A shape memory material-based catheter sampling tool and sampling method

Abstract

The application relates to the technical field of aerospace equipment manufacturing, and particularly discloses a guide pipe sampling tool based on a shape memory material and a use method, which comprises a guide pipe sampling tool body, the guide pipe sampling tool body is composed of one shape memory deformation structure and two end connecting structures, the two end connecting structures are respectively arranged at the two ends of the shape memory deformation structure, the two end connecting structures are matched with the same end hole expanding features of a target guide pipe, and the two end connecting structures are matched with end connecting components of the target guide pipe. The application has the advantages of simple operation, high adaptability, high precision, reusability, and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of aerospace equipment manufacturing technology, specifically to a conduit sampling tool and sampling method based on shape memory materials. Background Technology

[0002] In aerospace equipment, conduits are widely used for the transport of media such as fuel and hydraulic oil. Due to the complexity of the equipment structure, conduits typically require custom bending based on the actual installation location to ensure stress-free installation between their ends and interfaces, and between them and the fixing plates. However, due to manufacturing and installation errors, conduits manufactured using bending machines based on design models often cannot perfectly match the actual installation location, leading to assembly difficulties or stress, which affects safety and reliability.

[0003] Currently, catheter sampling mainly relies on manual operation by experienced operators. The catheter is repeatedly calibrated on a machine to meet stress-free installation conditions, and then the calibrated catheter shape is measured using equipment for sampling. A pipe bending machine is then used to manufacture a qualified catheter. The above-mentioned existing catheter sampling methods have the following problems: 1. High dependence on operator experience, making standardization difficult. 2. Large catheter diameters result in high rigidity, making manual calibration and sampling difficult and leading to excessively long operation cycles. 3. Low sampling accuracy, failing to meet high-precision assembly requirements. Therefore, there is an urgent need for a simple, adaptable, and reusable catheter sampling fixture and method to improve the efficiency and accuracy of catheter sampling. Summary of the Invention

[0004] This invention aims to solve the problems of high operational difficulty, low efficiency, poor accuracy, and reliance on experience in existing catheter sampling processes. It provides a catheter sampling tool and method based on shape memory polymer, which enables rapid and accurate sampling of complex catheter shapes and supports the reuse of the tool.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A catheter sampling fixture based on shape memory material includes a catheter sampling fixture body, which consists of a shape memory deformation structure and two end connection structures. The two end connection structures are respectively installed at both ends of the shape memory deformation structure. Both end connection structures are matched with the same end enlargement feature of the target catheter, and both end connection structures are matched and installed with the end connection component of the catheter.

[0006] Optionally, the shape memory deformation structure is formed by connecting multiple long strip-shaped columnar or tubular epoxy resin shape memory polymers by adhesive or mechanical connection. The interior of the shape memory deformation structure is solid or hollow. After being heated to a rubber state, the shape memory deformation structure can be bent into a temporary shape. After being cooled to a glass state, it can maintain the temporary shape to complete the memory sampling of the target catheter shape.

[0007] Optionally, the mechanical connection method includes at least two epoxy resin shape memory polymer segments, a connecting sleeve, and multiple first bolts. Both ends of the two epoxy resin shape memory polymer segments are provided with insertion portions. The outer diameter of the two insertion portions is smaller than the outer diameter of the epoxy resin shape memory polymer segments. The insertion portions of the two epoxy resin shape memory polymer segments with their adjacent ends are respectively inserted into the interior of the connecting sleeve. The interior of the connecting sleeve is provided with multiple first threaded holes. The multiple first bolts are threaded into the corresponding first threaded holes, and the adjacent ends of the multiple first bolts are respectively in close contact with the outer wall of the corresponding insertion portion.

[0008] Optionally, the outer diameter of the shape memory deformation structure is the same as the outer diameter of the target catheter, but its length is longer than that of the target catheter.

[0009] Optionally, the two end connection structures and the shape memory deformation structure are detachable mechanically connected.

[0010] Optionally, the mechanical connection includes multiple second threaded holes opened inside the two end connection structures. After the insertion parts at both ends of the shape memory deformation structure are respectively inserted into the two end connection structures, the interior of each of the multiple second threaded holes is threaded with a second bolt, and the ends of the multiple second bolts that are close to each other are tightly abutted against the outer wall of the insertion part.

[0011] Optionally, the epoxy resin shape memory polymer has a glass state temperature below 30°C, a rubber state temperature below 100°C, and the ratio of its elastic modulus E30°C at 30°C to its elastic modulus E60°C at 60°C is E=E30°C / E60°C>1000.

[0012] Optionally, a catheter sampling method based on shape memory materials is applied to the catheter sampling fixture described above, and the catheter sampling method further includes the following steps: Step 1: Based on the positions of the two end fixing points and the N middle fixing plates, and combined with the initial design shape of the target conduit, specify the preliminary bending scheme of the sampling fixture, set the M bending positions, bending directions and bending angles, start from one end of the conduit sampling fixture body, heat the bending part to the set temperature and then manually bend it, keep the bending shape unchanged and cool it to below the glass state temperature of the epoxy resin shape memory polymer, then release the external force, and complete the shape adjustment of all bending parts in sequence to obtain the preliminary bent conduit sampling fixture body; Step Two: Adjust the position of the initially bent catheter sampling fixture body from Step One, aligning one end with the corresponding fixed part of the target catheter end. Check whether there is any interference between the sampling fixture body and other structures when they are assembled together. If there is no obvious interference, install one end of the initially bent catheter sampling fixture body with the corresponding fixed part; if there is obvious interference, adjust the shape of part of the bend to eliminate the interference, and then install one end of the initially bent catheter sampling fixture body with the corresponding fixed part of the target catheter end. Step 3: Adjust the shape of the first section of the initially bent conduit sampling fixture body at a temperature lower than the glass state temperature of the epoxy resin shape memory polymer, and fix it on the first fixing plate. At this time, the first section of the initially bent conduit sampling fixture body has internal stress due to elastic deformation. Step 4: Simultaneously heat all the bent parts on the first section of the sampling fixture body of the initially bent conduit. The internal stress will disappear due to the softening of the bent parts. Then adjust the bending direction and bending angle of all the bent parts so that its shape fits the initial design shape of the target conduit and does not interfere with other structures. Step 5: Keep the new bending shape of the first section of the initially bent conduit sampling fixture body unchanged. After cooling to below 30°C, the first section of the initially bent conduit sampling fixture body can remember the new bending shape and there is no elastic stress inside, thus completing the correction of the first section of the initially bent conduit sampling fixture body. Step Six: Repeat the operation methods of Steps Three to Five above, and adjust the shape of the 2nd to Nth bending sections of the initially bent conduit sampling fixture body in sequence; Step 7: Repeat the operation methods of Steps 3 to 5 above, adjust the shape of the N+1th bent section of the initially bent conduit sampling fixture body, disassemble the end connection structure, trim the shape memory deformation structure to the preset size, and then reinstall the end connection structure so that the end of the calibrated conduit sampling fixture body is installed together with the other end fixed position without stress. Step 8: Disassemble the calibrated catheter sampling fixture body and use catheter measuring fixture equipment to measure the shape information of the catheter sampling fixture body, thus completing the sampling of the target catheter shape. Step 9: Heat all the bent parts of the heating conduit sampling fixture body to restore the entire conduit sampling fixture body to its initial straight shape for subsequent recycling.

[0013] Optionally, the heating method of the catheter sampling fixture body is one or more of the following: hot air gun, electric heating pad, or hot water; and the cooling method of the catheter sampling fixture body is natural cooling, fan cooling, or ice water cooling.

[0014] Optionally, the adjustment steps for the bending shape memory of the bending portion of the catheter sampling fixture body include: S1: Fix the bent part to keep the memory of the bent shape unchanged while heating the bent part of the tubing sampling fixture body to above 60°C. S2: Keep the temperature of the bending part above 60°C, and bend the fixed part to a new bending shape; S3: Keep the new bending shape unchanged. After cooling to room temperature, release the shape fixation of the catheter sampling fixture body. The catheter sampling fixture body itself can then maintain the new bending state.

[0015] The beneficial effects of this invention are: Easy to operate: No high-level skills or experience are required, and operators can quickly master the operation.

[0016] Highly adaptable: It can be used flexibly in complex field environments without the need for special equipment.

[0017] High precision: Through segment-by-segment calibration, the shape of the tooling is ensured to closely match the actual installation position.

[0018] Reusable: The tooling can be restored to its initial shape by heating, enabling multiple samplings.

[0019] High efficiency: Significantly shortens the catheter sampling cycle and improves production efficiency. Attached Figure Description

[0020] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the overall structure of a catheter sampling tool based on shape memory material proposed in this invention; Figure 2 This is a schematic diagram of the structure of the connecting sleeve before it is mechanically connected to the two sections of epoxy resin shape memory polymer in this invention; Figure 3 This is a schematic diagram of the structure after the connecting sleeve is mechanically connected to the two sections of epoxy resin shape memory polymer in this invention; Figure 4 This is a schematic diagram of the structure before the end connection structure and the shape memory deformation structure are mechanically connected in this invention; Figure 5 This is a schematic diagram of the structure after the end connection structure and the shape memory deformation structure are mechanically connected in this invention; Figure 6 This is a schematic flowchart of a catheter sampling method based on shape memory materials proposed in this invention.

[0022] In the figure: 1. The main body of the catheter sampling tool; 11. Shape memory deformation structure; 12. End connection structure; 13. Connecting sleeve; 14. First bolt; 15. Second bolt. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Reference Figures 1-6 A catheter sampling fixture based on shape memory material includes a catheter sampling fixture body 1. The catheter sampling fixture body 1 consists of a shape memory deformation structure 11 and two end connection structures 12. The two end connection structures 12 are respectively installed at both ends of the shape memory deformation structure 11. Both end connection structures 12 are matched with the same end expansion feature of the target catheter, and both end connection structures 12 are matched and installed with the end connection component of the target catheter.

[0025] As a technical optimization of the present invention, the shape memory deformation structure 11 is formed by connecting multiple long strip-shaped columnar or tubular epoxy resin shape memory polymers by adhesive or mechanical connection. The interior of the shape memory deformation structure 11 is solid or hollow. After being heated to a rubber state, the shape memory deformation structure 11 can be bent into a temporary shape. After being cooled to a glassy state, it can maintain the temporary shape to complete the memory sampling of the target catheter shape.

[0026] In this embodiment, the epoxy resin shape memory polymer is a thermally responsive shape memory polymer in the prior art. The shape memory and recovery process can be repeated multiple times. The catheter sampling fixture body 1 made of this epoxy resin shape memory polymer material remembers the temporary bending shape to realize the sampling of the target catheter. The catheter sampling fixture body 1 made of this epoxy resin shape memory polymer material can be reused by recovering the temporary shape.

[0027] At low temperatures, the epoxy resin shape memory polymer exists in a high-stiffness glassy state. Upon heating, its elastic modulus decreases sharply, reaching a low-stiffness rubbery state at higher temperatures. When an epoxy resin shape memory polymer structure is heated from its rigid glassy state to a soft rubbery state, an external force is applied to deform it into a temporary state. This temporary state is then maintained, and the polymer is cooled back to a rigid glassy state. After the external force is removed, the epoxy resin shape memory polymer stably retains this temporary state and remains rigid, thus "memorizing" the shape. Reheating the epoxy resin shape memory polymer causes it to gradually soften and transform into a low-stiffness rubbery state. Without external force, the epoxy resin shape memory polymer gradually returns to its initial shape. By repeating this process, the epoxy resin shape memory polymer repeatedly memorizes and recovers different complex configurations.

[0028] The catheter sampling fixture body 1 has sufficient rigidity at room temperature, and when one end is fixed, the other end cannot deform significantly due to gravity. The axis of this elongated structure can be a straight line or a continuous curve. For greater versatility, this embodiment recommends preparing the catheter sampling fixture body 1 of epoxy resin shape memory polymer material with a straight axis.

[0029] As a technical optimization of the present invention, the mechanical connection method includes at least two epoxy resin shape memory polymer segments, a connecting sleeve 13, and a plurality of first bolts 14. Both ends of the two epoxy resin shape memory polymer segments are provided with insertion portions. The outer diameter of the two insertion portions is smaller than the outer diameter of the epoxy resin shape memory polymer segments. The insertion portions of the two epoxy resin shape memory polymer segments with their adjacent ends are respectively inserted into the interior of the connecting sleeve 13. The interior of the connecting sleeve 13 is provided with a plurality of first threaded holes. The plurality of first bolts 14 are threadedly installed in the corresponding first threaded holes, and the adjacent ends of the plurality of first bolts 14 are respectively tightly abutted against the outer wall of the corresponding insertion portion.

[0030] like Figure 2 and Figure 3As shown, the mechanical connection method in this embodiment refers to using an intermediate connecting structure (i.e., connecting sleeve 13) to connect and install two sections of epoxy resin shape memory polymer together. The outer diameter of the intermediate connecting structure is the same as the outer diameter of the epoxy resin shape memory polymer. Each end of the epoxy resin shape memory polymer has a portion with a reduced outer diameter (i.e., an insertion part), the outer diameter of which is the same as the inner diameter of the intermediate connecting structure. After inserting the insertion parts of the two epoxy resin shape memory polymer sections into the intermediate connecting structure, multiple first bolts 14 are screwed in to connect and fix the two epoxy resin shape memory polymer sections, thus forming a mechanical connection and fixation between the two epoxy resin shape memory polymer sections. Furthermore, according to actual usage requirements, multiple standard lengths of epoxy resin shape memory polymer and intermediate connecting structures are prepared to facilitate the adjustment of the length of the catheter sampling fixture body 1, enabling modular fabrication of the catheter sampling fixture body 1, facilitating sampling of target catheters of different lengths, and improving the applicability of the catheter sampling fixture body 1.

[0031] As a technical optimization of the present invention, the outer diameter of the shape memory deformation structure 11 is the same as the outer diameter of the target catheter, but its length is longer than that of the target catheter. This structural design ensures that the outer diameter of the shape memory deformation structure 11 matches the outer diameter of the target catheter, guaranteeing accurate sampling of the target catheter's outer diameter data. Since the shape memory deformation structure 11 will be bent multiple times during the sampling process, to ensure that the end connection structures 12 installed at both ends of the shape memory deformation structure 11 after multiple bends correspond to the positions of both ends of the target catheter, and to prevent the shape memory deformation structure 11 from being shorter than the target catheter after subsequent trimming to a preset size, thus preventing inaccurate sampling of the target catheter, the length of the shape memory deformation structure 11 needs to be longer than that of the target catheter.

[0032] As a technical optimization of the present invention, the two end connection structures 12 and the shape memory deformation structure 11 are detachable mechanically connected.

[0033] As a technical optimization of the present invention, the mechanical connection includes a plurality of second threaded holes opened inside the two end connection structures 12. After the insertion parts at both ends of the shape memory deformation structure 11 are respectively inserted into the two end connection structures 12, the interior of the plurality of second threaded holes is threaded with second bolts 15, and the ends of the plurality of second bolts 15 that are close to each other are tightly abutted against the outer wall of the insertion part.

[0034] like Figure 4 and Figure 5As shown, the outer diameter of the two end connection structures 12 is the same as the outer diameter of the epoxy resin shape memory polymer. As mentioned above, there is a portion with a reduced outer diameter (i.e., a plug-in portion) at each end of the epoxy resin shape memory polymer. The outer diameter of this portion is the same as the inner diameter of the end connection structure 12. After the plug-in portion at one end of the epoxy resin shape memory polymer is inserted into the unflapped end of the end connection structure 12, it is installed in the corresponding second threaded hole by multiple second bolts 15. The plug-in portion is then abutted and fixed, realizing a detachable mechanical connection between the two end connection structures 12 and the shape memory deformation structure 11.

[0035] As a technical optimization of the present invention, the epoxy resin shape memory polymer has a glass state temperature below 30°C and a rubber state temperature below 100°C, and the ratio of its elastic modulus E30°C at 30°C to its elastic modulus E60°C at 60°C is E=E30°C / E60°C>1000. The higher the ratio of the elastic modulus of the epoxy resin shape memory polymer in the rigid glass state E1 to the soft rubber state E2, the better its memory effect on temporary shapes. Therefore, in this embodiment, an epoxy resin shape memory polymer with an elastic modulus ratio E greater than 1000 is selected. For ease of operation, an epoxy resin shape memory polymer with a glass state temperature near room temperature (25°C) and a rubber state temperature below 100°C is selected to prepare the conduit sampling tool body 1. As a typical example, an epoxy resin shape memory polymer material is selected to ensure that the rubber state temperature of the shape memory deformation structure 11 is about 60℃, and the ratio of its elastic modulus E30℃ at 30℃ to its elastic modulus E60℃ at 60℃ is E = E30℃ / E60℃ > 1000.

[0036] As a technical optimization of the present invention, a catheter sampling method based on shape memory material is applied to the catheter sampling fixture described above, and the catheter sampling method further includes the following steps: Step 1: Based on the positions of the two end fixing points and the N middle fixing plates, and combined with the initial design shape of the target conduit, specify the preliminary bending scheme of the sampling fixture, set the M bending positions, bending directions and bending angles, starting from one end of the conduit sampling fixture body 1, heat the bending part to the set temperature and then manually bend it, keep the bending shape unchanged and cool it to below the glass state temperature of the epoxy resin shape memory polymer, then release the external force, and complete the shape adjustment of all bending parts in sequence to obtain the preliminary bent conduit sampling fixture body 1; Step Two: Adjust the position of the initially bent catheter sampling fixture body 1 from Step One, aligning one end with the corresponding fixed part of the target catheter. Check whether there is any interference between the sampling fixture body 1 and other structures (these other structures include the fixing plate and other parts on the machine body) when they are assembled together. If there is no obvious interference, install one end of the initially bent catheter sampling fixture body 1 with the corresponding fixed part; if there is obvious interference, adjust the shape of part of the bend to eliminate the interference, and then install one end of the initially bent catheter sampling fixture body 1 with the corresponding fixed part of the target catheter. In this embodiment, the entire sampling fixture body 1 is divided into N+1 segments by two end fixing positions and N middle fixing plates. The first segment is the part of the sampling fixture body 1 from one end fixing position to the first fixing plate; the second segment is the part of the sampling fixture body 1 from the first fixing plate to the second fixing plate; the kth segment (1≤k≤N) is the part of the sampling fixture body 1 from the (k-1)th fixing plate to the kth fixing plate; and the N+1th segment is the part of the sampling fixture body 1 from the Nth fixing plate to the other end fixing position. Step 3: Adjust the shape of the first segment of the initially bent conduit sampling fixture body 1 at a temperature lower than that of the epoxy resin shape memory polymer, and fix it on the first fixing plate. At this time, the first segment of the initially bent conduit sampling fixture body 1 will have internal stress due to elastic deformation. Step 4: Simultaneously heat all the bent parts on the first section of the sampling fixture body 1 of the initially bent conduit. The internal stress will disappear due to the softening of the bent parts. Then, further adjust the bending direction and bending angle of all the bent parts so that its shape fits the initial design shape of the target conduit and does not interfere with other structures. Step 5: Keep the new bending shape of the first section of the initially bent conduit sampling fixture body 1 unchanged. After cooling to below 30°C, the first section of the initially bent conduit sampling fixture body 1 can remember the new bending shape and there is no elastic stress inside, thus completing the correction of the first section of the initially bent conduit sampling fixture body 1. Step Six: Repeat the operation methods of Steps Three to Five above, and adjust the shape of the second to Nth bending sections of the initially bent conduit sampling fixture body 1 in sequence; Step 7: Repeat the operation methods of Steps 3 to 5 above, adjust the shape of the N+1th bent section of the initially bent conduit sampling fixture body 1, disassemble the end connection structure 12, trim the shape memory deformation structure 11 to the preset size, and reinstall the end connection structure 12 so that the end of the corrected conduit sampling fixture body 1 is installed together with the other end fixed position without stress. Step 8: Disassemble the calibrated catheter sampling fixture body 1, and use catheter measuring fixture equipment to measure the shape information of the catheter sampling fixture body 1, thus completing the sampling of the target catheter shape. Step 9: Heat all the bent parts of the heating conduit sampling fixture body 1 so that the entire conduit sampling fixture body 1 returns to its initial straight shape for subsequent recycling.

[0037] As a technical optimization of the present invention, the heating method of the catheter sampling fixture body 1 is one or more of the following: hot air gun, electric heating pad or hot water, and the cooling method of the catheter sampling fixture body 1 is natural cooling, fan cooling or ice water cooling.

[0038] As a technical optimization of the present invention, the adjustment steps for the bending shape of the bent portion of the catheter sampling fixture body 1 include: S1: Fix the bent part to keep the memory of the bent shape unchanged while heating the bent part of the tubing sampling fixture body 1 to above 60°C. S2: Keep the temperature of the bending part above 60°C, and bend the fixed part to a new bending shape; S3: Keep the new bending shape unchanged. After cooling to room temperature, release the shape fixation of the catheter sampling fixture body 1. The catheter sampling fixture body 1 itself can maintain the new bending state.

[0039] In this invention, when using the device, the user first uses a hot air gun, heating pads, hot water, or other contact or non-contact heating methods to continuously heat the part of the tubing sampling fixture body 1 that needs to be bent. The tubing sampling fixture body 1 will gradually soften at the bending point. After determining that the temperature of the part to be bent is higher than 60°C using temperature sensors, thermal imagers, or other equipment, the user continues to heat the bending point while bending the tubing sampling fixture body 1 at a certain angle in a certain direction at that bending point. Then, the user keeps the bent shape of the tubing sampling fixture body 1 unchanged by hand or tool, stops heating, and cools the bent part of the tubing sampling fixture body 1 naturally or quickly using a fan or ice water. After determining that the temperature of the bent part of the tubing sampling fixture body 1 is close to room temperature (below 30°C) using temperature sensors, thermal imagers, or other equipment, the user releases the shape fixation of the tubing sampling fixture body 1, and the tubing sampling fixture body 1 itself can remember the bending state.

[0040] The steps for adjusting the memorized bending shape of the bending section of the catheter sampling fixture body 1 include: 1. Fix the bent part to maintain its memory of the bent shape while heating the bent part of the tubing sampling fixture body 1 to above 60°C. 2. Keep the temperature of the bent part above 60℃, and bend the fixed part to a new bending shape; 3. Keep the new bending shape unchanged. After cooling to room temperature (below 30°C), release the shape fixation of the catheter sampling fixture body 1. The catheter sampling fixture body 1 itself can maintain (memorize) the new bending state.

[0041] Taking a target catheter with its ends connected to two end fixing parts and its middle fixed to N fixing plates as an example, this paper introduces a method for sampling the shape of the target catheter using a shape memory polymer sampling tool. The target conduit is divided into N+1 segments by N+2 fixed points. The shape of the target conduit must perfectly fit the N+1 fixed points and avoid interference with surrounding structures to achieve stress-free installation. The conduit sampling fixture body 1 is bent and its bending shape is fixed segment by segment to meet the positional constraints of the N+2 fixed positions and the requirement of no interference with surrounding structures. Then, the shape of the conduit sampling fixture body 1 is measured using a conduit shape measuring device, thus completing the sampling of the target conduit shape. The conduit can then be manufactured using a bending machine based on the sampled shape. The specific operation steps are as follows: 1. Based on the positions of the two end fixing points and the N middle fixing plates, and combined with the initial design shape of the target conduit, specify the preliminary bending scheme for the conduit sampling fixture body 1, clarifying the positions, directions, and angles of a total of M bends. Starting from one end of the conduit sampling fixture body 1, heat the first bending point to 60°C, maintain the temperature while manually bending, and then cool it to below 30°C while keeping the bend shape unchanged. Remove the external force to complete the shape adjustment of one bending point. Using the same temperature and external force loading path, sequentially change the shape of the other M-1 bending points to obtain the initially bent conduit sampling fixture body 1. Since a manual bending method is used, the initial bending adjustment of the sampling fixture only needs to maintain the same direction as the bending scheme.

[0042] 2. Adjust the position of the initially bent conduit sampling fixture body 1, aligning one end with the corresponding end fixing part. Check whether assembling the two together will cause interference between the initially bent conduit sampling fixture body 1 and the fixing plate or other structures. If no obvious interference occurs, install one end of the initially bent conduit sampling fixture body 1 with the corresponding fixing part; if there is obvious interference, adjust the shape of part of the bend to eliminate the interference before installing one end of the initially bent conduit sampling fixture body 1 with the corresponding end fixing part.

[0043] 3. Adjust the shape of the first section of the initially bent tubing sampling fixture body 1 at room temperature and fix it on the first fixing plate. At this time, the first section of the initially bent tubing sampling fixture body 1 will have internal stress due to elastic deformation.

[0044] 4. Simultaneously heat all the bent parts on the first section of the sampling fixture body 1 of the initially bent conduit. The internal stress will disappear due to the softening of the bent parts. Then, further adjust the bending direction and bending angle of all the bent parts so that its shape fits the initial design shape of the target conduit and does not interfere with other structures.

[0045] 5. Keeping the newly bent shape of the first segment of the initially bent conduit sampling fixture body 1 unchanged, after cooling to below 30°C, the first segment of the initially bent conduit sampling fixture body 1 can remember the new bending shape and there is no elastic stress inside, thus completing the correction of the first segment of the initially bent conduit sampling fixture body 1.

[0046] 6. Using the operation methods from steps 3 to 5, adjust the shape of the second to Nth bent sections of the initially bent conduit sampling fixture body 1 in sequence.

[0047] 7. Using the operation methods of steps 3 to 5, adjust the shape of the N+1th bent section of the initially bent conduit sampling fixture body 1, disassemble the end connection structure 12, trim the shape memory deformation structure 11 to a suitable structure, and then reinstall the end connection structure 12 so that the end of the corrected conduit sampling fixture body 1 is installed together with the other end fixed position without stress.

[0048] 8. Disassemble the calibrated catheter sampling fixture body 1 and use catheter measuring fixture equipment to measure the shape information of the catheter sampling fixture body 1, thus completing the sampling of the target catheter shape.

[0049] 9. Heat all bent parts to restore the entire tubing sampling fixture body 1 to its initial straight shape for the next use.

[0050] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A catheter sampling fixture based on shape memory material, comprising a catheter sampling fixture body (1), characterized in that, The catheter sampling fixture body (1) consists of a shape memory deformation structure (11) and two end connection structures (12). The two end connection structures (12) are respectively installed at both ends of the shape memory deformation structure (11). The two end connection structures (12) are matched with the same end expansion features of the target catheter, and the two end connection structures (12) are matched and installed with the end connection components of the target catheter.

2. The conduit sampling fixture based on shape memory material according to claim 1, characterized in that, The shape memory deformation structure (11) is formed by connecting multiple long strip columnar or tubular epoxy resin shape memory polymers by adhesive or mechanical connection. The interior of the shape memory deformation structure (11) is solid or hollow. The shape memory deformation structure (11) can be bent into a temporary shape after being heated to a rubber state, and can maintain the temporary shape after being cooled to a glass state, so as to complete the memory sampling of the target catheter shape.

3. The conduit sampling fixture based on shape memory material according to claim 2, characterized in that, The mechanical connection method includes at least two epoxy resin shape memory polymer segments, a connecting sleeve (13), and multiple first bolts (14). Both ends of the two epoxy resin shape memory polymer segments are provided with insertion parts. The outer diameter of the two insertion parts is smaller than the outer diameter of the epoxy resin shape memory polymer segments. The insertion parts of the two epoxy resin shape memory polymer segments with their close ends are respectively inserted into the interior of the connecting sleeve (13). Multiple first threaded holes are opened inside the connecting sleeve (13). Multiple first bolts (14) are threaded into the corresponding first threaded holes, and the close ends of the multiple first bolts (14) respectively abut against the outer wall of the corresponding insertion part.

4. The conduit sampling fixture based on shape memory material according to claim 1, characterized in that, The outer diameter of the shape memory deformation structure (11) is the same as the outer diameter of the target catheter, and its length is longer than that of the target catheter.

5. A catheter sampling fixture based on shape memory material according to claim 3, characterized in that, The two end connection structures (12) are detachably mechanically connected to the shape memory deformation structure (11).

6. A conduit sampling fixture based on shape memory material according to claim 5, characterized in that, The mechanical connection includes multiple second threaded holes opened inside the two end connection structures (12). After the insertion parts at both ends of the shape memory deformation structure (11) are respectively inserted into the two end connection structures (12), the multiple second threaded holes are threaded with second bolts (15), and the ends of the multiple second bolts (15) that are close to each other abut against the outer wall of the insertion part.

7. A conduit sampling fixture based on shape memory material according to claim 2, characterized in that, The epoxy resin shape memory polymer has a glass state temperature below 30°C and a rubber state temperature below 100°C, and the ratio of its elastic modulus E30°C at 30°C to its elastic modulus E60°C at 60°C is E=E30°C / E60°C>1000.

8. A catheter sampling method based on shape memory material, applied to the catheter sampling fixture according to any one of claims 1-7, and the catheter sampling method further includes the following steps: Step 1: Based on the positions of the two end fixing parts and the N middle fixing plates, and combined with the initial design shape of the target conduit, formulate a preliminary bending scheme for the sampling fixture, set M bending positions, bending directions and bending angles, start from one end of the conduit sampling fixture body (1), heat the bending part to the set temperature and bend it, keep the bending shape unchanged and cool it to below the glass state temperature of the epoxy resin shape memory polymer, then release the external force, and complete the shape adjustment of all bending parts in sequence to obtain the preliminary bent conduit sampling fixture body (1). Step 2: Adjust the position of the initially bent catheter sampling fixture body (1) in Step 1, align one end of it with the corresponding end fixing part of the target catheter, check whether the sampling fixture body (1) interferes with other structures when they are assembled together. If there is no interference, install one end of the initially bent catheter sampling fixture body (1) with the corresponding fixing part; if there is interference, adjust the shape of some bending positions to eliminate interference, and then install one end of the initially bent catheter sampling fixture body (1) with the corresponding end fixing part of the target catheter. Step 3: Adjust the shape of the first section of the initially bent conduit sampling fixture body (1) at a temperature lower than that of the epoxy resin shape memory polymer, and fix it on the first fixing plate. At this time, the first section of the initially bent conduit sampling fixture body (1) has internal stress due to elastic deformation. Step 4: Simultaneously heat all the bent parts on the first section of the initially bent conduit sampling fixture body (1). The internal stress disappears due to the softening of the bent parts. Then adjust the bending direction and bending angle of all the bent parts so that its shape fits the initial design shape of the target conduit and does not interfere with other structures. Step 5: Keep the newly bent shape of the first section of the initially bent tubing sampling fixture body (1) unchanged, and cool it to below 30°C to complete the shaping of the first section of the initially bent tubing sampling fixture body (1). Step 6: Repeat the operation methods of Steps 3 to 5 above, and adjust the shape of the 2nd to Nth bending parts of the initially bent tubing sampling fixture body (1) in sequence; Step 7: Repeat the operation methods of Step 3 to Step 5 above, adjust the shape of the N+1th bent part of the initially bent conduit sampling fixture body (1), disassemble the end connection structure (12), trim the shape memory deformation structure (11) to the preset size, and reinstall the end connection structure (12) so that the end of the corrected conduit sampling fixture body (1) is installed together with the other end fixed position without stress. Step 8: Disassemble the calibrated catheter sampling fixture body (1), and use catheter measuring fixture equipment to measure the shape information of the catheter sampling fixture body (1), thus completing the sampling of the target catheter shape. Step 9: Heat all the bent parts of the tubing sampling fixture body (1) so that the entire tubing sampling fixture body (1) returns to its initial straight shape for subsequent recycling.

9. A method for sampling conduits based on shape memory materials according to claim 8, characterized in that, The heating method of the catheter sampling fixture body (1) is one or more of the following: hot air gun, electric heating pad or hot water. The cooling method of the catheter sampling fixture body (1) is natural cooling, fan cooling or ice water cooling.

10. A method for sampling conduits based on shape memory materials according to claim 8, characterized in that, The adjustment steps for the bending shape memory of the bending part of the catheter sampling fixture body (1) include: S1: Fix the bent part to keep the memory of the bent shape unchanged while heating the bent part of the tube sampling fixture body (1) to above 60°C; S2: Keep the temperature of the bending part above 60°C, and bend the fixed part to a new bending shape; S3: Keep the new bending shape unchanged. After cooling to room temperature, release the shape fixation of the catheter sampling fixture body (1). The catheter sampling fixture body (1) itself can maintain the new bending state.

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