JP2000342692A - Artificial coronary artery, coronary artery stunt performance evaluation simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a performance evaluation simulator under a dynamic situation of a coronary artery stent. SOLUTION: This device comprises a coronary circulation device provided with a pump to make pulsation at a specified interval to discharge physiological salt solution, and a silicone tube 11 disposed on a branch conduit 9 of a fluid passage 5 of the coronary circulation device. This silicone tube 11 is that adjusted to simulate a coronary artery of a person to which a coronary artery stent 17 is inserted. The branch conduit 9 has a restricting mechanism 12 close to the silicone tube 11. This restricting mechanism 12 can be synchronized with pulsation of the pump 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simulator for evaluating the performance of a coronary artery stent used to maintain the lumen of a coronary artery after the stenosis and occlusion of the coronary artery is expanded using a balloon. Further, the present invention relates to a performance evaluation simulator under dynamic conditions of an artificial coronary artery.

[0002]

In recent years, various treatments have been developed as treatments for ischemic heart diseases such as angina pectoris and myocardial infarction. Ischemic heart disease is a condition in which the coronary arteries that nourish the heart are narrowed by arteriosclerosis and the myocardium falls into insufficiency of blood flow. Percutaneous coronary angioplasty (PTCA) has been performed without the need for surgical treatment.

[0003] This PCTA is performed by inserting a balloon catheter from the artery at the base of the foot, inserting the balloon catheter into a lesion in the aorta of the heart, and inflating the balloon by inflating the balloon in the lumen of a stenotic coronary artery. . However, since PTCA using this balloon catheter is a treatment for increasing the luminal area of the blood vessel, the blood vessel after dilatation varies to some extent, and intimal detachment and coronary artery dissection occur. Thrombus and the like are likely to develop in such damaged blood vessels, and there is a possibility that the enlarged lesion may rapidly reocclude. Therefore, conventionally, PTCA was repeatedly performed on the stenosis site again, or an incision operation was performed.

In order to solve such a problem, PTCA
Insert a coronary stent, a metal support in the form of a coil or cylinder mesh to maintain the lumen in the posterior coronary artery, to keep the vessel open while resisting the tendency of the coronary artery to narrow again That is being done. As described above, such a coronary stent requires a sufficient radial support force against external pressure caused by occlusion of a blood vessel,
Since the coronary artery is covered by myocardium, the coronary artery also contracts when the myocardium contracts.However, if the flexibility of the coronary artery stent is poor, there is a risk of damaging the blood vessel from the inside, It is necessary to have flexibility, bending strength and the like. However, there is no measurement standard for the physical properties of these coronary stents, and at present, each company that supplies coronary stents manufactures them based on the results of animal experiments and clinical tests. Was.

The measurement of the physical properties of such a coronary stent is as follows.
For example, as shown in FIG. 11, a pipe 33 having a diameter of about 3 mmφ is horizontally provided in an external pressure tank 31 filled with water W and an internal pressure tank 32 containing only air, and the pipe 33 is extended into the external pressure tank 31. Therefore, a part thereof is constituted by a silicon tube 33A which looks like a coronary artery,
The coronary stent 34 is inserted into the silicon tube 33A from the insertion portion 33B formed in the conduit 33, and the water pressure P in the external pressure tank 31 is reduced to the external pressure applied to the coronary artery by the air pressure Q in the internal pressure tank 32. By simulating the internal pressure of the coronary artery, the physical properties of the coronary stent 34 due to changes in the external pressure and the internal pressure are evaluated. Separately, a pressure of about 300 mmHg is applied to a silicon tube into which a coronary stent has been inserted, and the shape change before and after the pressure is observed.

However, all of these methods can evaluate only the condition in which a certain pressure is applied to the coronary stent, that is, the static characteristics, and cannot evaluate the dynamic characteristics in the pulsating coronary artery.

In particular, the coronary artery is covered with myocardium, and is placed in a unique situation in which a load is periodically and repeatedly applied in the radial direction with contraction of the myocardium. There has been no device that can evaluate the above. If we can simulate the mechanical properties of a coronary stent under conditions close to the actual situation of the coronary artery and evaluate its mechanical properties,
It is possible to objectively provide a material for judging the effectiveness and safety of the coronary stent, and to meet a wide range of needs for coronary stents. In addition, if the artificial coronary artery can be placed under conditions close to the conditions in which the coronary artery is actually placed, it is possible to objectively provide information for determining the effectiveness and safety of the artificial coronary artery.

The present invention has been made in view of these problems, and has as its object to provide a simulator for evaluating the performance of a coronary stent under dynamic conditions. Another object of the present invention is to provide a performance evaluation simulator under dynamic conditions of an artificial coronary artery.

[0009]

A simulator for evaluating the performance of an artificial coronary artery and a coronary stent according to claim 1 of the present invention is a simulator for evaluating the performance of an artificial coronary artery and a coronary stent for predicting the behavior of the artificial coronary artery and the coronary stent. A coronary circulator having a pump mechanism for pulsating and discharging a liquid at a predetermined interval; a flexible tube into which a coronary artery stent provided in a liquid flow path of the coronary circulator is inserted; A restricting mechanism for the liquid flow path provided in the vicinity of the flexible tube, wherein the restricting mechanism can be synchronized with the pump mechanism.

Therefore, the liquid flow path of the coronary circulation device is filled with water such as physiological saline, and the pump mechanism is pulsated so that the water circulates at a predetermined pressure and at a predetermined interval. By synchronizing the mechanism and the restricting mechanism of the liquid flow path, a state similar to the blood flow accompanying the pulsation of the myocardium can be reproduced. By installing a coronary stent in a flexible tube provided in such a coronary circulation device, it is possible to measure the mechanical behavior in a dynamic state.

According to a second aspect of the present invention, there is provided an artificial coronary artery and coronary artery stent performance evaluation simulator according to the first aspect, wherein the pump mechanism has an air pump, and the throttle mechanism has an elastic tube provided in the liquid flow path. And a compression body close to the elastic tube, wherein the compression body is provided in conjunction with the air pump.
For this reason, the pump mechanism and the throttle mechanism can be easily synchronized, and the pressure for pressing the elastic tube can be easily adjusted by adjusting the amount of air supplied to the compression body, and can be adapted to various conditions. It is possible.

Further, in the simulator for evaluating the performance of an artificial coronary artery and a coronary stent according to a third aspect of the present invention, the flexible tube is a silicon tube according to the first or second aspect and is adjusted to imitate a human coronary artery. It is. Therefore, the behavior of the artificial coronary artery and the coronary stent can be simulated under conditions close to the coronary artery of the human body.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The artificial coronary artery and coronary stent performance evaluation simulator of the present invention will be described in detail below. FIG. 1 shows an artificial coronary artery and a coronary artery stent performance evaluation simulator according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a pump placed in the left ventricle of the heart,
The pump 1 discharges air intermittently at a predetermined cycle.
The drive device 2 having a function of inhaling is connected to pump out the physiological saline W. This pump 1
Is formed with a discharge port 3 and a suction port 4 having a discharge valve 3A and an inflow valve 4A, respectively. The start and end of the liquid flow path 5 are connected to the discharge port 3 and the suction port 4, respectively. . The liquid flow path 5 is provided with a compliance tank 6 for adjusting the pressure of the physiological saline W and an overflow tank 7, and a liquid flow path 5A between the two tanks is provided with a flow control mechanism 8 such as a pinch cock. Is provided. A branch channel 9 corresponding to a coronary artery is formed in the liquid flow path 5. The branch channel 9 includes a stent insertion member 10, a silicon tube 11 serving as a flexible tube, and a restricting mechanism 12. Is attached. The diaphragm mechanism 12 includes a rubber tube 13 which is an elastic tube,
It has a cuff 14 serving as a pressing body provided in the vicinity of the rubber tube 13 and a support member 15 for positioning the cuff 14. The cuff 14 communicates with the driving device 2 described above. The pump 1, the liquid flow path 5, and the branch conduit 9 constitute a coronary circulation device. In such a device, the silicon tube 11 corresponds to a coronary artery, and a coronary artery stent 17 is inserted into the silicon tube 11. In the simulator as described above, the silicon tube 11
Is adjusted by simulating a coronary artery of a living body.

The operation of the above configuration will be described. First, in order for the coronary circulation device 16 to be a circuit for simulating coronary artery circulation, the internal pressure of the pump 1 and the left ventricular pressure (equivalent to LVP) are set.
And the pressure of the physiological saline W flowing through the coronary circulation device 16 (corresponding to aortic pressure (AoP)). These pressures correspond to the head difference of the overflow tank 7 and the air pressure in the compliance tank 6, respectively. Therefore, it can be adjusted by the liquid level of the overflow tank 7, the air amount of the compliance tank 6, and the throttle amount of the flow rate adjusting mechanism 8.

Then, while the pump 1 is activated to discharge the physiological saline W from the discharge port 3 in the direction of the black arrow shown in the figure, the drive unit 2 periodically applies air pressure (white arrow in the figure). When the physiological saline W is beaten, the driving device 2
Since the cuff 14 is also communicated with the cuff 14, the cuff 14 repeatedly expands and contracts in synchronization with the pulsation of the pump 1, and presses the rubber tube 13 when the cuff 14 expands. Thus, by changing the pressure of the physiological saline W flowing through the branch conduit 9 in accordance with the contraction of the coronary artery accompanying the pulsation of the heart, it is possible to simulate the coronary artery pressure (CAP).

When the coronary artery stent 17 is evaluated in such a circuit for simulating the coronary artery, for example, a coronary artery stent 17 at a contact portion between the coronary artery stent 17 and the silicon tube 11 is measured by a digital microscope camera or the like.
The degree of elastic deformation of the coronary stent 17 can be determined by measuring the diameter of the silicon tube 11 and the diameter of the silicon tube 11 intermittently. Further, the performance as an artificial coronary artery can be evaluated from a change in the diameter of the silicon tube 11.

Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the length of the liquid channel 5 of the coronary stent performance evaluation simulator is:
Depending on the size of the simulator to be used and the arrangement of various components, it may be appropriately set so that disturbance of the entire pressure wave due to water hammer or turbulence of the discharge valve 3A and the inflow valve 4A is reduced as much as possible.

[0018]

The present invention will be described in more detail with reference to the following specific examples.
This will be described in detail.Examination with bovine coronary arteries  To make the silicon tube close to the living coronary artery
Then, carefully remove the coronary artery from the bovine heart,
The fine branch was tied with a thread to close the hole. Next shown in FIG.
Stopcocks 22 and 22A are attached to both ends of the coronary artery 21,
From above, it was tied with a thread 25 and fixed. And the length of the coronary artery 21
Fix the three-way stopcock 22, 22A to prevent deformation in the hand direction
And a pressure transducer 23 on one side stopcock 22 and the other.
A syringe 24 was attached to the three-way cock 22A.

Then, a small amount of the coronary artery 21 is
Water was injected one by one, and the pressure at that time was measured three times. The result
As shown in FIG.Fabrication of silicone tube for simulating coronary artery  The “test with bovine coronary artery” and human data (pressure
Model of human coronary artery based on the results of
A simulated silicone tube was made. Figure 4 shows this series.
The evaluation test of the simulated silicon tube below
Increase in internal pressure measured by the method described in
The relationship of the modulus to the elastic modulus of pressure strain in the human coronary artery
Indicates that they will follow.Evaluation test of simulated silicon tube  The simulated silicon tube 41 manufactured as shown in FIG.
Attached so that it spans the water tanks 42 and 43 with the connector 41A
A test circuit was constructed. And, in the water tank 42,
Syringe 44 and pressure transducer via stopcock 46
45 and provided. In addition, 46A is a three-piece provided in the water tank 41.
The stopcock 46A. In such a device water tank 4
Fill the water into 2 and 43 and reduce the pressure difference between the inside and outside of the silicon tube 41.
After adjusting the pressure to 0 mmHg, water was injected from the syringe 44 into the test circuit.
Inject 0.1 ml at a time.
Measured with spacer 45 and inside silicon tube 41
Calculate the external pressure difference and the volume increase rate of the tube
The one close to was attached to the simulator.Application test to coronary stent performance evaluation simulator  Simulation of coronary stent performance evaluation of this embodiment shown in FIG.
In the data, the simulation described above as the silicon tube 11
Air pump driving pressure 190
mmHg, reduced pressure condition -30mmHg, pump rate 70bp
m, systolic fraction 35%, aortic pressure (compliance
Air pressure in lance tank 6) 80 to 120 mmHg
Circulates physiological saline as working fluid at
The air pressure in the lance tank 6 and the pressure in the branch line 9 are reduced.
Each was measured. Each of these pressures
Aortic pressure (AoP) and coronary artery pressure (CAP)
(Hereinafter simply referred to as aortic pressure (AoP) and coronary artery
Pressure (CAP)). The results are shown in the graph in FIG.
Shown. Also, for comparison, the aortic pressure in the living body and
FIG. 7 shows the relationship with the coronary artery pressure.

From FIG. 7, it can be seen that the waveforms of the aorta and coronary artery in the living body are approximately the same. And
7 and 6, it can be seen that the simulator of the present invention sufficiently simulates biological data.

The cardiac output and coronary artery flow rate obtained by this simulator were 0.1 liter / min at 3.7 liter / min. According to in vivo data, the coronary flow in a normal adult heart is equivalent to 4-5% of the cardiac output,
In this embodiment, the coronary artery flow is about 2.5% of the cardiac output. This is because the simulator of the present embodiment simulates coronary circulation with one branch, and from this, the simulator sufficiently simulates biological data on the relationship between cardiac output and coronary artery. It can be said.

FIG. 8 shows the relationship between the aortic pressure (AoP) and the coronary artery flow (CAF) in the simulator of this embodiment.
FIG. 9 shows the relationship between aortic pressure and coronary artery flow in a living body.
Shown in FIG. 9 shows that in the living body, the flow rate in the coronary artery decreases during the systole and increases during the diastole. The decrease in coronary artery flow during systole is due to external compression of the coronary arteries by the myocardium. 9 and 8, the relationship between the aortic pressure and the coronary artery flow obtained by the simulator of this embodiment shows a tendency similar to that based on the data of the living body. It can be said that it simulates.

According to the present embodiment, these measurement data are used.
Pressure flow waveform close to coronary artery characteristics of living body by simulator
Was obtained. Therefore, this simulation
Evaluate the physical properties of coronary stents in vitro using a lator
It is possible toBeating behavior of coronary stent  Silico, a simulator for evaluating coronary stent performance
Coronary artery inside the tube 11 (simulated silicone tube)
When inserting the stent 17 and pulsing the physiological saline W
The rate of change in the diameter of the coronary stent 17
30 frames per second
Movement at the point of contact between the port 17 and the silicon tube 11
Measure the diameter of the vein stent and the diameter of the silicon tube 11.
And was calculated by: At this time, stop the pulsation of the simulator
The diameter of the coronary stent 17 and the silicon measured similarly
The diameter of the tube 11 was set as a reference value. The results are shown in FIG.
In addition, changes in the diameter of the coronary stent
The maximum and minimum values of the conversion rate were measured seven times each, and
Table 1 shows the results of calculating the average values.

[0024]

[Table 1] From FIG. 10 and Table 1, it can be seen that the diameter of the coronary stent also changed due to the pulsation. Comparing FIG. 10 with the pulsation cycle of the simulator, the change cycle of the coronary stent diameter and the silicon tube diameter coincided with the pulsation cycle of the simulator. In addition, it was found that the diameter of the coronary stent and the diameter of the silicon tube changed almost equally to the increase and decrease of the coronary artery pressure and the coronary artery flow rate.

Next, it can be seen from Table 1 that the coronary stent diameter under pulsation is expanded by about 0.4 to 1% from the reference value (diameter of coronary stent when pulsation is stopped).
This is considered to be because the inside of the silicon tube is pressurized by the aortic pressure (80 to 120 mmHg) of the simulator at the time of pulsation, and the inner diameter of the tube expands by that amount, and the coronary stent expands accordingly. Can be In addition, the cyclic deformation of the coronary artery stent diameter is limited to about 40 to a maximum of 80 to 120 mmHg in the silicon tube.
Due to the displacement of mmHg, the coronary stent is also compressed by a tube due to a pressure drop of at most about 40 mmHg in one beat. Thus, it is considered that the coronary artery stent diameter repeats periodic deformation every beat.

As described above, by using the simulator of this embodiment, the followability of the coronary artery stent to the silicon tube, the retention of the diameter of the silicon tube, and the change of these characteristics due to long-term pulsation can be obtained. The measurement can evaluate the mechanical properties of the coronary stent in the dynamic environment. Further, if the silicon tube is used as an artificial coronary artery, it is possible to evaluate the mechanical properties of the artificial coronary artery under the dynamic environment.

As described above, an example of the method of measuring the mechanical behavior of the coronary stent has been described.
By selecting a measurement method according to desired physical properties, physical properties of various coronary stents and artificial coronary arteries can be evaluated.

[0028]

The simulator for evaluating the performance of an artificial coronary artery and a coronary stent according to claim 1 of the present invention is a simulator for evaluating the performance of an artificial coronary artery and a coronary stent for predicting the behavior of an artificial coronary artery and a coronary stent. A coronary circulator having a pump mechanism for pulsating and discharging the liquid, a flexible tube into which a coronary stent provided in a liquid flow path of the coronary circulator is inserted, and a flexible tube close to the flexible tube. And a restricting mechanism for the liquid flow path provided therewith, and the restricting mechanism can be synchronized with the pump mechanism. Therefore, the artificial coronary artery and the coronary stent in a dynamic environment close to the coronary artery of a human body. Mechanical behavior can be measured.

Further, in the simulator for evaluating the performance of an artificial coronary artery and a coronary stent, according to claim 1, the pump mechanism has an air pump and the throttle mechanism is provided in an elastic tube provided in the liquid flow path. Since the compression body is provided in conjunction with the air pump, the compression mechanism can be easily synchronized with the pump mechanism and the amount of air supplied to the compression body. By adjusting the pressure, the pressure for pressing the elastic tube can be easily adjusted, and it is possible to cope with various conditions.

Further, the simulator for evaluating the performance of an artificial coronary artery and a coronary artery stent according to a third aspect is the simulator according to the first or second aspect, wherein the flexible tube is a silicon tube and is adjusted to imitate a human coronary artery. Therefore, the behavior of the artificial coronary artery and the coronary stent can be simulated under conditions close to the coronary artery of the human body.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a coronary stent performance evaluation simulator according to one embodiment of the present invention.

FIG. 2 is a plan view showing a test apparatus for bovine coronary artery characteristics.

FIG. 3 is a graph showing the relationship between volume and pressure in a bovine coronary artery.

FIG. 4 is a graph showing a measurement result of an increase rate of an internal pressure with an increase in a volume of a simulated silicon tube.

FIG. 5 is a schematic diagram showing a measurement device for measuring a rate of increase in internal pressure with an increase in the volume of a simulated silicon tube.

FIG. 6 is a graph showing measurement results of numerical values corresponding to aortic pressure (AoP) and coronary artery pressure (CAP) in a coronary stent performance evaluation simulator according to one embodiment of the present invention.

FIG. 7 is a graph showing values of aortic pressure and coronary artery pressure in a human body.

FIG. 8 is a graph showing the relationship between aortic pressure and coronary flow in the coronary stent performance evaluation simulator.

FIG. 9 is a graph showing the relationship between aortic pressure and coronary flow in a living body.

FIG. 10 is a graph showing the rate of change of the diameter of the coronary stent and the diameter of the silicon tube in the coronary stent performance evaluation simulator.

FIG. 11 is a schematic view showing a conventional coronary stent performance evaluation simulator in a static environment.

[Explanation of symbols]

Reference Signs List 1 pump (pump mechanism) 2 driving device (pump mechanism, air pump) 5 liquid flow path (coronary circulation apparatus) 5A liquid flow path (coronary circulation apparatus) 9 branch pipe (coronary circulation apparatus) 11 silicon tube (flexible tube) , Artificial coronary artery 12 squeezing mechanism 13 rubber tube (elastic tube, squeezing mechanism) 14 cuff (compression body, squeezing mechanism) 15 support member (squeezing mechanism) 16 coronary circulation device 17 coronary stent

Claims (3)

[Claims] An artificial coronary artery and coronary stent performance evaluation simulator for predicting the behavior of an artificial coronary artery and a coronary stent, comprising: a coronary circulator having a pump mechanism for pulsating at predetermined intervals to discharge a liquid; A flexible tube into which a coronary artery stent provided in the liquid flow path of the coronary circulator is inserted, and a liquid flow path restricting mechanism provided close to the flexible tube; A simulator for evaluating the performance of an artificial coronary artery and a coronary stent, wherein a throttle mechanism can be synchronized with the pump mechanism. 2. The pump mechanism has an air pump, and the throttle mechanism includes an elastic tube provided in the liquid flow path and a compression body close to the elastic tube, and the compression body is interlocked with the air pump. 2. The simulator for evaluating the performance of an artificial coronary artery and a coronary stent according to claim 1, wherein the simulator is provided in a manner as described above. 3. The simulator for evaluating the performance of an artificial coronary artery and a coronary artery stent according to claim 1, wherein the flexible tube is a silicon tube, and is adjusted to imitate a human coronary artery.