High-precision stainless steel capillary tube for cardiovascular intervention and processing method thereof

Abstract

The embodiment of the invention provides a high-precision stainless steel capillary tube for cardiovascular intervention and a machining method of the high-precision stainless steel capillary tube. The high-precision stainless steel capillary tube for cardiovascular intervention comprises a first tube body and a second tube body which are communicated in sequence, the first pipe body is provided with a first channel, the second pipe body is provided with a second channel, the first channel is communicated with the second channel, and the inner diameter of the first channel is smaller than that of the second channel; wherein one end, facing the second pipe body, of the first pipe body is provided with a first embedding part, one end, facing the first pipe body, of the second pipe body is provided with a second embedding part corresponding to the first embedding part, and the first pipe body and the second pipe body are coaxially and fixedly connected through embedding of the first embedding part and the second embedding part. According to the embodiment of the invention, the accurate coaxial butt joint of the first pipe body and the second pipe body is realized, the problem that the butt joint is easy to deviate in the existing pipe section fixing process is solved, the coaxial precision and the yield of finished products are favorably improved, and the requirements of clinical use and large-scale production are met.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a high-precision stainless steel capillary tube for cardiovascular intervention and a method for processing the high-precision stainless steel capillary tube for cardiovascular intervention. Background Technology

[0002] In minimally invasive cardiovascular and cerebrovascular surgeries, stainless steel capillary tubes are crucial interventional components. These delicate tubes typically require a specific asymmetrical structure with one end narrower than the other to accommodate surgical procedures. Currently, the industry primarily processes these capillary tubes by grinding different sized segments separately and then assembling them using threaded joints, adhesive bonding, or direct butt welding, or by integral stretching or electrolytic machining. However, existing processes have significant drawbacks. When processing segments, misalignment of the segments during assembly can easily occur, resulting in substandard coaxiality accuracy of the finished product. Integral molding processes struggle to accommodate the specific structural requirements of a narrower diameter at one end and an enlarged bore at the other, leading to insufficient processing precision and surface quality for clinical use, thus affecting the safety and effectiveness of minimally invasive cardiovascular and cerebrovascular surgeries. Stainless steel capillary tubes produced in this way not only fail to meet precision parameters but also suffer from structural defects, failing to meet the high-precision clinical demands for these instruments. Furthermore, the current processes result in a low yield rate, hindering production volume and making it difficult to meet the demands of large-scale production.

[0003] Application content Therefore, in order to overcome at least some of the defects and deficiencies in the prior art, this application provides a high-precision stainless steel capillary for cardiovascular intervention and a method for processing the high-precision stainless steel capillary for cardiovascular intervention, which can meet the high standards of structural precision, mechanical properties and biocompatibility of stainless steel capillary for minimally invasive cardiovascular and cerebrovascular surgery, improve the yield of capillary products and meet the needs of large-scale production.

[0004] Specifically, in one aspect, this application provides a high-precision stainless steel capillary tube for cardiovascular intervention, comprising: a first tube body and a second tube body connected in sequence; the first tube body has a first channel, the second tube body has a second channel, the first channel and the second channel are connected, and the inner diameter of the first channel is smaller than the inner diameter of the second channel; wherein, the first tube body has a first fitting portion at one end facing the second tube body, and the second tube body has a second fitting portion corresponding to the first fitting portion at one end facing the first tube body, and the first tube body and the second tube body are coaxially fixedly connected through the fitting of the first fitting portion and the second fitting portion.

[0005] In one embodiment of this application, the first fitting portion is provided with a first connecting portion, and the second fitting portion is provided with a second connecting portion corresponding to the first connecting portion, and the first connecting portion and the second connecting portion are fixedly connected.

[0006] In one embodiment of this application, the first tube body sequentially includes a first diameter-changing section and an enlarged section along a first direction. The inner diameter of the first diameter-changing section is smaller than the inner diameter of the enlarged section. The first fitting portion is at least a portion of the enlarged section. The first direction is the direction from the first tube body to the second tube body. The second tube body sequentially includes a second diameter-changing section and a first straight section along the first direction. The outer diameter of the second diameter-changing section is smaller than the outer diameter of the first straight section. The inner diameter of the second diameter-changing section is equal to the inner diameter of the first straight section. The second fitting portion includes the second diameter-changing section and the end of the first straight section near the second diameter-changing section. The second diameter-changing section extends into the first fitting portion and is clearance-fitted with the first fitting portion. The end of the first straight section near the second diameter-changing section abuts against the end of the first fitting portion near the second diameter-changing section.

[0007] In one embodiment of this application, the first connecting part is the end of the enlarged section facing the second tube body, and the second connecting part is the end of the first straight section near the second variable diameter section. The first connecting part and the second connecting part are welded and fixed.

[0008] In one embodiment of this application, the first tube body sequentially includes a third variable diameter section, a second straight section, and a fourth variable diameter section along a first direction; the first fitting portion includes the fourth variable diameter section and the end of the second straight section near the fourth variable diameter section; the second fitting portion is at least a portion of the second tube body; and the first direction is the direction from the first tube body to the second tube body. The fourth variable diameter section extends into the second tube body and is in clearance fit with the second fitting part, and the end of the second straight section near the fourth variable diameter section abuts against the end of the second tube body near the first tube body.

[0009] In one embodiment of this application, the first connecting part is the end of the second straight section near the fourth variable diameter section, the second connecting part is the end of the second pipe body near the first pipe body, and the first connecting part and the second connecting part are welded and fixed.

[0010] In one embodiment of this application, the gap between the first fitting portion and the second fitting portion in the radial direction is in the range of 0.005-0.01mm; with the central axis of the first tube body as a reference, the coaxiality tolerance of the central axis of the second tube body relative to the reference axis of the first tube body is ≤0.01mm.

[0011] On the other hand, embodiments of this application also provide a method for processing a high-precision stainless steel capillary for cardiovascular intervention, comprising: providing a first tube body to be processed and a second tube body to be processed, wherein the inner diameter of the first tube body to be processed is smaller than the inner diameter of the second tube body to be processed; forming a first fitting portion at one end of the first tube body; forming a second fitting portion at one end of the second tube body; fitting the first fitting portion and the second fitting portion together and fixing them together to form a high-precision stainless steel capillary for cardiovascular intervention with the first tube body and the second tube body being coaxial.

[0012] In one embodiment of this application, forming a first fitting portion at one end of the first tube and a second fitting portion at one end of the second tube specifically includes: calibrating and positioning the first tube to be processed; performing outer diameter reduction processing on one end of the first tube to be processed and enlarging processing on the other end of the first tube to be processed to form a first tube having a first diameter reduction section and an enlarged section, wherein the first fitting portion is at least a portion of the enlarged section; calibrating and positioning the second tube to be processed; performing outer diameter reduction processing on one end of the second tube to be processed to form a second tube having a second diameter reduction section and a first straight section, wherein the second fitting portion includes the ends of the second diameter reduction section and the first straight section near the second diameter reduction section.

[0013] In one embodiment of this application, forming a first fitting portion at one end of the first tube and a second fitting portion at one end of the second tube specifically includes: calibrating and positioning the first tube to be processed; performing outer diameter reduction processing on both ends of the first tube to be processed to form a first tube having a third diameter reduction section, a second straight section and a fourth diameter reduction section, wherein the first fitting portion includes the end of the fourth diameter reduction section and the second straight section near the end of the fourth diameter reduction section; calibrating and positioning the second tube to be processed, wherein the second fitting portion is at least a portion of the second tube.

[0014] As can be seen from the above, the high-precision stainless steel capillary tube for cardiovascular intervention provided in this application includes a first tube body with a first channel and a first fitting portion, and a second tube body with a second channel and a second fitting portion. The inner diameter of the first channel is smaller than the inner diameter of the second channel, which is suitable for surgical requirements where the capillary tube has a different diameter at one end and a larger end. This application achieves precise positioning and docking of the first and second tube bodies through the corresponding fitting of the first and second fitting portions, effectively avoiding the positional offset problem during tube segment docking in existing processes. This achieves high coaxiality accuracy when the two are connected, ensuring that the precision parameters of the finished capillary tube stably meet clinical use standards, improving the yield rate of the finished product, and satisfying the clinical needs for high-precision use and large-scale production of such devices. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of a high-precision stainless steel capillary tube for cardiovascular intervention provided in an embodiment of this application.

[0017] Figure 2 This is a cross-sectional schematic diagram of a high-precision stainless steel capillary tube for cardiovascular intervention provided in an embodiment of this application.

[0018] Figure 3 for Figure 2 Cross-sectional view of the first tube in the middle.

[0019] Figure 4 for Figure 2 Cross-sectional view of the second tube body.

[0020] Figure 5 for Figure 2 This is a cross-sectional schematic diagram of another high-precision stainless steel capillary tube for cardiovascular intervention provided in an embodiment of this application.

[0021] Figure 6 for Figure 5 Cross-sectional view of the first tube body.

[0022] Figure 7 for Figure 5 Cross-sectional view of the second tube body.

[0023] Figure 8 This is a schematic flowchart illustrating a method for processing high-precision stainless steel capillaries for cardiovascular interventional procedures, provided as an embodiment of this application.

[0024] Figure 9 for Figure 8 A flowchart illustrating steps S20 and S30.

[0025] Figure 10 for Figure 8 Another flowchart of steps S20 and S30.

[0026] Figure 11 A two-dimensional inspection diagram of the tube body processed using existing technology.

[0027] Figure 12 This is a two-dimensional inspection diagram of a tube processed using another existing process.

[0028] Figure 13This is a two-dimensional inspection diagram of another pipe body processed using existing technology.

[0029] Figure 14 This is a two-dimensional inspection diagram of a pipe body processed using existing technology.

[0030] Figure 15 A two-dimensional image of a high-precision stainless steel capillary tube for cardiovascular intervention provided in this application.

[0031] Main component numbers: 1: High-precision stainless steel capillary tube for cardiovascular intervention; 10: First tube body; 101: First fitting part; 102: First connecting part; 103: First diameter changing section; 104: Expanding section; 105: Third diameter changing section; 106: Second straight section; 107: Fourth diameter changing section; 108: First transition section; 109: Second transition section; 110: First channel; 20: Second tube body; 201: Second fitting part; 202: Second connecting part; 203: Second diameter changing section; 204: First straight section; 210: Second channel; 30: Connecting area. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments described in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] It should also be noted that the division of multiple embodiments in this application is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0035] See Figure 1This application provides a high-precision stainless steel capillary tube 1 for cardiovascular intervention. For example, this stainless steel capillary tube 1 can be applied in the field of minimally invasive cardiovascular and cerebrovascular surgery to deliver contrast agents and other substances during the operation, assisting in the operation of the lesion area. Of course, it can also be applied in other interventional medical scenarios that require delicate tubular components. The high-precision stainless steel capillary tube 1 for cardiovascular intervention includes a first tube body 10 and a second tube body 20 connected sequentially from the distal end to the proximal end; wherein, in this application, "distal end" refers to the end of the tube body closer to the surgical lesion when in use, and "proximal end" refers to the end of the tube body closer to the surgeon when in use.

[0036] Both the first tube 10 and the second tube 20 are made of medical-grade stainless steel, possessing good biocompatibility and mechanical strength. The first tube 10 has a first channel 110 arranged along its length, and the second tube 20 has a second channel 210 extending along its length. The first channel 110 and the second channel 210 are connected, and the inner diameter of the first channel 110 is smaller than the inner diameter of the second channel 210 to accommodate the different diameter structures required for surgery.

[0037] The first tube 10 has a first fitting part 101 at one end facing the second tube 20, and the second tube 20 has a second fitting part 201 corresponding to the first fitting part 101 at one end facing the first tube 10. The two can be fitted together in various matching forms, such as the insertion of the end inner expansion structure and the outer contraction structure, the fitting of the end outer contraction boss and the inner expansion slot, etc. The specific form is not limited, as long as it meets the requirement of accurate positioning when the tube segments are connected.

[0038] The first tube 10 and the second tube 20 are fixedly connected by the engagement of the first fitting part 101 and the second fitting part 201, forming an integral structure. In this embodiment, laser welding, plasma welding, or other methods can be used to ensure the sealing and structural stability of the joint. In other embodiments, a special adhesive conforming to medical standards can be used for fixing, or screw fixing can be used to ensure a stable sealing effect at the joint of the tubes. The specific fixing method can be flexibly selected according to the needs and the specific size and specifications of the tubes, as long as it meets the clinical use standards, and is not limited here.

[0039] In this embodiment, the specific application process of the high-precision stainless steel capillary tube 1 for cardiovascular intervention is as follows: During the operation, the distal end of the first tube 10 is inserted into the lesion location, and the proximal end of the second tube 20 is connected to external surgical instruments. With the help of the precise coaxiality of the first fitting part 101 and the second fitting part 201 after fitting, the catheter can be accurately operated in conjunction with the imaging during surgical operations such as drug therapy and targeted therapy.

[0040] Therefore, the high-precision stainless steel capillary tube 1 for cardiovascular intervention provided in this embodiment has different diameter settings for the first channel 110 and the second channel 210 to adapt to surgical requirements. Furthermore, through the corresponding cooperation of the first fitting part 101 and the second fitting part 201, this application achieves precise coaxial docking of the first tube body 10 and the second tube body 20, which solves the problem of easy misalignment during the existing tube segment fixing process. This helps to improve the coaxial accuracy and yield of the finished product and meet the requirements of clinical use and large-scale production.

[0041] Specifically, the first fitting portion 101 is provided with a first connecting portion 102, and the second fitting portion 201 is provided with a second connecting portion 202 corresponding to the first connecting portion 102. In this embodiment, the first connecting portion 102 and the second connecting portion 202 are fixedly connected, for example, by welding. During welding, welding is performed along the circumference of the end face at the joint of the two connecting portions. Based on this welding position, the connection area 30 after the two pipes are joined can be clearly defined as the circumferential area of ​​the joint end face at the joint of the first connecting portion 102 and the second connecting portion 202.

[0042] In this embodiment, the first fitting part 101 and the second fitting part 201 first achieve preliminary precise alignment through fitting, which can be used with a positioning fixture or positioning system to form a stable positioning support structure. Then, the first connecting part 102 and the second connecting part 202 are fixedly connected. In this way, the fitting structure can provide continuous and stable coaxial constraint for the tube body. During the welding process, this constraint can reduce the impact of high temperature on the tube body connection, prevent the tube body from shifting or deforming, and improve the positioning stability during the welding process. This greatly ensures the coaxiality accuracy of the first tube body 10 and the second tube body 20 after docking, and further improves the structural stability and processing qualification rate of the finished product.

[0043] Furthermore, the gap between the first fitting portion 101 and the second fitting portion 201 in the radial direction of the tube body ranges from 0.005 to 0.01 mm. This gap range ensures that the first fitting portion 101 and the second fitting portion 201 always maintain a tight fit, providing a stable coaxial constraint basis for subsequent welding. At the same time, the gap range of 0.005-0.01 mm improves assembly convenience and positioning accuracy, eliminating the need for additional positioning fixtures for assembly and controlling the coaxiality deviation after tube body docking to a lower range. This is beneficial for improving the accuracy of subsequent welding processes and the sealing performance of the product, as well as enhancing the structural stability and clinical reliability of the finished capillary tube. This embodiment utilizes precision grinding technology combined with a positioning system to control the dimensional tolerances of the aforementioned components, ensuring the gap falls precisely within the range of 0.005-0.01mm. Furthermore, it guarantees that the overall coaxiality of the inner and outer holes of the first tube 10 and the second tube 20, after being fixedly connected, meets preset requirements. Specifically, with the central axis of the first tube 10 as a reference, the coaxiality tolerance of the central axis of the second tube 20 relative to the reference axis of the first tube 10 is ≤0.01mm. The radial constraint formed by the aforementioned micro-gap fit ensures the alignment of the two tube axes, and combined with precision machining, the aforementioned coaxiality tolerance can be achieved. This high-precision control ensures smooth tube advancement during clinical intervention, improves delivery stability, increases product yield, and is suitable for large-scale production.

[0044] In one embodiment of this application, see Figure 2 and Figure 3 The first tube body 10 includes a first diameter-changing section 103 and a reamed section 104 sequentially along a first direction, wherein the first direction is the direction from the first tube body 10 toward the second tube body 20. The first fitting portion 101 is at least a portion of the reamed section 104; specifically, the first fitting portion 101 is, for example, the portion of the reamed section 104 near the second tube body 20. Figure 2 The first channel 110 is formed inside the first diameter-changing section 103. The inner diameter of the first diameter-changing section 103 is smaller than that of the inner diameter of the expanding section 104. The first diameter-changing section 103 is adapted to the distal area near the lesion during surgery. The smaller inner diameter can meet the needs of fine delivery. The larger inner diameter of the expanding section 104 can provide a space for the second fitting part 201 to be accommodated and positioned, and provide a structural basis for subsequent fitting and positioning.

[0045] Furthermore, a first transition section 108 is provided between the first diameter-changing section 103 and the expansion section 104. This first transition section 108 is, for example, a 45-60 degree inclined transition structure. Relying on the equipment's positioning reference, the grinding process is precisely controlled by inputting preset dimensional parameters through equipment programming. The diameter-changing grinding of the first diameter-changing section 103 is completed in one operation, eliminating the need for further correction or segmented processing afterward. The first transition section 108 ensures that the inner hole, outer wall, and wall thickness at the junction of the first diameter-changing section 103 and the expansion section 104 remain concentric and coaxial. This concentric and coaxial structure, along with the inclined transition, reduces stress concentration at the junction of the first diameter-changing section 103 and the expansion section 104, enhances the bending strength of the pipe, and optimizes the flow path of the medium within the pipe, reducing flow resistance.

[0046] See Figure 2 and Figure 4 The second tube body 20 includes a second variable diameter section 203 and a first straight section 204 in sequence along the first direction. The second fitting part 201 includes the end of the second variable diameter section 203 and the first straight section 204 near the end of the second variable diameter section 203, and the outer diameter of the second variable diameter section 203 is smaller than the outer diameter of the first straight section 204.

[0047] This embodiment uses specific dimensions as an example: a first tube blank with an initial specification of 25mm length, 1.2mm outer diameter, and 0.5mm inner diameter is selected, and a second tube blank with an initial specification of 750mm length, 1.2mm outer diameter, and 0.7mm inner diameter is selected. After processing, the length of the first diameter-changing section 103 of the first tube body 10 is 15mm, the outer diameter D2 is 0.7mm, and the inner diameter D1 is 0.5mm. The length of the enlarged section 104 of the first tube body 10 is 10mm, the outer diameter D4 is 1.2mm, and the inner diameter D3 is 0.9mm. The length of the second diameter-changing section 203 of the second tube body 20 is 10mm, the outer diameter D6 is 0.88-0.89mm, and the inner diameter D5 is 0.7mm. The first straight section 204 of the second tube body 20 maintains its initial outer diameter, that is, the outer diameter D7 of the first straight section 204 is equal to the outer diameter D4 of the enlarged section 104, both being 1.2mm. The inner diameter of the first straight section 204 is the same as the inner diameter of the second diameter-changing section 203. During assembly, the nesting depth of the first tube 10 and the second tube 20 is 10mm, and the radial expansion section 104 and the second diameter-changing section 203 form a micro gap of 0.005-0.01mm; the final product has a total length of 765mm, and the overall coaxiality is strictly controlled within the preset requirement range (i.e., the coaxiality must meet ≤0.01mm).

[0048] Specifically, the second variable diameter section 203 is manufactured by grinding the end region of the second tube body 20. During the machining process, only the outer diameter of this section is reduced, making its outer diameter slightly smaller than the inner diameter of the enlarged section 104. The inner diameter of the second variable diameter section 203 is consistent with the inner diameter of the first straight section 204, ensuring the smoothness of the internal channel of the tube body and avoiding obstruction of the delivery of contrast agent. In the axial direction, the length of the second variable diameter section 203 is less than or equal to the length of the enlarged section 104. This length adaptation design ensures that the second variable diameter section 203 is within the effective accommodating range of the enlarged section 104 and that there is sufficient contact length between the first fitting part 101 and the second fitting part 201, which can ensure the fit stability of the fitting part and maintain the coaxial constraint effect after docking.

[0049] See also Figure 2 The connecting region 30 is, for example, the outer peripheral region where the end of the first fitting portion 101 near the second diameter-changing section 203 abuts against the end of the first straight section 204 near the second diameter-changing section 203. The first connecting portion 102 is, for example, the end of the first fitting portion 101 (i.e., at least part of the enlarged section 104) facing the second tube body 20, and the second connecting portion 202 is the end of the first straight section 204 near the second diameter-changing section 203. The outer peripheral diameters of the first connecting portion 102 and the second connecting portion 202 are consistent, providing a structural basis for the smoothness of the outer wall of the connection after subsequent welding.

[0050] During assembly, first align the second variable diameter section 203 with the port of the enlarged hole section 104 and slowly insert it into the enlarged hole section 104. The slight gap between the second variable diameter section 203 and the enlarged hole section 104 allows for smooth insertion. Continue pushing the second tube body 20 until the end of the first straight section 204 near the second variable diameter section 203 abuts against the end of the first fitting part 101 near the second variable diameter section 203. At this point, precise positioning is achieved, and the outer periphery of the abutment point is the connection area 30. After positioning, weld the first connecting part 102 and the second connecting part 202 located within the connection area 30. Welding should be performed along the circumference of the connection area 30. In this embodiment, the welding process can be, for example, laser welding. Laser energy is concentrated and the heat-affected zone is small. During welding, welding must be performed uniformly along the circumference of the connection area 30, for example, accumulating 3 rounds with a 50% overlap per round. Argon gas protection is maintained simultaneously to ensure a uniform and smooth weld, avoid adverse effects of high welding temperatures on the tube body, and ensure docking accuracy and sealing performance. In other embodiments, plasma welding can be used instead, with parameters set at a welding current of 15A and a welding speed of 6mm / s. An argon-hydrogen mixture with a volume ratio of 95:5 is used as the protective gas. After processing using this welding method, the sealing performance and structural strength of the tube body joint can stably meet the stringent requirements of medical interventional devices. The specific choice of welding process is not limited here.

[0051] In this embodiment, a micro-gap fit is achieved by extending the second variable diameter section 203 into the first fitting part 101. Precise positioning is achieved by the abutment of the end of the first straight section 204 with the end of the first fitting part 101. This ensures the coaxial alignment accuracy of the first connecting part 102 and the second connecting part 202 without the need for additional fixtures. Furthermore, by welding along the outer circumference of the connecting area 30, the contrast agent delivery channel inside the tube body will not be obstructed or damaged. The continuous coaxial constraint formed by the cooperation of the first fitting part 101 and the second fitting part 201 reduces the offset deformation of the first tube body 10 and the second tube body 20 caused by the high temperature of welding. This effectively ensures the coaxiality accuracy, weld sealing, and outer wall flatness of the tube body after docking, further improving the processing qualification rate of the finished product.

[0052] In another embodiment of this application, see Figure 5 , Figure 6 and Figure 7The first tube 10 includes, along a first direction, a third diameter-changing section 105, a second straight section 106, and a fourth diameter-changing section 107. The first fitting portion 101 includes the ends of the fourth diameter-changing section 107 and the second straight section 106 near the fourth diameter-changing section 107. The second fitting portion 201 is at least a portion of the second tube 20, specifically the portion of the second tube 20 near the first tube 10. The first direction is the direction from the first tube 10 to the second tube 20. The third diameter-changing section 105 is adapted to the distal region near the lesion during surgery. The third diameter-changing section 105 is manufactured by grinding the end region of the first tube 10 away from the second tube 20, reducing only the outer diameter of this section during processing. The smaller inner and outer diameters of the third diameter-changing section 105 meet the requirements for precise delivery. The second straight section 106 provides stable structural support for the tube body, and the fourth diameter-changing section 107 is used to fit and position with the second fitting portion 201, providing a structural basis for subsequent fixed connection. In addition, a second transition section 109 is provided between the third variable diameter section 105 and the second straight section 106. The second transition section 109 is similar in structure, function and processing method to the first transition section 108 mentioned above, and will not be described in detail here.

[0053] Specifically, the fourth diameter-changing section 107 is manufactured by grinding the end region of the first tube 10 near the second tube 20. During the machining process, only the outer diameter of this section is reduced, making it slightly smaller than the inner diameter of the second tube 20. The inner diameter of the fourth diameter-changing section 107 is consistent with the inner diameter of the second straight section 106 and the third diameter-changing section 105, ensuring the smoothness of the first channel 110 inside the first tube 10 and avoiding obstruction to the delivery of the contrast agent. In the axial direction, the length of the fourth diameter-changing section 107 is less than or equal to the length of the second tube 20, ensuring that the fourth diameter-changing section 107 is within the effective accommodating range of the second tube 20, ensuring sufficient contact length between the first fitting part 101 and the second fitting part 201, ensuring the stability of the fitting part, and maintaining the coaxial constraint effect after docking.

[0054] During assembly, the fourth variable-diameter section 107 of the first fitting part 101 is aligned with the port of the second tube body 20 and slowly inserted into the interior of the second tube body 20. In this embodiment, through precise dimensional matching, the fourth variable-diameter section 107 and the second fitting part 201 form a micro-gap fit. At the same time, the end of the second straight section 106 near the fourth variable-diameter section 107 abuts against the end of the second tube body 20 near the first tube body 10. In this way, it can ensure that the fourth variable-diameter section 107 can smoothly extend into the interior of the second tube body 20, and achieve precise positioning through end abutment. The micro-gap fit structure keeps the tube walls of the two fitting parts in a tight fit, providing a stable coaxial constraint for tube body docking, effectively reducing possible offset errors during assembly, ensuring the docking accuracy of tubes of different specifications, and providing a reliable foundation for subsequent fixed connection.

[0055] See also Figure 5 The connecting region 30 is, for example, the outer peripheral region where the end of the second straight section 106 near the fourth diameter-changing section 107 abuts against the end of the second pipe body 20 near the first pipe body 10. The first connecting portion 102 is, for example, the end of the second straight section 106 near the fourth diameter-changing section 107, and the second connecting portion 202 is, for example, the end of the second pipe body 20 near the first pipe body 10. The outer diameter of the first connecting portion 102 (i.e., the end of the aforementioned second straight section 106) is consistent with the outer diameter of the second connecting portion 202 (i.e., the end of the aforementioned second pipe body 20), providing a structural basis for the smoothness of the outer wall of the connection after subsequent welding.

[0056] During assembly, first align the fourth reducing section 107 with the port of the second tube 20 and slowly insert it into the second tube 20. The slight gap between the fourth reducing section 107 and the second tube 20 allows for smooth insertion. Continue pushing the first tube 10 forward until the end of the second straight section 106 near the fourth reducing section 107 abuts against the end of the second tube 20 near the first tube 10. At this point, precise positioning is achieved, and the outer periphery of the abutment point is the connection area 30. After positioning, the first connecting part 102 and the second connecting part 202 located within the connection area 30 are welded and fixed. Welding is performed along the circumference of the connection area 30. The welding process, welding parameters, and protective measures used in this embodiment are consistent with the first embodiment described above, ensuring a uniform and smooth weld without welding defects; further details are omitted here.

[0057] In this embodiment, a micro-gap fit is achieved by extending the fourth variable diameter section 107 into the second fitting part 201. This, combined with the abutment between the end of the second straight section 106 and the end of the second tube body 20, ensures precise positioning and guarantees the coaxial alignment accuracy of the first connecting part 102 and the second connecting part 202. No additional fixtures are required. Furthermore, by welding along the outer circumference of the connecting area 30, the contrast agent delivery channel inside the tube body will not be obstructed or damaged. The continuous coaxial constraint formed by the cooperation of the first fitting part 101 and the second fitting part 201 reduces the offset deformation of the first tube body 10 and the second tube body 20 caused by the high temperature of welding. This effectively ensures the coaxiality accuracy and weld sealing of the tube bodies after docking, further improving the processing qualification rate of the finished product.

[0058] It should be noted that this application achieves precise coaxial positioning of the tube body through a micro-gap interlocking structure, and relies on this interlocking constraint to ensure the stability of the subsequent fixed connection. Based on this, the technical solution of this application can be implemented in various alternative ways according to actual processing conditions, equipment configuration, or specific clinical application scenarios without affecting the technical effect. For the processing of the aforementioned variable diameter section on the first tube body 10, in addition to grinding, electrolytic machining can also be used. Specifically, the processing voltage can be set to 12V and the current to 5A. This process can also accurately control the outer diameter of the variable diameter section to a range of 0.5-0.7mm, and ensure coaxiality ≤0.01mm, adapting to the equipment configuration requirements under different processing scenarios.

[0059] Meanwhile, key dimensional parameters can be flexibly set according to requirements to cover different application needs. For example, the structural design of this application has good dimensional scalability and can be flexibly adapted to the fine requirements of different interventional surgeries. For example, for different scenarios such as neurointervention and cardiovascular intervention, the length of the first tube 10 can be set to 20-25mm, the length of the variable diameter section is 8-15mm, the length of the reaming section is 8-10mm, and the inner hole reaming size can be adapted and adjusted to 0.6-0.9mm to ensure sufficient accommodation and positioning space for the second fitting part 201; the length of the second tube 20 can be set to 750-800mm, the variable diameter section... The length is 8-10mm, and the outer diameter is adapted to the inner diameter of the first tube 10, which is set to 0.59-0.885mm. The inner diameter is consistent with the straight section of the tube and not smaller than the inner diameter of the first tube, ensuring smooth internal passage. Of course, the above-mentioned size adjustment must ensure that the gap between the first fitting part 101 and the second fitting part 201 in the radial direction of the tube and the coaxiality of the first tube 10 and the second tube 20 meet the preset requirements. After processing according to the aforementioned fitting positioning and welding process, the finished product can meet the usage requirements of the corresponding clinical scenario. The above-mentioned alternative solutions and size range settings achieve application coverage of different scenarios only by adjusting the process parameters or adapting the size specifications. While ensuring the technical effect, it further broadens the applicability of the technical solution of this application and improves the flexibility and industrial adaptability of the solution.

[0060] This application also provides a method for processing a high-precision stainless steel capillary tube for cardiovascular intervention, which is applied to the high-precision stainless steel capillary tube 1 for cardiovascular intervention provided in the above embodiment.

[0061] See Figure 8 The method for processing high-precision stainless steel capillaries for cardiovascular intervention provided in this embodiment may include, for example, the following steps: S10, providing a first tube body to be processed and a second tube body to be processed, wherein the inner diameter of the first tube body to be processed is smaller than the inner diameter of the second tube body to be processed; S20, a first fitting part is formed at one end of the first tube body; S30, a second fitting part is formed at one end of the second tube body; S40, the first fitting part and the second fitting part are fitted together and fixedly connected to form a high-precision stainless steel capillary tube for cardiovascular intervention with the first tube body and the second tube body coaxial.

[0062] First, pretreatment is performed before processing. Stainless steel tubing meeting medical standards, such as 304 / 316L, is selected to ensure the biocompatibility and structural strength of the finished capillary tube. Based on the size requirements of the finished capillary tube, the selected stainless steel tubing is cut into two sections for processing: the first section and the second section. After cutting, the surfaces of both sections are degreased and derusted to remove oil, oxide layers, and other impurities, ensuring an initial surface finish of Ra≤0.3μm. This provides a clean and smooth surface foundation for subsequent precision machining and accurate positioning.

[0063] After pretreatment, step S10 is performed. Specifically, stainless steel tubing suitable for clinical use is selected to obtain the first and second tubing bodies to be processed, serving as the base blanks for subsequent segmented forming and butt jointing. To ensure the accuracy and stability of subsequent processing steps, precise one-time positioning calibration operations are required for both tubing bodies. For example, a combination positioning scheme using a high-precision CNC lathe and a CCD vision positioning system can be employed. Leveraging the system's ±0.002mm high-precision positioning capability, combined with end-face datum calibration, the synchronous positioning calibration of the inner bore and outer circle of the tubing is completed in one operation, establishing a unique processing datum. The entire tubing processing process requires no disassembly, secondary clamping, or calibration, achieving synchronous positioning calibration of the inner bore and outer circle, reducing installation deviations, and providing a unified and reliable datum for the precision processing of subsequent structural sections. This ensures that the coaxiality accuracy of all parts of the processed tubing meets the preset requirements. The one-time calibration positioning technology is a positioning method that quickly establishes the initial accuracy of the system through a single calibration process, aiming to reduce repeated calibration time and ensure positioning accuracy.

[0064] Compared to existing technologies where different processes require repeated disassembly, clamping, and recalibration, which can easily lead to cumulative accuracy deviations, the positioning and calibration method proposed in this application can avoid accuracy errors caused by reference switching, providing a unified and reliable reference for the precision machining of subsequent structural sections, and ensuring that the coaxiality accuracy of each part of the tube body after machining meets the preset requirements.

[0065] Step S20 employs a one-time calibration and positioning machining process to complete the forming of the first mating part. Specifically, designated areas of the first tube are machined to create a structural shape suitable for subsequent mating. The entire machining process is based on the initially established unified benchmark, eliminating the need for secondary clamping and calibration, effectively ensuring the dimensional accuracy of the first mating part. After machining, the first tube is cleaned and deburred to ensure that the surface and internal channels are free of impurities and burrs. Finally, the key dimensions and coaxiality of the first tube are inspected to ensure that the dimensions meet the preset requirements and the coaxiality is ≤0.01mm, avoiding the impact of accuracy deviations in a single tube on the overall mating effect.

[0066] Step S30 continues the initial calibration and positioning process, specifically machining a designated area of ​​the second tube to form a second fitting part that matches the first fitting part. The entire machining process is based on the initially established unified benchmark, eliminating the need for secondary clamping and calibration. Simultaneously, the dimensions of the second fitting part are precisely controlled to ensure a micro-gap nested fit with the first fitting part. After machining, the second tube is cleaned and deburred, and its key dimensions and coaxiality are checked to ensure the smooth progress of subsequent fitting processes.

[0067] In step S40, the first and second fitting parts are fitted and fixedly connected to form a high-precision stainless steel capillary tube for cardiovascular intervention, with the first and second tubes coaxial. Specifically, the reducing section of the second tube is aligned with the port of the expanding section of the first tube, and the tube is slowly advanced to achieve nesting assembly. Since both the first and second tubes have their coaxiality accuracy ensured through a single calibration and positioning process, no additional tooling or fixture is needed for calibration during fitting and docking; direct docking ensures a coaxiality accuracy of ≤0.01mm. Alternatively, auxiliary monitoring tools can be used to ensure the two tubes remain coaxial, further ensuring a coaxiality of ≤0.01mm. After fitting and positioning, the first and second connecting parts located within the connection area are welded and fixed. Welding is performed uniformly along the circumference of the connection area, using, for example, laser welding. Alternatively, plasma welding, electron beam welding, or other suitable processes can be selected based on actual processing requirements; no specific limitation is made here. After welding, the welded area is finely ground and polished to ensure the surface finish meets usage requirements and is free of defects such as pores and cracks.

[0068] After the post-welding process is completed, the finished product needs to be inspected in multiple dimensions. Specifically, for example, a two-dimensional measuring instrument is used to measure the dimensions to verify that the outer diameter, inner hole size and overall coaxiality of each section meet the preset requirements. In addition, the finished product should also be tested for sealing and performance, such as Ra value by surface roughness tester and bending strength by tensile testing machine, to ensure that it meets the performance requirements of medical interventional devices.

[0069] The processing method in this embodiment uses segmented forming, coaxial nesting, and welding as its core processes, forming an integrated process combination. A single-stage calibration and positioning process ensures the processing accuracy of each pipe segment. This process also ensures high-precision coaxiality of the pipe body, eliminating the need for secondary calibration when welding two pipe bodies together. Furthermore, a micro-gap nesting design achieves precise pipe body docking, effectively solving the processing challenges of complex structures in dissimilar and precision pipe bodies. It should be noted that, while meeting the requirements for single-stage calibration and positioning accuracy, micro-gap docking, and stable fixing processes, this processing method allows for flexible replacement of processing, welding, and positioning methods, significantly improving processing flexibility and applicability.

[0070] See Figure 9 In one embodiment of this application, steps S20 and S30, forming a first fitting portion at one end of the first tube and forming a second fitting portion at one end of the second tube, may include, for example, the following steps: S311, Perform a calibration and positioning of the first tube body to be processed; S312, perform outer diameter reduction processing on one end of the first tube body to be processed, and perform hole enlargement processing on the other end of the first tube body to be processed to form a first tube body having a first diameter reduction section and a hole enlargement section, and the first fitting part is at least part of the hole enlargement section. S313, Perform a calibration and positioning of the second tube to be processed; S314, perform outer diameter reduction processing on one end of the second tube body to be processed to form a second tube body having a second diameter reduction section and a first straight section, and the second fitting part includes the end of the second diameter reduction section and the first straight section near the end of the second diameter reduction section.

[0071] Specifically, in S311, the first tube body to be processed is calibrated and positioned. This step implements the core requirements of the aforementioned one-time calibration and positioning processing technology. By capturing the tube end face reference through a vision positioning system, the calibration and positioning of the inner hole and outer circle are completed simultaneously, establishing a processing reference and reducing the impact of installation deviations on the accuracy of subsequent processing.

[0072] Step S312 employs a single-calibration positioning machining process to complete the segmented forming of the first tube body. First, the outer diameter of one end of the first tube body is ground to form a corresponding diameter-reducing section structure. Then, the inner hole of the other end of the first tube body is enlarged to form a corresponding enlarged hole section structure. The entire machining process is based on the initially established benchmark and requires no further calibration. During machining, the diameter-reducing section is gradually formed using a progressive feed outer diameter grinding process, while the enlarged hole section is enlarged using a high-precision diamond reamer. During machining, the equipment's monitoring function tracks coaxiality to ensure controllable accuracy. Specifically, from the first tube body to the second tube body, the machined first tube body sequentially includes a first diameter-reducing section and an enlarged hole section. After machining, the first tube body is cleaned and deburred, and the key dimensions and coaxiality of the tube body are checked to ensure the smooth progress of subsequent fitting processes.

[0073] In S313, the second tube body to be processed is calibrated and positioned. This step continues the calibration and positioning process logic, reuses the positioning system and reference standard consistent with S311, and does not require re-establishing the reference. This ensures that the processing reference of the second tube body is consistent with that of the first tube body, and provides a reference consistency guarantee for the subsequent accurate docking of the two tube bodies.

[0074] In S314, the outer diameter of the second variable-diameter section is precisely controlled during processing with the help of a positioning system, ensuring a pre-set micro-gap of 0.005-0.01mm between it and the inner hole of the enlarged section formed in S312. Specifically, from the first tube body to the second tube body, the processed second tube body sequentially includes the second variable-diameter section and the first straight section. After processing, the second tube body is cleaned and deburred, and the key dimensions and coaxiality of the tube body are checked to ensure the smooth progress of subsequent fitting processes.

[0075] This embodiment uses a detailed segmented processing step, a positioning system, and precise processing methods such as progressive grinding and diamond reamer hole enlargement to accurately construct the adaptable structure required for micro-gap nesting, providing a reliable structural foundation for subsequent docking processing.

[0076] See Figure 10 In another embodiment of this application, steps S20 and S30, forming a first fitting portion at one end of the first tube and a second fitting portion at one end of the second tube, may include, for example, the following steps: S321, Perform a calibration and positioning of the first tube to be processed; S322, the outer diameter of the two ends of the first tube body to be processed is changed to form a first tube body having a third diameter changing section, a second straight section and a fourth diameter changing section, and the first fitting part includes the end of the fourth diameter changing section and the second straight section near the fourth diameter changing section. S323, perform a calibration and positioning of the second tube body to be processed, wherein the second fitting part is at least a portion of the second tube body.

[0077] Specifically, step S321 implements the core requirements of the one-time calibration and positioning machining process. It adopts the same positioning logic as S311, captures the tube end face reference through the vision positioning system, and simultaneously completes the calibration and positioning of the inner hole and outer circle, establishing the machining reference in one go, and avoiding the impact of installation deviation on the subsequent structural accuracy.

[0078] S322, the outer diameter of the first tube body to be processed is changed at both ends to form a first tube body with a third diameter-changing section, a second straight section, and a fourth diameter-changing section. The first fitting part includes the end of the fourth diameter-changing section and the second straight section near the fourth diameter-changing section. Specifically, from the first tube body to the second tube body, the processed first tube body sequentially includes the third diameter-changing section, the second straight section, and the fourth diameter-changing section. During processing, the third diameter-changing section and the fourth diameter-changing section at both ends are formed by outer diameter grinding, and the second straight section is formed in the middle area. During processing, the coaxiality is monitored with equipment to ensure that the dimensional accuracy of each section is controllable. After processing, the first tube body is cleaned and deburred. The outer diameter accuracy and coaxiality of the fourth diameter-changing section are checked, providing a structural basis for the subsequent micro-gap fit.

[0079] Step S323 continues the single-calibration positioning process logic, reusing the same positioning system and reference standard as S321, eliminating the need to re-establish the machining reference. The positioning system monitors the inner hole size, ensuring it forms a preset micro-gap of 0.005-0.01mm with the outer diameter of the fourth diameter-changing section formed in S322. After processing, the second tube body is cleaned and deburred, and the accuracy of the end inner hole is checked to ensure smooth engagement with the fourth diameter-changing section.

[0080] This embodiment processes the first tube into a three-section structure with varying diameters at both ends and a straight middle section. By relying on the insertion of the fourth variable-diameter section into the second tube, the aforementioned requirements for single-calibration positioning and micro-gap nesting are also met. This embodiment expands the processing scheme and provides another reliable technical path for the docking processing of tubes of different specifications.

[0081] Existing technologies for butt welding of stainless steel capillary tubes of different specifications suffer from several technical challenges, including cumulative accuracy deviations caused by multiple calibrations, limited adaptability of the fitting structure, and difficulty in consistently controlling the coaxiality of the weld. These technologies often employ a multi-clamping and calibration process, repeatedly adjusting the positioning reference during tube segmentation and butt welding. This not only increases processing time but also easily leads to cumulative deviations due to reference switching, resulting in the final product's coaxiality accuracy failing to meet the requirements of high-precision medical devices. Furthermore, traditional processing methods lack fitting structures, requiring additional clamps for positioning and fixation during butt welding. This is not only cumbersome but also easily affects the welding process, causing problems such as loose welds, high coaxiality errors, and insufficient product sealing.

[0082] This application introduces a one-time calibration and positioning process. Using a high-precision positioning system combined with end-face datum calibration, the inner and outer holes of the tube are simultaneously positioned in one operation. This eliminates the need for secondary calibration, supporting the entire process of segmented forming and fitting. It reduces the cumulative accuracy errors caused by multiple calibrations, ensuring uniform processing datum height for each section of the tube and stable coaxiality that meets preset standards. Furthermore, this application innovatively designs a fitting structure processing path, specifically performing diameter reduction and hole enlargement on the tube to create a suitable fitting structure and precisely control the mating clearance. This ensures docking accuracy without additional fixtures, effectively solving problems such as cumulative deviations in docking accuracy of tubes of different specifications, difficulty in controlling coaxiality, reliance on fixture positioning, and welding defects caused by insufficient docking accuracy. It achieves dual precision control of docking accuracy and coaxiality, significantly improving welding quality and finished product yield, simplifying processes, increasing efficiency, and expanding the range of applicable processing solutions.

[0083] To facilitate understanding of the method for processing high-precision stainless steel capillaries for cardiovascular intervention provided in the embodiments of this application, the specific process of the method for processing high-precision stainless steel capillaries for cardiovascular intervention is illustrated below with examples.

[0084] 1. 316L medical stainless steel tubing is selected, with the following chemical composition (mass fraction): Cr 16.0%-18.0%, Ni 10.0%-14.0%, Mo 2.0%-3.0%, C≤0.03%, and the remainder being Fe, to ensure biocompatibility and corrosion resistance.

[0085] 2. Processing equipment: (1) Positioning calibration equipment: high-precision CNC lathe (model: CK0630), CCD vision positioning system (positioning accuracy ±0.002mm); (2) Machining tools: diamond grinding tools (hardness HRC60-65), diamond reamers (precision H7); (3) Welding equipment: pulsed laser welding machine (model: YAG-200), welding parameters: power 120W, welding speed 8mm / s, spot diameter 0.15mm, argon flow rate 15L / min; (4) Testing equipment: 2D image measuring instrument (accuracy ±0.001mm), water pressure sealing tester (range 0-1MPa), surface roughness tester (accuracy ±0.01μm), tensile testing machine (range 0-1000N).

[0086] Detailed processing flow: 1. Preprocessing Select 316L stainless steel tubing that meets medical standards, and cut it into a first tube body with a length of 25mm and a second tube body with a length of 750mm according to the finished product size requirements; place the two cut tube sections in anhydrous ethanol for ultrasonic cleaning for 15 minutes to fully remove oil and impurities attached to the surface of the tube sections; after cleaning, dry the tube sections and set them aside for later use.

[0087] 2. First pipe body processing (1) Clamping and positioning: The first tube body is clamped and fixed on the fixture of the CNC lathe. The CCD vision positioning system is started to capture the end face reference of the first tube body. The coaxiality calibration of the inner hole and outer circle of the first tube body is completed simultaneously to establish a unified machining reference.

[0088] (2) Outer diameter grinding: The 15mm long section on the first tube body is processed by progressive grinding process, with a single feed rate of 0.005mm, and the outer diameter of the section is ground to 0.7mm. During the grinding process, the coaxiality of the first tube body is monitored in real time to ensure that the coaxiality error is ≤0.01mm throughout the process.

[0089] (3) Internal hole enlargement: The remaining 10mm section on the first tube body is enlarged using a diamond reamer. The reamer speed is set to 3000r / min and the feed rate is 0.01mm / r. The internal hole diameter of this section is 0.9mm.

[0090] (4) Cleaning and deburring: The first tube body after processing is ultrasonically cleaned again for 5 minutes. After cleaning, the burrs at both ends of the first tube body are removed by polishing with a polishing wheel and then put into use.

[0091] 3. Second pipe body processing (1) Clamping and positioning: Using the same clamping method and positioning logic as the first tube, the second tube is fixed to the CNC lathe fixture. The coaxiality reference of the inner hole and outer circle of the second tube is calibrated by the CCD vision positioning system to ensure that it is consistent with the machining reference of the first tube.

[0092] (2) Outer diameter grinding: The outer diameter of a 10mm section on the second tube body is ground until the outer diameter of the section reaches 0.885mm; the coaxiality is monitored in real time during the grinding process to ensure that the coaxiality error is ≤0.01mm.

[0093] (3) Cleaning and deburring: The same ultrasonic cleaning and polishing deburring process as the first tube body is used to process the processed second tube body, and the processed tube body is ready for use.

[0094] 4. Nested positioning Insert the variable-diameter end of the processed second tube into the enlarged end of the first tube, and adjust the relative position of the two tubes in real time using a CCD vision positioning system to ensure that the overall coaxiality after nesting is ≤0.01mm and the nesting depth is precisely controlled to 10mm.

[0095] 5. Laser welding Start the laser welding machine and perform welding operations along the circumference of the mating end faces of the two tubes, welding a total of 3 circles, and controlling the overlap rate of the welding trajectories of adjacent circles to 50%; argon gas is introduced throughout the welding process for protection to prevent oxidation in the weld area.

[0096] 6. Post-weld treatment The weld seam was finely ground using 800-grit sandpaper to remove protrusions and slag from the weld surface; the finely ground capillary was then ultrasonically cleaned for 10 minutes; and finally dried.

[0097] 7. Finished product inspection (1) Dimensional inspection: A two-dimensional measuring instrument is used to comprehensively inspect the outer diameter, inner hole size and overall coaxiality of each section of the finished capillary tube to ensure that all dimensional parameters meet the preset requirements.

[0098] (2) Sealing test: 0.5MPa water pressure is introduced into the finished capillary tube and the pressure is maintained for 30 minutes. The standard for acceptance is no leakage.

[0099] (3) Performance testing: The Ra value of the capillary surface is tested using a surface roughness tester; the bending strength of the finished product is tested using a tensile testing machine; and the conductivity of the finished product is tested using a multimeter.

[0100] 8. Packaging of qualified products: The finished capillary tubes that have passed the inspection will be sealed and packaged using aseptic packaging technology to complete the entire processing procedure and prepare them for subsequent use.

[0101] Through the processing steps described in this embodiment, the positioning accuracy is greatly improved and the cumulative deviation of accuracy is reduced by utilizing a CCD vision positioning system and a high-precision CNC lathe. A micro-gap nested structure is constructed through precise grinding and hole-expanding parameter control, achieving precise docking without fixture assistance. Argon-protected welding and multi-dimensional finished product inspection ensure stable welding quality and finished product performance. The coaxiality error of the final product can be stably controlled within 0.01mm, and indicators such as sealing performance and bending strength meet medical standards.

[0102] See Figure 11 and Figure 12 , Figure 11 and Figure 12 These are all two-dimensional inspection images of tubes processed using butt welding technology. In this type of butt welding processing of stainless steel capillary tubes of different specifications, the thinner tube body (i.e., Figure 11The end of the thinner tube in the upper half is processed into a flared, funnel-shaped opening, while the thicker tube (i.e., Figure 11 The thicker end of the lower half of the tube is ground, and then the ground thicker end is joined to the flared end of the thinner tube and welded. The existing technology aims to reduce coaxial deviation through this structure. However, in this method, the flared end and the ground end are only in line contact for positioning, lacking stable circumferential surface fit constraints. After joining, the coaxial deviation is difficult to control within 0.2mm. If it is necessary to further reduce the coaxial deviation to adapt to high-precision scenarios, problems such as joining offset and high-temperature deformation during welding will occur due to insufficient positioning constraints. The yield rate is low, and the fit clearance is not precisely controlled. After welding, it is easy to form pores and cracks at the weld, affecting the sealing performance and structural strength of the tube.

[0103] See Figure 13 and Figure 14 , Figure 13 and Figure 14 These are two-dimensional inspection images of pipes processed using telescoping or stretching techniques. In this existing technology, one end of a thicker pipe is fixed with a clamp, and a tensile force is applied to the end region of the pipe to gradually narrow it, forming a thinner pipe segment that matches the requirements. This replaces welding to achieve an integrated connection of pipes with different diameters, aiming to improve the sealing performance of the pipe through a weld-free structure. However, this process has significant drawbacks. During the stretching process, the deformation of the pipe material is easily affected by the uniformity of the tensile force and the precision of the clamp constraint, resulting in uneven distribution of wall thickness and outer diameter in the thinner segment. Furthermore, the coaxiality between the stretched thinner segment and the original thicker segment is difficult to control, typically failing to meet the precision requirement of within 0.2mm. At the same time, the uneven stress distribution after stretching can easily form hidden cracks or structurally weak areas in the thinner segment, making it prone to breakage during subsequent use. Moreover, this process has high requirements for the ductility of the pipe material, has a narrow range of applicability, and even a slight deviation in the stretching parameters can lead to the scrapping of the pipe, resulting in a low yield.

[0104] See Figure 15Compared to existing segmented butt welding methods, which suffer from large coaxiality deviations due to line contact positioning, weld defects, and low yield rates, as well as the aforementioned defects in uneven deformation, unbalanced stress distribution, and failure to meet coaxial accuracy standards when forming pipes of different diameters using stretching processes, this application replaces simple line contact fitting with an interlocking structure. Combined with a single calibration positioning process and precision machining, the coaxiality of the interlocked pipe is stably controlled within 0.01 mm. Simultaneously, this interlocking structure provides continuous coaxial constraint during the welding process, effectively preventing high-temperature deformation and reducing weld porosity and cracks. Furthermore, this application replaces material stretching deformation with segmented precision machining, ensuring uniform wall thickness across pipe segments while avoiding the risks of uneven stress and latent cracks associated with stretching processes. This application not only elevates the coaxial precision of connecting dissimilar tubes to the stringent standards of cardiovascular interventional devices, but also significantly improves the yield and production consistency, adapting to the needs of large-scale mass production, while ensuring the structural strength and sealing of the tubes, meeting the core requirements of clinical surgery for device reliability.

[0105] Furthermore, it is understood that the foregoing embodiments are merely illustrative examples of this application. Provided that the technical features do not conflict, the structure is not contradictory, and the purpose of this application is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A high-precision stainless steel capillary tube (1) for cardiovascular intervention, characterized in that, Including a first tube (10) and a second tube (20) connected in sequence. The first tube (10) has a first channel (110), and the second tube (20) has a second channel (210). The first channel (110) is connected to the second channel (210), and the inner diameter of the first channel (110) is smaller than the inner diameter of the second channel (210). The first tube (10) is provided with a first fitting part (101) at one end facing the second tube (20), and the second tube (20) is provided with a second fitting part (201) corresponding to the first fitting part (101) at one end facing the first tube (10). The first tube (10) and the second tube (20) are coaxially fixedly connected by the fitting of the first fitting part (101) and the second fitting part (201).

2. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 1, characterized in that, The first fitting part (101) is provided with a first connecting part (102), and the second fitting part (201) is provided with a second connecting part (202) corresponding to the first connecting part (102). The first connecting part (102) and the second connecting part (202) are fixedly connected.

3. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 2, characterized in that, The first tube body (10) includes a first variable diameter section (103) and an enlarged hole section (104) in sequence along a first direction. The inner diameter of the first variable diameter section (103) is smaller than the inner diameter of the enlarged hole section (104). The first fitting part (101) is at least a portion of the enlarged hole section (104). The first direction is the direction from the first tube body (10) to the second tube body (20). The second tube body (20) includes a second variable diameter section (203) and a first straight section (204) in sequence along the first direction. The outer diameter of the second variable diameter section (203) is smaller than the outer diameter of the first straight section (204), and the inner diameter of the second variable diameter section (203) is equal to the inner diameter of the first straight section (204). The second fitting part (201) includes the second variable diameter section (203) and the end of the first straight section (204) near the second variable diameter section (203). The second variable diameter section (203) extends into the first fitting part (101) and is in clearance fit with the first fitting part (101), and the end of the first straight section (204) near the second variable diameter section (203) abuts against the end of the first fitting part (101) near the second variable diameter section (203).

4. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 3, characterized in that, The first connecting part (102) is the end of the enlarged section (104) facing the second tube body (20), and the second connecting part (202) is the end of the first straight section (204) near the second variable diameter section (203). The first connecting part (102) and the second connecting part (202) are welded and fixed.

5. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 2, characterized in that, The first tube body (10) includes, in sequence along a first direction, a third variable diameter section (105), a second straight section (106), and a fourth variable diameter section (107). The first fitting portion (101) includes the fourth variable diameter section (107) and the second straight section (106) near the end of the fourth variable diameter section (107). The second fitting portion (201) is at least a portion of the second tube body (20). The first direction is the direction from the first tube body (10) to the second tube body (20). The fourth variable diameter section (107) extends into the second tube body (20) and is in clearance fit with the second fitting part (201), and the end of the second straight section (106) near the fourth variable diameter section (107) abuts against the end of the second tube body (20) near the first tube body (10).

6. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 5, characterized in that, The first connecting part (102) is the end of the second straight section (106) near the fourth variable diameter section (107), and the second connecting part (202) is the end of the second tube body (20) near the first tube body (10). The first connecting part (102) and the second connecting part (202) are welded and fixed.

7. The high-precision stainless steel capillary tube (1) for cardiovascular intervention as described in claim 3 or 5, characterized in that, The gap between the first fitting part (101) and the second fitting part (201) in the radial direction is 0.005-0.01mm; with the central axis of the first tube (10) as the reference, the coaxiality tolerance of the central axis of the second tube (20) relative to the reference axis of the first tube (10) is ≤0.01mm.

8. A method for processing a high-precision stainless steel capillary tube for cardiovascular intervention, characterized in that, include: A first tube body to be processed and a second tube body to be processed are provided, wherein the inner diameter of the first tube body to be processed is smaller than the inner diameter of the second tube body to be processed. A first fitting portion is formed at one end of the first tube body; A second fitting portion is formed at one end of the second tube; The first fitting part and the second fitting part are fitted together and fixedly connected to form a high-precision stainless steel capillary tube for cardiovascular intervention with the first tube body and the second tube body coaxial.

9. The method for processing high-precision stainless steel capillary tubes for cardiovascular intervention as described in claim 8, characterized in that, The formation of a first fitting portion at one end of the first tube body and a second fitting portion at one end of the second tube body specifically includes: Perform a calibration and positioning on the first tube to be processed; One end of the first tube body to be processed is subjected to outer diameter reduction processing, and the other end of the first tube body to be processed is subjected to hole enlargement processing to form a first tube body having a first diameter reduction section and a hole enlargement section, and the first fitting part is at least part of the hole enlargement section; Perform a calibration and positioning on the second tube to be processed; One end of the second tube to be processed is subjected to outer diameter reduction processing to form a second tube having a second diameter reduction section and a first straight section, and the second fitting part includes the second diameter reduction section and the end of the first straight section near the second diameter reduction section.

10. The method for processing high-precision stainless steel capillary tubes for cardiovascular intervention as described in claim 8, characterized in that, The formation of a first fitting portion at one end of the first tube body and a second fitting portion at one end of the second tube body specifically includes: Perform a calibration and positioning on the first tube to be processed; The outer diameter of the two ends of the first tube to be processed is changed to form a first tube with a third diameter changing section, a second straight section and a fourth diameter changing section, and the first fitting part includes the end of the fourth diameter changing section and the second straight section near the end of the fourth diameter changing section; The second tube to be processed is calibrated and positioned once, and the second fitting part is at least a portion of the second tube.

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