CN113654774B - Vascular stent fatigue test equipment - Google Patents

Abstract

The invention provides a vascular stent fatigue test device, which belongs to the technical field of medical appliances and comprises: the device comprises a loading device, an acquisition and control system, a driving device, a circulating pipeline and a temperature control system. The vascular stent fatigue test equipment disclosed by the invention is characterized in that the acquisition and control system is operated by test software, the simulated loading device and the temperature control device are controlled, the mechanical load similar to the physiological environment is applied to the stent in the compliant fatigue vessel, the mechanical environment of the stent after being implanted into a human body is simulated, meanwhile, the equipment can simulate the near-physiological mechanical load and physiological temperature such as near-physiological pulsating flow shearing force, periodic compression, traction force and the like for the stent, and the fatigue test aims of accelerating the fatigue stress of the stent, accelerating the degradation speed of the degradable stent and the like can be achieved by accelerating the loading frequency and improving the fluid temperature.

Description

A kind of vascular stent fatigue testing equipment

technical field

The invention relates to the technical field of medical devices, in particular to a vascular stent fatigue testing device.

Background technique

Cardiovascular stent intervention is a minimally invasive surgical treatment with simple operation, small trauma and fast postoperative recovery. However, the failure of the stent due to fatigue may cause serious adverse reactions such as myocardial infarction. Therefore, the fatigue life analysis of cardiovascular stents is very important.

In the existing commercial fatigue testing equipment, the staff closes the simulated blood vessels to achieve a higher frequency of pressure changes.

However, in this method, the liquid in the simulated blood vessel hardly flows, and it cannot simulate the near-physiological mechanical loads and physiological temperatures in the real environment, such as shear stress, periodic compression, stretch stress, physiological temperature, etc. , making it impossible to accurately simulate the use environment of the vascular stent, making the measurement results inaccurate.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art that the liquid in the simulated blood vessel hardly flows, so that the use environment of the vascular stent cannot be accurately simulated, and the measurement results are inaccurate, thereby providing a A vascular stent fatigue testing device.

In order to solve the above-mentioned technical problems, a kind of vascular stent fatigue testing equipment provided by the present invention comprises:

The loading device has a test cavity inside; the test cavity is equipped with a simulated blood vessel; the simulated blood vessel is suitable for setting a stent to be tested;

The driving device is set in communication with the simulated blood vessel in the loading device through the circulation line; the drive device drives the simulated liquid to flow in the circulation line and the simulated blood vessel;

The acquisition and control system is connected with the driving device and the sensor;

The driving device can provide a nearly physiological pulsating flow for the circulation pipeline, so that the pressure and flow waveforms at the inlet of the loading device are similar to the physiological state.

As a preferred solution, the loading device includes a loading body; the loading body includes:

The main body has a test cavity inside; multiple pipeline interfaces are arranged oppositely at both ends;

The top cover is set on the main body.

As a preferred solution, the carrier is made of plexiglass.

As a preferred option, it also includes:

A temperature control system is arranged inside the loading device; the temperature control system is used to detect and regulate the temperature in the test cavity and the simulated blood vessel.

As a preferred solution, the simulated blood vessels have multiple roots, which are arranged side by side in the test cavity.

As a preferred solution, the loading device is a pulsating loading device; there is a detection section for placing the stent to be tested in the simulated blood vessel; the detection section is arranged in the test cavity of the loading body;

The pressure in the test chamber has a first state in which the pressure in the test chamber is greater than the pressure in the human blood vessel, causing the simulated blood vessel to contract, and also has a second state in which it is lower than the pressure in the human blood vessel, causing the simulated blood vessel to contract and relax.

As a preferred solution, a connection interface is provided on the surface of the main body opposite to the top cover; a reciprocating pump is provided on the connection interface; and the reciprocating pump is arranged in communication with the test cavity of the loading body.

As a preferred solution, the loading device is a composite loading device; in the composite loading device, the simulated blood vessel includes:

The endothelial layer is cylindrical; the inner part of the endothelial layer has a first cavity;

The blood vessel wall layer is cylindrical; the blood vessel wall layer is sheathed on the outer surface of the endothelial layer; a second cavity is formed between the endothelial layer and the blood vessel wall layer;

The stent to be tested is sleeved on the outer surface of the inner cortex;

The first cavity and the second cavity are respectively communicated with circulation pipelines, and simulated liquid flows through them.

As a preferred solution, the compliance of the material of the endothelial layer is greater than the compliance of the material of the blood vessel wall layer; the compliance of the material of the blood vessel wall layer is the same as that of human blood vessels.

As a preferred solution, the simulated liquid is water, physiological saline, buffer solution or glycerol solution.

The technical solution of the present invention has the following advantages:

1. The vascular stent fatigue testing equipment provided by the present invention comprises a loading device, a driving device and an acquisition and control system; the stent to be tested is implanted in a simulated blood vessel, the simulated blood vessel is assembled into the test chamber of the loading device, and the simulated blood vessel and The circulation pipeline is connected to form a loop, and the simulated liquid is injected. Driven by the driving device, the simulated liquid flows; the test chamber of the loading device is filled with liquid, forming a closed cavity with the outside of the simulated blood vessel, and the closed cavity is controlled by a reciprocating pump. The high-frequency addition/decompression of the liquid in the body makes the simulated blood vessels contract and relax periodically under external pressure changes, and applies high-frequency periodic mechanical loads to the internally loaded stents; the temperature control system adjusts the loading device in the test chamber and The temperature in the circulation pipeline can simulate the real physiological temperature environment of the human body and is applicable to the accelerated fatigue degradation of the degradable stent at a higher temperature; the device can achieve the purpose of accelerating the fatigue stress of the stent.

2. In the vascular stent fatigue testing equipment provided by the present invention, when the loading device is a pulsating loading device, the pressure change at both ends of the test chamber is monitored through the acquisition and control device, and the fluid resistance and compliance in the pipeline system are adjusted in feedback, and at the same time cooperate The driving device jointly adjusts the pressure waveform in the circulation pipeline, so that a near-physiological pulsating flow waveform is generated in the circulation pipeline, which solves the nearly physiological pulsating loading problem of vascular stent fatigue detection, and makes vascular stent fatigue detection more scientific and reliable.

3. The vascular stent fatigue testing equipment provided by the present invention, when the loading device is a composite loading device, the simulated blood vessel includes an endothelial layer and a blood vessel wall layer; through the setting of the endothelial layer, and cooperate with the reciprocating pump to adjust the pressure in the test chamber Changes, so that the simulated blood vessel with the stent to be tested in it undergoes periodic contraction and relaxation under the action of the pressure difference, completely simulating the endothelialization of the stent after it is implanted in the blood vessel, so that the fatigue performance of the stent to be tested can be improved The test is more accurate.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a structural schematic diagram of the fatigue testing equipment of the present invention.

Fig. 2 is a schematic perspective view of the three-dimensional structure of the carrier of the present invention.

Fig. 3 is a schematic perspective view of the main body of the carrier of the present invention.

Fig. 4 is a schematic structural diagram of the pulsation loading device of the present invention.

Fig. 5 is a schematic structural diagram of a simulated blood vessel in the composite loading device of the present invention.

Explanation of reference signs:

1. Loading device; 2. Acquisition and control system; 3. Driving device; 4. Simulated blood vessel; 5. Circulation pipeline; 6. Loading carrier; 7. Main body; 8. Top cover; Connection interface; 11. Temperature control system; 12. Reciprocating pump; 13. First pressure detection module; 14. Detection section; 15. Test chamber; 16. Endothelial layer; 17. Vascular wall layer;

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

A kind of blood vessel stent fatigue test equipment provided by the present embodiment, as shown in Figure 1, comprises loading device 1, acquisition and control system 2 and driving device 3; The stent to be tested 18 is implanted in the simulated blood vessel 4, the simulated blood vessel 4 Assembled into the test cavity 15 of the loading device 1, the simulated blood vessel 4 communicates with the circulation pipeline 5 to form a loop, and injects the simulated liquid, driven by the driving device 3, the simulated liquid flows, and the whole system is adjusted through the acquisition and control system The pressure in the pipeline makes it close to the environment of the human body; the device can make the simulated liquid flow in the simulated blood vessel 4, accurately simulate the use environment of the vascular stent, and ensure the accuracy of the measurement results.

As shown in Figures 2 and 3, the loading device 1 has a loading body 6, and the loading body 6 includes a main body 7 and a top cover 8; the loading body 6 is made of high-strength plexiglass, and the transparent material is convenient for observing the working state inside the test chamber 15. And ensure the overall strength and rigidity to meet the requirements of frequent and rapid pressure changes in the test chamber 15;

The lower surface of the top cover 8 adopts an upwardly concave structure, and the highest point is the pressure sensor interface, which is convenient for the exhaust operation inside the cavity before the experiment starts; the top cover 8 and the main body 7 are threaded to facilitate the installation of the simulated blood vessel 4. At the same time, the sealing performance in the test cavity 15 is guaranteed;

The central position of the main body 7 is the test cavity 15, and the two sides of the main body 7 are symmetrically provided with pipeline interfaces 9, and the simulated blood vessels 4 are connected between the inner sides of the two groups of pipeline interfaces 9, and the outer sides of the pipeline interfaces 9 are connected with Circulation line 5.

A temperature control system 11 is provided inside the loading device 1, and the temperature control system 11 has a temperature sensor and a heating rod, and the temperature in the test cavity 15 and the simulated blood vessel 4 is detected and adjusted by the temperature control system 11, which can be improved by increasing The temperature in the blood vessel 4 and the test chamber 15 is simulated to achieve the purpose of accelerated fatigue testing such as accelerating the fatigue force of the stent 18 to be tested and accelerating the degradation rate of the stent 18 to be tested.

A plurality of simulated blood vessels 4 can be connected in parallel in the test chamber 15, and 2-4 test stents can be placed in each simulated blood vessel 4. Therefore, the fatigue test equipment is expected to carry out accelerated simulation tests to 38 stents to be tested 18 at the same time; Under the condition that two fatigue testing devices are performed simultaneously, high-throughput simulation of the fatigue testing of the bracket 18 to be tested can be realized.

Operate the acquisition and control system 2, the loading device 1 and the temperature control system 11 through the software system, and apply mechanical loads (compression force, tension force, fluid shear force, temperature) similar to the physiological environment to the stent 18 to be tested in the simulated blood vessel 4 ), to simulate the mechanical environment of the stent 18 to be tested after being implanted into the human body; at the same time, in some positions of the device, pressure, flow, and pipe diameter sensors are arranged to measure the parameters in the fluid circuit in the test process, and the data acquisition system feeds back to the test software to achieve closed-loop control.

The present invention realizes near-physiological mechanical loads such as physiological pulsating flow shear force, periodic compression, stretching stress, and physiological temperature through the above-mentioned method, and can also accelerate the fatigue force of the bracket and accelerate the acceleration by accelerating the loading frequency and increasing the fluid temperature. Degradation stent degradation speed and other accelerated fatigue testing purposes.

Specifically, the loading device 1 can be a pulsating loading device 1 or a composite loading device 1 , and the two loading methods will be described separately below.

In the pulsation loading device 1, as shown in Figure 4, a simulated blood vessel 4 is installed in the test cavity 15 in the loading body 6, and simulated liquid circulates inside the simulated blood vessel 4. There is a detection section 14 on the simulated blood vessel 4, and in the detection section 14 into the test bracket 18; in the installation process, the detection section 14 of the simulated blood vessel 4 should be set inside the test cavity 15 of the loading body 6.

The main body 7 of the loading body 6 is provided with a connection interface 10, the connection interface 10 is provided with a reciprocating pump 12, and the reciprocating pump 12 is communicated with the test chamber 15; through the process of sucking air by the reciprocating pump 12, changes can be realized. Test the pressure in the chamber 15. When the pressure in the test chamber 15 is higher than the pressure in the simulated blood vessel 4, the simulated blood vessel 4 will be in a contracted state. When the pressure in the test chamber 15 is lower than the pressure in the simulated blood vessel 4, the simulated Blood vessel 4 will be in a dilated state;

When the stent 18 to be tested is subjected to a fatigue test, the pressure in the test cavity 15 is changed by the reciprocating pump 12, so that the compliance simulated blood vessel 4 containing the stent to be tested 18 therein undergoes periodic contraction and contraction under the action of the pressure difference. relax.

The loading body 6 is provided with a first pressure detection module 13; the first pressure detection module 13 has a first pressure sensor arranged in the test cavity 15 of the loading body 6, and during the test, the reciprocating pump 12 will be continuously adjusted The pressure in the test chamber 15 is collected in real time by the probe of the first pressure sensor, and the pressure waveform is read, processed and displayed on the host computer through software, and the nearly physiological pulsation waveform is observed through the waveform curve, the data is stored, and the feedback control reciprocates Pump 12 works.

In the composite loading device 1, as shown in Figure 5, the simulated blood vessel 4 includes: an endothelial layer 16 and a vessel wall layer 17; the endothelial layer 16 is cylindrical; the inside of the endothelial layer 16 has a first cavity; The wall layer 17 is also cylindrical; the blood vessel wall layer 17 is sleeved on the outer surface of the endothelial layer 16; a second cavity is formed between the endothelial layer 16 and the blood vessel wall layer 17; the endothelial layer 16 Used for simulating the endothelialization after the stent 18 to be tested is implanted in the blood vessel in the fatigue test; the blood vessel wall layer 17 is used for simulating the blood vessel wall after the stent 18 to be tested is implanted in the fatigue test;

The compliance of the material of the blood vessel wall layer 17 is similar to that of the blood vessel, so as to simulate the environment after the stent 18 to be tested is implanted in the blood vessel.

The endothelial layer 16 is made of a material with high compliance, and its compliance is higher than that of the blood vessel wall layer 17, so as to simulate the endothelial effect after the stent 18 to be tested is implanted in the blood vessel. At the same time, by placing the stent 18 to be tested between the blood vessel wall layer 17 and the endothelial layer 16 with different compliances, it can be simulated that when the blood pressure rises, the stent 18 to be tested expands and deforms with the endothelial layer 16 due to the effect of inner wallization. And squeeze the blood vessel wall layer 17 to expand and deform; when the blood pressure drops, the blood vessel wall layer 17 rebounds, and compressive force is applied to the stent 18 to be tested. Therefore, a composite load of periodic tension and compression forces is formed on the test stent 18 according to the blood pulsation.

The materials of the endothelial layer 16 and the vascular wall layer 17 are silica gel or other elastic materials; in this embodiment, silica gel is preferred; however, the compliance of the two materials is different.

In the fatigue test, the composite loading device 1 is placed in the fatigue test equipment, and through the setting of the endothelial layer 16, the endothelialization of the blood vessel 4 stent after being implanted into the blood vessel is completely simulated, so that the test of the fatigue performance of the stent to be tested 18 It is more accurate; through the effect of different compliances of the blood vessel wall layer 17 and the endothelial layer 16, it is possible to simulate the loading of the blood vessel on the test stent 18 by the periodic stretching force and compression force after the test stent 18 is implanted.

The first cavity in the loading device 1 communicates with the first circulation pipeline 5 on the fatigue testing equipment; driven by the driving device 3, the first simulated liquid in the first circulation pipeline 5 moves at a certain flow rate and amplitude. The flow in the first cavity generates pulsation waves, so that the first simulation liquid can simulate the pulsation waves generated by the real blood flow in the blood vessels as much as possible;

The second cavity communicates with the second circulation pipeline 5 on the fatigue testing equipment; driven by the driving device 3, the second simulated liquid in the second circulation pipeline 5 flows in the second cavity at a certain flow rate to realize Simulate the fluid shear force generated by blood flow on the stent 18 to be tested. Simulate the real stress situation after the stent 18 to be tested is implanted. For the degradable stent, the simulated liquid flowing in the second cavity provides a degradation environment for the stent to be tested 18 ; thus, the degradation process of the stent to be tested 18 after being implanted into the blood vessel is simulated.

In summary, the device can simulate near-physiological mechanical loads such as pulsating flow shear stress, periodic compression, stretch stress, and physiological temperature for the stent 18 to be tested, and can also achieve The purpose of accelerated fatigue testing is to accelerate the fatigue force of the stent and accelerate the degradation rate of the degradable stent.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (7)

1. A vascular stent fatigue testing device, characterized in that, comprising: The loading device (1) has a test cavity (15) inside; the test cavity (15) is equipped with a simulated blood vessel (4); the simulated blood vessel (4) is suitable for setting a stent to be tested (18); The driving device (3) is set in communication with the simulated blood vessel (4) in the loading device (1) through the circulating pipeline (5); the driving device (3) drives the simulated liquid in the circulating pipeline (5) and simulated Flow in the blood vessel (4); The acquisition and control system (2) is connected with the drive device (3) and the sensor; The driving device (3) can provide a near-physiological pulsating flow for the circulation pipeline, so that the pressure and flow waveform at the inlet of the loading device (1) are similar to the physiological state; The loading device (1) includes a loading body (6); the loading body (6) includes: The main body (7) has a test cavity (15) inside; a plurality of pipeline interfaces (9) are arranged oppositely at both ends; the two ends of the simulated blood vessel (4) are respectively connected to the oppositely arranged pipeline interfaces (9); a top cover (8), which is set on the main body (7); The loading device (1) is a composite loading device (1); in the composite loading device (1), the simulated blood vessel (4) includes: The inner skin layer (16) is cylindrical; the inner skin layer (16) has a first cavity inside; The blood vessel wall layer (17) is cylindrical; the blood vessel wall layer (17) is sleeved on the outer surface of the endothelial layer (16); between the endothelial layer (16) and the blood vessel wall layer (17) Form a second cavity between; The bracket to be tested (18) is sleeved on the outer surface of the inner cortex (16); The first cavity and the second cavity are respectively communicated with the circulation pipeline (5), and simulated liquid flows through them respectively; The compliance of the material of the endothelial layer (16) is greater than that of the material of the blood vessel wall layer (17); the compliance of the material of the blood vessel wall layer (17) is the same as that of human blood vessels. 2. The vascular stent fatigue testing device according to claim 1, characterized in that, the carrier (6) is made of plexiglass. 3. stent fatigue test equipment according to claim 1, is characterized in that, also comprises: The temperature control system (11) is arranged inside the loading device (1); the temperature control system (11) is used for detecting and regulating the temperature in the test cavity (15) and the simulated blood vessel (4). 4. The vascular stent fatigue testing device according to claim 1, characterized in that, the simulated blood vessels (4) have a plurality of roots, and are arranged side by side in the test cavity (15). 5. vascular stent fatigue testing equipment according to claim 1, is characterized in that, described loading device (1) is the pulsation loading device (1); In the simulated blood vessel (4), there is a stent (18) for placing the stent to be tested (18). The detection section (14); the detection section (14) is arranged in the test cavity (15) of the loading body (6); The pressure in the test cavity (15) has a first state in which the simulated blood vessel (4) contracts when it is greater than the pressure in the simulated blood vessel, and a second state in which the simulated blood vessel (4) contracts and relaxes when it is lower than the pressure in the blood vessel of human blood. Two states. 6. vascular stent fatigue test equipment according to claim 5, is characterized in that, described main body (7) is provided with connection interface (10) on the side opposite to described top cover (8); (10) is provided with a reciprocating pump (12); the reciprocating pump (12) is arranged in communication with the test cavity (15) of the loading body (6). 7. The vascular stent fatigue testing device according to any one of claims 1-6, wherein the simulated liquid is water, physiological saline, buffer solution or glycerol solution.

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