Method of making a radial catheter, coating mold, radial catheter

Abstract

The application provides a preparation method of a radial catheter, a coating mold and the radial catheter. The preparation method comprises the following steps: providing a tubular intermediate layer; placing the intermediate layer in a cavity of the coating mold to form an outer layer cavity located at the outer periphery of the intermediate layer, an inner layer cavity located at the inner periphery of the intermediate layer, and a through portion of the intermediate layer communicating with the outer layer cavity and the inner layer cavity; injecting a polymer solution into the cavity, and solidifying after the injection is completed; the wall thickness of the radial catheter can be reduced on the basis of maintaining the interventional performance of the radial catheter, and there is no problem of tight adhesion between the polymer solution and the intermediate layer; in addition, the outer surface of the radial catheter is smoother, and the stability of the radial catheter is improved.

Description

Technical Field

[0001] This invention relates to the field of medical technology, and more particularly to a method for preparing a radial catheter, a coating mold for preparing the radial catheter, and the radial catheter itself. Background Technology

[0002] Transradial catheters used in interventional therapy to insert into blood vessels typically employ a composite structure consisting of an outer layer of polymer, a middle layer of metal, and an inner layer of polymer, arranged from the outside in. The use of a middle layer with high mechanical properties enables the transradial catheter to meet the requirements for maneuverability and flexibility in interventional therapy.

[0003] The intermediate layer made of metal typically includes a braided tube or spring coil made of woven or wound metal wires, or a hypotube made by cutting metal tubing. The hypotube is laser-engraved to form a regular through-section, which limits a maximum bending angle, enabling precise control of the maximum bending angle of the radial catheter. It also provides properties including anti-bending, pushing, and torque resistance. Furthermore, it allows for thinner wall thicknesses to achieve higher performance, meaning a larger inner diameter for greater compatibility while maintaining a larger outer diameter, reducing damage to blood vessels.

[0004] The current manufacturing method for transradial catheters (TDCs) generally involves inserting a tubular inner layer into a tubular middle layer, and then thermally fusing an outer layer onto the periphery of the middle layer to form the outer layer. However, this method presents the following problems: 1) Gaps between the inner and middle layers increase the overall wall thickness of the TDC; 2) When the middle layer is a thiourea tube, the unique groove-shaped through-hole of the thiourea tube causes the inner and outer layers to become concave during the fusion of the outer layer, resulting in an uneven outer surface of the TDC and potential snagging on blood vessels; 3) The through-hole in the middle layer is relatively small, making it difficult for the outer layer to flow into the middle layer and adhere to the inner layer during the fusion process, leading to decreased stability of the TDC; 4) Existing outer layers are prone to sudden changes in hardness at material interfaces, affecting the delivery effect. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a radial catheter, a coating mold for preparing the radial catheter, and the radial catheter itself.

[0006] To achieve the above-mentioned objective, the present invention provides a method for preparing a radial catheter, which includes the following steps:

[0007] A tubular intermediate layer is provided, the tube wall of the intermediate layer having a through portion that radially communicates the inside and outside of the intermediate layer;

[0008] The intermediate layer is placed in the cavity of the coating mold to form an outer cavity located on the outer periphery of the intermediate layer and an inner cavity located on the inner periphery of the intermediate layer. The through portion connects the outer cavity and the inner cavity.

[0009] A polymer solution is injected into the cavity and cured after injection. The cured polymer solution in the outer cavity forms the outer layer of the radial conduit, and the cured polymer solution in the inner cavity forms the inner layer of the radial conduit. The cured polymer solution in the through-hole forms the connecting part between the outer layer and the inner layer.

[0010] Demolding.

[0011] As a further improvement of the present invention, "injecting a polymer solution into the cavity and then curing" specifically means: injecting a polymer solution into the outer cavity, and the polymer solution in the outer cavity flows into the inner cavity through the penetration portion.

[0012] As a further improvement of the present invention, while injecting a polymer solution into the cavity, an ultrasonic generator acting on the cavity is activated.

[0013] As a further improvement of the present invention, before "injecting the polymer solution into the cavity", the method for preparing the radial conduit further includes the following steps:

[0014] The heating assembly is activated to raise the temperature inside the cavity to be injected to a first preset temperature and maintain the temperature until the injection is completed. The first preset temperature is not lower than the melting point of the polymer material that forms the polymer solution to be injected.

[0015] As a further improvement of the present invention, "curing after injection" specifically means: turning off the heating component and starting the water circulation system to cool the cavity after injection until the temperature inside the cavity drops to a second preset temperature, wherein the second preset temperature is lower than the melting point of the polymer material that forms the polymer solution.

[0016] As a further improvement of the present invention, from the bottom to the top, the cavity includes multiple interconnected sub-cavities, each sub-cavity including an outer sub-cavity and an inner sub-cavity corresponding to the sub-cavity, and the multiple sub-cavities correspond to various polymer solutions respectively; after injecting and solidifying the corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, the corresponding type of polymer solution is then injected and solidified into the upper sub-cavity.

[0017] As a further improvement of the present invention, "after injecting and curing a corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, and then injecting and curing a corresponding type of polymer solution into the upper sub-cavity" specifically includes the following steps:

[0018] When injecting a polymer solution of the corresponding type into the lower sub-cavity until the liquid level of the polymer solution is 2mm to 3mm from the top of the sub-cavity, while continuing to inject the corresponding polymer solution into the lower sub-cavity, a polymer solution corresponding to the upper sub-cavity is injected into the lower sub-cavity to form a mixture. The injection ends when the liquid level of the mixture exceeds the bottom of the upper sub-cavity by 2mm to 3mm, and the polymer solution is then cured.

[0019] After the polymer solution is cured, the corresponding type of polymer solution is injected into the sub-cavity located on the upper side and cured.

[0020] As a further improvement of the present invention, after the injection is completed and before curing, the method for preparing the radial conduit further includes the following step: conveying the polymer solution in the delivery pipe for conveying the polymer solution in a direction away from the cavity, so as to empty the delivery pipe.

[0021] As a further improvement of the present invention, from the bottom to the top of the cavity, the cavity includes multiple interconnected sub-cavities, each sub-cavity including an outer sub-cavity and an inner sub-cavity corresponding to the sub-cavity. The multiple sub-cavities correspond to various polymer solutions. After injecting and solidifying the corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, the corresponding type of polymer solution is then injected and solidified into the upper sub-cavity. "Starting the heating component to raise the temperature inside the cavity to the first preset temperature and holding it at that temperature until the injection is completed" specifically means: starting the heating component corresponding to the sub-cavity to be injected to raise the temperature of the sub-cavity to be injected to the first preset temperature and holding it at that temperature until the injection is completed.

[0022] As a further improvement of the present invention, from the bottom to the top of the cavity, the cavity includes multiple interconnected sub-cavities. Each sub-cavity includes an outer sub-cavity and an inner sub-cavity corresponding to the sub-cavity. The multiple sub-cavities correspond to various polymer solutions. After injecting and solidifying the corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, the corresponding type of polymer solution is then injected and solidified into the upper sub-cavity. "Starting the water circulation system to cool the cavity until the temperature inside the cavity drops to the second preset temperature" specifically means: starting the water circulation system corresponding to the sub-cavity where the injection is completed, so as to reduce the temperature inside the sub-cavity where the injection is completed to the second preset temperature.

[0023] As a further improvement of the present invention, the first preset temperature is 15°C to 25°C higher than the melting point of the polymer material forming the polymer solution.

[0024] As a further improvement of the present invention, the second preset temperature is 45°C to 55°C lower than the melting point of the polymer material forming the polymer solution.

[0025] As a further improvement of the present invention, the polymeric material forming the polymeric solution includes silicone oil.

[0026] As a further improvement of the present invention, the intermediate layer is a sodium hypochlorite tube.

[0027] To achieve the above-mentioned objectives, the present invention also provides a coating mold, comprising:

[0028] A hot melt assembly, comprising a hot melt box for holding polymer materials and a hot melt heating element for hot melting the polymer materials into a polymer solution;

[0029] A molding assembly, the molding assembly including a housing having a mounting cavity for placing a tubular workpiece to be coated, and a mandrel disposed within the mounting cavity to form a cavity with the cavity wall of the mounting cavity, the mandrel being inserted into the workpiece to be coated;

[0030] The conveying assembly includes a conveying pipe connecting the hot melt box and the cavity, and a conveying pump disposed on the conveying pipe to convey the polymer solution.

[0031] As a further improvement of the present invention, the molding assembly further includes a heating assembly for heating the cavity.

[0032] As a further improvement of the present invention, the heating component is a heating wire embedded in the housing and arranged around the mounting cavity.

[0033] As a further improvement of the present invention, the cavity extends in the vertical direction; from the bottom up, the cavity includes multiple interconnected sub-cavities; the heating component corresponds to each of the sub-cavities.

[0034] As a further improvement of the present invention, the molding assembly further includes a water circulation system for cooling the cavity.

[0035] As a further improvement of the present invention, the cavity extends in the vertical direction; from the bottom up, the cavity includes multiple interconnected sub-cavities; the water circulation system corresponds one-to-one with the sub-cavities.

[0036] As a further improvement of the present invention, the cavity extends in the vertical direction; from the bottom up, the cavity includes multiple interconnected sub-cavities; the hot melt assembly corresponds one-to-one with the sub-cavities.

[0037] As a further improvement of the present invention, the coating mold includes a plurality of forming components arranged circumferentially around the hot melt component, and a conveying component that respectively connects the hot melt component and the plurality of forming components.

[0038] As a further improvement of the present invention, the molding assembly further includes an ultrasonic generator disposed on the housing and close to the mounting cavity.

[0039] As a further improvement of the present invention, the housing is provided with a plurality of inlets communicating with the mounting cavity, the plurality of inlets are arranged in pairs, and a pair of inlets are arranged radially opposite to each other in the mounting cavity.

[0040] To achieve the above-mentioned objectives, the present invention also provides a radial catheter, which is prepared by the above-described method for preparing a radial catheter; or the radial catheter is prepared by the above-described coating mold.

[0041] To achieve the above-mentioned objective, the present invention also provides a radial conduit, comprising a tubular intermediate layer, an outer layer located on the outer periphery of the intermediate layer, and an inner layer located on the inner periphery of the intermediate layer. The tube wall of the intermediate layer has a through portion that connects the inside and outside of the intermediate layer radially. The through portion has a connecting portion that connects the inner layer and the outer layer. The inner layer, the outer layer, and the connecting portion are integrally formed coatings.

[0042] As a further improvement of the present invention, in the direction from the proximal end to the distal end, the coating comprises multiple sub-coating segments, wherein the hardness of the sub-coating segment closer to the proximal end in two adjacent sub-coating segments is greater than the hardness of the sub-coating segment closer to the distal end.

[0043] As a further improvement of the present invention, the material at the junction of adjacent sub-coatings is a mixture of polymer materials corresponding to the two adjacent sub-coatings.

[0044] The beneficial effects of this invention are as follows: In the preparation method of the transradial catheter of this invention, by placing an intermediate layer in the cavity of a coating mold, gaps are formed on both the outer and inner circumferences of the intermediate layer. Then, a polymer solution is injected into the gaps. After the polymer solution solidifies, an integral coating is formed on the inner and outer circumferences and the through-holes of the intermediate layer to form a transradial catheter. On the one hand, there is no assembly gap between the inner layer and the intermediate layer, which reduces the wall thickness of the transradial catheter while maintaining its interventional performance, and there is no problem of loose adhesion between the polymer solution and the intermediate layer. On the other hand, the outer surface of the formed transradial catheter is smoother, and the liquid polymer solution fills all the through-holes, thereby forming a connection between the inner and outer layers in each through-hole, improving the stability of the transradial catheter. Attached Figure Description

[0045] Figure 1 This is a flowchart of the preparation method of the radial catheter in this invention;

[0046] Figure 2 This is a simplified structural diagram of a coating mold according to a specific embodiment of the present invention;

[0047] Figure 3 yes Figure 2 A schematic diagram of the molding components in the diagram;

[0048] Figure 4 yes Figure 3 A cross-sectional view of the molding components (the intermediate layer is located inside the cavity);

[0049] Figure 5 yes Figure 3 A structural schematic diagram of the molding component from another angle. Detailed Implementation

[0050] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. Please refer to the accompanying drawings for further details. Figures 1 to 5 The figures shown represent preferred embodiments of the present invention. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent modifications or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0051] In this invention, terms describing position and direction are used with the operator of the instrument as a reference, with the end closer to the operator being the proximal end and the end farther from the operator being the distal end. The axial direction in this invention refers to the length direction of the component. Furthermore, the terms "first," "second," etc., used in this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0052] Combination Figures 1-5 As shown, the present invention provides a method for preparing a radial catheter and a coating mold 100. The method for preparing a radial catheter is carried out by the coating mold 100 to prepare a radial catheter.

[0053] The method for preparing the radial catheter includes the following steps:

[0054] A tubular intermediate layer 10 is provided, the tube wall of the intermediate layer 10 having a through portion that radially communicates the inside and outside of the intermediate layer 10;

[0055] The intermediate layer 10 is placed in the cavity of the coating mold 100 to form an outer cavity 23 located on the outer periphery of the intermediate layer 10 and an inner cavity 24 located on the inner periphery of the intermediate layer 10. The through portion connects the outer cavity 23 and the inner cavity 24.

[0056] A polymer solution is injected into the cavity and cured after injection. The cured polymer solution in the outer cavity 23 forms the outer layer of the radial conduit, and the cured polymer solution in the inner cavity 24 forms the inner layer of the radial conduit. The cured polymer solution in the through-hole forms the connecting part between the outer layer and the inner layer.

[0057] Demolding.

[0058] In this invention, an intermediate layer 10 is placed in the cavity of a coating mold 100, and gaps are formed on both the outer and inner peripheries of the intermediate layer 10, namely an outer cavity 23 on the outer periphery of the intermediate layer 10 and an inner cavity 24 on the inner periphery of the intermediate layer 10. Then, a polymer solution is injected into the gaps. After the polymer solution solidifies, an integral coating is formed on the inner periphery, outer periphery, and through portion of the intermediate layer 10. The coating on the inner periphery of the intermediate layer 10 forms the inner layer of the radial conduit, the coating on the outer periphery of the intermediate layer 10 forms the outer layer of the radial conduit, and the coating in the through portion forms a connecting portion connecting the inner layer and the outer layer. On the one hand, there is no assembly gap between the inner layer and the intermediate layer 10, which can reduce the wall thickness of the radial catheter while maintaining the interventional performance of the radial catheter, and there is no problem of loose adhesion between the polymer solution and the intermediate layer 10; on the other hand, the outer surface of the formed radial catheter is smoother, and the liquid polymer solution will fill all the penetrations, so that a connection between the inner layer and the outer layer will be formed in each penetration, thereby improving the stability of the radial catheter.

[0059] In one specific embodiment, the tubular intermediate layer 10 is a sodium hypochlorite tube, and the through portion is a cut pattern penetrating the wall of the sodium hypochlorite tube. The specific pattern / cutting density and other parameters of the cut pattern can be set according to requirements, and will not be elaborated here. Of course, this is not a limitation. In other embodiments, the tubular intermediate layer 10 can also be a braided tube, a spring tube, or any combination of sodium hypochlorite tube, braided tube, and spring tube.

[0060] Combination Figure 2As shown, the coating mold 100 includes a hot-melt assembly 1 for melting polymer materials into a polymer solution, a molding assembly 2, a conveying assembly 3 for conveying the polymer solution in the hot-melt assembly 1 to the molding assembly 2, and a control unit for controlling the operation of the coating mold 100. The hot-melt assembly 1 and the conveying assembly 3 are both communicatively connected to the control unit.

[0061] Specifically, the hot-melt assembly 1 includes a hot-melt box 11 for holding polymer materials and a hot-melt heating element for melting the polymer materials into a polymer solution. The hot-melt heating element is communicatively connected to the control unit. After the polymer materials are placed into the hot-melt box 11 and the hot-melt heating element is activated to heat the temperature inside the hot-melt box 11 to the melting point of the polymer materials, the polymer materials inside the hot-melt box 11 melt into a polymer solution.

[0062] Combination Figures 3-5 As shown, the molding assembly 2 includes a housing 21 having a mounting cavity for placing a tubular workpiece to be coated, and a mandrel 22 disposed within the mounting cavity to form a cavity with the cavity wall of the mounting cavity, the mandrel 22 being inserted into the workpiece to be coated.

[0063] The coating mold 100 will now be described in detail using the example of its application in preparing the radial conduit of the present invention. In this case, the part to be coated refers to the tubular intermediate layer 10. Of course, this is not a limitation; the coating mold 100 can also be used to coat other tubular parts.

[0064] Specifically, the housing 21 has an opening communicating with the mounting cavity and a door 211 for opening and closing the opening. The opening allows for the placement and removal of the mandrel 22, the placement of the intermediate layer 10, and the removal of the formed radial guide tube. When the door 211 closes the opening, the mounting cavity is closed.

[0065] Both the mounting cavity and the mandrel 22 are cylindrical, and the axial extension direction of the mounting cavity and the mandrel 22 is consistent with the extension direction of the intermediate layer 10. After the intermediate layer 10 is fitted onto the mandrel 22, that is, the mandrel 22 is inserted into the intermediate layer 10, and then the mandrel 22 fitted with the intermediate layer 10 is placed in a preset position in the mounting cavity from the opening and the door 211 is closed, an outer cavity 23 is formed between the outer peripheral surface of the intermediate layer 10 and the cavity wall of the mounting cavity, and an inner cavity 24 is formed between the inner peripheral surface of the intermediate layer 10 and the mandrel 22. That is, an outer cavity 23 is formed on the outer periphery of the intermediate layer 10, and an inner cavity 24 is formed on the inner periphery of the intermediate layer 10.

[0066] It is known that the mandrel 22 is detachably connected to the mounting cavity.

[0067] Furthermore, both the mounting cavity and the mandrel 22 extend vertically, and the corresponding intermediate layer 10 within the mounting cavity also extends vertically, forming a cavity that also extends vertically. Specifically, after placing the mandrel 22 with the intermediate layer 10 fitted inside the mounting cavity, the lower end of the mandrel 22 is limited and connected to the bottom wall of the mounting cavity, the upper end of the mandrel 22 is limited and connected to the top wall of the mounting cavity, and the lower end of the intermediate layer 10 is supported on the bottom wall of the mounting cavity. This ensures that a preset gap is maintained between the mandrel 22 and the intermediate layer 10, and between the intermediate layer 10 and the wall of the mounting cavity, facilitating the subsequent injection of a polymer solution to form an outer layer on the outer periphery of the intermediate layer 10 and an inner layer on the inner periphery of the intermediate layer 10.

[0068] Furthermore, the conveying assembly 3 includes a conveying pipe 31 connecting the hot melt box 11 and the cavity, and a conveying pump disposed on the conveying pipe 31 to convey the polymer solution. The conveying pump is communicatively connected to the control unit. After the polymer material in the hot melt box 11 is hot-melted into a polymer solution, and the mandrel 22 with the intermediate layer 10 is placed in a preset position in the mounting cavity and the door 211 is closed, the polymer solution is conveyed forward by the conveying pump to transport the polymer solution from the hot melt box 11 to the cavity.

[0069] In one specific embodiment, the mounting cavity includes a periphery wall extending upward from the periphery of the cavity bottom wall. An inlet 25, corresponding to the periphery wall, is provided on the housing 21 and communicates with the mounting cavity. The conveying pipe 31 is connected to the inlet 25. After the mandrel 22, fitted with the intermediate layer 10, is placed in a predetermined position within the mounting cavity through the opening and the door 211 is closed, the conveying pipe 31 communicates with the outer cavity 23. The polymer solution conveyed to the outer cavity 23 flows into the inner cavity 24 through the through-hole of the intermediate layer 10, thereby filling the outer cavity 23, the through-hole, and the inner cavity 24 with the polymer solution.

[0070] Correspondingly, the step "injecting polymer solution into the cavity and then curing" specifically means: injecting polymer solution into the outer cavity 23, and the polymer solution in the outer cavity 23 flows into the inner cavity 24 through the through part.

[0071] Furthermore, the housing 21 is provided with a plurality of inlet ports 25, which are arranged in pairs, with one pair of inlet ports 25 arranged radially opposite to each other in the mounting cavity. When the polymer solution is injected into the cavity, the polymer solution simultaneously enters the outer cavity 23 through the pair of inlet ports 25, which can further prevent the intermediate layer 10 from shifting and improve the stability of the coating mold 100; at the same time, it can improve the injection efficiency and the production efficiency of the radial guide tube.

[0072] Specifically, one of the conveying components 3 corresponds to one or more pairs of the feed inlets 25.

[0073] Furthermore, the molding assembly 2 also includes a heating assembly 26 for heating the cavity, and the heating assembly 26 is communicatively connected to the control unit. Before injecting the polymer solution into the cavity, the heating assembly 26 is turned on to heat the cavity, raising the temperature inside the cavity to a first preset temperature and maintaining it at the first preset temperature until the injection is completed. The first preset temperature is not lower than the melting point of the polymer material forming the polymer solution to be injected. Thus, the polymer solution injected into the cavity remains liquid until the injection is completed, which is beneficial for the polymer solution to fill the outer cavity 23, the through portion, and the inner cavity 24.

[0074] Specifically, the first preset temperature is 15°C to 25°C higher than the melting point of the polymer material forming the polymer solution.

[0075] In one specific embodiment, the heating component 26 is a heating wire embedded in the housing 21 and arranged around the mounting cavity. This allows for uniform heating of the cavity. However, this is not a limitation.

[0076] Correspondingly, before "injecting the polymer solution into the cavity", the method for preparing the transradial conduit further includes the following steps:

[0077] The heating component 26 is activated to raise the temperature inside the cavity to be injected to a first preset temperature and maintain the temperature until the injection is completed. The first preset temperature is not lower than the melting point of the polymer material that forms the polymer solution to be injected.

[0078] Specifically, the first preset temperature is 15°C to 25°C higher than the melting point of the polymer material forming the polymer solution.

[0079] Furthermore, the step "curing after injection" in the preparation method of the radial conduit specifically involves turning off the heating component 26 so that the polymer solution injected into the cavity cures to form the coating located on the intermediate layer 10.

[0080] Furthermore, the molding assembly 2 also includes a water circulation system (not shown) for cooling the cavity, which is communicatively connected to the control unit. After injection, the water circulation system cools the cavity, increasing the cooling rate and thus improving the curing speed of the polymer solution and the preparation efficiency via the radial conduit.

[0081] Specifically, the water circulation system includes pipes embedded in the housing 21 and arranged around the mounting cavity, and a water supply assembly for supplying water to the pipes. The pipes are spaced apart from the heating wire.

[0082] Correspondingly, the step "curing after injection" in the preparation method of the radial conduit specifically involves: turning off the heating component 26 and starting the water circulation system to cool the cavity after injection until the temperature inside the cavity drops to a second preset temperature, wherein the second preset temperature is lower than the melting point of the polymer material forming the polymer solution. This allows the polymer solution injected into the cavity to cure and form the coating located on the intermediate layer 10.

[0083] Specifically, the second preset temperature is 45°C to 55°C lower than the melting point of the polymer material forming the polymer solution.

[0084] Furthermore, the delivery pump is a forward and reverse delivery pump, that is, the delivery pump can deliver the polymer solution in the forward direction, so that the polymer solution flows into the cavity in the forward direction through the delivery pipe 31, and the delivery pump can also deliver the polymer solution in the reverse direction, so that the polymer solution flows back into the hot melt box 11 in the reverse direction away from the cavity through the delivery pipe 31.

[0085] Correspondingly, in the method for preparing the radial conduit, after the injection is completed and before curing, the method further includes the following step: conveying the polymer solution in the delivery pipe 31 for conveying the polymer solution in a direction away from the cavity, so as to empty the delivery pipe 31. Specifically, driving the delivery pump to convey the polymer solution in the reverse direction to empty the polymer solution in the delivery pipe 31. This avoids the polymer solution in the delivery pipe 31 solidifying and clogging the delivery pipe 31 during the subsequent cooling and curing process.

[0086] Furthermore, the molding assembly 2 also includes an ultrasonic generator 27 acting on the cavity. Activating the ultrasonic generator 27 while injecting the polymer solution into the cavity allows the polymer solution to flow through each corresponding through-hole, improving the stability of the final injection conduit; simultaneously, it removes air bubbles from the polymer solution.

[0087] Specifically, the ultrasonic generator 27 is disposed on the housing 21 and close to the corresponding mounting cavity to improve the vibration effect of the ultrasonic generator 27 on the polymer solution in the cavity.

[0088] Correspondingly, in the method for preparing the radial conduit, while "injecting the polymer solution into the cavity", the ultrasonic generator 27 acting on the cavity is activated.

[0089] Furthermore, the cavity comprises multiple interconnected sub-cavities arranged in a vertical direction. Each sub-cavity includes an outer sub-cavity and an inner sub-cavity corresponding to that sub-cavity. Each hot-melt assembly 1 corresponds to one of the sub-cavities, and multiple hot-melt assemblies 1 are spaced apart in a vertical direction. Different types of polymer solutions can be injected into different sub-cavities as needed to meet the performance requirements of the prepared radial conduit, such as ensuring that the hardness of the radial conduit gradually decreases and it softens from the proximal to the distal end.

[0090] It is known that the types of polymer solutions in the outer sub-cavity, inner sub-cavity, and the penetrating portion connecting the outer sub-cavity and the inner sub-cavity are consistent with each sub-cavity.

[0091] Furthermore, in the embodiment where the cavity includes multiple interconnected sub-cavities arranged vertically, the heating component 26 corresponds one-to-one with each sub-cavity, and the water circulation system corresponds one-to-one with each sub-cavity. Thus, only the sub-cavities to be filled need to be heated and kept at a constant temperature, preventing the temperature from affecting the already solidified polymer solution in other cavities; simultaneously, only the sub-cavities where the polymer solution needs to be solidified immediately after filling are cooled, improving the cooling effect.

[0092] In embodiments where the cavity comprises multiple interconnected sub-cavities arranged vertically, the "injection of a polymer solution into the cavity and curing after injection" step in the preparation method of the radial conduit specifically involves: injecting and curing a polymer solution of the corresponding type into the lower sub-cavity of two adjacent sub-cavities, then injecting and curing the same polymer solution into the upper sub-cavity. That is, the coating in each sub-cavity is formed sequentially from bottom to top. This avoids mixing of different types of polymer solutions within the cavity, which could affect the overall performance of the final radial conduit.

[0093] Furthermore, the process of "injecting a corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities and curing it, then injecting a corresponding type of polymer solution into the upper sub-cavity and curing it" specifically includes the following steps:

[0094] When injecting a polymer solution of the corresponding type into the lower sub-cavity until the liquid level of the polymer solution is 2mm to 3mm from the top of the sub-cavity, while continuing to inject the corresponding polymer solution into the lower sub-cavity, a polymer solution corresponding to the upper sub-cavity is injected into the lower sub-cavity to form a mixture. The injection ends when the liquid level of the mixture exceeds the bottom of the upper sub-cavity by 2mm to 3mm, and the polymer solution is then cured.

[0095] After the injected polymer solution is cured, the corresponding type of polymer solution is injected into the sub-cavity located on the upper side and cured.

[0096] That is, forming a mixed segment at the interface of two polymer materials can reduce the sudden change in hardness caused by the interface of different polymer materials. As a result, the hardness change of the prepared radial catheter at the interface of different polymer materials is smaller, thus improving the pushing effect of the radial catheter.

[0097] Specifically, before injecting the corresponding polymer solution into the corresponding sub-cavity, the heating component 26 corresponding to the sub-cavity to be injected is first activated to raise the temperature of the sub-cavity to be injected to the first preset temperature and keep it at that temperature until the injection is completed.

[0098] It is known that the first preset temperature is 15°C to 25°C higher than the melting point of the polymer material forming the polymer solution corresponding to the sub-cavity.

[0099] Meanwhile, the aforementioned end of injection refers to the point when the liquid level of the mixture exceeds the bottom of the upper sub-cavity by 2mm to 3mm.

[0100] Specifically, after the filling of the lower sub-cavity is completed, the heating component 26 corresponding to the lower sub-cavity is turned off. At the same time, the water circulation system corresponding to the lower sub-cavity after the filling is completed is started to cool the lower sub-cavity, so as to reduce the temperature inside the sub-cavity after the filling is completed to the second preset temperature, so as to solidify the polymer solution inside the lower sub-cavity and the mixture at the junction of the upper and lower sub-cavities.

[0101] It is known that the second preset temperature is 45°C to 55°C lower than the melting point of the polymer material that forms the polymer solution corresponding to the sub-cavity.

[0102] Furthermore, after shutting down the heating component 26 corresponding to the lower sub-cavity, and simultaneously before starting the water circulation system corresponding to the lower sub-cavity after the injection is completed, the preparation method of the radial conduit further includes: starting the delivery pump in the delivery component 3 corresponding to the two adjacent sub-cavities, so that the delivery pumps both reverse the delivery of the corresponding polymer components, so that the polymer solution in the delivery pipes 31 in the two delivery components 3 is drawn back into the corresponding hot melt box 11, avoiding subsequent cooling that could cause blockage of the delivery pipes 31.

[0103] Furthermore, the polymer material forming the polymer solution includes silicone oil. This gives the polymer material a certain degree of lubricity, allowing the coating formed by the curing of the polymer solution to replace the existing inner layer of the radial catheter and meet the performance requirements of the inner layer of the radial catheter.

[0104] Furthermore, combined Figure 2 As shown, the coating mold 100 includes a plurality of forming components 2 arranged circumferentially around the hot-melt component 1, and a conveying component 3 that connects the hot-melt component 1 to the plurality of forming components 2. Therefore, multiple radial catheters can be formed simultaneously, improving the preparation efficiency of the radial catheters.

[0105] It is understood that when the coating mold 100 includes a plurality of molding components 2 arranged circumferentially around the hot melt component 1, and each molding component 2 has a plurality of sub-cavities, the plurality of hot melt components 1 are arranged circumferentially around each hot melt component 1.

[0106] The following describes the preparation method of the radial conduit using the coating mold 100 of the present invention, taking the housing 21 having one mounting cavity and each cavity having three sub-cavities as an example. From bottom to top, the three sub-cavities are a lower sub-cavity, a middle sub-cavity, and an upper sub-cavity. The hot-melt components corresponding to the lower, middle, and upper sub-cavities are: a lower hot-melt component, a middle hot-melt component, and an upper hot-melt component, respectively. The conveying components corresponding to the lower, middle, and upper sub-cavities are: a lower conveying component, a middle conveying component, and an upper conveying component, respectively. The components include an upper conveying assembly; heating assemblies corresponding to the lower, middle, and upper sub-cavities are: a lower heating assembly, a middle heating assembly, and an upper heating assembly; water circulation systems corresponding to the lower, middle, and upper sub-cavities are: a lower water circulation system, a middle water circulation system, and an upper water circulation system; and polymer solutions (polymer materials) corresponding to the lower, middle, and upper sub-cavities are: TPU, PEBAX, and nylon, respectively, with nylon having a melting point of 190℃, PEBAX having a melting point of 160℃, and TPU having a melting point of 120℃. From the proximal end to the distal end, the inner and outer layers of the ultimately formed radial conduit are made of nylon, PEBAX, and TPU, respectively, to meet the conveying performance requirement of the radial conduit having gradually decreasing hardness from the proximal end to the distal end. However, this is not a limitation.

[0107] The specific method for preparing a radial catheter is as follows:

[0108] Take out the mandrel 22, put the intermediate layer 10 on the mandrel 22, and then install the mandrel 22 with the intermediate layer 10 on it in the preset position in the installation cavity, and close the door 211.

[0109] TPU, PEBAX, and nylon are placed into the hot melt boxes of the lower hot melt assembly, the middle hot melt assembly, and the upper hot melt assembly, respectively. The hot melt heating elements in each hot melt assembly are activated to melt the polymer materials into a polymer solution. Silicone oil is added to the polymer solution.

[0110] The lower heating assembly is activated to heat the lower mold cavity to 140°C, and the temperature is maintained at 140°C.

[0111] Start the pump of the lower conveying component to deliver TPU solution to the lower mold cavity in the forward direction. When the liquid level of the TPU solution is 2mm to 3mm from the top of the lower mold cavity, simultaneously start the pump of the middle conveying component to deliver PEBAX solution in the forward direction until the liquid level of the mixture of TPU solution and PEBAX solution exceeds the bottom of the neutron mold cavity by 2mm to 3mm. Then, control the pumps in the lower and middle conveying components to stop the injection process.

[0112] The pumps in the lower and middle conveying components are activated to reverse the flow of the polymer solution, thereby emptying the corresponding polymer solution from the conveying pipes in the lower and middle conveying components.

[0113] The water circulation system is activated to cool the lower sub-cavity until the temperature inside the lower sub-cavity drops to 70°C. At this time, the TPU solution inside the lower sub-cavity and the mixed liquid located at the junction of the lower sub-cavity and the neutron cavity solidify to form the lower coating.

[0114] During startup, the heating assembly heats the neutron cavity to 180°C and maintains the temperature inside the neutron cavity at 180°C.

[0115] When the pump of the middle conveying component is started, it delivers PEBAX solution into the neutron cavity in the forward direction. When the liquid level of the PEBAX solution is 2mm to 3mm away from the top of the neutron cavity, the pump of the upper conveying component is started to deliver nylon solution in the forward direction until the liquid level of the mixture of nylon solution and PEBAX solution exceeds the bottom of the upper neutron cavity by 2mm to 3mm. Then, the pumps in the middle conveying component and the upper conveying component are stopped to end the feeding process.

[0116] The pumps in the in-process conveying assembly and the upper conveying assembly reverse the flow of polymer solution to clear the corresponding polymer solution in the conveying pipes of the air conveying assembly and the upper conveying assembly.

[0117] The water circulation system is activated to cool the neutron cavity until the temperature inside the neutron cavity drops to 110°C. At this point, the PEBAX solution inside the neutron cavity and the mixed liquid located at the junction of the neutron cavity and the upper neutron cavity solidify to form the middle section coating.

[0118] The upper heating assembly is activated to heat the upper sub-cavity to 210°C, and the temperature is maintained at 210°C.

[0119] The upper conveying assembly's conveying pump is started to convey nylon solution forward into the upper mold cavity. When the upper mold cavity is filled with nylon solution, the conveying pump in the upper conveying assembly is controlled to stop the injection process.

[0120] Start the pump in the upper conveying assembly to reverse the flow of the polymer solution in order to empty the nylon solution in the conveying pipe of the upper conveying assembly;

[0121] The water circulation system is activated to cool the upper mold cavity until the temperature inside the upper mold cavity drops to 140°C. At this point, the nylon solution inside the upper mold cavity solidifies to form the upper coating.

[0122] Finally, after cooling to room temperature, open the door 211, remove the formed radial conduit along with the mandrel 22, and then remove the core to obtain the radial conduit.

[0123] Furthermore, the present invention also provides a radial catheter prepared using the above-described method for preparing a radial catheter; or a radial catheter prepared using the above-described coating mold 100. The method for preparing the radial catheter and the coating mold 100 are as described above, and will not be repeated here.

[0124] The transradial catheter includes a tubular intermediate layer 10, an outer layer located on the outer periphery of the intermediate layer 10, and an inner layer located on the inner periphery of the intermediate layer 10. The wall of the intermediate layer 10 has a through portion that connects the inside and outside of the intermediate layer 10 radially. The through portion has a connecting portion that connects the inner layer and the outer layer. The inner layer, outer layer, and connecting portion are integrally formed coatings. On the one hand, there is no assembly gap between the inner layer and the intermediate layer 10, which can reduce the wall thickness of the transradial catheter while maintaining its interventional performance, and there is no problem of loose adhesion between the polymer coating and the intermediate layer 10. On the other hand, the outer surface of the formed transradial catheter is smoother, and the integral formation of the inner layer, outer layer, and connecting portion can improve the stability of the transradial catheter.

[0125] In one specific embodiment, the tubular intermediate layer 10 is a sodium hypochlorite tube, and the through portion is a cut pattern penetrating the wall of the sodium hypochlorite tube. The specific pattern / cutting density and other parameters of the cut pattern can be set according to requirements, and will not be elaborated here. Of course, this is not a limitation. In other embodiments, the tubular intermediate layer 10 can also be a braided tube, a spring tube, or any combination of sodium hypochlorite tube, braided tube, and spring tube.

[0126] Furthermore, in the direction from the proximal end to the distal end, the coating comprises multiple sub-coatings, wherein the hardness of the sub-coating closer to the proximal end in two adjacent sub-coatings is greater than the hardness of the sub-coating closer to the distal end. In one specific embodiment, the coating comprises three sub-coatings, in the direction from the proximal end to the distal end, wherein the polymer materials of the three sub-coatings are nylon, PEBAX, and TPU, respectively.

[0127] Furthermore, the material at the interface between adjacent sub-coatings is a mixture of the polymer materials corresponding to the two adjacent sub-coatings. This results in a smaller abrupt change in hardness at the interface between adjacent sub-coatings of the transradial conduit, improving the pushing effect of the transradial conduit.

[0128] In summary, the method for preparing the transradial catheter of the present invention involves placing an intermediate layer 10 within the cavity of a coating mold 100, forming gaps on both the outer and inner circumferences of the intermediate layer 10, and then injecting a polymer solution into these gaps. After the polymer solution solidifies, an integral coating is formed on the inner and outer circumferences and through-holes of the intermediate layer 10, thus forming the transradial catheter. On one hand, there is no assembly gap between the inner layer and the intermediate layer 10, which reduces the wall thickness of the transradial catheter while maintaining its interventional performance, and there is no problem of loose adhesion between the polymer solution and the intermediate layer 10. On the other hand, the outer surface of the formed transradial catheter is smoother, and the liquid polymer solution fills all the through-holes, thereby forming a connection between the inner and outer layers in each through-hole, improving the stability of the transradial catheter.

[0129] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0130] The detailed descriptions listed above are merely specific descriptions of feasible implementations of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a radial catheter, characterized in that: The steps include the following: A tubular intermediate layer is provided, the tube wall of the intermediate layer having a through portion that radially communicates the inside and outside of the intermediate layer; The intermediate layer is placed in the cavity of the coating mold to form an outer cavity located on the outer periphery of the intermediate layer and an inner cavity located on the inner periphery of the intermediate layer. The through portion connects the outer cavity and the inner cavity. A polymer solution is injected into the cavity and cured after injection. The cured polymer solution in the outer cavity forms the outer layer of the radial conduit, and the cured polymer solution in the inner cavity forms the inner layer of the radial conduit. The cured polymer solution in the through-hole forms the connecting part between the outer layer and the inner layer. Demolding.

2. The method for preparing a transradial catheter according to claim 1, characterized in that: "Injecting a polymer solution into the cavity and then curing it" specifically means: injecting a polymer solution into the outer cavity, and the polymer solution in the outer cavity flows into the inner cavity through the penetration portion.

3. The method for preparing a transradial catheter according to claim 1, characterized in that: While injecting the polymer solution into the cavity, the ultrasonic generator acting on the cavity is activated.

4. The method for preparing a transradial catheter according to claim 1, characterized in that: Before "injecting the polymer solution into the cavity", the method for preparing the transradial conduit further includes the following steps: The heating assembly is activated to raise the temperature inside the cavity to be injected to a first preset temperature and maintain the temperature until the injection is completed. The first preset temperature is not lower than the melting point of the polymer material that forms the polymer solution to be injected.

5. The method for preparing a transradial catheter according to claim 4, characterized in that: "Cure after injection" specifically means: turn off the heating component and start the water circulation system to cool the cavity after injection until the temperature inside the cavity drops to a second preset temperature, wherein the second preset temperature is lower than the melting point of the polymer material that forms the polymer solution.

6. The method for preparing a transradial catheter according to claim 1, characterized in that: From bottom to top, the cavity includes multiple interconnected sub-cavities, each sub-cavity including an outer sub-cavity and an inner sub-cavity corresponding to it. The multiple sub-cavities correspond to various polymer solutions. After injecting and solidifying the lower sub-cavity of two adjacent sub-cavities, the corresponding polymer solution is then injected and solidified into the upper sub-cavity.

7. The method for preparing a transradial catheter according to claim 6, characterized in that: "After injecting and curing a corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, and then injecting and curing the corresponding type of polymer solution into the upper sub-cavity" specifically includes the following steps: When injecting a polymer solution of the corresponding type into the lower sub-cavity until the liquid level of the polymer solution is 2mm to 3mm from the top of the sub-cavity, while continuing to inject the corresponding polymer solution into the lower sub-cavity, a polymer solution corresponding to the upper sub-cavity is injected into the sub-cavity to form a mixture. The injection ends when the liquid level of the mixture exceeds the bottom of the upper sub-cavity by 2mm to 3mm, and the polymer solution is then cured. After the polymer solution is cured, the corresponding type of polymer solution is injected into the sub-cavity located on the upper side and cured.

8. The method for preparing a transradial catheter according to claim 1, characterized in that: After the injection is completed and before curing, the method for preparing the radial conduit further includes the following step: conveying the polymer solution in the delivery pipe for conveying the polymer solution in a direction away from the cavity, so as to empty the delivery pipe.

9. The method for preparing a transradial catheter according to claim 4, characterized in that: From bottom to top, the cavity includes multiple interconnected sub-cavities. Each sub-cavity includes an outer sub-cavity and an inner sub-cavity corresponding to it. The multiple sub-cavities correspond to various polymer solutions. After injecting and solidifying the corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, the corresponding type of polymer solution is then injected and solidified into the upper sub-cavity. "Starting the heating component to raise the temperature inside the cavity to the first preset temperature and holding it until the injection is finished" specifically means: starting the heating component corresponding to the sub-cavity to be injected to raise the temperature of the sub-cavity to be injected to the first preset temperature and holding it until the injection is finished.

10. The method for preparing a transradial catheter according to claim 4, characterized in that: From bottom to top, the cavity includes multiple interconnected sub-cavities. Each sub-cavity includes an outer sub-cavity and an inner sub-cavity corresponding to it. The multiple sub-cavities correspond to various polymer solutions. After injecting and solidifying the corresponding type of polymer solution into the lower sub-cavity of two adjacent sub-cavities, the corresponding type of polymer solution is then injected and solidified into the upper sub-cavity. "Starting the water circulation system to cool the cavity until the temperature inside the cavity drops to the second preset temperature" specifically means: starting the water circulation system corresponding to the sub-cavity where the injection is completed, so as to reduce the temperature inside the sub-cavity where the injection is completed to the second preset temperature.

11. The method for preparing a transradial catheter according to claim 4, characterized in that: The first preset temperature is 15°C to 25°C higher than the melting point of the polymer material forming the polymer solution.

12. The method for preparing a transradial catheter according to claim 5, characterized in that: The second preset temperature is 45°C to 55°C lower than the melting point of the polymer material that forms the polymer solution.

13. The method for preparing a transradial catheter according to claim 1, characterized in that: Polymer materials that form polymer solutions include silicone oil.

14. The method for preparing a transradial catheter according to claim 1, characterized in that: The intermediate layer is a sodium hypochlorite tube.

15. A radial conduit comprising a tubular intermediate layer, an outer layer located at the outer periphery of the intermediate layer, and an inner layer located at the inner periphery of the intermediate layer, wherein the wall of the intermediate layer has a through portion communicating radially with the inside and outside of the intermediate layer, and the through portion has a connecting portion connecting the inner layer and the outer layer; characterized in that: The inner layer, outer layer, and connecting portion are integrally formed coatings; the radial catheter is prepared using the radial catheter preparation method described in any one of claims 1 to 14.

16. The transradial catheter according to claim 15, characterized in that: The coating comprises multiple sub-coatings in the direction from the proximal end to the distal end of the radial conduit, wherein the hardness of the sub-coating closer to the proximal end in two adjacent sub-coatings is greater than that of the sub-coating closer to the distal end.

17. The transradial catheter according to claim 16, characterized in that: The material at the junction of adjacent sub-coatings is a mixture of the polymer materials corresponding to the two adjacent sub-coatings.

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