JP6579519B2 - Coronary flow simulation device, coronary flow simulation method, and roller pump used therefor - Google Patents

Description

  The present invention relates to a coronary artery flow simulation device and a coronary artery flow simulation method, and a coronary artery flow simulation method, which are used when a medical device such as a stent used in a coronary artery and a medical material are tested in the same coronary blood flow environment as a human body. It relates to a roller pump.

  The blood pumped out from the human heart passes through the aorta, reaches the various arteries that branch from the aorta to the whole body, joins the corresponding veins to the vena cava, and performs systemic circulation that returns to the heart. Here, an artery that branches from the aorta is a coronary artery stretched around the myocardium, which circulates blood from the base of the aorta to the base of the vena cava and supplies energy and oxygen to the heart. ing. Such blood circulation through the coronary artery is called coronary circulation.

  By the way, when the coronary artery is narrowed or occluded due to arteriosclerosis or the like, myocardial necrosis called myocardial infarction occurs. As a treatment for such stenosis and occlusion of the coronary artery, catheter therapy and coronary artery bypass surgery are known in addition to drug therapy. Catheter therapy expands the blood flow path that is narrowed by inflating the balloon in the stenotic coronary artery, and maintains the expanded state of the blood flow path by placing a vascular dilator called a stent at the expanded site. Is.

  As stents, in addition to conventional metal stents, recently, bioabsorbable stents that have been absorbed into the body and disappeared within a few months to several years after vascular placement have emerged, and clinical trials are currently underway. ing. According to the standards of the International Organization for Standardization (ISO), mechanical evaluation, repeated fatigue durability, physical characteristics of degradation, and material composition evaluation are performed for an intracardiac absorbable implant including the bioabsorbable stent. There is a guideline that items should be evaluated non-clinically in vitro. However, specific test methods for each evaluation item have not yet been established, and establishment of the specific test methods is widely requested. Therefore, the present inventors, as one of the evaluations peculiar to the bioabsorbable stent, are the time-lapse of the bioabsorbable stent placed in a stenotic blood vessel model simulated by an artificial material in a coronary circulation environment. Focusing on the relationship between general decomposition state and strength reduction, we developed a device for conducting an evaluation test of this relationship in an artificial environment.

  By the way, Patent Document 1 discloses a performance evaluation simulator for evaluating the performance of a coronary stent in a dynamic environment.

Japanese Patent No. 4166905

  The actual coronary flow of the human body sometimes has a flow rate of zero during one systole during one period, and it has two flow waveforms with two peaks of blood flow. This phenomenon is considered to be caused by a body structure in which the coronary artery branches from the aorta in the vicinity of the aortic valve. That is, during the systole of the heart where the aortic valve opens, the aortic valve blocks the entrance portion of the coronary artery, making it difficult for blood to flow into the coronary artery and reducing the blood flow in the coronary artery. On the other hand, in the diastole of the heart in which the aortic valve is occluded, the entrance portion of the coronary artery is not blocked by the aortic valve, and blood easily flows into the coronary artery, increasing the blood flow volume of the coronary artery.

  In the performance evaluation simulator of Patent Document 1, there is no time when the blood flow rate of the coronary artery becomes zero even in a state corresponding to the systole of the heart due to its structure. In addition, as described above, the test of the bioabsorbable stent conducted by the present inventors aims to evaluate the relationship between the degradation state over time and the strength reduction, and thus it is necessary to operate the test apparatus for a long period of time. . However, the performance evaluation simulator uses a pulsating flow pump that generates pulsating flow by flowing in and out of air at a predetermined cycle, and the performance of the device is large because the device configuration is large. When the evaluation simulator is used for the performance evaluation test of the bioabsorbable stent, it is difficult to maintain the accurate driving state of the pulsating flow pump and the flow state in the flow path for a long period of time. For this reason, it is necessary to frequently perform monitoring and adjustment of the operating state of the apparatus during the test, which is complicated when performing a long-term test.

  The present invention has been devised to solve such a problem, and its purpose is to simulate the blood flow state of the coronary artery with a relatively simple configuration that does not use a pulsating flow pump, An object of the present invention is to provide a coronary flow simulation device and a coronary flow simulation method that can easily perform a long-term evaluation test of a medical device, a medical material, and the like under a coronary flow, and a roller pump used for these.

  In order to achieve the above object, the present invention is mainly constituted by a fluid circuit for circulating a predetermined test fluid, a predetermined test object is placed in the middle of the fluid circuit, and the coronary artery of the human body is placed in the test fluid. A coronary artery flow simulation device for applying a flow simulating the blood flow state of the test object to test the test object, the flow channel configured to flow the test fluid in one direction, and the flow channel And a roller pump that generates a flow of the test fluid in the flow path, and the roller pump presses and crushes the flow path while rotating along the flow path. A pressure roller that generates the flow, and the pressure roller is configured to be capable of periodically changing a crushing amount with respect to the flow path when pressing against the flow path. Periodic By the flow conditions of the test fluid which simulates the coronary flow adopts a configuration that generates the flow path.

  According to the present invention, a roller pump with a simple structure can be used to accurately simulate the blood flow state of the coronary artery with a simple circuit with few components, and even when a long-term test is performed. It is possible to reduce the work to monitor and adjust the operating state of the device, and perform evaluation tests under coronary circulation environment such as medical equipment and medical materials considering the change in properties over time, such as performance evaluation tests of bioabsorbable stents. It can be done easily and reliably.

The conceptual diagram showing the structure of the coronary-flow simulation apparatus which concerns on this embodiment. The schematic plan view of a press roller. (A) is a conceptual diagram showing the state in which the 1st roller is crushing the flow path, (B) is a conceptual diagram showing the state in which the 2nd roller is crushing the flow path. (A) is a schematic plan view of the pressing roller according to the first modification, and (B) is a schematic plan view of the pressing roller according to the second modification. The schematic plan view of the press roller which concerns on a 3rd modification. (A) is a schematic plan view of a pressure roller according to a fourth modification, and (B) is a schematic exploded perspective view of the pressure roller.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a conceptual diagram showing the configuration of the coronary artery flow simulation device according to this embodiment. In this figure, the coronary flow simulation device 10 is constituted by a fluid circuit that simulates the blood flow state of a human coronary artery, and a predetermined test fluid is circulated by placing a test object in a part of the fluid circuit. Thus, it is an apparatus for performing a performance evaluation test over time of the test object. Here, examples of the test object include various stents such as a bioabsorbable stent. Examples of the test fluid include phosphate buffered saline (PBS).

  The coronary flow simulation device 10 includes an annular flow path 11 in which a test fluid circulates in one direction in a non-air contact state, a test object indwelling portion 12 provided in the middle of the flow path 11, and a flow path. The roller pump 13 that generates the flow of the test fluid in the flowmeter 11, the pressure adjusting means 15 that adjusts the pressure of the test fluid in the flow path 11, and the inlet pressure of the test fluid on the inlet side of the indwelling portion 12 are measured. And a flow meter 18 for measuring the flow rate of the test fluid on the inlet side of the indwelling unit 12.

  Although the flow path 11 is not particularly limited, the flow path 11 is made of an elastic tube made of resin or the like, and a test fluid is shown in FIG. 1 by driving the roller pump 13 and a backflow prevention valve 20 provided in the vicinity thereof. It is configured to circulate in one direction that is clockwise.

  The indwelling portion 12 is provided so as to be detachable with respect to the flow path 11. For example, a stenotic blood vessel model in which an internal space is connected to the flow path 11 by being simulated by an artificial material such as a resin can be used. In the stenotic blood vessel model, a bioabsorbable stent (not shown) in an expanded state is placed as a test object, and the test fluid circulating in the flow path 11 is caused to flow through the bioabsorbable stent, thereby the bioabsorbable stent. A time-dependent performance evaluation test is performed on the stent.

  The roller pump 13 includes a pressing roller 22 capable of pressing the flow path 11 at regular intervals while rotating along the flow path 11, and is handled by periodically crushing the flow path 11 with the pressing roller 22. The test fluid is sent from the upstream side of the roller pump 13 to the downstream side. In the present invention, the structure of a known roller pump is adopted except for the structure of the pressing roller 22, and the apparatus configuration of the roller pump excluding the pressing roller 22 is not an essential element of the present invention. Omitted.

  The pressing roller 22 is configured to be able to periodically change the crushing amount with respect to the flow path 11 when pressed against the flow path 11. That is, as conceptually shown in FIGS. 2 and 3, the pressing roller 22 includes first and second rollers 24 and 25 for crushing the flow path 11 on the circumferential surface in different modes. These first and second rollers 24, 25 are arranged at regular intervals by being respectively supported by end portions of a support body 27 that is substantially L-shaped in plan view. The pressing roller 22 is rotated as a whole by power from a motor (not shown) with the vicinity of the bent portion of the support 27 as a rotation center C. With the configuration of the pressing roller 22 described above, a part of the flow path 11 is pressed at a constant cycle by the first and second rollers 24 and 25. Specifically, while the pressing roller 22 makes one rotation, the first time zone in which the flow path 11 is crushed only by the first roller 24 and the second time period in which the flow path 11 is crushed only by the second roller 25. And a third time zone in which none of the first and second rollers 24 and 25 crush the flow path 11 occurs. In addition, it is also possible to design the shape of the pressing roller 22 so that the 4th time slot | zone which crushes the flow path 11 with both the 1st and 2nd rollers 24 and 25 arises. Further, the pressing roller 22 rotates in the rotation direction (arrow direction in the figure) in which the second roller 25 precedes the first roller 24 on the inner angle side of the bent portion of the support body 27.

  The distance between the first roller 24 and the center of rotation C is longer than that of the second roller 25 due to the shape of the support 27, and as shown in FIG. Therefore, the amount of crushing of the flow path 11 is designed to be large. Therefore, when the flow path 11 is crushed only by the first roller 24 and when the flow path 11 is crushed only by the second roller 25, the peak flow rate on the outlet side of the roller pump 13 is large. In contrast, during one rotation of the pressing roller 22, two large and small flow peaks can be generated in the test fluid flowing in the flow path 11 like an actual coronary artery flow. In other words, the first roller 24 with the larger crushing amount is configured to simulate the flow rate peak with the larger coronary flow seen in the diastole of the heart. The peripheral surface constitutes a diastolic pressure region 29 for simulating the peak flow state of coronary flow in the diastole of the heart. On the other hand, the second roller 25 with the smaller crushing amount is configured to simulate the smaller flow rate peak of the coronary artery flow seen in the systole of the heart. The peripheral surface constitutes a systolic pressure region 30 for simulating the flow peak state of coronary artery flow during the systole of the heart. Further, the first and second rollers 24 and 25 are adjusted so that the flow rate of the test fluid that flows instantaneously through the test object becomes zero during one cycle. That is, the overall shape and size of the pressing roller 22 including the distance from the rotation center C to each of the rollers 24 and 25 and the separation distance between the rollers 24 and 25 are the periodicity of the flow rate in the actual coronary artery flow. It is set to correspond to the change state. For example, by adjusting the separation angle between the diastolic pressure region 29 and the systolic pressure region 30 that is the inner angle of the bent portion of the support 27, the time adjustment between the two large and small flow peaks described above can be performed. It becomes possible.

  As shown in FIG. 1, the pressure adjusting means 15 includes a compliance tube 32 (compliance portion) disposed between the indwelling unit 12 and the upstream side of the roller pump 13, and a downstream side of the indwelling unit 12 and the roller pump 13. A capacity-increasing tube 35 disposed between the resistance tube 36 and a resistance applying portion 36 disposed between the compliance tube 32 on the downstream side of the indwelling portion 12.

  The compliance tube 32 is formed of an elastic tube that elastically deforms so that its inner diameter can be expanded and contracted in accordance with a change in pressure of the test fluid that passes through the compliance tube 32, and has a larger inner diameter than the tube constituting the flow path 11. Yes. In addition, although it does not specifically limit, the thing made from silicone is used for the compliance tube 32 of this embodiment. The compliance tube 32 has the following pressure adjustment action. That is, a vacuum suction force (negative pressure) is generated on the roller pump 13 side at the timing when the pressure of the flow path 11 by the pressure roller 22 is released in the roller pump 13, but at that time, due to the elasticity of the compliance tube 32. By contracting the inner diameter, the pressure drop of the test fluid due to the generation of the vacuum suction force is suppressed, and the pressure fluctuation range of the test fluid simulating the blood pressure range in the coronary artery flow of the human body can be reproduced.

  The capacity increasing tube 35 has an inner diameter larger than that of the tube constituting the flow path 11, and functions as a reservoir for temporarily storing the test fluid flowing in the flow path 11.

  The resistance applying unit 36 is configured by a clamp or the like that applies a throttle resistance to the flow path 11, but the present invention is not limited to this, and various types of valves and the like can be used as long as the same function is achieved. Equipment can be employed alternatively.

  In the pressure adjusting means 15 described above, with respect to the inlet pressure of the indwelling portion 12 measured by the pressure gauge 17, a roller waveform and a maximum pressure and a minimum pressure are obtained so as to approximate the coronary flow of the human body. The length and inner diameter of the compliance tube 32 and the capacity increasing tube 35 are set corresponding to the 13 driving conditions, and a predetermined flow resistance is added to the flow path 11 by the resistance applying unit 36.

  The pressing roller 22 is not limited to the configuration of the above embodiment, and various types can be adopted. Therefore, a modified example of the pressing roller 22 will be described below. In the description, the same reference numerals are used for the same or equivalent components as in the embodiment, and the description will be omitted or simplified.

  As shown in FIG. 4A, the pressing roller 22 according to the first modification is pressed around the first and second rollers 24 and 25 against the pressing roller 22 of the embodiment. It is possible to adopt a type in which the portion 38 is further provided and the pressing area against the flow path 11 is increased. The pressing portion 38 is disposed on the outer side of the first roller 24 opposite to the second roller 25 and has a first pressing portion 38A having a fan shape in plan view, the first and second rollers 24, And a second pressing portion 38B which is disposed between 25 and has a fan shape in plan view.

  The first pressing portion 38 </ b> A has a fan shape having a radius that is substantially the same as the distance from the rotation center C to the tip of the first roller 24. On the other hand, the second pressing portion 38B has a fan shape having a radius slightly shorter than the distance from the rotation center C to the tip of the second roller 25. Therefore, the arc-shaped outer peripheral surface of the first pressing portion 38A, together with the peripheral surface of the first roller 24, has a larger amount of crushing when it comes into contact with the flow path 11, and coronary artery flow during the diastole of the heart. A diastolic pressure region 29 for simulating a flow rate peak state is formed. In addition, the arc-shaped outer peripheral surface of the second pressing portion 38B, together with the peripheral surface of the second roller 25, has a smaller crushing amount when contacting the flow path 11, and coronary artery flow during the systole of the heart. A systolic pressure region 30 for simulating the flow rate peak state is formed.

  In the pressure roller 22 according to the first modified example described above, both the expansion period pressing area 29 and the contraction period pressing area 30 are expanded with respect to the pressure roller 22 of the above embodiment. According to these experimental results, it is possible to make the pressure waveform over time of the test fluid flowing through the test object a gentler waveform.

  As shown in FIG. 4B, the pressing roller 22 according to the second modification example is different from the pressing roller 22 according to the first modification example of FIG. The regions of the rollers 24, 25, the first and second pressing portions 38A, 38B, and the support 27 are integrated into a plate shape, and the overall shape is adjusted. A diastolic pressure region 29 and the systolic pressure region 30 are formed.

  As shown in FIG. 5, the pressing roller 22 according to the third modification is obtained by changing the outer peripheral surface shape of the pressing roller 22 according to the second modification. That is, the pressing roller 22 of this modification includes six first to sixth protruding portions 41 to 46 protruding outward, and the protruding portions 41 to 46 correspond to the flow path 11 (FIG. 1). And the like). These protrusions 41 to 46 each have a semicircular outer peripheral shape in plan view, and the first and second protrusions 41 and 42 (first portions) at the two left ends in FIG. The distance between the center P and the rotation center C of the pressing roller 22 is set to L1 that is the same. In addition, the third, fourth and fifth protrusions 43, 44, 45 (second part) located at three positions on the right side of the second protrusion 42 in the figure are the center P of those arcs. The distance from the rotation center C is set to L2 that is the same. Further, the sixth protrusion 46 (third portion) located on the right side of the fifth protrusion 45 in the drawing has a distance between the center P of the arc and the rotation center C set to L3. Yes. These distances L1, L2, and L3 are set to a size that maximizes L1 and minimizes L2, that is, a size that satisfies L1> L3> L2. Moreover, in this modification, the 1st and 2nd protrusion parts 41 and 42 comprise the said diastolic pressure area | region 29, and the 3rd-6th protrusion parts 43-46 are the said presses for systole. Region 30 is configured. In addition, the dashed-dotted line in FIG. 5 is a virtual line segment for demonstrating distance L1, L2, L3.

  As shown in FIG. 6, the pressing roller 22 according to the fourth modified example is replaced with first to sixth rotations instead of the first to sixth protruding portions 41 to 46 according to the third modified example. The shafts 51 to 56 are attached. That is, the pressing roller 22 according to this modification is rotated by the power from a motor (not shown) and the shaft member 58 serving as the rotation center C and the extension of the shaft member 58 are shown in FIG. A pair of disk members 59, 59 fixed to both ends in the outgoing direction, and a cylindrical shape attached to the disk members 59, 59 so as to be able to rotate via a bearing 60 so as to be spanned between the disk members 59, 59. The first to sixth rotating shafts 51 to 56 are configured. The outer peripheral surfaces of the rotary shafts 51 to 56 are provided so as to be rotatable relative to the disk member 59 and press the flow path 11 while reducing the frictional resistance against the flow path 11 when the flow path 11 is handled. It becomes. Here, the first and second rotary shafts 51 and 52 (first portion) at two places on the left end in FIG. 5A are between the rotation center P and the rotation center C of the entire pressing roller 22. The distance is set to L1 that is the same. Further, the third, fourth, and fifth rotation shafts 53, 54, and 55 (second portions) located at three positions on the right side of the second rotation shaft 52 in the figure are the rotation center P and the above-described rotation center P. The distance to the rotation center C is set to L2 that is the same. Further, the sixth rotation shaft 56 (third portion) located on the right side of the fifth rotation shaft 55 in the drawing has a distance L3 between the rotation center P and the rotation center C. . These distances L1, L2, and L3 are the sizes at which L1 is the maximum and L2 is the minimum, that is, the size that satisfies L1> L3> L2, similarly to the relationship between the protrusions 41 to 46 according to the third modification. Is set to In the present modification, the first and second rotating shafts 51 and 52 constitute the diastolic pressing region 29, and the third to sixth rotating shafts 53 to 56 include the systolic pressing region 30. Configure. In addition, the dashed-dotted line in FIG. 6 (A) is a virtual line segment for demonstrating distance L1, L2, L3.

  Even in the pressing roller 22 according to each of the modified examples, various sizes and shapes are set so as to correspond to a cyclic change state of the flow rate and pressure in the actual coronary artery flow. As the roller 22, various other structures and shapes described above can be employed. For example, in the third and fourth modified examples, the flow rate drop amount between the two large and small flow rate peaks described above can be made variable by adjusting the size of the distance L2. Further, the angle formed between the straight line portion corresponding to the distance L1 and the straight line portion corresponding to the distance L3, that is, the maximum separation angle between the diastolic pressure region 29 and the systolic pressure region 30 is adjusted. Thus, it is possible to adjust the time between the above-described two large and small flow rate peaks.

  In the coronary artery flow simulating apparatus 10, a desired coronary circulation environment can be adjusted or selected by adopting a mode in which a pressure roller 22 having a different shape and size can be selectively attached to the roller pump 13. You can also.

  In addition, the configuration of each part of the apparatus in the present invention is not limited to the illustrated configuration example, and various modifications are possible as long as substantially the same operation is achieved.

DESCRIPTION OF SYMBOLS 10 Coronary flow simulation apparatus 11 Flow path 12 Indwelling part 13 Roller pump 15 Pressure adjusting means 22 Pressing roller 29 Diastolic pressing area 30 Shrinkage pressing area 32 Compliance tube (compliance part)
41 1st protrusion (1st part)
42 2nd protrusion (1st part)
43 3rd protrusion (2nd part)
44 4th protrusion (2nd part)
45 Fifth protrusion (second part)
46 6th protrusion (3rd part)
51 First rotating shaft (first portion)
52 Second axis of rotation (first part)
53 3rd rotating shaft (2nd part)
54 Fourth axis of rotation (second part)
55 Fifth axis of rotation (second part)
56 6th axis of rotation (3rd part)

Claims (9)

A fluid circuit that circulates a predetermined test fluid, a predetermined test object is installed in the fluid circuit, and a flow that simulates the blood flow state of a human coronary artery is applied to the test fluid. A coronary flow simulator for testing an object,
A flow path configured to flow the test fluid in one direction, and a roller pump provided in the flow path and generating the flow of the test fluid in the flow path,
The roller pump includes a pressing roller that generates the flow by pressing and crushing the flow path while rotating along the flow path,
The pressing roller is configured to be able to periodically change the amount of crushing with respect to the flow path when pressed against the flow path, and the blood flow of the coronary artery due to the periodic change in the amount of crushing. coronary flow simulation apparatus and generates the flow state of the test fluid which simulates a state in the flow channel. The pressure roller includes a diastolic pressure region for simulating a flow peak state of coronary flow in the diastole of the heart, and a systolic pressure region for simulating the flow peak state of coronary flow in the systole of the heart. With
The coronary flow simulation device according to claim 1, wherein the diastolic pressing area is configured to have a larger amount of crushing with respect to the flow path than the systolic pressing area.   3. The time between the flow rate peaks is provided by adjusting a separation angle between the diastolic pressure region and the systolic pressure region. Coronary flow simulator. The systolic pressure area is constituted by second and third parts that are shorter from the rotation center of the pressure roller than the first part constituting the diastole pressure area,
The second portion is disposed between the first and third portions, the distance is set shorter than the third portion, and the distance is adjusted between the flow rate peaks by adjusting the distance. 4. The coronary artery flow simulator according to claim 2, wherein the flow rate drop amount of the coronary artery is adjustable. In the middle of the flow path, pressure adjusting means for adjusting the pressure of the test fluid is provided,
5. The coronary flow simulation device according to claim 1, wherein the pressure adjusting means approximates the pressure of the test fluid flowing through the test object to a state of a coronary flow of a human body . The pressure adjusting means includes a compliance section provided between the upstream side of the roller pump and the test object,
6. The coronary flow simulation device according to claim 5, wherein the compliance unit functions to simulate the minimum pressure of the test fluid flowing through the test object in the state of the coronary artery flow.   The compliance portion is configured by an elastic tube having a diameter larger than that of the flow path, and the diameter of the compliance fluid is temporarily reduced when the suction force to the roller pump is generated. 7. The coronary artery flow simulation device according to claim 6, wherein a significant pressure drop is suppressed. A predetermined test object is installed in the middle of a flow path for circulating a predetermined test fluid in one direction, and a flow simulating the blood flow state of a human coronary artery is applied to the test fluid to test the test object. A method for performing
A roller pump that generates a flow of the test fluid in the flow path is pressed against the flow path by pressing and crushing the flow path while rotating along the flow path. The amount of crushing with respect to the flow path is periodically changed, and the flow state of the test fluid that simulates the blood flow state of the coronary artery is generated in the flow path by periodically changing the amount of crushing. A method for simulating coronary artery flow. A predetermined test object is installed in the middle of a flow path for circulating a predetermined test fluid in one direction, and a flow simulating the blood flow state of a human coronary artery is applied to the test fluid to test the test object. In a roller pump that is used in a coronary flow simulation device for performing the above, and is provided in the middle of the flow path to generate a flow of the test fluid in the flow path,
The roller pump includes a pressing roller that generates the flow by pressing and crushing the flow path while rotating along the flow path,
The pressure roller is set so that a diastolic pressure region for simulating a flow peak state of coronary flow in the diastole of the heart and a crushing amount with respect to the flow path are smaller than the diastolic pressure region. A systolic pressure region for simulating the peak flow state of coronary flow during the systole of the heart, a first time zone in which the flow path is crushed only by the diastolic pressure region, and the systole A second time zone in which the flow path is crushed only by the pressing area and a third time period in which neither the diastolic pressure area or the systolic pressure area is crushed the flow path A flow state of the test fluid simulating the blood flow state of the coronary artery is generated in the flow path by periodically changing the amount of crushing with respect to the flow path. Features a roller Amplifier.

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