Double-layer conduit capable of eliminating stress and manufacturing method

Abstract

The invention discloses a double-layer catheter capable of eliminating stress and a manufacturing method. The double-layer catheter capable of eliminating stress comprises a main catheter body, and the main catheter body is provided with a catheter wall and a main catheter cavity; the main catheter cavity is used for establishing a conventional catheter working passage; the main catheter body comprises a supporting section and a pressure relief section, the supporting section is arranged close to the near end of the main catheter body, and the pressure relief section is arranged close to the far end of the main catheter body; a first lining layer, a first supporting layer and a first outer pipe layer are sequentially arranged on the pipe wall of the supporting section from inside to outside; a second lining layer, a second supporting layer, an inner pipe layer, a third supporting layer and a second outer pipe layer are sequentially arranged on the pipe wall of the pressure relief section from inside to outside; a pressure relief cavity is formed between the inner pipe layer and the second outer pipe layer; the pressure relief cavity deforms when the pressure relief section is stressed and restores to the original shape after pressure is released. The problem of instrument tension accumulation in the interventional operation process can be solved, and the operation risk is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of medical catheters, and in particular to a double-layer catheter capable of eliminating stress and a manufacturing method thereof. Background Art

[0002] With the continuous development of neurointerventional surgery, neurointerventional catheters are used more and more deeply in the skull and are placed higher and higher. The higher the placement, the longer the distance of the blood vessels that the catheter needs to pass. The blood vessels in the nervous system are the most tortuous in the human body, so the requirements for the performance of the catheter are getting higher and higher. The neurointerventional catheters currently used are all hardness gradient catheters made of a variety of materials. This type of catheter can only be pushed into place by the softness of the material itself and the support of the proximal end during the use process. The main problem with this type of catheter in clinical practice is that, with the increasing placement, the more bends in the blood vessels, the more obvious the tension accumulation of each curved part of the catheter. Even if the catheter is finally in place, it will cause great tension in the entire distal vascular pathway. In addition, most interventional catheters are used to establish pathways. The catheter will produce slight deformation when it bends, which affects the space of the pathway. During use, other devices such as stents, balloons, micro-guidewires / catheters are pushed into the catheter cavity. The promotion of the intermediate devices will cause secondary tension accumulation in the catheter pathway, and the tension of the entire pathway system is extremely high. It often happens that the catheter is in place before surgery and treatment can be achieved during surgery. However, after the intermediate instruments are removed, the catheter tension cannot be eliminated due to the long-term accumulation during the treatment period. Finally, the catheter cannot be withdrawn and hugs the blood vessel, usually resulting in catheter deformation / tearing, vascular irritation / spasm, etc., which increases the surgical risk and time. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a double-layer catheter capable of eliminating stress and a manufacturing method thereof, which can solve the problem of instrument tension accumulation during interventional surgery and reduce surgical risks.

[0004] The first aspect of the present invention provides a double-layer catheter capable of eliminating stress, comprising a main body, the main body having a tube wall and a main cavity; the main cavity is used to establish a conventional catheter working passage; the main body comprises a support section and a pressure relief section, the support section is arranged near the proximal end of the main body, and the pressure relief section is arranged near the distal end of the main body;

[0005] The support section pipe wall is provided with a first inner lining layer, a first support layer and a first outer pipe layer in sequence from the inside to the outside;

[0006] The pipe wall of the pressure relief section is provided with a second lining layer, a second supporting layer, an inner tube layer, a third supporting layer and a second outer tube layer in sequence from the inside to the outside; a pressure relief cavity is formed between the inner tube layer and the second outer tube layer; the pressure relief cavity is deformed when the pressure relief section is subjected to force, and returns to its original state after the pressure is relieved.

[0007] In the first aspect of the present invention, as a preferred embodiment, developing rings are provided at both ends of the pressure release section, and the developing rings are made of platinum-iridium alloy and can be developed under radiation.

[0008] In the first aspect of the present invention, as a preferred embodiment, the pressure relief chamber has an outer cavity wall and an inner cavity wall, the outer cavity wall is the side wall of the pressure relief chamber close to the second outer tube layer, and the inner cavity wall is the side wall of the pressure relief chamber close to the inner layer tube; the outer cavity wall has a first central axis, and the first central axis is the center line connecting the two ends of the outer cavity wall; the inner cavity wall has a second central axis, and the second central axis is the center line connecting the two ends of the inner cavity wall; under normal circumstances, the first central axis coincides with the second central axis, and when the pressure relief section is subjected to force, the first central axis deviates from the second central axis.

[0009] In the first aspect of the present invention, as a preferred embodiment, the cross-section of the outer cavity wall is circular in a normal state; when the pressure release section is subjected to force, the cross-section of the outer cavity wall is deformed into an elliptical shape.

[0010] In the first aspect of the present invention, as a preferred embodiment, the distal end of the main pipe is formed with a conical head end; the length of the main pipe is 130cm to 170cm; the length of the pressure release section is 2cm to 20cm; the surface of the main pipe is coated with a hydrophilic coating, and the length of the hydrophilic coating is 60 to 100cm; the inner diameter of the main cavity of the main pipe is 0.5mm to 2.5mm; the outer diameter of the main pipe is 1.0mm to 3.3mm.

[0011] In the first aspect of the present invention, as a preferred embodiment, the first inner lining layer material includes polytetrafluoroethylene; the first supporting layer includes a first spring wound layer and a first braided layer; the first outer tube layer material includes polyamide, polyetheramide resin and barium sulfate.

[0012] In the first aspect of the present invention, as a preferred embodiment, the second lining layer material includes polytetrafluoroethylene; the second supporting layer is a second spring winding layer; the inner tube layer material includes polyurethane; the third supporting layer is a second braided layer; the second outer tube layer material includes polyurethane, polyetheramide resin and barium sulfate.

[0013] In the first aspect of the present invention, as a preferred embodiment, the second braided layer is woven from a plurality of braided wires, the braided wires are stainless steel wires, and the braided wires are round wires, flat wires, round-flat mixed braids, or round-flat mixed twists;

[0014] The second spring winding layer is formed by winding a plurality of spring winding wires, the spring winding wires are stainless steel wires, and the braided wires are round wires, flat wires, a mixture of round and flat, or a mixture of round and flat.

[0015] In the first aspect of the present invention, as a preferred embodiment, it also includes a catheter seat, which is installed at the proximal end of the main pipe body, and the catheter seat is a quasi-Luer connector made of polycarbonate; a stress relief tube is provided at the connection between the catheter seat and the main pipe body.

[0016] A second aspect of the present invention provides a method for manufacturing a double-layer catheter capable of eliminating stress, comprising the following steps:

[0017] An inner liner tube and two developing rings are provided, the two developing rings are respectively a first developing ring and a second developing ring; the inner liner tube has a first segment and a second segment in sequence from the proximal end to the distal end; the first developing ring is fixed between the first segment and the second segment, and the second developing ring is fixed at the end of the second segment;

[0018] Providing a plurality of strands of spring wires, winding the spring wires around the surfaces of the first segment and the second segment of the inner liner tube to form a spring layer, and the ends of the spring wires are fixedly connected to the second developing ring;

[0019] Providing a plurality of braided wires, braiding the braided wires on the surface of the first segment of the inner liner tube to form a braided layer; the ends of the braided wires are fixedly connected to the second developing ring;

[0020] Providing a first outer tube layer material, the first outer tube layer material comprising polyamide, polyetheramide resin and barium sulfate; rheologically combining the first outer tube layer material with the braided layer, the spring wound layer and the inner lining layer on the surface of the first segment to form the first outer tube layer;

[0021] Providing an inner tube material, the inner tube material comprising polyurethane; rheologically making the inner tube material bonded to the spring wound layer and the inner lining layer on the surface of the second segment;

[0022] Provide a plurality of braided wires and a tube, braid the braided wires on the surface of a supporting tube to form a braided layer; provide a second outer tube layer material, the second outer tube layer material includes polyurethane, polyetheramide resin and barium sulfate; rheologically allow the second outer tube layer material to combine with the braided layer on the surface of the tube; remove the tube to obtain a composite tube body of the second outer tube layer and the braided layer; sleeve the composite tube body on the second segment, and fix the two ends of the composite tube body to the first developing ring and the second developing ring respectively;

[0023] Coating a hydrophilic coating on the surface of the first outer tube layer and the composite tube body;

[0024] A catheter seat and a stress relief tube are provided, and the catheter seat and the stress relief tube are installed to the proximal end of the main tube body.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The double-layer catheter capable of eliminating stress of the present invention has a support section at the proximal end which is a composite single-layer tube to improve the strength, realize the conveying support of the tube body, and ensure the transmission of force. A pressure relief section is arranged at the distal end for double-layer partitioning, which is used to realize the product in place and tension release. The pressure relief cavity can absorb tension in the inner bend of the blood vessel when the main body passes through the multi-layer tortuous blood vessels. Through the slight deformation of the outer layer structure of the pressure relief cavity and the displacement of the inner layer structure of the pressure relief cavity at the center of the catheter, the tension is released, the vascular stimulation is alleviated, and the risk of device use is reduced. The inner layer structure of the pressure relief cavity is responsible for the realization of the passage. The outer layer structure of the pressure relief cavity allows partial elliptical deformation during use. When the pressure relief cavity is compressed, its outer cavity wall contacts the inner cavity wall, that is, it plays an anti-deformation ability at the same time to avoid the excessive deformation of the product and the bending of the catheter, which makes it unusable. That is, the deformation of the outer layer structure of the pressure relief cavity does not affect the actual catheter passage through which the device passes, and there is no cavity loss, so that the high position of the internal carotid artery and the stress release during the process are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a double-layer conduit capable of eliminating stress according to the present invention;

[0028] Figure 2 It is a structural schematic diagram of the AA section of the double-layer conduit capable of eliminating stress of the present invention;

[0029] Figure 3 It is a partial enlarged view of the double-layer catheter part B that can eliminate stress of the present invention;

[0030] Figure 4 This is a schematic diagram of the use status of a conventional catheter in a blood vessel;

[0031] Figure 5 It is a schematic diagram of the use state of the double-layer catheter capable of eliminating stress of the present invention in a blood vessel;

[0032] Figure 6 It is a partial enlarged view of the double-layer catheter part C that can eliminate stress of the present invention;

[0033] In the figure: 10, main tube body; 11, supporting section; 111, first inner lining layer; 112, first supporting layer; 113, first outer tube layer; 12, pressure relief section; 121, second inner lining layer; 122, second supporting layer; 123, inner tube layer; 124, pressure relief cavity; 125, third supporting layer; 126, second outer tube layer; 13, main tube cavity; 14, tapered head end; 15, developing ring; 20, catheter seat; 90, blood vessel. DETAILED DESCRIPTION

[0034] Below, in conjunction with the accompanying drawings and specific embodiments, the invention is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except as otherwise specified, the materials and equipment used in this embodiment can be purchased from the market. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0035] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Example 1

[0039] Please refer to Figure 1-6 As shown, this embodiment provides a double-layer catheter that can eliminate stress. The double-layer catheter that can eliminate stress in this embodiment belongs to the field of medical catheters and is specially designed for neurointerventional surgery to solve the problem of instrument tension accumulation during interventional surgery and reduce surgical risks.

[0040] The double-layer catheter capable of relieving stress in this embodiment includes a main body 10 , a catheter seat 20 , and a stress relief tube disposed at the connection between the catheter seat 20 and the main body 10 .

[0041] The main body 10 of the present embodiment has a proximal end and a distal end, wherein the proximal end is the end closer to the operator when in use, and the distal end is the end farther from the operator when in use. The main body 10 has a central axis, which is a line connecting the center of the distal end of the outer tube and the center of the proximal end of the outer tube in a natural state; the inner side of the present embodiment refers to the side relatively close to the central axis, and the outer side refers to the side relatively far from the central axis; the proximal end of the main body 10 of the present embodiment is used to connect with operating equipment such as a stress relief tube and a regulating handle, and the distal end is used for access, which can be understood by those skilled in the art.

[0042] The main body 10 has a tube wall and a main cavity 13; the main cavity 13 is used to establish a conventional catheter working passage; the main body 10 includes a support section 11 and a pressure relief section 12, the support section 11 is arranged near the proximal end of the main body 10, and the pressure relief section 12 is arranged near the distal end of the main body 10.

[0043] The support section 11 has a first inner lining layer 111, a first support layer 112 and a first outer tube layer 113 arranged in sequence from the inside to the outside of the tube wall;

[0044] The tube wall of the pressure relief section 12 is provided with a second lining layer 121, a second supporting layer 122, an inner tube layer 123, a third supporting layer 125 and a second outer tube layer 126 in sequence from the inside to the outside; a pressure relief chamber 124 is formed between the inner tube layer 123 and the second outer tube layer 126; the pressure relief chamber 124 is deformed when the pressure relief section 12 is subjected to force, and returns to its original state after the pressure is released.

[0045] Based on the above structure, the double-layer catheter capable of eliminating stress in this embodiment is made into a double-layer catheter structure by setting a pressure relief cavity 124 inside the pressure relief section 12 at the distal end of the main body 10. The double layer referred to in this embodiment is formed by different catheter functional areas after different reinforcement layers are compounded with polymer materials. The pressure relief cavity 124 can absorb tension in the inner bend of the blood vessel 90 when the catheter passes through the multi-layer tortuous blood vessel 90. The tension is released by slightly deforming the outer layer structure of the pressure relief cavity 124 and offsetting the inner layer structure of the pressure relief cavity 124 on the central axis. The support section 11 at the proximal end of the main body 10 of this embodiment is a composite single-layer tube, which is made of double-layer partitions with the distal pressure relief section 12. The proximal support section 11 is mainly used to improve the strength to ensure the transmission of the transport support force, and the distal pressure relief section 12 is mainly used to achieve product placement and tension release. Its stage length is designed based on the length of the clinical intracranial blood vessel 90, which can be known to those skilled in the art. The stress-relieving double-layer catheter of the present embodiment is realized by the interconnected first inner lining layer 111 and the second inner lining layer 121 being responsible for the passage. This part maintains the passage environment, and the outer layer structure of the pressure relief chamber 124 is allowed to partially elliptical deform during use. The partial deformation and the deformation of the pressure relief chamber 124 are combined to realize tension release. When the pressure relief section 12 is compressed, the outer layer structure contacts the inner layer structure, which simultaneously plays a role in resisting deformation and avoiding situations such as excessive deformation of the product and bending of the catheter, which makes it unusable. This solves the problem of instrument tension accumulation during interventional surgery and reduces surgical risks.

[0046] In this embodiment, both ends of the pressure relief section 12 are provided with developing rings 15, which are made of platinum-iridium alloy and can be developed under radiation. By placing a developing ring 15 before and after the pressure relief section 12, it is used to indicate the position of the catheter head end and the length of the tension-releasing portion during the operation.

[0047] Specifically, the pressure relief chamber 124 has an outer wall and an inner wall, wherein the outer wall is the side wall of the pressure relief chamber 124 close to the second outer tube layer 126, and the inner wall is the side wall of the pressure relief chamber 124 close to the inner tube layer; the outer wall has a first central axis, which is the center line connecting the two ends of the outer wall; the inner wall has a second central axis, which is the center line connecting the two ends of the inner wall; the first central axis coincides with the second central axis under normal conditions, and when the pressure relief section 12 is subjected to force, the first central axis deviates from the second central axis. On the other hand, the cross section of the outer wall is circular under normal conditions; when the pressure relief section 12 is subjected to force, the cross section of the outer wall is deformed into an ellipse.

[0048] The elliptical deformation of the outer wall of the pressure relief chamber 124 caused by the outer layer structure, and the offset of the first central axis of the outer wall of the pressure relief chamber 124 and the second central axis of the inner wall of the pressure relief chamber 124 on the central axis, both can occur separately or in coordination with each other, and both can achieve the release of the tension of the pressure relief segment 12 in the circuitous blood vessel 90, ensure the realization of its internal passage and avoid the occurrence of tension accumulation problems.

[0049] In this embodiment, a conical head 14 is formed at the distal end of the main body 10, and the edges of the conical head 14 are all provided with smooth chamfers, so that the catheter can pass through the blood vessel 90 more easily, and the positioning accuracy of the catheter at the target position is improved, especially in complex vascular systems or cavities, so that the catheter can be more easily positioned at the desired position.

[0050] The effective length of the main body 10 of this embodiment is preferably 130cm to 170cm; the length of the pressure release section 12 is 2cm to 20cm from the end head; the surface of the main body 10 is coated with a hydrophilic coating, and the length of the hydrophilic coating is preferably 60 to 100cm; the inner diameter of the main cavity 13 of the main body 10 is 0.5mm to 2.5mm; the outer diameter of the main body 10 is 1.0mm to 3.3mm.

[0051] In the support section 11 at the proximal end of the main body 10, the first inner lining layer 111 is made of PTFE (polytetrafluoroethylene), which establishes a flat and lubricated inner cavity, which is convenient for other instruments to pass through. The first support layer 112 includes a first spring layer and a first braided layer; the first braided layer is woven from a plurality of braided wires, the braided wires are stainless steel wires, the braided wires are round wires, flat wires, round and flat mixed braids or round and flat mixed braids; the first spring layer is wound from a plurality of spring wires, the spring wires are stainless steel wires, the braided wires are round wires, flat wires, round and flat mixed braids or round and flat mixed braids. Thus, the support force of the support section 11 is stronger, and the transmission of the pushing force is more efficient and uniform. The first outer tube layer 113 is made of a biocompatible polymer material, including PA (polyamide) and Pebax (polyetheramide resin), and the barium sulfate material contained therein can be developed under radiation, so that the support section 11 has a stronger hardness than the distal end of the main body 10, providing higher support.

[0052] In the pressure relief section 12 at the distal end of the main tube 10, the second lining layer 121 is made of PTFE (polytetrafluoroethylene), which creates a flat and lubricated inner cavity, which is convenient for other instruments to pass through. The second support layer 122 is a second spring layer; the second spring layer is formed by winding a plurality of spring wires, the spring wires are stainless steel wires, the braided wires are round wires, flat wires, round and flat mixed or round and flat mixed, and the second spring layer improves the compliance of the inner layer structure of the pressure relief chamber 124, as well as the torsion control and anti-deformation capabilities, and can improve the retention and tear resistance of the main cavity 13, which helps to continuously maintain a complete and smooth inner cavity state. The material of the inner tube layer 123 includes TPU (polyurethane). The third support layer 125 is a second braided layer; the second braided layer is formed by braiding a plurality of braided wires, the braided wires are stainless steel wires, the braided wires are round wires, flat wires, round and flat mixed or round and flat mixed; so that the outer layer structure of the pressure relief chamber 124 has a corresponding support force to ensure that the push force is evenly transmitted. The material of the second outer tube layer 126 includes TPU (polyurethane) and Pebax (polyetheramide resin), and the barium sulfate material contained therein can be developed under radiation.

[0053] The catheter seat of this embodiment is made of PC (polycarbonate) material and is a standard Luer connector. The stress relief sleeve is connected to the catheter seat at the proximal end of the main body 10 to facilitate the operator to control the main body 10 during the operation to avoid stress concentration and catheter breakage.

[0054] Figure 4 What is shown is a schematic diagram of the use status of a conventional catheter in a blood vessel 90. As there are more bends in the blood vessel 90, tension accumulates significantly in each curved part of the catheter, causing great tension in the entire distal blood vessel 90 passage; and as the catheter deforms and bends when making bends, there is lumen loss, which affects the space of the passage. Figure 5-6The figure shows a schematic diagram of the use state of the stress-relieving double-layer catheter of this embodiment in a blood vessel 90. The proximal support section 11 is a composite single-layer tube to improve strength, realize tube body transportation support, and ensure force transmission. The distal pressure relief section 12 is made of double-layer partitions to achieve product placement and tension release. The pressure relief chamber 124 can absorb tension in the inner bend of the blood vessel 90 when the main body 10 passes through the multi-layer tortuous blood vessel 90. The tension is released through the slight deformation of the outer layer structure of the pressure relief chamber 124 and the displacement of the inner layer structure of the pressure relief chamber 124 at the center of the catheter, which reduces the stimulation of the blood vessel 90 and reduces the risk of device use. The inner structure of the pressure relief chamber 124 is responsible for the realization of the passage, and the outer structure of the pressure relief chamber 124 allows partial elliptical deformation during use. When the pressure relief chamber 124 is compressed, its outer cavity wall contacts the inner cavity wall, which simultaneously plays an anti-deformation ability to avoid the product from excessive deformation, catheter bending, and other unusable situations. That is, the deformation of the outer structure of the pressure relief chamber 124 does not affect the catheter passage through which the actual instrument passes, and there is no cavity loss, thereby achieving high positioning of the internal carotid artery and stress release during the process.

[0055] Based on the above structure, the method for using the double-layer catheter capable of eliminating stress in the present embodiment in a neurointerventional surgery is as follows, comprising the following steps:

[0056] Step S101: Check whether the outside of the packaging box is obviously damaged. Take out the sterile bag from the packaging box and check whether it is damaged (ie, torn, punctured, scratched, etc.). If the sterile bag has been opened or damaged, do not use it.

[0057] Step S102: Carefully open the sterile bag, take out the angiography catheter, check whether the product is damaged, and flush the inner and outer cavities of the catheter with heparinized saline. Note: If the product is damaged, do not use it.

[0058] Step S103: A guide wire of suitable size that has been pre-soaked in heparinized saline is inserted into the double-layer catheter capable of relieving stress in this embodiment through the catheter seat until it passes through a length of about 5 cm from the head end.

[0059] Step S104: Select relevant equipment to establish blood vessel 90 access.

[0060] Step S105: After the passage is established, the double-layer catheter capable of eliminating stress of this embodiment is inserted into the blood vessel 90 along the guide wire (or other interventional catheters are coaxially inserted into the blood vessel 90).

[0061] Step S106: Perform superselection under X-ray fluoroscopy to confirm whether the tip of the main tube 10 is inserted into the target site, and then perform contrast agent or drug injection. Note: Before injecting contrast agent or drug, ensure that the main tube 10 is not knotted, broken, twisted, or blocked.

[0062] Step S107: If the main tube 10 needs to be delivered to the distal end of the blood vessel 90, the guide wire is inserted again, with the guide wire advanced first, and the main tube 10 is carefully inserted along the guide wire.

[0063] Step S108: When performing the surgery using the coaxial method, the guide wire is pulled out, and a sub-catheter (micro-catheter) is carefully inserted into the main lumen 13 .

[0064] Step S109: When replacing other catheters, move the main body 10 away from the target site, insert the guide wire again, and make it pass a little from the tip of the main body 10, and carefully replace the catheter along the guide wire.

[0065] Step S110: After the predetermined operation is completed, the main body 10 is moved away from the target position, and a guide wire is inserted so that the guide wire slightly extends out of the distal end of the catheter, and the catheter and the guide wire are carefully removed together.

[0066] Example 2

[0067] This embodiment provides a method for manufacturing a double-layered catheter capable of eliminating stress, which is mainly used to manufacture a double-layered catheter capable of eliminating stress as in Example 1, and comprises the following steps:

[0068] Step S201: providing an inner liner tube and two developing rings 15; the developing ring 15 is made of a platinum-iridium alloy, and the two developing rings 15 are respectively a first developing ring and a second developing ring; the inner liner tube is made of PTFF (polytetrafluoroethylene), and the inner liner tube has a first segment and a second segment in sequence from the proximal end to the distal end; fixing the first developing ring between the first segment and the second segment, and fixing the second developing ring at the end of the second segment;

[0069] Step S202: providing a plurality of strands of spring wire, winding the spring wire around the surfaces of the first segment and the second segment of the inner liner tube to form a spring winding layer, and the ends of the spring wire are fixedly connected to the second developing ring;

[0070] Step S203: providing a plurality of braided wires, and braiding the braided wires on the surface of the first segment of the inner liner tube to form a braided layer; and the ends of the braided wires are fixedly connected to the second developing ring;

[0071] Step S204: providing a first outer tube layer 113 material, the first outer tube layer 113 material comprising PA (polyamide), Pebax (polyetheramide resin) and barium sulfate; rheologically combining the first outer tube layer 113 material with the braided layer, the spring wound layer and the inner lining layer on the surface of the first segment to form the first outer tube layer 113;

[0072] Step S205: providing an inner tube layer 123 material, wherein the inner tube layer 123 material includes polyurethane; rheologically adjusting the inner tube layer 123 material to be combined with the spring wound layer and the inner lining layer on the surface of the second segment;

[0073] Step S206: providing a plurality of braided wires and a tube, braiding the braided wires on a surface of a supporting tube to form a braided layer; providing a second outer tube layer 126 material, the second outer tube layer 126 material comprising TPU (polyurethane), TPU (polyurethane) and barium sulfate; rheologically adjusting the second outer tube layer 126 material to combine with the braided layer on the surface of the tube; taking out the tube to obtain a composite tube body of the second outer tube layer 126 and the braided layer; sleeve the composite tube body on the second segment, and fix the two ends of the composite tube body to the first developing ring and the second developing ring respectively;

[0074] Step S207: coating a hydrophilic coating on the surface of the first outer tube layer 113 and the composite tube body;

[0075] Step S208: Provide a catheter seat 20 and a stress relief tube, and install the catheter seat 20 and the stress relief tube to the proximal end of the main body 10. The above embodiments are only preferred embodiments of the present invention, and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by those skilled in the art on the basis of the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A double-layer catheter capable of relieving stress, characterized in that: It comprises a main body, the main body having a tube wall and a main cavity; the main cavity is used to establish a conventional catheter working passage; the main body comprises a support section and a pressure relief section, the support section is arranged near the proximal end of the main body, and the pressure relief section is arranged near the distal end of the main body; The support section pipe wall is provided with a first inner lining layer, a first support layer and a first outer pipe layer in sequence from the inside to the outside; The pipe wall of the pressure relief section is provided with a second lining layer, a second supporting layer, an inner tube layer, a third supporting layer and a second outer tube layer in sequence from the inside to the outside; a pressure relief cavity is formed between the inner tube layer and the second outer tube layer; the pressure relief cavity is deformed when the pressure relief section is subjected to force, and returns to its original state after the pressure is relieved.

2. A double-layered catheter capable of relieving stress according to claim 1, characterized in that: Both ends of the pressure release section are provided with developing rings, which are made of platinum-iridium alloy and can be developed under radiation.

3. A double-layered catheter capable of relieving stress according to claim 2, characterized in that: The pressure relief chamber has an outer cavity wall and an inner cavity wall, the outer cavity wall is the side wall of the pressure relief chamber close to the second outer tube layer, and the inner cavity wall is the side wall of the pressure relief chamber close to the inner layer tube; the outer cavity wall has a first central axis, and the first central axis is the center line connecting the two ends of the outer cavity wall; the inner cavity wall has a second central axis, and the second central axis is the center line connecting the two ends of the inner cavity wall; under normal circumstances, the first central axis coincides with the second central axis, and when the pressure relief section is subjected to force, the first central axis deviates from the second central axis.

4. A double-layered catheter capable of relieving stress according to claim 3, characterized in that: The cross section of the outer cavity wall is normally circular; when the pressure release section is subjected to force, the cross section of the outer cavity wall is deformed into an ellipse.

5. A double-layered catheter capable of relieving stress according to claim 1, characterized in that: The distal end of the main pipe is formed with a conical head end; the length of the main pipe is 130cm to 170cm; the length of the pressure release section is 2cm to 20cm; the surface of the main pipe is coated with a hydrophilic coating, and the length of the hydrophilic coating is 60 to 100cm; the inner diameter of the main pipe cavity of the main pipe is 0.5mm to 2.5mm; the outer diameter of the main pipe is 1.0mm to 3.3mm.

6. A double-layered catheter capable of relieving stress according to claim 1, characterized in that: The material of the first inner lining layer includes polytetrafluoroethylene; the first supporting layer includes a first spring wound layer and a first braided layer; the material of the first outer tube layer includes polyamide, polyetheramide resin and barium sulfate.

7. A double-layered catheter capable of relieving stress according to claim 1, characterized in that: The second lining layer material includes polytetrafluoroethylene; the second supporting layer is a second spring wound layer; the inner tube layer material includes polyurethane; the third supporting layer is a second braided layer; the second outer tube layer material includes polyurethane, polyetheramide resin and barium sulfate.

8. A double-layered catheter capable of relieving stress according to claim 7, characterized in that: The second braided layer is formed by braiding a plurality of braided wires, the braided wires are stainless steel wires, and the braided wires are round wires, flat wires, a mixture of round and flat wires, or a mixture of round and flat wires; The second spring winding layer is formed by winding a plurality of spring winding wires, the spring winding wires are stainless steel wires, and the braided wires are round wires, flat wires, a mixture of round and flat, or a mixture of round and flat.

9. A double-layered catheter capable of relieving stress according to claim 1, characterized in that: It also includes a catheter seat, which is installed at the proximal end of the main pipe body and is a quasi-Luer connector made of polycarbonate; a stress relief tube is provided at the connection between the catheter seat and the main pipe body.

10. A method for manufacturing a double-layer catheter capable of eliminating stress, characterized in that: The following steps are involved: An inner liner tube and two developing rings are provided, wherein the two developing rings are respectively a first developing ring and a second developing ring; The inner liner tube has a first section and a second section in sequence from the proximal end to the distal end; Fixing a first developing ring between the first segment and the second segment, and fixing a second developing ring at the end of the second segment; Providing a plurality of strands of spring wires, winding the spring wires around the surfaces of the first segment and the second segment of the inner liner tube to form a spring layer, and the ends of the spring wires are fixedly connected to the second developing ring; Providing a plurality of braided wires, braiding the braided wires on the surface of the first segment of the inner liner tube to form a braided layer; the ends of the braided wires are fixedly connected to the second developing ring; Providing a first outer tube layer material, the first outer tube layer material comprising polyamide, polyetheramide resin and barium sulfate; rheologically combining the first outer tube layer material with the braided layer, the spring wound layer and the inner lining layer on the surface of the first segment to form the first outer tube layer; Providing an inner tube material, the inner tube material comprising polyurethane; rheologically making the inner tube material bonded to the spring wound layer and the inner lining layer on the surface of the second segment; Provide a plurality of braided wires and a tube, braid the braided wires on the surface of a supporting tube to form a braided layer; provide a second outer tube layer material, the second outer tube layer material includes polyurethane, polyetheramide resin and barium sulfate; rheologically allow the second outer tube layer material to combine with the braided layer on the surface of the tube; remove the tube to obtain a composite tube body of the second outer tube layer and the braided layer; sleeve the composite tube body on the second segment, and fix the two ends of the composite tube body to the first developing ring and the second developing ring respectively; Coating a hydrophilic coating on the surface of the first outer tube layer and the composite tube body; A catheter seat and a stress relief tube are provided, and the catheter seat and the stress relief tube are installed to the proximal end of the main tube body.

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