Medical catheter

Abstract

A connector (10) is provided at one end of the tube (90). A through hole (20) passes through the connector to connect the first end (11) and the second end (12) of the connector. The connector has a connecting portion (30) at the first end and a tube insertion portion (40) at the second end. The tube insertion portion has a fixing portion (41) to which the tube is fixed to the connector via a fixing layer (80); and a separating portion (42) disposed at the second end relative to the fixing portion. In the separating portion, the inner circumferential surface of the through hole is separated from the outer circumferential surface (95) of the tube in the radial direction. The fixing layer end (81) at the second end of the fixing layer separates from the second end along the axis (19) of the connector toward the first end.

Description

Technical Field

[0001] This invention relates to a medical catheter with a connector at one end of the tube. Background Technology

[0002] Enteral nutrition is a known method for administering liquids containing nutrients, medications, etc., to patients who are unable to ingest food orally. In enteral nutrition, a catheter is inserted into the patient from outside until its tip reaches the digestive tract (e.g., the stomach). Known catheters include nasal (or oral) catheters inserted through the patient's nose (or mouth) and PEG (Percutaneous Endoscopic Gastrostomy) catheters inserted into the stomach formed in the patient's abdomen. The catheter has a flexible, hollow tube and a connector (e.g., referring to Patent Document 1) located at one end of the tube (upstream end or proximal end). Figure 2 ).

[0003] During enteral nutrition, with the catheter inserted into the patient, another connector (the other connector) is connected to the catheter's connector (patient-side connector). When connecting the other connector to the patient-side connector, to prevent reflux of the patient's gastric contents and leakage from the patient-side connector, a procedure is sometimes performed to bend the tube connected to the patient-side connector, thus closing its flow path (hereinafter referred to as a "tube bending operation"). In the tube bending operation, the tube is usually bent at approximately a right angle or greater relative to the connector's axis at the base of the patient-side connector of the exit tube (e.g., the tube is approximately "U"-shaped).

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2021-159129 Patent Document 2: Japanese Patent Application Publication No. 2023-056709 Summary of the Invention

[0005] The problem that the invention aims to solve Typically, connectors are fixed to the tube by adhesive (e.g., see Patent Document 2). Figure 4 If a pipe bending operation is performed, stress will concentrate in the vicinity of the axial end portion of the adhesive (hereinafter referred to as the "end-near portion").

[0006] The catheter remains in place in the patient for an extended period. During this time, if the aforementioned tube bending operation is performed each time enteral nutrition is administered, the portion near the end is repeatedly subjected to stress. As a result, sometimes the tube separates from the connector starting from the portion near the end, or the portion of the tube breaks (e.g., a hole in the tube, a break in the tube). In such cases, the catheter needs to be replaced with a new one, which hinders the successful implementation of enteral nutrition.

[0007] The purpose of this invention is to prevent the tube from separating from the connector starting from the end portion and to prevent damage to the tube at the end portion due to the tube bending operation of bending the tube at the base end of the connector.

[0008] Methods for solving problems The medical catheter of the present invention comprises a flexible, hollow tube and a connector disposed at one end of the tube. A through-hole extends through the connector along its axis to connect a first end to a second end of the connector. The connector has a connecting portion at the first end for connection to a counterpart connector, and a tube insertion portion at the second end into which the tube is inserted. The tube insertion portion comprises: a fixing portion, wherein the tube is fixed to the connector via a fixing layer; and a separating portion disposed at the second end relative to the fixing portion. In the separating portion, the inner circumferential surface of the through-hole is separated from the outer circumferential surface of the tube in a radial direction. The fixing layer end, which is the end of the fixing layer at the second end, exits from the second end at the first end along the axial direction of the connector.

[0009] Invention Effects In the medical catheter of the present invention, the end of the second end of the fixing layer, i.e., the fixing layer end, separates from the second end of the connector towards the first end. Therefore, even if the catheter is repeatedly bent during prolonged periods of indwelling in the patient, it is possible to prevent the catheter from separating from the connector starting from the portion near the fixing layer end (the end-near portion) or from breaking at the end-near portion. Therefore, the catheter of the present invention exhibits excellent durability against bending operations. Attached Figure Description

[0010] Figure 1A This is a perspective view of a medical catheter according to Embodiment 1 of the present invention.

[0011] Figure 1B yes Figure 1A The image shows a cross-sectional view of a medical catheter.

[0012] Figure 1C yes Figure 1B Enlarged sectional view of part 1C.

[0013] Figure 2 This is a cross-sectional view of the connector according to Embodiment 1 of the present invention.

[0014] Figure 3 This is a cross-sectional view illustrating the manufacturing method of a medical catheter according to Embodiment 1 of the present invention.

[0015] Figure 4 This is a cross-sectional view of a medical catheter according to a comparative embodiment.

[0016] Figure 5 This is a cross-sectional view of a medical catheter used in a comparative embodiment during a tube bending operation.

[0017] Figure 6 This is a cross-sectional view of the medical catheter of Embodiment 1 of the present invention during the tube bending operation.

[0018] Figure 7 This is an enlarged cross-sectional view of a first modified example of the medical catheter according to Embodiment 1 of the present invention.

[0019] Figure 8 This is an enlarged cross-sectional view of a second modified example of the medical catheter according to Embodiment 1 of the present invention.

[0020] Figure 9 This is an enlarged cross-sectional view of a third modified example of the medical catheter according to Embodiment 1 of the present invention.

[0021] Figure 10 This is a cross-sectional view of a medical catheter according to Embodiment 2 of the present invention.

[0022] Figure 11 This is a cross-sectional view illustrating the manufacturing method of a medical catheter according to Embodiment 2 of the present invention. Detailed Implementation

[0023] (1) The medical catheter of the present invention comprises a flexible, hollow tube and a connector disposed at one end of the tube. A through-hole extends through the connector along the axis of the connector in such a way that a first end of the connector is connected to a second end. The connector has a connecting portion at the first end side for connecting to a counterpart connector, and a tube insertion portion at the second end side in which the tube is inserted into the through-hole. The tube insertion portion comprises: a fixing portion, wherein the tube is fixed to the connector via a fixing layer; and a separating portion disposed at the second end side relative to the fixing portion. In the separating portion, the inner circumferential surface of the through-hole is separated from the outer circumferential surface of the tube in the radial direction. The fixing layer end, which is the end of the fixing layer at the second end side, exits from the second end at the first end side along the axial direction of the connector.

[0024] (2) In the medical catheter of item (1) above, the length L along the axis of the connector from the second end to the end of the fixing layer may be 5 mm or more and 10 mm or less.

[0025] The method described in (2) helps to reduce the likelihood of tube separation from the connector or breakage of the tube near the end, starting from the portion near the end of the bonding layer (end-side portion).

[0026] (3) In the medical catheter of item (1) or item (2) above, when the opening diameter at the second end of the through hole is set as Dc, the outer diameter of the tube is set as Dt, and the length along the axis of the connector from the second end to the end of the fixing layer is set as L, [(Dc-Dt) / 2] / L≤0.10 is satisfied.

[0027] The method described in (3) helps to reduce the likelihood of tube separation from the connector or breakage of the tube near the end, starting from the portion near the end of the bonding layer (end-side portion).

[0028] (4) In any of the medical catheters in items (1) to (3) above, when the opening diameter at the second end of the through hole is set as Dc and the outer diameter of the tube is set as Dt, Dc / Dt≤1.30 is satisfied.

[0029] The method described in item (4) helps to reduce the possibility of tube separation from the connector or breakage of the tube near the end, starting from the portion near the end of the bonding layer (end-side portion).

[0030] (5) In any of the medical catheters described in items (1) to (4) above, the inner circumferential surface of the through hole in the insertion portion may include an enlarged portion. The enlarged portion may also be a curved surface whose inner diameter increases toward the second end. The end of the fixing layer may be located in the enlarged portion.

[0031] The method described in item (5) helps to reliably prevent the tube from separating from the connector, starting from the portion near the end of the fixed layer (the end-near portion), during the tube bending operation.

[0032] (6) In any of the medical catheters described in items (1) to (5) above, the inner circumferential surface of the through hole in the insertion portion may include a first tapered portion, an enlarged diameter portion, and a cylindrical portion arranged adjacent to each other from the first end toward the second end. The first tapered portion may also be a conical surface whose inner diameter increases toward the second end. The enlarged diameter portion may also be a curved surface whose inner diameter increases toward the second end. The cylindrical portion may also be a cylindrical surface whose inner diameter is constant in the axial direction of the connector. The inner diameter of the cylindrical portion may be larger than the outer diameter of the tube. The fixing layer may extend from the first tapered portion toward the enlarged diameter portion. The end of the fixing layer may be located at the enlarged diameter portion.

[0033] The fixed end is located in the enlarged diameter section, which helps to stably prevent the pipe from separating from the connector starting from the part near the fixed end (the end area) when performing pipe bending operations.

[0034] Compared to the enlarged diameter portion, the cylindrical portion provided on the second end side makes it easier to reduce the opening diameter Dc at the second end of the through hole. This helps to reduce the possibility of the tube separating from the connector starting from the portion near the end of the bonding layer (end-side portion) or the tube breaking in the end-side portion.

[0035] (7) In any of the medical catheters described in (1) to (6) above, the inner circumferential surface of the through hole may also include a first tapered portion and a second tapered portion arranged adjacent to each other from the second end toward the first end. Both the first tapered portion and the second tapered portion may be conical surfaces whose inner diameter increases toward the second end. The fixing layer fixes the outer circumferential surface of the tube to the first tapered portion. Alternatively, the proximal end of the outer circumferential surface of the tube, i.e., the outer circumferential end, may abut against the second tapered portion.

[0036] The method described in item (7) above helps to prevent the fixation strength of the tube relative to the connector from being reduced due to the sterilization process of the medical catheter.

[0037] (8) In any of the medical catheters described in (1) to (7) above, the connecting part may be a male connector used in enteral nutrition, which includes: a cylindrical male component having the through hole; an outer cylinder that coaxially surrounds the male component; and a female thread provided on the inner circumferential surface of the outer cylinder.

[0038] The medical catheter of item (8) above, equipped with the aforementioned male connector, can be left in a patient for enteral nutrition. In enteral nutrition, the catheter is frequently bent while in place in the patient. The catheter of the present invention exhibits excellent durability against bending operations, therefore, when used as a catheter left in place in a patient for enteral nutrition, the catheter of item (8) above can significantly demonstrate the aforementioned effects of the present invention.

[0039] (9) In any of the medical catheters described in (1) to (8) above, a side hole that communicates with the through hole and is not parallel to the axis of the connector may be provided in the tube insertion part.

[0040] The side hole in item (9) above can be used to inject adhesive in the manufacture of medical catheters, which is used to fix the tube to the connector. Therefore, the catheter in item (9) above is easy to manufacture, which is beneficial to improving the yield.

[0041] Hereinafter, the present invention will be described in detail while showing preferred embodiments. However, the present invention is not limited to the embodiments described below. The figures referred to in the following description are simplified representations of the main components constituting the embodiments of the present invention for ease of explanation. Therefore, the present invention can include any components not shown in the following figures. In addition, within the scope of the present invention, the components shown in the following figures can be changed or omitted. In the drawings referenced in the description of each embodiment, components corresponding to the components shown in the drawings referenced in the previous embodiments are labeled with the same reference numerals as those labeled in the drawings of the previous embodiments. For such components, repeated descriptions are omitted, and appropriate reference should be made to the description of the previous embodiments.

[0042] In this invention, the “axis” of a component (e.g., connector, connection, tube insertion, through hole) refers to the central axis of the component. The “axis” passes through the center of the shape (e.g., circle) contained in the component and / or coincides with the central axis of the cylinder (e.g., round cylinder), cylindrical surface, or conical surface (cone) contained in the component. Unless otherwise stated, the direction parallel to the axis is referred to as the “axial direction.” The direction along a straight line orthogonal to the axis is referred to as the “radial direction.” In the radial direction, the side closer to the axis is referred to as the “inner” side, and the side farther from the axis is referred to as the “outer” side. The direction of rotation about the axis is referred to as the “circumferential direction.” Those skilled in the art can readily and uniquely identify the axis; therefore, in the accompanying drawings referenced in the following description, the axis is omitted for simplicity.

[0043] In this invention, the "proximal" side refers to the side closer to the surgeon (or user), and the "distal" side refers to the side farther from the surgeon (or user) (see below). Figure 1B Here, "operator (or user)" refers to a person (e.g., a doctor, nurse, caregiver, etc.) who uses the medical catheter of the present invention. In the following description, the axial end (terminal) of the component is sometimes referred to as the "front end," and the end opposite to the "front end" is sometimes referred to as the "base end." The "front end" can be located on either the "proximal side" or the "distal side" relative to the "base end."

[0044] (Example 1) Figure 1A This is a perspective view of a medical catheter (hereinafter referred to as "catheter") 1 according to Embodiment 1 of the present invention. Figure 1B This is a cross-sectional view of catheter 1. Catheter 1 has a flexible, hollow tube 90 and a connector 10 disposed at one end (proximal end) of the tube 90. Catheter 1 can be used as a transnasal catheter.

[0045] Figure 2 This is a cross-sectional view of connector 10. Connector 10 is located at one end (proximal end) along its length. Figure 2 The middle (upper end) has a first end 11, and at the other end (far end, in Figure 2 The lower end of the connector 10 has a second end 12. The shaft 19 of the connector 10 connects the first end 11 and the second end 12. The through hole 20 passes through the connector 10 along the shaft 19 of the connector 10 in such a way that the first end 11 and the second end 12 of the connector 10 are connected.

[0046] The connector 10 has a connecting portion 30 on its first end 11 side, which connects to a different connector (the other connector, not shown). In this invention, the structure of the connecting portion 30 is not limited. In this embodiment 1, the connecting portion 30 has a cylindrical male component 31 and an outer cylinder 35 coaxially surrounding the male component 31. A female thread 36 is provided on the inner circumferential surface of the outer cylinder 35 opposite to the male component 31. A through hole 20 passes through the male component 31 and opens at the front end of the male component 31 (i.e., the first end 11 of the connector 10). The outer circumferential surface 32 of the male component 31 is a conical surface (so-called male conical surface) whose outer diameter decreases as it approaches the front end of the male component 31. The inner circumferential surface 33 of the male component 31 (the inner circumferential surface in the male component 31 of the through hole 20) is not limited and can be composed of a single curved surface or multiple curved surfaces adjacent to each other in the axial direction 19. In this embodiment 1, the inner circumferential surface 33 is composed of multiple conical surfaces adjacent to each other in the axial direction. The multiple conical surfaces are conical surfaces (conical surfaces) whose inner diameter increases toward the front end (first end 11) of the sun-facing component 31, and the inner diameter and cone angle of the multiple conical surfaces are different from each other. However, in this invention, the inner circumferential surface 33 is not limited to this, and may include, for example, a cylindrical surface with a constant inner diameter in the axial direction, or an arbitrary curved surface with an inner diameter that changes non-linearly in the axial direction.

[0047] like Figure 1A As shown, connector 10 has a generally cylindrical base 50 on the second end 12 side. The base 50 is coaxially arranged with male member 31. A pair of grips 52 protrude radially outward from the base 50. The grips 52 make it easy for the surgeon to hold connector 10 and apply rotational force to connector 10. In this invention, the structure on the second end 12 side of connector 10 is not limited to embodiment 1. For example, connector 10 may not have a pair of grips 52. Alternatively, instead of a pair of grips 52, a pair of plate-like bodies protruding in opposite directions along the radial direction may be provided on the outer peripheral surface of base 50. The shape of base 50 is not limited to a generally cylindrical shape; for example, the outer peripheral surface of base 50 may have a rectangular prism face with a cross-sectional shape perpendicular to the axis of connector 10. The pair of plate-like bodies and the outer peripheral surface of the base 10 with prism faces, like the pair of grips 52, make it easy for the surgeon to hold connector 10 and apply rotational force.

[0048] return Figure 2The through hole 20 penetrates the base cylinder 50 and opens at the front end of the base cylinder 50 (i.e., the second end 12 of the connector 10).

[0049] The inner diameter of the through hole 20 varies along the axial direction of the connector 10. In this embodiment 1, the inner circumferential surface of the through hole 20 includes multiple portions (parts) with different shapes. Specifically, the inner circumferential surface of the through hole 20 from the first end 11 toward the second end 12 includes a second tapered portion 22, a first tapered portion 21, an enlarged diameter portion 23, and a cylindrical portion 25.

[0050] The second tapered portion 22 is disposed on the side of the second end 12 relative to the inner peripheral surface 33 of the male component 31. The second tapered portion 22 is composed of a tapered surface (conical surface, so-called female tapered surface) whose inner diameter increases toward the second end 12.

[0051] The first tapered portion 21 is disposed on the side of the second end 12 relative to the second tapered portion 22, and is adjacent to the second tapered portion 22. The first tapered portion 21 is composed of a tapered surface (conical surface, so-called negative tapered surface) whose inner diameter increases towards the second end 12. The cone angle of the tapered surface of the first tapered portion 21 is smaller than the cone angle of the tapered surface of the second tapered portion 22. The minimum inner diameter of the first tapered portion 21 (the inner diameter of the side end of the first end 11 of the first tapered portion 21) is the same as the maximum inner diameter of the second tapered portion 22 (the inner diameter of the side end of the second end 12 of the second tapered portion 22).

[0052] The enlarged diameter portion 23 is disposed on the second end 12 side relative to the first conical portion 21 and is adjacent to the first conical portion 21. The enlarged diameter portion 23 is composed of a curved surface whose inner diameter increases toward the second end 12. In this embodiment 1, the curved surface of the enlarged diameter portion 23 is composed of a conical surface (a conical surface, a so-called negative conical surface) whose inner diameter increases toward the second end 12. The cone angle of the cone surface of the enlarged diameter portion 23 is greater than the cone angle of the cone surface of the first conical portion 21. The minimum inner diameter of the enlarged diameter portion 23 (the inner diameter of the first end 11 side of the enlarged diameter portion 23) is the same as the maximum inner diameter of the first conical portion 21 (the inner diameter of the second end 12 side of the first conical portion 21).

[0053] The cylindrical portion 25 is disposed on the second end 12 side relative to the enlarged diameter portion 23, adjacent to the enlarged diameter portion 23. The cylindrical portion 25 is formed by a cylindrical surface whose inner diameter is constant in the axial direction (the length direction of the through hole 20). The inner diameter of the cylindrical portion 25 is the same as the maximum inner diameter of the enlarged diameter portion 23 (the inner diameter of the second end 12 side of the enlarged diameter portion 23). The through hole 20 opens at the second end 12 side of the cylindrical portion 25. The second end 12 side of the cylindrical portion 25 is located in the axial direction at substantially the same position as the second end 12 of the connector 10.

[0054] The material of connector 10 is not limited, and a hard material (rigid material) with mechanical strength (rigidity) that is substantially resistant to deformation under external force can be used. For example, resin materials such as acrylic resin, polycarbonate, rigid polyvinyl chloride, polypropylene, polyethylene, acrylonitrile-butadiene-styrene copolymer, polyacetal, polystyrene, and polyamide can be used. As an example, acrylic resin can be used. Connector 10 can be manufactured as a single component using the aforementioned resin materials through injection molding or similar methods.

[0055] like Figure 1B As shown, tube 90 is inserted into through hole 20 from the second end 12 side.

[0056] The tube 90 has a hollow cylindrical shape. In a cross-section of the tube 90 along a plane perpendicular to its length, the outer and inner circumferential surfaces of the tube 90 are concentric circles. The outer and inner diameters of the tube 90 are constant along its length, except for deviations caused by manufacturing errors. There are no restrictions on the material of the tube 90; flexible resins such as soft polyvinyl chloride, polybutadiene, silicone, polyurethane, polypropylene, polyethylene, polybutadiene, and styrene-based elastomers can be used. The tube 90 can be manufactured continuously using the aforementioned materials, for example, by extrusion molding. The tube 90 can be easily bent and deformed by applying external force, and can also be compressed and deformed radially, after which it returns to its initial state when the external force is removed.

[0057] Even considering manufacturing errors in the tube 90 (or deviations in the outer diameter of the tube 90), the inner diameter of the cylindrical portion 25 (which is the same as the maximum inner diameter of the expanded diameter portion 23) is larger than the outer diameter of the tube 90. Furthermore, even considering manufacturing errors in the tube 90 (or deviations in the outer diameter of the tube 90), the minimum inner diameter of the second tapered portion 22 (the inner diameter of the side end of the first end 11 of the second tapered portion 22) is smaller than the outer diameter of the tube 90. The minimum inner diameter of the expanded diameter portion 23 (which is the same as the maximum inner diameter of the first tapered portion 21) and the minimum inner diameter of the first tapered portion 21 (which is the same as the maximum inner diameter of the second tapered portion 22) are approximately the same as the outer diameter of the tube 90 (they may be slightly larger or slightly smaller than the outer diameter of the tube 90). In addition, in the above description, the "outer diameter" of the tube 90 refers to its outer diameter before insertion into the through hole 20 of the connector 10, in a state where no external force is applied to the tube 90 (unloaded state or initial state).

[0058] The tube 90 is inserted until its proximal end 91 of its outer peripheral surface 95 abuts against the inner peripheral surface of the second tapered portion 22. In this invention, the portion in the connector 10 where the tube 90 is inserted is referred to as the tube insertion portion 40. More specifically, the tube insertion portion 40 extends axially from the second end 12 of the connector 10 to the outer peripheral end 91 (or proximal end) of the tube 90. In this embodiment 1, the tube insertion portion 40 includes a cylindrical portion 25, an expanded diameter portion 23, and a first tapered portion 21, and may also include a portion of the first tapered portion 21 side of the second tapered portion 22.

[0059] The tube 90 is fixed to the connector 10 via a fixing layer 80. The fixing layer 80 exists between the connector 10 (the inner circumferential surface of the through hole 20) and the outer circumferential surface 95 of the tube 90, and is continuous in the circumferential direction, surrounding the tube 90. The fixing layer 80 exists only in a portion of the tube insertion portion 40 in the axial direction. Figure 1B Enlarged sectional view of part 1C, i.e. Figure 1C As shown, the tube insertion portion 40 has: a fixing portion 41, on which the tube 90 is fixed to the connector 10 by means of a fixing layer 80; and a separation portion 42, which is disposed relative to the fixing portion 41 on the second end 12 side and adjacent to the fixing portion 41. The fixing layer 80 is not present in the separation portion 42. More specifically, in the separation portion 42, the outer peripheral surface 95 of the tube 90 is not fixed to the inner peripheral surface of the through hole 20, and the inner peripheral surface of the through hole 20 is separated from the outer peripheral surface 95 of the tube 90 in the radial direction. Therefore, if a force is applied to the portion of the tube 90 extending outward in the radial direction from the connector 10, the tube 90 can move in the radial direction in the separation portion 42. The end (terminal) of the fixing layer 80 located on the second end 12 side (separation portion 42 side), i.e., the fixing layer end 81, separates from the second end 12 (the front end of the base cylinder 50 or the open end of the through hole 20 located on the second end 12 side) towards the first end 11 side along the axis of the connector 10. In this embodiment 1, the fixing layer end 81 is located in the enlarged diameter portion 23. The fixing layer 80 extends from the fixing layer end 81 toward the first end 11, preferably extending to the outer peripheral surface end 91 of the tube 90. Therefore, the fixing layer 80 may also exist in a part of the enlarged diameter portion 23 and the first tapered portion 21 in the tube insertion portion 40, and also in a part of the second tapered portion 22.

[0060] The bonding layer 80 can have any structure capable of bonding (connecting) the tube 90 to the connector 10. The method of bonding the tube 90 to the connector 10 can be selected based on the materials of the connector 10 and the tube 90, without limitation; for example, methods using adhesives (adhesive bonding) or welding (welding) can be used. Examples of adhesives that can be used in adhesive bonding include solvent-based adhesives, UV adhesives, and instant adhesives. In the case of adhesive bonding, the bonding layer 80 is an adhesive layer derived from the adhesive. As for welding, there are no limitations; examples include laser welding and high-frequency welding. In the case of welding, the bonding layer 80 is a welded layer formed by melting and solidifying the two materials of the tube 90 and the connector 10.

[0061] An example of the manufacturing method of conduit 1 will be described using a solvent-based adhesive.

[0062] First, prepare connector 10 and tube 90. (As follows) Figure 3 As shown, connector 10 is held by a clamp or the like (not shown) such that the axis of connector 10 is parallel to the vertical direction, while the second end 12 faces upward. The outer diameter of tube 90 is smaller than the inner diameter of cylindrical portion 25 and larger than the minimum inner diameter of second tapered portion 22. Tube 90 is cut to a predetermined length. The cut surface on the proximal side of tube 90 is called proximal end face 92. Proximal end face 92 is essentially a flat surface, approximately perpendicular to the length direction of tube 90. The boundary between the outer peripheral surface 95 of tube 90 and proximal end face 92 is outer peripheral end 91. Solvent-based adhesive 85 is applied to the outer peripheral surface 95 of tube 90, extending from outer peripheral end 91 over a predetermined length. The proximal end face 92 of tube 90 is coaxially aligned with the opening on the second end 12 side of the through hole 20 of connector 10. Then, tube 90 is inserted into through hole 20. Because the diameter of tube 90 is smaller than that of cylindrical portion 25, tube 90 can enter the through hole 20 relatively easily. Then, tube 90 enters the first tapered portion 21. Excess solvent-based adhesive 85 on the outer peripheral surface 95 may be shaved off at the second end 12 of the first tapered portion 21 and remain in the enlarged diameter portion 23. In the first tapered portion 21, the solvent-based adhesive 85 spreads thinly and substantially uniformly in the narrow gap between the outer peripheral surface 95 of tube 90 and the inner peripheral surface of the first tapered portion 21. Tube 90 is inserted into the through hole 20 until its outer peripheral end 91 abuts against the inner peripheral surface of the second tapered portion 22. The second tapered portion 22 can define the insertion depth of tube 90 relative to the through hole 20. The solvent-based adhesive 85 dissolves the outer peripheral surface 95 of the tube 90 and the inner peripheral surface of the through hole 20 (especially the first tapered portion 21) that are in contact with the solvent-based adhesive 85, and solidifies during the solvent evaporation process to form an adhesive layer 80 (see reference). Figure 1C Then, connector 10 and tube 90 are sterilized. This yields... Figures 1A-1C The connector 10 shown is fixed to the conduit 1 of the tube 90 via the fixing layer 80. Furthermore, in Figure 3 In the manufacturing method shown, the connector 10 is held with the second end 12 facing upwards, but the orientation of the connector 10 is not limited to this. For example, the connector 10 may be held with its axis horizontal, or the connector 10 may be held with the first end 11 facing upwards. Alternatively, instead of the connector 10, the tube 90 may be held in a specified orientation, and the connector 10 may be inserted externally into the tube 90.

[0063] As described above, the solvent-based adhesive 85 typically contains an organic solvent, capable of dissolving both surfaces of the connector 10 and the tube 90 that come into contact with the solvent-based adhesive 85. Therefore, when using the solvent-based adhesive 85 as the adhesive, the inner diameter of the through hole 20 and the outer diameter of the tube 90 (outer diameter under no-load condition) before assembly are preferably set considering the thickness dissolved by the solvent-based adhesive 85. Specifically, it is preferable that the minimum inner diameter of the expanded diameter portion 23 (which is the same as the maximum inner diameter of the first tapered portion 21) and the minimum inner diameter of the first tapered portion 21 (which is the same as the maximum inner diameter of the second tapered portion 22) are slightly smaller than the outer diameter of the tube 90 (outer diameter under no-load condition). This prevents air bubbles from being mixed into the bonding layer 80 obtained after the solvent-based adhesive 85 has cured, which is beneficial for improving the bonding strength of the tube 90 relative to the connector 10.

[0064] Catheter 1 (reference) Figures 1A-1C There are no limitations; for example, it can be used as a nasal cannula in enteral nutrition. In this case, tube 90 is inserted into the patient's nasal cavity. At the distal end of tube 90 (or the distal end of tube 90, at...) Figure 1A , Figure 1B (Not shown in the diagram) The catheter 1 reaches the patient's digestive tract (e.g., stomach), and with a connector 10 located at the proximal end of the tube 90 extending from the patient, the catheter 1 remains in place in the patient long-term. When administering enteral nutrition, a different connector (parallel connector) is connected to the connection portion 30 of the connector 10. The parallel connector can be located at the end of a tube communicating with a container holding the liquid to be administered to the patient, or it can be located at the tip of a syringe barrel. Alternatively, the tip of the syringe barrel can also be the parallel connector. With the parallel connector connected to the connector 10, the liquid is administered to the patient sequentially through the parallel connector, connector 10, and tube 90.

[0065] The effect of catheter 1 in this embodiment 1 will be explained by comparing it with that of a conventional catheter, i.e., a comparative embodiment.

[0066] Figure 4This is a cross-sectional view of a medical catheter 9 according to a comparative embodiment. The catheter 9 includes a flexible, hollow tube 90 and a connector 910 disposed at one end (proximal end) of the tube 90. A through-hole 20 extends through the connector 910 along its axis (not shown) to connect a first end 11 and a second end 12. The inner circumferential surface of the through-hole 20 from the first end 11 toward the second end 12 includes a small-diameter portion 927, a stepped portion 922, a cylindrical portion 921, and a tapered portion 925. The cylindrical portion 921 is formed by a cylindrical surface whose inner diameter is constant in the axial direction (the length direction of the through-hole 20). The tapered portion 925 is disposed on the second end 12 side relative to the cylindrical portion 921 and adjacent to the cylindrical portion 921. The tapered portion 925 is formed by a tapered surface (conical surface, so-called female conical surface) whose inner diameter increases toward the second end 12. The small-diameter portion 927 is formed by a cylindrical or conical surface with a diameter smaller than that of the cylindrical portion 921. A stepped portion 922 is disposed between the small-diameter portion 927 and the cylindrical portion 921, and is formed by an annular flat surface perpendicular to the axis of the connector 910. The proximal end face 92 of the tube 90 is axially opposed to the stepped portion 922. The tube 90 is fixed to the connector 910 via a fixing layer 980 made of adhesive. The fixing layer 980 extends throughout the stepped portion 922, the cylindrical portion 921, and the conical portion 925. More specifically, the fixing layer 980 exists between the annular flat surface of the stepped portion 922 and the proximal end face 92 of the tube 90. Furthermore, the fixing layer 980 exists between the inner circumferential surfaces of the cylindrical portion 921 and the conical portion 925 and the outer circumferential surface 95 of the tube 90. Moreover, the fixing layer 980 bulges axially from the second end 12 of the connector 910 in a dome shape. The structure of the bonding layer 980 and its vicinity is common in conventional conduits, for example, in Patent Document 2. Figure 6 As shown in the image.

[0067] The conduit 9 does not have a portion equivalent to the separation portion 42 of the conduit 1 in Embodiment 1. The end (terminal) of the second end 12 side of the fastening layer 980, namely the fastening layer end 981, separates from the second end 12 along the axial direction of the connector 910 on the side opposite to the first end 11.

[0068] Like catheter 1, catheter 9 can be used as a nasal catheter in enteral nutrition. During enteral nutrition, with catheter 90 inserted into the patient, a different connector (parallel connector) is connected to the connection portion 30 of connector 910. When connecting the parallel connector to connector 910, to prevent reflux of the patient's gastric contents from leaking out from the first end 11 of connector 910, a "tube bending operation" is sometimes performed to close the flow path of catheter 90.

[0069] Figure 5This is a cross-sectional view of the conduit 9 during a tube bending operation. To easily and reliably close the flow path of the tube 90, during the tube bending operation, the tube 90 is typically bent at approximately a right angle (or greater) relative to the axis (not shown) of the connector 910, using the fixed layer end 981 as a fulcrum. To achieve this bending, the tube 90 needs to be bent outwards in an approximately radial direction relative to the axis of the connector 910 (in... Figure 5 The tension T is from the center to the right. Therefore, the stress is concentrated on the side opposite to the direction of the tension T. Figure 5 The portion 982 near the end of the fixed layer 981 (left side) in the middle. This stress is along the direction of the bent tube 90, i.e., the tension T (in the direction of the tension T). Figure 5 The stress acts on the portion 982 near the end (from center to right). This stress causes the tube 90 to move from the fixing layer 980 in a direction approximately right-angled with the axis relative to the connector 910 in the portion 982 near the end (from center to right). Figure 5 It has the function of separating from the middle to the right, and also has the function of locally bending and deforming the tube 90 at approximately a right angle in the portion 982 near the end.

[0070] During the extended period that catheter 9 is left in the patient, the portion near the end 982 is repeatedly subjected to the aforementioned stress through the tube bending operations performed each time enteral nutrition therapy is administered. As a result, tube 90 may detach from the bonding layer 980 starting from the portion near the end 982, eventually detaching from the connector 910, or tube 90 may break at the portion near the end 982 (e.g., an opening in tube 90 or a breakage of tube 90). In such cases, it is necessary to replace catheter 9 with a new catheter before the end of the pre-planned period (the intended indwelling period) of catheter 9 being left in the patient, which hinders the smooth implementation of enteral nutrition therapy.

[0071] Figure 6 This is a cross-sectional view of the conduit 1 in Embodiment 1 during the pipe bending operation. During the pipe bending operation, with... Figure 5 Similarly, an outward radial direction relative to the axis of connector 10 is applied to tube 90 (in... Figure 6 The tension T (from center to right). As a result, the tube 90 bends approximately at a right angle relative to the axis (not shown) of the connector 10 with the second end 12 as the fulcrum, and the flow path of the tube 90 is closed. However, in this embodiment 1 (refer to Figure 6 In the comparative implementation method () Figure 5 Unlike the second end 12, the fixing layer end 81 is located closer to the first end 11 than the second end 12. Therefore, within the range from the second end 12 to the fixing layer end 81, the tube 90 is slightly inclined relative to the direction of the axial tension T of the connector 10 within the through hole 20. Figure 5 Similarly, in Figure 6 In the middle, the stress is also concentrated on the side opposite to the direction of the tension T (in Figure 6The portion 82 near the end of the fixing layer 81 (left side) is shown. However, compared with the comparative embodiment (see reference...) Figure 5 Unlike in this implementation method 1 () Figure 6 In the portion 82 near the end, the inclination of the tube 90 relative to the axis of the connector 10 is small. The direction of stress and tension T (in...) Figure 6 (From center to right) along the inclined direction of the tube 90 near the end portion 82. Therefore, in this embodiment 1, the effect of the stress to separate the tube 90 from the connector 10 (the inner peripheral surface of the through hole 20) is greater than in the comparative embodiment (see reference). Figure 5 Smaller. Furthermore, in the portion 82 near the end, the angle (bending angle) at which the stress causes the tube 90 to bend is smaller than in the comparative embodiment (see reference). Figure 5 The bending angle of the tube 90 near the end of the tube is small at 982.

[0072] As described above, in this embodiment 1, the fixing layer end 81 moves away from the second end 12 toward the first end 11 along the axis 19 of the connector 10 (i.e., the fixing layer end 81 retracts into the through hole 20). Therefore, when a tube bending operation is performed at the second end 12 of the connector 10 to bend the tube 90, firstly, the stress generated in the portion near the fixing layer end 81 (the end-near portion) 82, which has a weak effect on separating the tube 90 from the connector 10 (the inner circumferential surface of the through hole 20), and secondly, the bending angle of the tube 90 at the end-near portion 82 is small. As a result, even if the tube bending operation is repeatedly performed during a long period of time while the catheter 1 is left in the patient, this embodiment 1 can prevent the tube 90 from separating from the connector 10 starting from the end-near portion 82 and eventually falling off the connector 10, or prevent the tube 90 from breaking at the end-near portion 82 (e.g., an opening in the tube 90, or a break in the tube 90). According to this embodiment 1, the catheter 1 can be left in the patient until the intended indwelling period ends, which facilitates the smooth implementation of enteral nutrition and prevents increased burden on the patient caused by the re-insertion of the catheter 1.

[0073] In this invention, the length L along the axis 19 of the connector 10 from the second end 12 to the fixing layer end 81 (refer to...) Figure 1C There are no restrictions. However, if from Figure 6As can be easily understood, the longer the length L, the smaller the inclination (bending angle) of the tube 90 near the end portion 82 relative to the axis of the connector 10 during the tube bending operation. This helps reduce the possibility of the tube 90 separating from the connector 10 starting from the end portion 82, and the possibility of breakage of the tube 90 near the end portion 82. From this point of view, a longer length L is preferred; specifically, a length L is preferably 5 mm or more, more preferably 6 mm or more, and particularly preferably 7 mm or more. However, if the length L becomes longer, the overall axial length of the connector 10 may increase, and the process of fixing the tube 90 to the connector 10 by adhesive method (see reference) may be affected. Figure 3 This addresses issues such as increased difficulty. Therefore, the length L is preferably 10 mm or less, more preferably 9 mm or less, and particularly preferably 8 mm or less.

[0074] Additionally, when the opening diameter at the second end 12 of the through hole 20 is set to Dc, the outer diameter of the tube 90 (outer diameter under no-load condition) is set to Dt, and the length from the second end 12 to the fixed layer end 81 along the axis 19 of the connector 10 is set to L (refer to...) Figure 1C ), where [(Dc-Dt) / 2] / L≤0.10.

[0075] Furthermore, it is preferable to satisfy [(Dc-Dt) / 2] / L≤0.095.

[0076] In addition, the opening diameter Dc at the second end 12 of the through hole 20 and the outer diameter (outer diameter under no-load condition) Dt of the pipe 90 are Dc / Dt≤1.30.

[0077] Therefore, Dc / Dt≤1.28 The preferred option is to satisfy Dc / Dt≤1.25.

[0078] The smaller [(Dc-Dt) / 2] / L and Dc / Dt are, the more the tube 90 near the end 82 during the tube bending operation is tilted relative to the axis of the connector 10 (bending angle, refer to...). Figure 6 The smaller the value, the better. This helps reduce the likelihood of the tube 90 separating from the connector 10 starting from the end portion 82, and the tube 90 breaking at the end portion 82.

[0079] However, if both [(Dc-Dt) / 2] / L and Dc / Dt become smaller, then the process of fixing the tube 90 to the connector 10 using an adhesive method (refer to...) Figure 3 The difficulty has increased.

[0080] Therefore, [(Dc-Dt) / 2] / L≥0.020 Furthermore, it is preferable to satisfy [(Dc-Dt) / 2] / L≥0.030.

[0081] Additionally, Dc / Dt ≥ 1.01 Therefore, it is preferable to satisfy Dc / Dt≥1.02.

[0082] In this embodiment 1, the inner circumferential surface of the through hole 20 in the tube insertion portion 40 includes a first tapered portion 21, an enlarged diameter portion 23, and a cylindrical portion 25 arranged adjacent to each other from the first end 11 toward the second end 12. The fixing layer 80 extends from the first tapered portion 21 toward the enlarged diameter portion 23 and terminates at the fixing layer end 81. This fixing layer end 81 is located at the enlarged diameter portion 23.

[0083] Unlike Embodiment 1, we consider the case where the enlarged diameter portion 23 is omitted, and the cylindrical portion 25 and the first tapered portion 21 are axially adjacent (hereinafter referred to as the "Comparative Example"). In this Comparative Example, the inner diameter of the through hole 20 changes drastically between the first tapered portion 21 and the cylindrical portion 25. When the fixing layer end 81 is located near the boundary between the first tapered portion 21 and the cylindrical portion 25, the thickness (radial dimension) of the fixing layer 80 at the fixing layer end 81 changes drastically due to a slight difference in the axial position of the fixing layer end 81. The thickness of the fixing layer 80 affects the fixing strength of the tube 90 relative to the connector 10. Therefore, when a tension T is applied to the tube 90 by bending the tube, the effect of the fixing layer 80 near the fixing layer end 81 (the end-near portion) 82 in preventing the tube 90 from separating from the connector 10 (the inner circumferential surface of the through hole 20) easily becomes unstable.

[0084] In contrast, in this embodiment 1, the thickness (radial dimension) of the fixing layer 80 gradually increases from the first tapered portion 21 toward the second end 12 at the enlarged diameter portion 23. Thus, the fixing layer end 81 is positioned at the enlarged diameter portion 23 where the thickness of the fixing layer 80 gradually increases toward the second end 12. Due to manufacturing errors, even if the axial position of the fixing layer end 81 changes within the enlarged diameter portion 23, the change in the thickness of the fixing layer 80 is relatively small. Therefore, the change in the fixing strength of the tube 90 relative to the connector 10 at the portion near the fixing layer end 81 (the end-near portion) 82 is also small. This is beneficial for stably preventing the tube 90, starting from the end-near portion 82, from separating from the connector 10 during tube bending operations.

[0085] Furthermore, in this invention, the inner circumferential surface of the through hole 20 in the tube insertion portion 40 is not limited to that in Embodiment 1.

[0086] Figure 7 This is an enlarged cross-sectional view of the medical catheter 1a of the first modified example. The enlarged portion 23 of the connector 10 (see reference) Figure 1CSimilarly, the enlarged diameter portion 23a of connector 10a is formed by a curved surface whose inner diameter increases toward the second end 12. However, the inner diameter of the enlarged diameter portion 23a differs from that of the enlarged diameter portion 23, and varies non-linearly in the axial direction. More specifically, the cross-sectional shape of the enlarged diameter portion 23a along the surface containing the axis of connector 10a is a generally circular arc protruding toward the tube 90. This generally circular arc connects the first tapered portion 21 to the cylindrical portion 25. The fixing layer end 81 of the fixing layer 80 is located in the enlarged diameter portion 23a. The conduit 1a is the same as the conduit 1 except as described above.

[0087] Figure 8 This is an enlarged cross-sectional view of the medical catheter 1b of the second variation. The enlarged portion 23b of connector 10b and the enlarged portion 23 of connector 10 (see reference). Figure 1C Similarly, it is formed by a curved surface whose inner diameter increases toward the second end 12. However, the inner diameter of the expanded diameter portion 23b is different from that of the expanded diameter portion 23, and varies non-linearly in the axial direction. More specifically, the cross-sectional shape of the expanded diameter portion 23b along the plane containing the axis of the connector 10b is a generally circular arc that recedes away from the tube 90. This generally circular arc connects the first tapered portion 21 to the cylindrical portion 25. The fixing layer end 81 of the fixing layer 80 is located in the expanded diameter portion 23b. The conduit 1b is the same as the conduit 1 except as described above.

[0088] Figure 9 This is an enlarged cross-sectional view of the medical catheter 1c of the third variation. The enlarged portion 23 of the connector 10 (see reference) Figure 1C Similarly, the expanded diameter portion 23c of connector 10c is composed of a conical surface (a conical surface, also known as a female conical surface) whose inner diameter increases toward the second end 12. The cone angle of the conical surface of the expanded diameter portion 23c is greater than the cone angle of the conical surface of the first conical portion 21. The minimum inner diameter of the expanded diameter portion 23c (the inner diameter of the side end of the first conical portion 21 of the expanded diameter portion 23c) is the same as the maximum inner diameter of the first conical portion 21 (the inner diameter of the side end of the second end 12 of the first conical portion 21). Connector 10c does not have a cylindrical portion 25 (see reference) on the side of the second end 12 of the expanded diameter portion 23, which corresponds to that of connector 10. Figure 1B and Figure 1C The cylindrical portion of the tube 23c extends to the second end 12. The fixing end 81 of the fixing layer 80 is located in the expanding portion 23c. The conduit 1c is the same as the conduit 1 except as described above.

[0089] In catheters 1a, 1b, and 1c mentioned above, also with catheter 1 (refer to...) Figure 1C Similar to the conduit 1, the fixing layer end 81 is located in the enlarged diameter section (23a, 23b, 23c). Since the fixing layer end 81 is arranged in the enlarged diameter section where the thickness of the fixing layer 80 gradually increases toward the second end 12, similar to the conduit 1, it is beneficial to stably prevent the tube 90 from separating from the connector 10 starting from the portion (end-side portion) 82 near the fixing layer end 81 when the tube is bent.

[0090] In this invention, the shape of the inner circumferential surface of the through hole 20 in the tube insertion part 40 is not limited to that of Embodiment 1.

[0091] For example, the first tapered portion 21 can be replaced with a cylindrical portion (the second cylindrical portion). This second cylindrical portion is formed by a cylindrical surface whose inner diameter is constant in the axial direction (the length direction of the through hole 20). The inner diameter of the second cylindrical portion is the same as the maximum inner diameter of the second tapered portion 22 (the inner diameter of the side end of the second end 12 of the second tapered portion 22) and the minimum inner diameter of the expanded diameter portion 23 (the inner diameter of the side end of the first end 11 of the expanded diameter portion 23). The inner diameter of the second cylindrical portion is not limited, but can be set to be approximately the same as the outer diameter of the tube 90 (the outer diameter under no-load conditions).

[0092] Alternatively, the cylindrical portion 25 can be replaced with a conical portion (a third conical portion). This third conical portion is formed by a conical surface (a conical surface, also known as a conical surface) whose inner diameter increases towards the second end 12. The conical angle of the third conical portion's conical surface is not limited, but it is preferably smaller than the conical angle of the conical surface of the expanded diameter portion 23. The minimum inner diameter of the third conical portion (the inner diameter at the side end of the expanded diameter portion 23 of the third conical portion) is the same as the maximum inner diameter of the expanded diameter portion 23 (the inner diameter at the side end of the second end 12 of the expanded diameter portion 23). Figure 9 As shown, the cylindrical part 25 can also be omitted.

[0093] Furthermore, as in Embodiment 1, the cylindrical portion 25 is provided adjacent to the opening on the second end 12 side of the through hole 20, which makes it easier to reduce the opening diameter Dc at the second end 12 of the through hole 20 (see reference). Figure 1C Furthermore, it is easy to reduce [(Dc-Dt) / 2] / L and Dc / Dt. This helps to reduce the possibility of the tube 90 separating from the connector 10 starting from the end portion 82 and the tube 90 breaking at the end portion 82.

[0094] In this embodiment 1, the inner circumferential surface of the through hole 20 has a second tapered portion 22 disposed on the first end 11 side relative to the first tapered portion 21 and adjacent to the first tapered portion 21. The proximal end (more specifically, the outer circumferential end 91) of the tube 90 abuts against the second tapered portion 22. The effect of the second tapered portion 22 will be explained.

[0095] In conventional catheters 9, such as Figure 4As shown, the proximal end face 92 of the tube 90 is axially opposed to the stepped surface 922 formed on the inner circumferential surface of the through hole 20. The bonding layer 980 between the inner circumferential surface of the through hole 20 and the tube 90 exists not only in the cylindrical portion 921 but also in the stepped portion 922. In this structure, depending on the atmosphere (e.g., temperature, pressure) during sterilization after the tube 90 is bonded to the connector 910 by adhesive bonding, air bubbles in the bonding layer 980 between the proximal end face 92 and the stepped portion 922 may expand. This expansion of the air bubbles causes the tube 90 to separate from the inner circumferential surface of the through hole 20. This reduces the bonding strength of the tube 90 relative to the connector 910. Therefore, for example, if tension is applied to the tube 90 when using the conduit 9, the tube 90 may detach from the connector 910.

[0096] In contrast, the connector 10 of this embodiment 1 does not have a stepped portion 922 with the proximal end face 92 of the tube 90 facing each other in the axial direction. Therefore, in this embodiment 1, the aforementioned problem of conventional conduits 9, where air bubbles expand in the fixing layer 980 between the proximal end face 92 and the stepped portion 922 during sterilization, resulting in a decrease in the fixing strength of the tube 90 relative to the connector 910, is avoided. The absence of a stepped portion 922 on the inner circumferential surface of the through hole 20 helps prevent a decrease in the fixing strength of the tube 90 relative to the connector 10 due to sterilization. However, in this invention, similar to conventional conduits 9, a stepped portion 922 with the proximal end face 92 of the tube 90 facing each other in the axial direction may be provided on the inner circumferential surface of the through hole 20, with the proximal end face 92 fixed to the stepped portion 922 via a fixing layer (e.g., an adhesive layer) 80.

[0097] In this invention, the dimensions (axial length, inner diameter, cone angle, etc.) of each part (second tapered part 22, first tapered part 21, expanded diameter part 23, cylindrical part 25) constituting the inner peripheral surface of the through hole 20 in the tube insertion part 40 can be appropriately changed.

[0098] (Example 2) Figure 10 This is a cross-sectional view of the medical catheter 2 according to Embodiment 2 of the present invention. The catheter 2 differs from the catheter 1 of Embodiment 1 in that a side hole 55 is provided in the base tube 50 of the connector 210. The side hole 55 communicates with the through hole 20 (i.e., the inner cavity of the base tube 50) and penetrates the base tube 50 in a manner that allows the through hole 20 to communicate with the outside of the base tube 50. The side hole 55 is along a surface containing the axis (not shown) of the connector 210 (this surface is parallel to...). Figure 10 (The cross-section is consistent) extends non-parallel to the axis of connector 210. Figure 10 In the example, the side hole 55 is tilted relative to the axis of connector 210 in such a way that it approaches the second end 12 as it moves outward in the radial direction away from the axis of connector 210.

[0099] Side hole 55 is useful in the manufacture of catheter 2. An example illustrating the manufacturing method of catheter 2 is provided.

[0100] First, prepare a connector 210 and a tube 90 with side holes 55. For example... Figure 11 As shown, connector 210 is held by a clamp or similar device (not shown) such that the axis of connector 210 is parallel to the vertical direction, with the second end 12 facing upwards. Tube 90 is inserted into through-hole 20 through the opening on the side of the second end 12. At this stage, no adhesive is applied to either tube 90 or connector 210. Figure 11 As shown, the outer peripheral end 91 of the tube 90 is inserted into the through hole 20 until it abuts against the inner peripheral surface of the second tapered portion 22 of the connector 210. The outer peripheral end 91 of the tube 90 is in close contact with the second tapered portion 22 in a liquid-tight manner, forming a continuous, circumferentially annular seal between the outer peripheral end 91 and the second tapered portion 22. The tube 90 is held in place by a clamp or the like (not shown) so that the tube 90 extends straight along the axis of the connector 210 within the through hole 20.

[0101] Prepare uncured adhesive. The adhesive is stored in a container (not shown) connected to an elongated nozzle 287. The container may also be a syringe, for example. Insert the nozzle 287 into the side hole 55 and inject a predetermined amount of uncured adhesive 285 into the through hole 20 through the nozzle 287. After leaving the nozzle 287, the adhesive 285 flows downward (towards the first end 11) in the gap between the outer peripheral surface 95 of the tube 90 and the inner peripheral surface of the through hole 20. However, because a liquid-tight seal is formed between the outer peripheral end 91 of the tube 90 and the second tapered portion 22, the adhesive 285 cannot flow past the outer peripheral end 91 toward the first end 11 (male member 31).

[0102] Remove nozzle 287 from side hole 55. Then, allow adhesive 285 to cure. Afterward, sterilize connector 210 and tube 90. This yields... Figure 10 The connector 210 shown is fixed to the conduit 2 of the tube 90 via the fixing layer 80.

[0103] In the manufacturing method of the conduit 1 described in Embodiment 1, an adhesive 85 is applied to the outer peripheral surface 95 of the tube 90, and then the tube 90 is inserted into the through hole 20 of the connector 10 (see reference). Figure 3This method is suitable for situations where adhesives, such as solvent-based adhesives, can be easily applied thinly to the outer peripheral surface 95 of the tube 90. However, when inserting the tube 90 into the through hole 20, an operational error may occur, causing the adhesive 85 to incorrectly adhere to the inner peripheral surface (e.g., the cylindrical portion 25) near the second end 12 of the through hole 20. In contrast, in the manufacturing method of the conduit 2 described in Embodiment 2, the tube 90 is inserted into the through hole 20 of the connector 210, and then the adhesive 285 is injected via nozzle 287 into the gap between the outer peripheral surface 95 of the tube 90 and the inner peripheral surface of the through hole 20. In Embodiment 2, the aforementioned operational error of Embodiment 1 can be prevented. The conduit 2 of Embodiment 2 is easy to manufacture, which is beneficial for improving the yield.

[0104] In this embodiment 2, the adhesive 285 preferably has fluidity. Specifically, a UV adhesive or a transient adhesive can be used as the adhesive 285. When using a UV adhesive, the connector 210 preferably has light transmittance (or transparency) so that UV light can be irradiated onto the adhesive 285 between the outer peripheral surface 95 of the tube 90 and the inner peripheral surface of the through hole 20.

[0105] To allow the adhesive 285 injected via nozzle 287 to flow between the outer peripheral surface 95 of pipe 90 and the inner peripheral surface of through hole 20, it is preferable to form a radial gap between the outer peripheral surface 95 of pipe 90 and the inner peripheral surface of through hole 20. Therefore, it is preferable that the minimum inner diameter of enlarged portion 23 (which is the same as the maximum inner diameter of first tapered portion 21) and the minimum inner diameter of first tapered portion 21 (which is the same as the maximum inner diameter of second tapered portion 22) are slightly larger than the outer diameter of pipe 90 (outer diameter under no-load condition).

[0106] The position of the side hole 55 in the axial direction of the connector 10 is not limited. For example, the opening 55a on the through hole 20 side of the side hole 55 (refer to...) Figure 10 The opening 55a can also be located near the second end 12, for example, in the cylindrical portion 25. However, if the opening 55a is located in the cylindrical portion 25, it is possible to form a fixing layer 80 that fixes the tube 90 to the cylindrical portion 25. Therefore, it is preferable that the opening 55a is located in the enlarged diameter portion 23. As a result, it is easy to manufacture a conduit 2 with the fixing layer end 81 located in the enlarged diameter portion 23 (see reference). Figure 10 Furthermore, in the enlarged diameter section 23, the gap between the outer peripheral surface 95 of the tube 90 and the inner peripheral surface of the through hole 20 is relatively large. Therefore, for example, compared to the case where the opening 55a is located in the first tapered section 21, the opening 55a being located in the enlarged diameter section 23 is advantageous in ensuring the flowability of the adhesive 285 flowing out from the nozzle 287.

[0107] As can be understood from the manufacturing method described above, the side hole 55 is tilted toward the second end 12 as it moves away from the outer side in the axial radial direction of the connector 210. This helps to prevent the adhesive 285 that is not cured from flowing out of the base cylinder 50 through the side hole 55 after the nozzle 287 is pulled out of the side hole 55 and before the adhesive 285 is cured.

[0108] Multiple side holes 55 can also be provided in the connector 210. Multiple nozzles 287 can be inserted into the multiple side holes 55 respectively, and adhesive 285 can be injected through each nozzle 287. The number of side holes 55 is not limited, but they can be arranged at equal angular intervals in the circumferential direction relative to the axis of the connector 210. By injecting adhesive 285 from the multiple nozzles 287 respectively, adhesive 285 can be easily injected into the gap between the outer circumferential surface 95 of the tube 90 and the inner circumferential surface of the through hole 20 in a short time and approximately evenly in the circumferential direction.

[0109] This embodiment 2 is the same as embodiment 1 except as described above. The description of embodiment 1 also applies to this embodiment 2.

[0110] The embodiments 1 and 2 described above are merely illustrative. The present invention is not limited to the embodiments 1 and 2 described above, and can be appropriately modified.

[0111] The connector (10, 210) of embodiments 1 and 2 described above has a connecting portion 30 that is a male connector for enteral nutrition. It includes a cylindrical male member 31 with a through hole 20, an outer cylinder 35 coaxially surrounding the male member 31, and a female thread 36 on the inner circumferential surface of the outer cylinder 35. The catheter (1, 2) equipped with this connector can be used in enteral nutrition. In enteral nutrition, the catheter placed in the patient is frequently bent. As described above, the catheter of the present invention exhibits excellent durability against bending operations. Therefore, the catheter of the present invention performs particularly well when used as a catheter placed in a patient in enteral nutrition. However, in the present invention, the structure of the connecting portion 30 is not limited to embodiments 1 and 2 described above. For example, the connecting portion 30 may be a medical female connector having a hollow cylindrical tubular portion, a female conical surface with an increased inner diameter towards the front end of the tubular portion located on the inner circumferential surface of the tubular portion, and a spiral protrusion located on the outer circumferential surface of the tubular portion (see, for example, Patent Document 2). The structure of the connecting portion 30 is not limited to the above structure and may be appropriately modified according to the application of the medical catheter.

[0112] The catheters 1 and 2 described in Embodiments 1 and 2 are used in patients during enteral nutrition, but the catheters of the present invention are not limited thereto. In Embodiments 1 and 2, the effect of the catheter of the present invention was explained by relating it to the stress generated in the portion 82 near the end during a tube bending operation performed during enteral nutrition. However, such stress may also be generated by applying radial outward tension to the tube, in addition to tube bending operations. The effect of the present invention can also be achieved when radial outward tension is applied to the tube. Therefore, the catheter of the present invention can be any medical catheter that allows such tension to be applied to the tube. Specifically, the catheter of the present invention can also be a catheter used in infusion, anesthesia, and dialysis (hemodialysis, peritoneal dialysis), or a catheter used in endotracheal intubation.

[0113] Industrial applicability This invention can be used as a medical catheter with a connector at one end of a flexible, hollow tube. The catheter of this invention is preferably used in enteral nutrition, more preferably as an indwelling catheter in a patient, and particularly preferably as a nasal catheter.

[0114] Explanation of reference numerals in the attached figures 1, 1a, 1b, 1c, 2 Medical catheters (catheters) 10, 10a, 10b, 10c, 210 connectors 11 First End 12 Second End 19. Connector shaft 20 Through Holes 21 First conical part 22 Second conical part 23, 23a, 23b, 23c Expanded diameter section 25. Cylindrical section 30 Connecting part 31. Male component 35 outer cylinder 36 Female thread 40 tube insertion section 41 Fixed part 42 Separation section 55 side hole 80 Fixed layer 81 Fixed layer end 82. Part near the end 90 tubes 91. Outer circumferential end of the tube 95mm outer circumference

Claims

1. A medical catheter comprising a flexible, hollow tube and a connector disposed at one end of said tube, wherein, A through hole extends through the connector along its axis to connect the first end to the second end of the connector. The connector has a connecting portion on the first end side for connecting with the other connector, and a tube insertion portion on the second end side for inserting the tube into the through hole. The tube insertion portion includes a fixing portion where the tube is fixed to the connector via a fixing layer and a separating portion disposed on the second end side relative to the fixing portion. In the separation section, the inner circumferential surface of the through hole separates radially from the outer circumferential surface of the tube. The end of the second end of the bonding layer, i.e. the bonding layer end, separates from the first end along the axial direction of the connector from the second end.

2. The medical catheter according to claim 1, wherein, The length L along the axis of the connector from the second end to the end of the fixing layer is more than 5 mm and less than 10 mm.

3. The medical catheter according to claim 1, wherein, When the opening diameter at the second end of the through hole is set as Dc, the outer diameter of the tube is set as Dt, and the length along the axis of the connector from the second end to the end of the fixing layer is set as L, [(Dc-Dt) / 2] / L≤0.10 is satisfied.

4. The medical catheter according to claim 1, wherein, Let the opening diameter at the second end of the through hole be Dc. When the outer diameter of the tube is set to Dt, Dc / Dt ≤ 1.30 is satisfied.

5. The medical catheter according to claim 1, wherein, In the tube insertion portion, the inner circumferential surface of the through hole includes an enlarged diameter portion. The enlarged diameter section is a curved surface whose inner diameter increases towards the second end. The end of the bonding layer is located in the enlarged diameter section.

6. The medical catheter according to claim 1, wherein, In the tube insertion portion, the inner circumferential surface of the through hole includes a first tapered portion, an enlarged diameter portion, and a cylindrical portion arranged adjacent to each other from the first end toward the second end. The first tapered portion is a conical surface whose inner diameter increases toward the second end. The enlarged diameter section is a curved surface whose inner diameter increases towards the second end. The cylindrical portion is a cylindrical surface whose inner diameter is constant along the axial direction of the connector, and the inner diameter of the cylindrical portion is larger than the outer diameter of the tube. The bonding layer extends from the first tapered portion toward the expanded diameter portion. The end of the bonding layer is located in the enlarged diameter section.

7. The medical catheter according to claim 1, characterized in that, The inner circumferential surface of the through hole includes a first tapered portion and a second tapered portion arranged adjacent to each other from the second end toward the first end. Both the first tapered portion and the second tapered portion are conical surfaces whose inner diameter increases towards the second end. The bonding layer secures the outer circumferential surface of the tube to the first tapered portion. The proximal end of the outer peripheral surface of the tube, i.e., the outer peripheral end, abuts against the second tapered portion.

8. The medical catheter according to claim 1, wherein, The connecting part is a male connector used in enteral nutrition, which includes a cylindrical male component with the through hole, an outer cylinder coaxially surrounding the male component, and a female thread provided on the inner circumferential surface of the outer cylinder.

9. The medical catheter according to claim 1, wherein, The tube insertion portion is provided with a side hole that communicates with the through hole but is not parallel to the axis of the connector.

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