A testing device for the radial mechanical properties of a small-diameter artificial blood vessel

Abstract

The present invention provides a test device for the radial tensile performance of small-diameter artificial blood vessels. The test device for the radial tensile performance of small-diameter artificial blood vessels includes a first blood vessel stretching component and a second blood vessel stretching component. Among them, the first blood vessel stretching component includes a first component main body and a first blood vessel stretching rod. During use, the first arc-shaped portion of the first blood vessel stretching rod and the second arc-shaped portion of the second blood vessel stretching rod are respectively supported in the inner wall of the blood vessel. Then, the first blood vessel stretching rod is installed on the first component main body, and the second blood vessel stretching rod is installed on the second component main body. The first component main body is connected to the test equipment through a first connecting portion, and the second component main body is connected to the test equipment through a second connecting portion. Finally, the test equipment pulls the first component main body and the second component main body to both sides respectively to conduct a mechanical property test on the blood vessel, which can effectively improve the adaptability of the tooling for the radial tensile performance test of artificial blood vessels.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a device for testing the radial tensile performance of a small-diameter artificial blood vessel. Background Art

[0002] As a permanent implant, an artificial blood vessel should have good biological stability. Biological stability refers to the ability of a material to maintain its physical and chemical properties stable after being transplanted into living tissue. After an artificial blood vessel is implanted into the human body, it is subjected to the action of systolic pressure and diastolic pressure for a long time, and it will undergo periodic deformation in the axial and radial directions. Therefore, the mechanical properties of the artificial blood vessel in the axial and radial directions are extremely important. For the measurement of the radial tensile strength of an artificial blood vessel, the international standard ISO7198 and the Chinese pharmaceutical industry standard YY 0500-2004 recommend the reference structure of a radial tensile clamp.

[0003] However, the separation rod part and the supporting part of the reference fixture are connected through a groove. This structure makes the components at the connection of the fixture bear extremely high loads within a very short distance, and the components are prone to fracture and slippage. Under a certain force, the smaller the cross-sectional area, the easier an accident occurs. Therefore, this fixture is difficult to be applied to measure the radial mechanical properties of small-diameter artificial blood vessels. And currently, there are few research reports on using a fixture that can completely maintain the tubular shape of the material, which causes stress concentration at the contact part between the artificial blood vessel and the fixture during the measurement process, and has a certain impact on the stability of the results. Summary of the Invention

[0004] The main purpose of the present invention is to provide a device for testing the radial tensile performance of a small-diameter artificial blood vessel to solve the problem of poor tooling adaptability in the test of the radial tensile performance of an artificial blood vessel in the prior art.

[0005] To achieve the above object, the present invention provides a device for testing the radial tensile performance of a small-diameter artificial blood vessel, including: a first blood vessel stretching component, including: a first component main body, on which a first connection part connected to a test device is formed; a first blood vessel stretching rod, detachably installed on the first component main body, and a first arc-shaped part adapted to the inner wall of the blood vessel is formed on the first blood vessel stretching rod; a second blood vessel stretching component, including: a second component main body, on which a second connection part connected to the test device is formed; a second blood vessel stretching rod, detachably installed on the second component main body, and a second arc-shaped part adapted to the inner wall of the blood vessel is formed on the second blood vessel stretching rod, and the second arc-shaped part and the first arc-shaped part cooperate to support in the inner wall of the blood vessel.

[0006] In one embodiment, both the first arc-shaped part and the second arc-shaped part are semi-cylindrical, and the first arc-shaped part and the second arc-shaped part can form a cylinder to be filled in the inner wall of the blood vessel.

[0007] In one embodiment, two ends of the first blood vessel stretching rod are respectively mounted on the first component main body, and / or two ends of the second blood vessel stretching rod are respectively mounted on the second component main body.

[0008] In one embodiment, the first blood vessel stretching rod is in the shape of a first L, including a first cross bar and a first vertical bar connected to each other. A first arc portion is formed on the first cross bar. Free ends of the first cross bar and the first vertical bar are respectively mounted on the first component main body; the second blood vessel stretching rod is in the shape of a second L, including a second cross bar and a second vertical bar connected to each other. A second arc portion is formed on the second cross bar. Free ends of the second cross bar and the second vertical bar are respectively mounted on the second component main body.

[0009] In one embodiment, the first end and the second end of the first blood vessel stretching rod are detachably mounted on the first component main body. The first blood vessel stretching component includes a first fastener and a second fastener respectively cooperating with the first end and the second end of the first blood vessel stretching rod; the first end and the second end of the second blood vessel stretching rod are detachably mounted on the second component main body. The second blood vessel stretching component includes a third fastener and a fourth fastener respectively cooperating with the first end and the second end of the second blood vessel stretching rod.

[0010] In one embodiment, a first jack and a second jack respectively cooperating with the first end and the second end of the first blood vessel stretching rod are formed on the first component main body; a third jack and a fourth jack respectively cooperating with the first end and the second end of the second blood vessel stretching rod are formed on the second component main body.

[0011] In one embodiment, the first blood vessel stretching rod and the second blood vessel stretching rod are stainless steel rods.

[0012] In one embodiment, the first blood vessel stretching component and the second blood vessel stretching component have the same structure.

[0013] By applying the technical solution of the present invention, during use, the first arc portion of the first blood vessel stretching rod and the second arc portion of the second blood vessel stretching rod are respectively supported on the inner wall of the blood vessel. Then, the first blood vessel stretching rod is mounted on the first component main body, and the second blood vessel stretching rod is mounted on the second component main body. The first component main body is connected to the testing device through a first connecting portion, and the second component main body is connected to the testing device through a second connecting portion. Finally, the testing device pulls the first component main body and the second component main body in two sides respectively to perform mechanical property testing on the blood vessel. This technical solution can effectively improve the adaptability of the tooling to the radial stretching performance testing of the artificial blood vessel.

[0014] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments and descriptions thereof of the invention are used to explain the invention and shall not unduly limit the invention. In the drawings:

[0016] Figure 1 Fig. 6 shows a schematic structural diagram of Embodiment 1 of a small-diameter artificial blood vessel radial stretching performance testing device according to the present invention;

[0017] Figure 2 shows Figure 1 a schematic structural diagram of the first component main body and the first blood vessel stretching rod of the small-diameter artificial blood vessel radial stretching performance testing device;

[0018] Figure 3 Fig. 16 shows a schematic structural diagram of Embodiment 2 of the small-diameter artificial blood vessel radial stretching performance testing device according to the present invention. Detailed Embodiments

[0019] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so as to describe the embodiments of the present invention here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Figure 1 and Figure 2 Figure 2 shows an embodiment of a small-caliber artificial blood vessel radial tensile property testing device of the present invention. The small-caliber artificial blood vessel radial tensile property testing device includes a first blood vessel stretching component 10 and a second blood vessel stretching component 20. Among them, the first blood vessel stretching component 10 includes a first component main body 11 and a first blood vessel stretching rod 12. Wherein, a first connecting portion 111 connected to the testing device is formed on the first component main body 11, the first blood vessel stretching rod 12 is detachably installed on the first component main body 11, and a first arc portion 121 adapted to the inner wall of the blood vessel is formed on the first blood vessel stretching rod 12. The second blood vessel stretching component 20 includes a second component main body 21 and a second blood vessel stretching rod 22. Wherein, a second connecting portion 211 connected to the testing device is formed on the second component main body 21, the second blood vessel stretching rod 22 is detachably installed on the second component main body 21, and a second arc portion 221 adapted to the inner wall of the blood vessel is formed on the second blood vessel stretching rod 22. The second arc portion 221 and the first arc portion 121 cooperate to support in the inner wall of the blood vessel.

[0024] Applying the technical solution of the present invention, when in use, the first arc portion 121 of the first blood vessel stretching rod 12 and the second arc portion 221 of the second blood vessel stretching rod 22 are respectively supported in the inner wall of the blood vessel, then the first blood vessel stretching rod 12 is installed on the first component main body 11, and the second blood vessel stretching rod 22 is installed on the second component main body 21, so that the first component main body 11 is connected to the testing device through the first connecting portion 111, and the second component main body 21 is connected to the testing device through the second connecting portion 211. Finally, the testing device pulls the first component main body 11 and the second component main body 21 respectively to both sides to perform a mechanical property test on the blood vessel. This technical solution can effectively improve the adaptability of the tooling to the radial tensile property test of the artificial blood vessel.

[0025] Optionally, the first connecting portion 111 and the second connecting portion 211 are connected to a tensile testing machine that can move at a constant speed and complies with ISO5081 through threaded holes.

[0026] Such as Figure 1 and Figure 2As shown, both the first arc portion 121 and the second arc portion 221 are semi-cylindrical. The first arc portion 121 and the second arc portion 221 can form a cylinder to be filled in the inner wall of the blood vessel. In this way, when the first arc portion 121 and the second arc portion 221 form a complete cylinder, the tubular shape of the artificial blood vessel is maintained during stretching, reducing the influence of stress concentration on the measurement stability.

[0027] Optionally, both ends of the first blood vessel stretching rod 12 are respectively installed on the first component main body 11, and both ends of the second blood vessel stretching rod 22 are respectively installed on the second component main body 21. As Figure 1 and Figure 2 shown, in the technical solution of this embodiment, the first blood vessel stretching rod 12 is in the shape of a first L, including a connected first cross bar and a first vertical bar. The first arc portion 121 is formed on the first cross bar. The free ends of the first cross bar and the first vertical bar are respectively installed on the first component main body 11. The second blood vessel stretching rod 22 is in the shape of a second L, including a connected second cross bar and a second vertical bar. The second arc portion 221 is formed on the second cross bar. The free ends of the second cross bar and the second vertical bar are respectively installed on the second component main body 21. During use, the first cross bar of the first blood vessel stretching rod 12 and the second cross bar of the second blood vessel stretching rod 22 are used to penetrate the inner wall of the blood vessel to support the blood vessel, and both ends of the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 are used for installation. When installing the blood vessel in this implementation manner and performing mechanical property tests, the stress application method of the cross bar and the vertical bar of the L-shaped blood vessel stretching rod does not easily allow the blood vessel to slip from the side, and the fixture is not easily broken.

[0028] As Figure 1 shown, in the technical solution of Embodiment 1, the first end and the second end of the first blood vessel stretching rod 12 are detachably installed on the first component main body 11. The first blood vessel stretching component 10 includes a first fastener 13 and a second fastener 14 that respectively cooperate with the first end and the second end of the first blood vessel stretching rod 12. The first end and the second end of the second blood vessel stretching rod 22 are detachably installed on the second component main body 21. The second blood vessel stretching component 20 includes a third fastener 23 and a fourth fastener 24 that respectively cooperate with the first end and the second end of the second blood vessel stretching rod 22. During use, first use the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 to install the blood vessel. After the blood vessel installation is completed, then install the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 on the first component main body 11 and the second component main body 21. Finally, use the first fastener 13 and the second fastener 14 to fasten the first end and the second end of the first blood vessel stretching rod 12, and use the third fastener 23 and the fourth fastener 24 to fasten the second blood vessel stretching rod 22.

[0029] As Figure 1As shown, in the technical solution of this embodiment, the first component body 11 is provided with a first jack and a second jack that respectively cooperate with the first end and the second end of the first blood vessel stretching rod 12. The second component body 21 is provided with a third jack and a fourth jack that respectively cooperate with the first end and the second end of the second blood vessel stretching rod 22. Among them, the first jack and the third jack are jacks with openings, which facilitate the horizontal insertion of the first blood vessel stretching rod 12 and the vertical rod of the second component body 21, and the second jack and the fourth jack are common round holes. As Figure 3 shown, the present invention also provides a second embodiment of a small-diameter artificial blood vessel radial stretching performance testing device. The difference between the second embodiment and the first embodiment is that the first jack and the third jack are common round holes, and the second jack and the fourth jack are jacks with openings.

[0030] Preferably, in the technical solution of this embodiment, the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 are stainless steel rods. Stainless steel rods have better corrosion resistance and are suitable for the stretching test of blood vessels.

[0031] In the technical solutions of the above-mentioned first embodiment and the second embodiment, the first blood vessel stretching component 10 and the second blood vessel stretching component 20 are two components with exactly the same structure. The first blood vessel stretching component 10 and the second blood vessel stretching component 20 are installed in a vertically centrally symmetric structure. As another alternative implementation manner, the first blood vessel stretching component 10 and the second blood vessel stretching component 20 can also be two components with incomplete structures.

[0032] Specifically, in the technical solution of this embodiment, the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 are L-shaped stainless steel metal rods, and the first component body 11 and the second component body 21 are L-shaped stainless steel metal plates. The lower half of the cylinder of the L-shaped metal rod is cut off to form the above-mentioned first arc portion 121 and the second arc portion 221. Optionally, in the technical solution of this embodiment, the first fastener 13, the second fastener 14, the third fastener 23, and the fourth fastener 24 are set screws. As another alternative implementation manner, the first fastener 13, the second fastener 14, the third fastener 23, and the fourth fastener 24 can also be snap-fasteners or buckle-fasteners.

[0033] As Figure 2 shown, the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 are composed of three parts: a cylinder, a bend, and a semi-cylinder. The cylindrical part is fixed to the upper end of the first component body 11 and the lower end of the second component body 21 by set screws. The two semi-cylindrical parts are relatively combined to form a complete cylinder. When in use, the blood vessel sample to be measured is placed on this complete cylinder, and the end of the semi-cylinder is fixed to the lower end of the first component body 11 and the upper end of the second component body 21 by another set screw.

[0034] Optionally, in the technical solution of this embodiment, when in use, the semi-cylindrical end of the L-shaped metal rod passes through the horizontally oriented jack of the L-shaped stainless steel plate and is placed between the set screw and the L-shaped stainless steel plate. Its cylindrical surface fits against the inner side of the jack of the L-shaped stainless steel plate, and its flat surface fits against the set screw. Its position is fixed by tightening the set screw. Specifically, there is a pair of set screws at the horizontally oriented limit holes of the L-shaped stainless steel plate, which can adjust the front and back positions of the cylindrical part, so that the entire L-shaped metal rod is in the same vertical plane, avoiding the L-shaped metal rod from being distorted before measurement.

[0035] Optionally, each part of the above-mentioned first blood vessel stretching component 10 and second blood vessel stretching component 20 is a structure or component with adjustable dimensions. Optionally, multiple groups of first blood vessel stretching rods 12 and second blood vessel stretching rods 22 with different diameters of 2, 3, 4, 5, and 6 mm can be provided, which are suitable for small-caliber artificial blood vessels with an inner diameter of 2-6 mm. When in use, select the separating rod closest to the inner diameter of the blood vessel. Specifically, according to the requirements of the international standard ISO7198 for the measuring fixture, a separating rod with a suitable size should be selected to measure artificial blood vessels with different diameters. In this case, a separating rod with a diameter of 3 mm is selected.

[0036] When the technical solution of the present invention is in use, the radial ultimate tensile strength of the composite tubular stent can be calculated from the maximum tensile load before fracture and the effective cross-sectional area. The effective cross-sectional area is defined as 2 * wall thickness * axial length of the annular sample. Therefore, the calculation formula for the radial ultimate strength is as follows:

[0037] Radial ultimate strength = F / 2TL

[0038] Specifically, F is the maximum tensile load before fracture, with the unit of N; T is the thickness of the annular sample, with the unit of m; L is the axial length of the annular sample, with the unit of m; the unit of the calculated radial ultimate strength is expressed in MPa.

[0039] In this embodiment, using the technical solution of the present invention to test the artificial blood vessel under the above conditions, the calculated radial tensile fracture strength is 10.96 ± 0.67 Mpa. This value is significantly higher than the radial tensile fracture strength of the human saphenous vein, meeting the requirements for the radial tensile performance of the artificial blood vessel and being able to fully withstand the pressure generated during blood flow. Even under the high pressure caused by lesions, the blood vessel will not burst.

[0040] The technical solution of the present invention is applicable to measuring at least one of the radial mechanical properties of a blood vessel sample, including elastic modulus, ultimate tensile strength, maximum load force, etc.

[0041] The small-caliber artificial blood vessel radial tensile performance testing device of the present invention has at least the following technical effects:

[0042] 1. During measurement, the tubular shape of the artificial blood vessel is maintained, reducing the influence of stress concentration on measurement stability. The fixing method inside the fixture is optimized, avoiding the problems of easy side slipping and fixture fracture of the small-diameter fixture, improving the safety of the fixture. At the same time, by using separation rods of different specifications, the number of fixtures is reduced.

[0043] 2. Since the cylindrical shape formed by the combination of the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 fits the inside of the artificial blood vessel, it ensures the continuity of the tubular shape of the artificial blood vessel during radial stretching and reduces the possibility of stress concentration. The above fixing method for the first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 avoids the problems of easy side slipping and ejection of the fixture chuck.

[0044] 3. The first blood vessel stretching rod 12 and the second blood vessel stretching rod 22 have a large contact area with the constraint part, avoiding the problem of easy fracture of the small-diameter fixture chuck under high loads.

[0045] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the sake of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0046] For the sake of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationship of one device or feature shown in the figure with other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0047] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test device for the radial tensile performance of a small-diameter artificial blood vessel, characterized in that, Comprising: A first blood vessel stretching component (10), comprising: A first component body (11) formed with a first connection portion (111) connected to a testing device thereon; A first blood vessel stretching rod (12) detachably mounted on the first component body (11), and a first arc portion (121) adapted to the inner wall of the blood vessel is formed on the first blood vessel stretching rod (12); A second blood vessel stretching component (20), comprising: A second component body (21) formed with a second connection portion (211) connected to a testing device thereon; A second blood vessel stretching rod (22) detachably mounted on the second component body (21), and a second arc portion (221) adapted to the inner wall of the blood vessel is formed on the second blood vessel stretching rod (22), and the second arc portion (221) and the first arc portion (121) cooperate to support in the inner wall of the blood vessel; Both ends of the first blood vessel stretching rod (12) are respectively mounted on the first component body (11), and / or both ends of the second blood vessel stretching rod (22) are respectively mounted on the second component body (21). The first blood vessel stretching rod (12) is in a first L shape, including a first cross bar and a first vertical bar connected to each other. The first arc portion (121) is formed on the first cross bar, and the free ends of the first cross bar and the first vertical bar are respectively mounted on the first component body (11); The second blood vessel stretching rod (22) is in a second L shape, including a second cross bar and a second vertical bar connected to each other. The second arc portion (221) is formed on the second cross bar, and the free ends of the second cross bar and the second vertical bar are respectively mounted on the second component body (21); The first end and the second end of the first blood vessel stretching rod (12) are insertably mounted on the first component body (11), and the first blood vessel stretching component (10) includes a first fastener (13) and a second fastener (14) respectively cooperating with the first end and the second end of the first blood vessel stretching rod (12); The first end and the second end of the second blood vessel stretching rod (22) are insertably mounted on the second component body (21), and the second blood vessel stretching component (20) includes a third fastener (23) and a fourth fastener (24) respectively cooperating with the first end and the second end of the second blood vessel stretching rod (22); The first L shape and the second L shape are arranged in central symmetry.

2. The small-caliber artificial blood vessel radial tensile property testing device according to claim 1, characterized in that Both the first arc portion (121) and the second arc portion (221) are semi-cylindrical, and the first arc portion (121) and the second arc portion (221) form a cylinder to be filled in the inner wall of the blood vessel.

3. The small-diameter artificial blood vessel radial tensile property testing device according to claim 1, characterized in that The first component body (11) is provided with a first jack and a second jack respectively cooperating with the first end and the second end of the first blood vessel stretching rod (12); The second component body (21) is provided with a third jack and a fourth jack respectively cooperating with the first end and the second end of the second blood vessel stretching rod (22).

4. The small-caliber artificial blood vessel radial tensile property testing device according to claim 1, characterized in that, The first blood vessel stretching rod (12) and the second blood vessel stretching rod (22) are stainless steel rods.

5. The small-caliber artificial blood vessel radial tensile property testing device according to claim 1, characterized in that, The first blood vessel stretching component (10) and the second blood vessel stretching component (20) have the same structure.

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