, a peak detector is used to measure the peak value of the blood flow, and a parameter value related to the thickness is obtained to calculate the vessel wall thickness and the diameter of the vessel.

The blood flow is calculated through the above two processes, and these values are analyzed by the program unit 300 to output diagnostic information on the PC monitor. 9 illustrates a process of extracting flow rate information from data acquired by the Doppler sensor according to the present invention.

The screen of the system for monitoring the cardiovascular diagnosis according to the present invention is largely composed of Patient's information, Wave analysis, Diagnosis, History and remarks. 10 shows a display configuration according to the present invention.

Patient's Information is a place for entering patient information, which consists of name, gender, age, height, weight and BMI.

Wave Analysis outputs ECG, PPG, and ultrasonic waveforms from the data obtained from the sensor, enabling the user to immediately check the change of the biological signal on the graphic.

Diagnosis is the part that shows the value of the diagnosis result finally signaled and outputs the blood vessel thickness, blood flow rate, blood flow, cardiac output, pulse rate, systolic blood pressure and diastolic blood pressure. Blood pressure values are measured using a conventional sphygmomanometer.

History is a part of the medical history and shows the patient's measurements (high and low blood pressure).

Findings are where doctors describe patients' abnormalities based on measurement results.

By pressing the output button on the display screen, the diagnosis results can be output to a diagnosis result paper of a predetermined format and stored in a hospital or divided into patients.

The system for monitoring cardiovascular diagnosis according to the present invention can be generally used for cardiovascular diagnosis of all people and can be utilized even when it cannot be measured by conventional measuring methods such as infants, hypotensive patients, and critical patients. In addition, it can be utilized as a holter monitor (holter monitor) that requires a long time measurement, the use range is very wide. This system is a complex ultrasound cardiovascular diagnostic system employing various ultrasound parameters, and shows various cardiovascular diagnostic values at the same time without any hassle. It is more accurate than conventional methods and has advantages in price. In terms of economics, it is possible to secure competitiveness in the domestic medical device field as a new type of multifunctional ultrasound cardiovascular diagnostic device, thereby establishing its position as a comparative advantage abroad, and the effect of import substitution will continue to increase in the future. have.

As described above, the system and method for cardiovascular diagnostic monitoring according to the present invention calculate various data for diagnosing cardiovascular disease, and perform the tests that had to be performed in the past as systems and methods for continuous monitoring. By executing at a time, simple and comprehensive diagnostic information can be calculated.

Claims (6)

An analog circuit unit directly receiving a signal from a human body; A digital circuit unit which receives the signal obtained from the analog circuit unit and converts A / D (Analogue / Digital) to perform an interface with a PC; And A program unit comprising a part for processing a signal by applying an algorithm to the obtained signal and a monitoring program part for indicating a result of processing the signal; System for cardiovascular diagnostic monitoring comprising a. The method according to claim 1, The analog circuit portion A Doppler sensor circuit unit having a single vibrator having a transmitter and a receiver separately manufactured, and configured to measure a signal by making the vibrator of the sensor have a predetermined angle; Amplification unit, low pass filter, and notch filter that amplify the signal with high input impedance at the input part are manufactured to amplify the signal before A / D conversion by ADC (Analogue / Digital Converter) chip. An electrocardiogram (ECG) sensor circuit portion having a filter portion to have a resolution; And A pulse pressure sensor circuit part which amplifies the signal and removes noise; System for cardiovascular diagnostic monitoring comprising a. The method according to claim 2, The ECG sensor circuitry is a system for cardiovascular diagnostic monitoring, characterized in that having a bandwidth of 1 ~ 25Hz bandwidth. The method according to claim 1, And the digital circuit unit transmits the received wave received from the Doppler sensor to the PC using a high speed A / D board. The method according to claim 1, The system for processing a signal by applying an algorithm to the acquired signal of the program unit is a system for cardiovascular diagnostic monitoring, characterized in that for measuring the flow rate and flow rate by measuring the Doppler frequency variation. A first step of calculating a velocity of blood flow by measuring a degree of Doppler frequency deflection by comparing a center frequency of the Doppler sensor by comparing a waveform with a FFT (Fast Fourier Transformation), and comparing the center frequency value of a sensor previously input; A second step of measuring a peak value of the blood flow using a peak detector, calculating a parameter value related to the thickness, and calculating the vessel wall thickness and the diameter of the vessel; And A third step of calculating blood flow through the first and second steps and analyzing the values of the blood flow in a program unit to output diagnostic information on a PC monitor; Method for monitoring cardiovascular diagnostics, including.

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