KR102106631B1 - blood flow simulator of coronary artery - Google Patents

Abstract

The blood flow simulator of the present invention can provide a physical environment similar to a coronary artery. Specifically, in the stenosis model, anterior and posterior blood flows can be measured simultaneously, and each of them can be measured separately, and the wedge pressure can be calculated using this, and fractional reserve blood flow (FFR) can be predicted non-invasively. By adjusting the static pressure of the entire system using a reservoir, hyperemia conditions can be reproduced, which can be useful for evaluating the severity of stenosis. By reproducing the human body's automatic control ability, it is possible to simulate a real blood flow.
In addition, the blood flow system of the present invention has excellent accuracy because it is measured similarly to a waveform measured clinically. Therefore, it can be used for quality control of the FFR measurement device, and it can also replace animal experiments that measure FFR.
Additionally, based on clinical data such as imaging of a patient, 3D printing of a patient's vascular model and analysis of the patient's FFR enables accurate and easy analysis of the patient's FFR, which can be used as a diagnostic device.

Description

Blood flow simulator of coronary artery

The present invention relates to a coronary blood flow simulator, and more particularly, to a blood flow simulator capable of extracting hemodynamic information, such as pressure or blood flow, depending on stenosis in a coronary artery and applying it to a study to conduct a simulation. .

Coronary arteries are arteries that supply oxygen to the heart through blood. Diseases occurring in coronary arteries are very closely related to blood flow, and ischemia of the heart occurs when blood flow is insufficient due to stenosis.

Various indicators have been proposed to determine myocardial ischemia. These indicators, calculated through the pressure and blood flow in the coronary artery, determine whether or not the arterial procedure has progressed, and among the many indicators, the coronary flow reserve (CFR) and fractional flow reserve (FFR) are high. Is being used.

 CFR is a method of measuring the ratio of steady-state blood flow to blood flow at maximum hyperemia of peripheral blood vessels. FFR refers to the ratio of blood flow during maximal hyperemia before and after stenosis. FFR was defined as the ratio of the difference between the distal pressure (Pd) and the coronary wedge pressure (Pw) and the proximal pressure (Pa) and the coronary wedge pressure (Pw) at the time of maximal hyperemia.

When measuring FFR and CFR, it creates the maximum congestion state of the capillaries. The reason is to overcome the auto-regulating ability that does not change blood flow compared to changes in blood pressure inside the blood vessels of the human body. Mainly, adenosine is administered to create the maximum congestion state. At this time, the capillaries expand and the average pressure decreases and blood flow increases in the coronary artery. However, there is a problem that the test time is longer and may cause discomfort to the patient, and other blood vessel dilatation agents may be required because the congestion state is not created, and reproducibility is poor.

Recently, IFR (Instantaneous wave-free ratio) has been proposed. This method determines the average ratio of blood pressure in the proximal and distal blood vessels in the absence of two waves by determining the presence of forward and backward blood flow by wave intensity analysis (WIA). The presence of forward and posterior blood flow in the coronary artery was demonstrated by WIA. However, WIA can determine the intensity of forward and backward blood flow, but there is a limitation that direct pressure cannot be obtained.

Reflection magnitude (RM) is used to examine the stiffness of the arteries in the central artery. In this method, blood pressure in an artery can be calculated directly by dividing the arterial blood pressure into an anterior and posterior blood pressure. It is a value expressed by the ratio of the posterior blood pressure and the forward blood pressure of the central artery, and the forward and backward blood pressures can be calculated using the pressure, characteristic resistance of blood flow and blood vessels. However, it has not been applied to coronary arteries.

In vitro experiment systems have been developed to study various diseases currently occurring in coronary arteries. However, there is no system for creating a congestion condition of the capillaries and calculating wedge pressure by separating forward and backward blood flow.

The simulator of the present invention is a device made to reproduce a phenomenon similar to actual physical properties, and can be applied to research by implementing various hemodynamic properties occurring in the coronary artery of the human body. In other words, it is possible to realize the cardiovascular condition of various patients at a relatively low cost.

Republic of Korea Patent Publication No. 10-2016-0131493

In the coronary artery required for FFR measurement, wedge pressure is defined as the distal pressure when the artery is blocked, and in general, a balloon is used to block the artery. In clinical trials, measuring wedge pressure is limited to lesions and can be very dangerous, making it difficult to measure.

Accordingly, the present invention provides a blood flow simulator and method for calculating the wedge pressure through separation of the backward and forward blood flows and reproducing hyperemia to measure the correct FFR.

In order to achieve the above object, the blood flow simulator of the present invention is a simulated blood vessel portion forming a blood vessel model, a reservoir that can accommodate fluid, a first tube connecting the reservoir and the simulated blood vessel portion, the reservoir and the simulated blood vessel A second tube that connects a portion, a first pump disposed on the first tube, a first valve disposed on the first tube, a second valve disposed on the second tube, and the first valve and the agent It includes a third tube connecting the two valves, the first pump, the fluid to be accommodated in the reservoir to flow to the first valve, the fluid is the simulated blood vessel portion and the third tube by the first valve control It flows to the second valve connected through, and the second valve is characterized in that the fluid flows to the reservoir and the simulated blood vessel.

A pressure control device disposed in the water storage tank and controlling the pressure of the fluid may be further included.

The third tube may further include a resistance having an inner diameter of 100 to 200% of the inner diameter of the simulated blood vessel part.

It is disposed on the first tube and may further include a sensor that measures the pressure and flow rate of the fluid at a location before or after the stenosis of the simulated blood vessel portion.

One side is further connected to the first tube between the first valve and the simulated blood vessel part, the other side further comprises a second pump connected to the second tube between the second valve and the reservoir, the second pump is the The first pump may be to apply pressure to the fluid in the opposite direction of the reverberation that circulates the fluid.

Coronary artery blood flow simulation method of the present invention comprises the steps of preparing a simulated blood vessel by analyzing the stenosis of a patient's blood vessel, measuring the pressure or flow rate of the fluid before (proximal) the stenosis of the simulated blood vessel, and measuring the flow. And calculating the forward blood pressure and the backward blood pressure using the measured pressure or flow velocity.

It may further include the step of measuring the wedge pressure by reducing the static pressure to implement the congestion condition and closing the forward blood flow.

The blood flow simulator of the present invention can provide a physical environment similar to a coronary artery. Specifically, in the stenosis model, the forward and backward blood flows can be measured simultaneously, and each of these can be measured separately, and the wedge pressure can be measured using this. The simulated venous system pressure can be controlled by adjusting the static pressure of the entire system using a reservoir. Through these, hyperemia conditions can be reproduced, which can be useful for evaluating the severity of stenosis. In addition, by reproducing the autoregulation of the human body, it is possible to simulate the blood flow.

In addition, the blood flow system of the present invention has excellent accuracy because it is measured similarly to a waveform measured clinically. Therefore, it can be used for the quality control of the implantable pressure sensor, and it can be used for the study of coronary artery disease by variously simulating clinical symptoms and results in advance.

Additionally, based on clinical data such as imaging of a patient, 3D printing of a patient's vascular model and analysis of the patient's FFR enables accurate and easy analysis of the patient's FFR, which can be used as a diagnostic device.

1 is a schematic diagram of a blood flow simulator according to an embodiment of the present invention.
2 is a schematic diagram of a blood flow simulator according to another embodiment of the present invention.
3 is a schematic view of a water storage tank according to an embodiment of the present invention.
4 is a schematic diagram of a simulated blood vessel part according to an embodiment of the present invention.
5 is a schematic diagram of a blood flow simulator according to another embodiment of the present invention.
6 is a schematic diagram of a blood flow simulator according to another embodiment of the present invention.
7 is a schematic diagram of a blood flow simulator according to another embodiment of the present invention.
8 is a schematic diagram of a blood flow simulator according to another embodiment of the present invention.
Figure 9 shows the flow of fluid according to the control of the valve in the embodiment (condition 1) of the present invention. (Conditions with forward and backward blood flow)
Figure 10 shows the flow of fluid according to the control of the valve in the embodiment (condition 2) of the present invention. (Only forward blood flow and no backward blood flow)
Figure 11 shows the flow of fluid according to the control of the valve in the embodiment (condition 3) of the present invention. (Wedge pressure measurement condition without forward blood flow)
12 is a graph showing changes in blood flow and blood pressure according to regulation of static pressure.
13 is a result of analyzing a change in the pressure ratio (Pd / Pa) of the distal and proximal portions according to the degree of stenosis of the simulated blood vessels in the blood flow simulator.
Figure 14 is a mock blood vessel with stenosis produced according to an embodiment of the present invention (mock blood vessel with 48, 71, 88% stenosis from the top).
15 is a view showing a resistance according to an embodiment of the present invention.
16 is a graph showing the similarity to retrograde blood pressure by subtracting the static pressure for each situation to the measured wedge pressure.
17 is a graph showing the correlation between the calculated wedge pressure and the measured wedge pressure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

1 is a schematic diagram showing a blood flow simulator according to an embodiment of the present invention.

Referring to FIG. 1, a blood flow simulator according to an embodiment of the present invention will be described in detail.

Referring first to FIG. 1, the blood flow simulator of an embodiment of the present invention includes a reservoir 100, a simulated blood vessel part 200, a first pump 300, a first valve 400, a second valve 500, and 1 to 3 tubes (600, 700, 800).

The inside of the water storage tank 100 is empty and fluid can be accommodated.

One side of the first tube 600 is connected to one side of the water storage tank 100. One side of the second tube 700 is connected to the other side of the reservoir 100. The other side of the first tube 600 is connected to one side of the simulated blood vessel part 200. The other side of the second tube 700 is connected to the other side of the simulated blood vessel part 200.

The first valve 400 is disposed on the first tube 600, and the second valve 500 is disposed on the second tube 700. The third tube 800 connects the first valve 400 and the second valve 500.

The detailed configuration of the first valve 400 and the second valve 500 is the same as the well-known three-way valve, so a detailed description thereof will be omitted.

The first pump 300 is disposed between the reservoir 100 and the first valve 400 in the first tube 600. Due to the operation of the first pump 300, the fluid in the reservoir 100 may flow in the direction of the simulated blood vessel unit 200.

The fluid may be introduced into one side of the simulated blood vessel unit 200 under the control of the first valve 400. And it flows in the direction of the second valve 500 through the third tube 800. The second valve 500 controls the fluid to flow in the direction of the other side of the simulated blood vessel part 200 and the reservoir 100.

The simulator according to the embodiment of the present invention allows the forward blood flow and the backward blood flow to be simultaneously present in the simulated blood vessel portion 200 such as a coronary heart.

The first pump 300 may adjust the amount of blowout once and the number of blowouts per minute. Through the first pump 300, blood flow and blood pressure ejected from the heart may be realized.

The first to third tubes 600, 700, and 800 may be formed of polyvinyl chloride (PVC) or silicon. The first to third tubes 600, 700, and 800 may be silicon tubes. The inner diameters of the first to third tubes 600, 700, and 800 may be 5 to 9 mm.

The blood flow simulator according to an embodiment of the present invention may control the flow direction of the fluid by controlling the first valve 400 or the second valve 500, and measure the forward pressure or the wedge pressure separately.

The blood flow simulator according to the embodiment of the present invention may further include a pressure regulating device 110 disposed in the reservoir 100.

Referring to FIG. 2, the pressure regulating device 110 is connected to the water storage tank 100 and adjusts the pressure of the water storage tank 100 to adjust the static pressure. The pressure regulating device 110 includes an actuator. However, it is not limited as long as it is a device for regulating normal pressure.

3 is a view showing the water storage tank 100 shown in FIG. 1.

1 and 3, the reservoir 100 is formed on one side of the storage tank 140, the storage tank 140, in which the fluid is accommodated, and the outlet 120 through which the fluid is discharged, and the other side of the storage tank 140, through which fluid is introduced. It includes an inlet 130.

One side of the simulated blood vessel 200 is connected to the outlet 120 of the reservoir 100 through the first tube 600. The other side of the simulated blood vessel part 200 is connected to the inlet 140 of the reservoir 100 through the second tube 700.

The fluid flowing from the second tube 700 to the reservoir 100 is accommodated in the reservoir 140 through the inlet 130. The fluid received in the reservoir 140 flows along the first tube 600 through the outlet 120.

4 is a view showing a mock blood vessel shown in FIG. The simulated blood vessel portion 200 includes a proximal portion 210 and a distal portion 220 and a removable removable blood vessel 230. The simulated blood vessel 230 is a 3D vascular model having a stenosis, and may be manufactured by 3D printing based on a result of analyzing blood vessels in a stenosis region of a coronary artery stenosis patient. 14 is an example of manufacturing a simulated blood vessel 230 according to an embodiment of the present invention. Mock blood vessel 230 may be made of silicon, filament, resin, or the like.

Here, the analysis of blood vessels may be performed using computed tomography, selective computed tomography, or magnetic resonance imaging.

The proximal portion 210 is connected to the first tube 600, and the distal portion 230 is connected to the second tube 700. The fluid introduced through the first tube 600 passes through the proximal portion 210 and passes through the simulated blood vessel 220 and is discharged through the distal portion 230. In addition, the fluid flowing from the third tube 800 to the second valve 500 may flow into the simulated blood vessel 220 through the distal portion 230.

The blood flow simulator according to another embodiment of the present invention may further include a resistor 900.

Referring to FIG. 5, the resistor 900 is disposed on the third tube 800.

The resistor 900 has an inner diameter of 100 to 200% of the inner diameter of the simulated blood vessel portion. 15 is a diagram of resistance according to an embodiment of the present invention.

By adjusting the inner diameter of the resistance, it is possible to control the amount of fluid flowing through the third tube. Therefore, the ratio of forward and backward blood flow can be adjusted. Through this, an auto-regulating phenomenon similar to a living body can be reproduced. When the inner diameter is less than 100%, there is a phenomenon in which the amount of backward blood flow is greater than the amount of forward blood flow, and when it is greater than 200%, a problem that excessive pressure is applied to the connecting portion may occur, and the auto-regulating ability of blood vessels cannot be reproduced.

The blood flow simulator according to another embodiment of the present invention may further include a second pump 1000.

Referring to FIG. 6, the second pump 100 has one side connected to the first tube 600 and the other side connected to the second tube 700. The second pump 1000 reproduces the pressure appearing in the diastolic state of the heart. Specifically, the first pump 300 applies pressure to the fluid in the opposite direction to the reflection that circulates the fluid.

The blood flow simulator according to another embodiment of the present invention may further include an air tank 1100.

Referring to FIG. 7, the air tank 11000 is disposed on the first tube 600. Specifically, it may be formed between the first pump 300 and the first valve 400. The air tank 1100 removes negative pressure and zero fluid velocity in the simulator.

The blood flow simulator according to another embodiment of the present invention may further include a sensor 1200 disposed in a sensor insertion port (not shown) formed on the first tube 600.

Referring to FIG. 8, a sensor insertion port (not shown) is formed on the first tube 600 between the first valve 400 and the simulated blood vessel unit 200.

The sensor 1200 is formed in a wire shape and is located inside the first tube 600 through a sensor insertion hole (not shown). The inserted sensor 1200 measures the pressure and flow velocity of the fluid at a location before or after the stenosis of the simulated blood vessel portion 200.

Using the blood flow simulator according to an embodiment of the present invention, the flow direction of the fluid may be controlled to measure pressure, forward pressure, and wedge pressure when both forward and backward blood flows are present simultaneously.

It will be described in detail with reference to FIGS. 9, 10 and 11 in detail.

First, FIG. 9 is a condition in which both the first valve 400 and the second valve 500 are opened. The fluid accommodated in the reservoir 100 by the operation of the first pump 300 passes from the first tube 600 through the first valve 400 and flows into one side (proximal portion) of the simulated blood vessel part 200. The fluid flowing into the simulated blood vessel portion 200 passes through the simulated blood vessel 230 and is discharged to the other side (distal portion) and flows into the reservoir through the second tube 700. At this time, a part of the fluid flowing through the operation of the first pump 300 flows from the first valve 400 to the second valve 500 through the third tube 800. The flow of fluid is separated from the second valve 500, and some fluid flows into the reservoir 100, and the remaining fluid flows to the other side (distal part) of the simulated blood vessel part 200. Therefore, the forward and backward blood flows simultaneously exist in the simulated blood vessel unit 200. At this time, the total pressure can be measured.

10 is a view showing simulation conditions in which only forward blood flow is present.

In the present invention, “forward blood flow” refers to the flow of fluid that is ejected from the pump and passes through the simulated blood vessel from the proximal to the distal.

Referring to FIG. 10, the direction connected to the third tube 800 in the first valve 400 is closed. Accordingly, the fluid flows from the first pump 300 through the first tube 600 into the simulated blood vessel part 200 and penetrates through the simulated blood vessel part 200 into the reservoir 100 through the second tube 700. do. Therefore, only the forward pressure, that is, the forward pressure, can be measured.

11 is a driving condition for measuring the wedge pressure. Referring to FIG. 11, a direction connected to the simulated blood vessel part 200 of the first valve 400 is closed. Therefore, the fluid flows from the first valve 400 to the third tube 800, and is separated from the second valve 500 into the simulated blood vessel part 200 and the reservoir 100. In this case, the wedge pressure may be measured by measuring the pressure of the blood flow flowing through the simulated blood vessel unit 200.

Coronary artery blood flow simulation method according to an embodiment of the present invention comprises the steps of preparing a simulated blood vessel by analyzing the stenosis of a patient's blood vessel, measuring the pressure or flow rate of the fluid before (proximal) the stenosis of the simulated blood vessel, and And calculating forward and posterior blood pressure using the pressure or flow rate measured in the measuring step.

Analysis of the stenosis of blood vessels is performed using computed tomography, selective computed tomography, and magnetic resonance imaging. Based on the analysis results of the vascular section, 3D printing is performed to produce a simulated blood vessel that simulates the patient and the stenosis. The simulated blood vessel is characterized by reproducing at least one of the length of the vascular portion of the patient's blood vessel, the thickness of the blood vessel wall, the minimum inner diameter of the vessel, and the diameter of the stenosis region.

Specifically, a wire-type sensor is inserted into the simulated blood vessel portion 200 to measure the pressure and flow of the fluid in the entire portion of the simulated blood vessel stenosis.

It is characterized in that the calculated pressure and flow are calculated by separating forward blood pressure and backward blood pressure using Equations 1 and 2.

Pf is forward blood pressure, Pb is backward blood pressure, P is blood pressure, Zc is characteristic resistance, and F is flow.

The characteristic resistance (Zc) is theoretically defined as a resistance without reflected waves, and the measured pressure and the frequency of the blood flow are analyzed to obtain an input impedance, and the frequency analyzed pressure and the blood flow are evaluated for phase and sound It is defined as the point at which a value is converted to a positive value or close to the first zero.

In the present invention, the characteristic resistance is characterized in that it is 4 harmonics of the fundamental frequency after the point where the phase difference is converted from a negative value to a positive value.

In the embodiment of the present invention, the forward pressure and the backward pressure are separated using Equations 1 and 2, and the wedge pressure is calculated using the separated backward pressure, and the calculated wedge pressure and the measured wedge pressure are very strong. It was confirmed to have a. Therefore, the wedge pressure can be simulated in the coronary artery using the simulation method of the present invention, and the FFR can be analyzed using the simulation method.

The method for simulating coronary blood flow according to an embodiment of the present invention may reduce blood pressure to implement a congestion condition, close the forward blood flow, measure wedge pressure, and further include a step.

In the embodiment of the present invention, the static pressure was reduced from 30 mmHg to 10 mmHg by about 20 mmHg. When the static pressure was lowered to 10 mmHg or less, bubbles (cavitation) due to negative pressure in the blood flow system occurred, which became a problem in measuring blood flow using ultrasound. In addition, the reason for setting the 30mmHg as the default state is due to the limit value that can raise the height of the reservoir. If the pressure regulating device disposed in the reservoir is used, the maximum value of the static pressure can be raised more than 30mmHg.

The constant pressure control is to specifically adjust the height of the water storage tank or to reduce or increase the pressure of the water storage tank using a pressure control device.

In the bleeding condition, the degree of static pressure reduction may be different for each patient. This simulator can implement different congestion conditions for each patient by adjusting the static pressure using a pressure control device.

In the embodiment of the present invention, the static pressure was reduced from 30 mmHg to 10 mmHg to about 33.3% of the initial static pressure.

Accordingly, the decrease in the static pressure may be reduced to a level of 50% to 10% of the static pressure initially set in the simulator. When the static pressure in the congestion condition is less than 10% of the initial static pressure before the decrease, there is a problem in that it is difficult to measure ultrasonic blood flow due to air bubbles in the fluid due to negative pressure.In the congestion condition, when the static pressure exceeds 50% of the initial static pressure, congestion A problem may arise where the condition is not well implemented.

In the embodiment of the present invention, the static pressure is reduced by using a water storage tank, and the flow of the fluid in the direction of the first valve and the third tube is closed to realize only the backward blood flow. It was confirmed that the hyperemia was reproduced in the artery, and accordingly, the wedge pressure can be predicted through the separated posterior blood pressure based on the patient's blood vessel image information.

<Experiment Method>

Example 1. Preparation of blood flow simulator

Unlike the existing circulatory model of the arterial system, the forward and posterior blood flows of the stenosis model to be observed were simultaneously implemented in the systole and the blood flow to the reservoir during the diastolic system was implemented. In order to measure the fractional blood reserve (FFR), the difference between wedge or retrograde blood flow should be determined from distal blood pressure. It was implemented as follows.

In order to control static pressure in the blood flow simulator, a reservoir was used, and the static pressure was adjusted by changing the height of the reservoir.

A pulsatile cycle pump was used to simulate the heartbeat, and to compare data in various environments, the pulsatile rate of the pump was fixed at 60 r / min and the OPR of 57. As the emulsion, 1.5 L of Doppler Fluid (Doppler test fluid model 707, ATS laboratories, Bridgeport, USA) was used, and the viscosity is similar to that of blood and contains a scattering body.

The conduit used an IXAK® silicon tube (SL-0710, TOMMYHECO, KOREA) with an inner diameter of 7 mm. In order to reflect the coronary artery with stenosis in the system, a stenosis vessel with a minimum lumen area ratio of 48, 71, and 88% was produced as a 3D printer as shown in FIG. 14 to perform the experiment. In order to match the waveform and phase difference of the blood flow and blood pressure of the human coronary artery, a windkessel model was manufactured using an air tank. This allowed the simulator to eliminate negative pressure and zero blood flow velocity in the simulator.

The minimum lumen area ratio is expressed by Equation 3.

The A0 is the vascular inner diameter area of the stenosis area, and A1 is the vascular minimum inner diameter area of the stenosis area.

The data was measured using Catheter (ComboWire XT®, Volcano Corporation, San Diego, California), which can be inserted into a tube to measure blood pressure and flow rate. CFR and FFR can be measured simultaneously because pressure and flow rate can be measured. The pressure was measured 20 mm before (proximal) and 20 mm (distal) before the stenosis point, and the catheter was inserted 200 mm before the stenosis.

Example 1-1. Condition 1-1st direction open, 2nd direction open

9 is an experimental condition in which both forward and backward blood flow are present.

The ratio of the anterior and posterior blood flows can be controlled by using the stenosis resistance. The pressure measured before (proximal) and after the stenosis (distal) exists in both the anterior and posterior blood pressures. (Pf) and posterior blood pressure (Pb) were separated using Equation 1 and Equation 2.

Example 1-2. Condition 2-1st direction open, 2nd direction closed

Next, in order to measure the forward blood pressure, as shown in FIG. 10, only the second direction (connected to the third tube) was closed so that the fluid flowed only in the first direction connected to the simulated blood vessel, thereby implementing a condition in which only forward blood flow exists. . Condition 1 was assumed to be a steady state, static pressure was reduced from 30 mmHg to 10 mmHg in condition 2, and a condition of 10 mmHg was assumed to be capillary hyperemia.

13 shows the change in Pd / Pa according to stenosis before and after congestion.

Example 1-3. Condition 3-closed in the first direction, opened in the second direction

In clinical trials, the wedge pressure is measured by distal pressure when the artery is blocked using a balloon. To measure the wedge pressure, as shown in FIG. 11, the direction connected to the simulated blood vessel of the first valve (the first direction) is closed to measure the pressure of the distal portion under the condition that the fluid flows only in the backward direction to measure the wedge pressure in the blood flow simulator. .

<Result>

Experimental Example 1. Confirmation of capillary hyperemia through regulating the reservoir pressure

The results of changes in blood flow and blood pressure according to stenosis before and after congestion are shown in FIG. 12, and CFR measurement results are shown in Table 1 using the simulator of the present invention. Looking at the blood pressure and blood flow in the normal and congested state of FIG. 12, it was confirmed that the blood pressure (yellow line) is lowered and the blood flow (blue line) is increased in the congested state.

Stenosis (%) 49 71 87 CFR 2.2 1.5 1.2

In Table 1, it was confirmed that CFR was significantly decreased according to the degree of stenosis.

13 is a graph showing the pressure ratio (Pd / Pa) of the distal portion and the proximal portion measured according to the degree of stenosis in the device of the embodiment of the present invention. The pressure ratio (Pd / Pa) due to the stenosis of the distal and proximal regions has a lower value in the situation where only the forward and backward blood flows exist and there is no backward blood flow, and the hydrostatic pressure is 10 mm at 30 mmHg. When it was lowered to Hg, it was confirmed that the pressure ratio had a lower value. This confirms that the sensitivity to evaluate the stenosis increases when the static pressure is lowered and blood flow is increased in this simulator. That is, it was confirmed that the stenosis degree can be more accurately judged when the static pressure is reduced by using the reservoir, the forward blood flow is increased, and the backward blood flow is reduced to minimize the effect of wedge pressure. That is, the reason why the simulation device creates the congestion condition when measuring FFR in the clinic is well explained, and it was confirmed that the accuracy of the measurement can be improved by reproducing the congestion condition similar to the actual clinical practice.

As a result of the analysis, it was confirmed that accurate simulation is possible because the pressure decreases and the blood flow increases, showing results similar to those observed in hyperemia in the actual coronary artery.

Experimental Example 2. Correlation between calculated back pressure and measured wedge pressure

The wedge pressure measured in the simulator (condition 3) and the backward blood pressure calculated by measuring under condition 1 with forward and backward blood flow were compared, and it was confirmed that the graph had a similar shape to the two graphs. As a result of analyzing the correlation between the pressure and the hydrostatic pressure, it was confirmed that a very strong correlation was shown (FIG. 16).

Experimental Example 3. Correlation between calculated wedge pressure and measured wedge pressure

The wedge pressure was calculated using the calculated backward pressure, and the correlation between the calculated wedge pressure and the wedge pressure measured in the simulator was confirmed. 17 is a result of analyzing the correlation between the calculated wedge pressure and the measured wedge pressure. As a result of the analysis, it was confirmed that the calculated wedge pressure and the measured wedge pressure had a very strong correlation with Rho = 0.990 and p <0.0001.

Therefore, after measuring the pressure and blood flow at the distal portion without blocking the arteries, and calculating the measured value using the characteristic resistance as Equations 1 to 2, it can be divided into forward pressure and backward pressure, and the calculated backward pressure is used. The wedge pressure can be predicted. In addition, fractional blood reserve (FFR) can be predicted.

100: reservoir 110: pressure control device
120: outlet 130: inlet
140: reservoir 200: simulated blood vessel
210: proximal 220: distal
230: simulated blood vessel 300: first pump
400: first valve 500: second valve
600: first tube 700: second tube
800: third tube 900: resistance
1000: second pump 1100: air tank
1200: sensor

Claims (7)

A mock blood vessel part forming a blood vessel model;
A storage tank capable of receiving a fluid;
A first tube connecting the reservoir and the simulated blood vessel part;
A second tube connecting the reservoir and the simulated blood vessel part;
A first pump disposed on the first tube;
A first valve disposed on the first tube;
A second valve disposed on the second tube; And
A third tube connecting the first valve and the second valve;
It includes,
The first pump flows the fluid received in the reservoir to the first valve, and the fluid flows to the second valve connected through the simulated blood vessel part and the third tube under the control of the first valve, and the first pump. The 2 valve allows the fluid to flow to the reservoir and simulated blood vessels,
A blood flow simulator further disposed in the third tube and further comprising a resistance having an inner diameter of 100 to 200% of the inner diameter of the simulated blood vessel part. According to claim 1,
A blood flow simulator further disposed in the reservoir and further comprising a pressure regulating device for controlling the pressure of the fluid. delete According to claim 1,
A blood flow simulator further disposed in the first tube and further comprising a sensor for measuring the pressure and flow rate of the fluid at a location before or after the stenosis of the simulated blood vessel portion. The method of claim 1
One side is further connected to the first tube between the first valve and the simulated blood vessel part, the other side further comprises a second pump connected to the second tube between the second valve and the reservoir, the second pump is the A blood flow simulator in which the first pump applies pressure to the fluid in the opposite direction to that in which the fluid circulates. Preparing a simulated blood vessel by analyzing a stenosis of a patient's blood vessel;
Measuring the pressure or flow rate of the fluid before (proximal) the stenosis of the simulated blood vessel;
Calculating forward and posterior blood pressure using the pressure or flow rate measured in the measuring step; And
Reducing the static pressure to implement a congestion condition, and closing the forward blood flow to measure the wedge pressure;
A method of simulating coronary blood flow, comprising a. delete

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