Catheter assembly

Abstract

To provide a catheter assembly that is easily operated and can effectively suppress deformation of an inner needle at the time of puncture.SOLUTION: A catheter assembly 10A includes a needle support part 20 supporting an inner needle 16 via a catheter 12. The needle support part includes: a pair of support arms 68 that can be opened / closed in a right / left direction; and a frame-shaped constraint part 69 that can constrain the pair of support arms 68 in a closed state and cancel the constraint. The constraint part 69 cancels the constraint to the pair of support arms 68 as a hub operation part 24a advances.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a catheter assembly that punctures and indwells in a blood vessel, for example, when performing infusion on a patient.

Background Art

[0002] Conventionally, when performing infusion on a patient, for example, a catheter assembly is used. This type of catheter assembly includes a hollow catheter, a catheter hub fixed to the proximal end of the catheter, an inner needle inserted into the catheter and having a sharp needle tip at the distal end, and a needle hub fixed to the proximal end of the inner needle. When performing infusion on a patient using the catheter assembly, the catheter is punctured into the patient's blood vessel together with the inner needle. After this puncture, the inner needle is withdrawn from the catheter while the catheter remains punctured in the patient. Next, a connector provided at the end of the infusion tube is connected to the proximal end of the catheter hub, and an infusion agent is supplied into the patient's blood vessel through the infusion tube, the catheter hub, and the catheter.

[0003] In such a catheter assembly, in order to suppress the bending of the inner needle during puncture, a means for supporting the inner needle through the catheter is known (see, for example, Japanese Patent Publication No. 10-503094, U.S. Patent Application Publication No. 2011 / 0282285).

[0004] In Japanese Patent Publication No. 10-503094, two openable and closable arms extending in the distal direction are provided on the needle hub. Before use, the two arms are open and do not support the inner needle. During puncture, the user can pinch the arms to perform puncture while suppressing the bending of the inner needle. After puncture, by weakening the force with which the user pinches the two arms, the two arms open and the catheter hub can move forward.

[0005] In U.S. Patent Application Publication No. 2011 / 0282285, two openable arms extending in the tip direction are provided on the needle hub. Before use, the two arms are closed to support the inner needle via a catheter, and are constrained in the closed state by a restraining portion. During use, when the restraining portion is advanced, the restraint by the restraining portion is released. Thereafter, when the two arms are opened in the vertical direction, the catheter hub can be advanced. The two arms are connected via a hinge portion at the proximal end of the catheter assembly.

[0006] In the catheter assembly of Japanese Patent Publication No. 10-503094, in order to support and release the inner needle, an operation for the user to increase or decrease the force of pinching the two arms is required, and the operation is complicated.

[0007] In the catheter assembly of U.S. Patent Application Publication No. 2011 / 0282285, since the two arms for supporting the inner needle open in the vertical direction, the protruding length of the inner needle from the arm is increased to avoid interference with the patient's skin, and the inner needle is easily bent. Also, at the time of puncture, the vicinity of the tip of the arm is held to facilitate puncture, but after release of the restraint of the arm, it is necessary to change the holding position to the vicinity of the proximal end of the arm (the proximal end of the catheter assembly) in order to open the arm, and the operation is complicated.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been made in consideration of such problems, and an object thereof is to provide a catheter assembly that is easy to operate and can effectively suppress the bending of the inner needle during puncture.

Means for Solving the Problems

[0009] To achieve the above object, the present invention provides a catheter assembly including a catheter, a catheter hub fixed to the proximal end of the catheter, an inner needle having a needle tip and inserted through the catheter, a needle hub connected to the inner needle, a needle support portion, and a hub operation portion for operating the catheter hub. The needle support portion supports the inner needle via the catheter and includes a pair of support arms that can be opened and closed in the left-right direction, and a frame-shaped restraint portion that can restrain the pair of support arms in a closed state and can release the restraint, and that surrounds the pair of support arms. The restraint portion releases the restraint on the pair of support arms as the hub operation portion advances. The catheter assembly is characterized by this structure.

Advantages of the Invention

[0010] According to the catheter assembly of the present invention, the operation is easy, and the bending of the inner needle during puncture can be effectively suppressed.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of the catheter assembly according to the present invention will be given and described with reference to the accompanying drawings.

[0013] Fig. 1 is a perspective view showing the overall configuration of the catheter assembly 10A according to the first configuration. Fig. 2 is an exploded perspective view of the catheter assembly 10A. Fig. 3 is a longitudinal sectional view of the catheter assembly 10A.

[0014] The catheter assembly 10A includes a tubular catheter 12 that functions as an outer needle, a catheter hub 14 connected to the proximal end side of the catheter 12, a tubular inner needle 16 having a sharp needle tip 17 at its distal end and insertable into the catheter 12, a needle hub 18 connected to the inner needle 16, and a needle support portion 20 for suppressing the deflection of the inner needle 16 during puncture.

[0015] For the catheter assembly 10A, the user (such as a doctor or a nurse) grips the needle hub 18, and its distal end is punctured into the patient's blood vessel. In the initial state before use (before puncturing the patient), the catheter assembly 10A has a double-tube structure in which the inner needle 16 is inserted into the catheter 12, and the inner needle 16 protrudes from the distal end of the catheter 12 by a predetermined length.

[0016] In the initial state, the catheter assembly 10A is composed of a double-tube structure of the catheter 12 and the inner needle 16, the catheter hub 14, the needle hub 18, and the needle support portion 20, which are combined to form a single assembly and can be handled integrally.

[0017] The catheter 12 is a flexible, small-diameter tubular member formed to a predetermined length. As the constituent material of the catheter 12, a resin material, particularly a soft resin material, is suitable. In this case, for example, fluorine-based resins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroalkoxy fluororesin (PFA), olefin-based resins such as polyethylene and polypropylene, or mixtures thereof, polyurethane, polyester, polyamide, polyether nylon resin, and mixtures of the olefin-based resin and ethylene-vinyl acetate copolymer can be mentioned. The catheter 12 may be made of a transparent resin so that all or part of its interior can be visually recognized.

[0018] The catheter hub 14 is connected and fixed to the proximal end of the catheter 12. A flange portion 22 that protrudes outward and extends in the circumferential direction is provided at the proximal end of the catheter hub 14. Notches 23 are provided on both the left and right sides of the flange portion 22.

[0019] The catheter hub 14 is provided with a hub operation part 24 for operating the catheter hub 14. As shown in FIG. 1, the hub operation part 24 in this illustrated example is a tab protruding upward from the tip of the catheter hub 14 and is integrally formed with the catheter hub 14. The hub operation part 24 may be configured as a separate part from the catheter hub 14 and may be detachable from the catheter hub 14. The user can operate the catheter hub 14 in the axial direction by touching, gripping, or pressing the hub operation part 24. Note that the position where the hub operation part 24 is provided is not limited to the tip of the catheter hub 14 and may be between the tip and the proximal end of the catheter hub 14.

[0020] Hereinafter, the members including the catheter 12, the catheter hub 14, and the hub operation part 24 are referred to as "catheter member 25".

[0021] When using the catheter assembly 10A, the catheter hub 14 is exposed on the patient's skin with the catheter 12 puncturing the blood vessel and is affixed and retained on the skin with a dressing material, tape, or the like. Such a catheter hub 14 is preferably made of a material harder than the catheter 12. The constituent material of the catheter hub 14 is not particularly limited, and for example, thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used.

[0022] In FIGS. 1 and 2, the inner needle 16 is a tubular member having rigidity capable of puncturing the patient's skin. The inner needle 16 is formed to be sufficiently longer than the catheter 12, and in the initial state of the catheter assembly 10A, its needle tip 17 protrudes from the tip opening of the catheter 12 by a predetermined length. Also, in the initial state, the middle part of the inner needle 16 in its longitudinal direction is inserted into the catheter hub 14, and its proximal end side is held by the needle hub 18.

[0023] Examples of the constituent material of the inner needle 16 include metal materials such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy.

[0024] The needle hub 18 has a hub body 36 arranged in series with the catheter hub 14 in the initial state, and an extension portion 38 extending from the hub body 36 in the distal direction. The hub body 36 has an inner needle holding portion 39 for fixedly holding the proximal end portion of the inner needle 16.

[0025] In this configuration, a pair of extension portions 38 facing each other along the inner needle 16 on both sides of the inner needle 16 and the catheter hub 14 are provided on both the left and right sides of the hub body 36. In the initial state of the catheter hub 14, the extension portion 38 extends to the distal side of the proximal end of the catheter hub 14. That is, the distal end of the extension portion 38 is located on the distal side of the distal end of the catheter hub 14. The extension portion 38 is formed to have an appropriate size (thickness, length) so that the user can easily grip and operate it when using the catheter assembly 10A.

[0026] Guide protrusions 40 extending along the axial direction of the inner needle 16 are provided on the inner surfaces of the pair of extension portions 38 facing each other. The left and right guide protrusions 40 are respectively inserted into the left and right notches 23 provided in the flange portion 22 of the catheter hub 14. Thereby, in the initial state, the catheter hub 14 is stably supported by the needle hub 18, and the rotation of the catheter hub 14 with respect to the needle hub 18 is prevented, so that the hub operation portion 24 can be held upward. Also, when advancing the catheter hub 14 with respect to the needle hub 18, the catheter hub 14 can be smoothly advanced by the guiding action of the guide protrusion 40.

[0027] Next, the needle support portion 20 will be described. The needle support portion 20 supports the inner needle 16 via the catheter 12 on the distal side of the catheter hub 14 in the initial state of the catheter assembly 10A. The needle support portion 20 is movably provided with respect to the needle hub 18 so as to change from a first state of supporting the inner needle 16 to a second state of releasing the support of the inner needle 16 and allowing the passage of the catheter hub 14.

[0028] In this configuration, specifically, the needle support portion 20 has a pair of support arms 42 that can be opened and closed, and a restraint portion 44 that can restrain the pair of support arms 42 in a closed state and can release the restraint. Hereinafter, when distinguishing and explaining one and the other of the pair of support arms 42 from each other, one will be denoted as "support arm 42a" and the other will be denoted as "support arm 42b".

[0029] The pair of support arms 42 are rotatably connected to the extension portion 38 via a pair of support pins 43. In the illustrated example of this figure, the pair of support pins 43 have axes in the vertical direction, and the pair of support arms 42 supported thereby can be opened and closed in the left-right direction. In the initial state, the connection portion between the pair of support arms 42 and the extension portion 38 is on the distal end side of the proximal end of the catheter hub 14.

[0030] The extension portion 38 and the support arm 42 are rotatably connected via a hinge structure 48 having a first structure 45 and a second structure 46. In this configuration, the first structure 45 is provided at the distal end of the extension portion 38, and the second structure 46 is provided at the proximal end of the support arm 42. The first structure 45 has a plurality of connection pieces 49 that are spaced apart in the vertical direction and face each other, and a recess 50 formed between the connection pieces 49. The second structure 46 has a connection protrusion 51 disposed in the recess 50. On each of the left and right sides, the support pins 43 are inserted through the connection protrusion 51 and the two connection pieces 49. In a modified example, the first structure 45 may be provided at the proximal end of the support arm 42, and the second structure 46 may be provided at the distal end of the extension portion 38.

[0031] Each support arm 42 is provided with a support groove 53 for holding the inner needle 16 in a state where the pair of support arms 42 are closed. In a state where the pair of support arms 42 are closed, a support hole 54 for supporting the inner needle 16 (the inner needle 16 inserted into the catheter 12) is formed by the two support grooves 53. In the initial state of the catheter assembly 10A, the support hole 54 extends along the extending direction of the inner needle 16.

[0032] Each support arm 42 is provided with bent engagement grooves 56a and 56b in a front view in the closed state. Each of the engagement grooves 56a and 56b penetrates the support arm 42 in the front-rear direction. One of the engagement grooves 56a (hereinafter referred to as the "first engagement groove 56a") and the other engagement groove 56b (hereinafter referred to as the "second engagement groove 56b") bend in opposite directions. Specifically, the first engagement groove 56a bends downward, and the second engagement groove 56b bends upward.

[0033] In addition, as shown in FIG. 3, the lower part of the support arm 42 may be trimmed so that the support arm 42 does not interfere with the skin S when puncturing the skin S of the patient at a small angle.

[0034] The restraining portion 44 is slidably disposed with respect to the pair of support arms 42. As the catheter hub 14 advances and the restraining portion 44 is pushed by the catheter hub 14, the restraint on the pair of support arms 42 is released.

[0035] Specifically, the restraining portion 44 has a first restraining protrusion 58a that slidably engages with the first engagement groove 56a and a second restraining protrusion 58b that slidably engages with the second engagement groove 56b. In the illustrated example of this figure, the first restraining protrusion 58a and the second restraining protrusion 58b protrude in opposite directions so as to conform to the shapes of the first engagement groove 56a and the second engagement groove 56b provided in the pair of support arms 42. When the restraining portion 44 is in the initial position (retracted position), the first restraining protrusion 58a and the second restraining protrusion 58b of the restraining portion 44 engage with the first engagement groove 56a and the second engagement groove 56b of the pair of support arms 42, respectively. For this reason, the pair of support arms 42 are restrained in the closed state.

[0036] As the second restraint protrusion 58b moves in the distal direction of the restraint portion 44, it disengages from the second engagement groove 56b of the support arm 42 in the distal direction. When the second restraint protrusion 58b disengages from the second engagement groove 56b, the restraint of the restraint portion 44 on the pair of support arms 42 is released, and the pair of support arms 42 can be expanded. Even after the second restraint protrusion 58b disengages from the second engagement groove 56b, the restraint portion 44 is held by the support arm 42a because the engagement between the first restraint protrusion 58a and the first engagement groove 56a is maintained.

[0037] In a state where the second restraint protrusion 58b has disengaged from the second engagement groove 56b, the second restraint protrusion 58b protrudes to the side opposite to the side where the inner needle 16 is present (see FIG. 4). For this reason, when the support arm 42 opens with the inner needle 16 bent toward the restraint portion 44 side, the inner needle 16 is prevented from being caught by the second restraint protrusion 58b. In a modified example, the second restraint protrusion 58b may protrude to the side where the inner needle 16 is present. In this case, the bent shape of the second engagement groove 56b provided in the support arm 42b is formed in accordance with the protruding direction of the second restraint protrusion 58b.

[0038] A pressed portion 60 is provided at the proximal end of the restraint portion 44. When the catheter hub 14 advances relative to the needle hub 18, the restraint portion 44 advances relative to the pair of support arms 42 by the proximal end of the catheter hub 14 pressing the pressed portion 60. The surface of the pressed portion 60 facing the catheter hub 14 is provided with a taper that inclines so as to be displaced laterally outward to the left and right as it goes in the proximal direction.

[0039] The catheter assembly 10A is basically configured as described above, and its operation and effects will be described below.

[0040] As shown in FIGS. 1 and 3, the catheter assembly 10A in the initial state is in the following state. The inner needle 16 is inserted into the catheter 12, and the needle tip 17 protrudes from the tip of the catheter 12 by a predetermined length. The catheter hub 14 is located at the proximal end side to the maximum extent with respect to the needle hub 18, and extension portions 38 exist on both the left and right sides of the catheter hub 14. The distal end side of the inner needle holding portion 39 of the needle hub 18 is inserted into the proximal end of the catheter hub 14. The restraint portion 44 is in the retracted position within the movable range, and the pair of support arms 42 are restrained in the closed state by the restraint portion 44. The inner needle 16 is supported via the catheter 12 by the pair of support arms 42 in the closed state.

[0041] In the use of the catheter assembly 10A, the user (such as a doctor or a nurse) grips the needle hub 18 and punctures the blood vessel of the patient with the catheter 12 and the inner needle 16. At this time, since the inner needle 16 is supported via the catheter 12 by the support hole 54 formed between the pair of closed support arms 42, the deflection of the inner needle 16 during puncture is suppressed. Thereby, stable puncture is possible.

[0042] After puncture, place a finger on the hub operation portion 24 protruding upward from the catheter hub 14, and push the hub operation portion 24 in the distal direction. Then, the catheter hub 14 and the catheter 12 connected to the hub operation portion 24 move in the distal direction with respect to the needle hub 18, and the insertion length of the catheter 12 into the blood vessel increases.

[0043] As shown in FIG. 4, as the catheter hub 14 advances, the hub operation portion 24 pushes the restraint portion 44 in the distal direction. Thereby, the restraint portion 44 moves in the distal direction with respect to the pair of support arms 42, and the second restraint protrusion 58b disengages from the second engagement groove 56b. When the second restraint protrusion 58b disengages from the second engagement groove 56b, the restraint of the pair of support arms 42 by the restraint portion 44 is released, and the pair of support arms 42 can be expanded.

[0044] Then, as the catheter hub 14 further advances, as shown in FIG. 5, the pair of support arms 42 are pushed from behind by the hub operation portion 24 and the catheter hub 14 and expand. In this way, the needle support portion 20 suppresses the deflection of the inner needle 16 during puncture by supporting the inner needle 16 in the initial state, while after puncture, the pair of support arms 42 open to prevent interference with the catheter hub 14.

[0045] After inserting the catheter 12 into the blood vessel by a predetermined length, next, while holding the position of the catheter member 25, the needle hub 18 is pulled in the proximal direction. Then, the inner needle 16 moves in the proximal direction within the catheter member 25, and eventually, the inner needle 16 is completely removed from the catheter member 25 as shown in FIG. 5. As a result, only the catheter member 25 of the catheter assembly 10A remains indwelling on the patient side.

[0046] After pulling out the inner needle 16 from the catheter member 25, the catheter hub 14 is fixed to the patient with a dressing material, tape, or the like. Then, a connector of an infusion tube (not shown) is connected to the proximal end side of the catheter hub 14, and the supply of an infusion agent (drug solution) from the infusion tube to the patient is carried out.

[0047] As described above, according to the catheter assembly 10A, since the inner needle 16 is supported by the pair of support arms 42 during puncture, the deflection of the inner needle 16 during puncture is suppressed, and stable puncture is possible.

[0048] In particular, in the present invention, the support and release of the inner needle 16 are not performed by adjusting the gripping force by the user, but the restraint of the pair of support arms 42 and its release are performed by the action of the restraint portion 44, so the operation is easy.

[0049] Further, since the pair of support arms 42 that open in the left - right direction do not interfere with the skin S of the patient, it is not necessary to make the inner needle 16 unnecessarily long for interference avoidance, and the deflection of the inner needle 16 can be effectively suppressed.

[0050] Furthermore, since the support arm 42 is provided on the distal side of the proximal end of the catheter hub 14, for example, by gripping the extension portion 38 on the distal side of the proximal end of the catheter hub 14, the puncture operation and the advancement operation of the catheter hub 14 can be sequentially performed with the same hand without having to change hands. Therefore, the operability is excellent.

[0051] Particularly, in the case of this configuration, since the restraint on the pair of support arms 42 is automatically released in conjunction with the advancement operation on the hub operation portion 24, an independent release operation is not required, and the operability is excellent.

[0052] Also, in the case of this configuration, since the first and second engagement grooves 56a and 56b provided on the pair of support arms 42 are respectively engaged with the first and second restraint protrusions 58a and 58b provided on the restraint portion 44, the needle support portion 20 can be configured compactly.

[0053] Furthermore, in the case of this configuration, when the restraint portion 44 is in the advanced position, the restraint portion 44 is held by the support arm 42a provided with the first engagement groove 56a, and the second restraint protrusion 58b disengages from the second engagement groove 56b. According to this configuration, after releasing the restraint on the pair of support arms 42, the restraint portion 44 moves together with one of the support arms 42, so that it does not interfere with the advancement of the catheter hub 14.

[0054] Particularly, since the second restraint protrusion 58b protrudes on the side opposite to the side where the inner needle 16 is present, it is possible to prevent the second restraint protrusion 58b from being caught by the inner needle 16 when the support arm 42a holding the restraint portion 44 opens.

[0055] In the case of this configuration, the extension portion 38 and the support arm 42 are rotatably connected via a hinge structure 48 having a first structure 45 and a second structure 46. Since the first structure 45 and the second structure 46 are in a meshing relationship with each other, play in the hinge structure 48 can be suppressed.

[0056] In the above-described configuration, the restraint on the pair of support arms 42 is released when the restraint portion 44 is pushed by the hub operation portion 24. However, instead of such a configuration, the restraint on the pair of support arms 42 may be released when the restraint portion 44 is pushed by the catheter hub 14 itself. Alternatively, the catheter assembly 10A may further include a guide wire G inserted through the inner needle 16 and a guide wire operation portion 64 connected to the guide wire G for operating the guide wire G (see FIG. 3). In this case, as the guide wire operation portion 64 advances, the restraint on the pair of support arms 42 may be released when the restraint portion 44 is pushed by the guide wire operation portion 64.

[0057] Instead of the above-described needle support portion 20, the needle support portions 20a to 20c shown in FIGS. 7A to 8 may be employed. In FIGS. 7A to 8, illustration of the inner needle 16, the catheter 12, and the catheter hub 14 is omitted.

[0058] In the needle support portion 20a shown in FIG. 7A, a pair of support arms 65 that are slidable in the left-right direction with respect to the left and right extension portions 38 are provided. In this case, the extension portion 38 is provided with, for example, slide holes 38a for slidably holding the support arms 65 in the left-right direction. With such a configuration of FIG. 7A as well, the pair of support arms 65 can be opened and closed in the left-right direction. Therefore, it is possible to change from the first state of supporting the inner needle 16 to the second state of releasing the support of the inner needle 16 and allowing the passage of the catheter hub 14.

[0059] In the needle support portion 20b shown in FIG. 7B, a pair of support arms 66 that are rotatably supported by a pair of support pins 67 parallel to the axial direction of the inner needle 16 are provided. In this case, for example, the tips of the left and right extension portions 38 are connected to each other, and a pair of support pins 67 are fixed to the connecting portion 38b. With such a configuration of FIG. 7B as well, the pair of support arms 66 can be opened and closed in the left-right direction. Therefore, it is possible to change from the first state of supporting the inner needle 16 to the second state of releasing the support of the inner needle 16 and allowing the passage of the catheter hub 14.

[0060] The needle support portion 20c shown in Fig. 8 has a pair of support arms 68 that can be opened and closed in the left-right direction, and a restraint portion 69 that can restrain the pair of support arms 68 in a closed state and can release the restraint. In Fig. 8, the restraint portion 69 is formed in a frame shape surrounding the tip of the support arm 68 and can restrain the pair of support arms 68 in a closed state. Instead of the hub operation portion 24, a hub operation portion 24a is provided. The hub operation portion 24a is connected to the restraint portion 69. When the hub operation portion 24a is advanced, the restraint portion 69 disengages from the pair of support arms 42 in the tip direction, so the restraint on the pair of support arms 68 is released. Note that instead of the hub operation portion 24a, a guide wire operation portion may be provided.

[0061] In the case of the configuration of Fig. 8, the restraint portion 69 is formed in a frame shape surrounding the tip of the support arm 68, and the left and right inward protruding ends 69a of the restraint portion 69 enter the stepped portion 68a provided at the lower part of the tip of the support arm 68. Due to such a configuration, it is possible to avoid an increase in the size of the structure existing below the inner needle 16. On the other hand, when the stepped portion 68a into which the inward protruding end 69a of the restraint portion 69 enters is not provided on the support arm 68, the structure existing below the inner needle 16 becomes larger, making it easier to interfere with the patient's skin.

[0062] Instead of the hinge structure 48 described above, the hinge structure 48a shown in Figs. 9A and 9B may be adopted. Note that Fig. 9B is a cross-sectional view taken along line IXB-IXB in Fig. 9A. In the hinge structure 48a, the support arm 42 and the extension portion 38 are integrally formed via a thin-walled portion 70. In this case, the thin-walled portion 70 functions as a bending portion, so that the support arm 42 can rotate with respect to the extension portion 38.

[0063] As in the hinge structure 48b shown in FIG. 9C, a configuration may be adopted in which one connecting piece 71 provided at the proximal end of the support arm 42 and one connecting piece 72 provided at the distal end of the extending portion 38 are vertically overlapped and rotatably connected by a support pin 43. Alternatively, in the hinge structure 48b, the support pin 43 may be integrally formed with the support arm 42. Further, instead of using the support pin 43, a configuration in which the support arm 42 and the extending portion 38 are integrally formed via a thin-walled portion may be adopted.

[0064] In the above-described configuration, since the support grooves 53 are provided in each support arm 42 and the support holes 54 are formed by the two support grooves 53, the position of the mating surface of the support arms 42 in the left-right direction becomes substantially the same as the axis of the inner needle 16 supported by the support holes 54. For this reason, when a force greater than a predetermined value acts on the inner needle 16 in the vertical direction, the inner needle 16 may come off from the pair of closed support arms 42. Therefore, instead of the support holes 54, for example, the support holes 54a to 54d shown in FIGS. 10A to 10D may be adopted. FIGS. 10A to 10D schematically show the structures of the support holes 54a to 54d, omitting the restraining portion 44 and the first and second engaging grooves 56a and 56b.

[0065] In the structure of the support hole 54a shown in FIG. 10A, no support groove is provided in one support arm 42a, and only the support groove 53a (a groove deeper than the support groove 53) is provided in the other support arm 42b. In a state where the pair of support arms 42 are closed, the support hole 54a is formed by the inner surface of one support arm 42a and the support groove 53a provided in the other support arm 42b. In the case of this configuration, the position of the mating surface of the pair of support arms 42 is displaced in the left-right direction with respect to the center of the inner needle 16 supported by the support hole 54a. For this reason, even when a vertical force acts on the inner needle 16, the inner needle 16 is less likely to come off from the pair of closed support arms 42.

[0066] In the structure of the support hole 54b shown in FIG. 10B, a protrusion 73 protruding inward (toward the other support arm 42b side) is provided on one support arm 42a, and a deeper support groove 53b is provided on the other support arm 42b. In a state where the pair of support arms 42 are closed, the protrusion 73 is inserted into the support groove 53b, and the support hole 54b is formed by the protrusion 73 and the support groove 53b. Also in this configuration, since the position of the mating surface of the pair of support arms 42 is displaced in the left - right direction with respect to the center of the inner needle 16 supported by the support hole 54b, the inner needle 16 is difficult to come off.

[0067] In the structure of the support hole 54c shown in FIG. 10C, stepped portions 74, 75 are provided on the inner surface of one support arm 42a. In a state where the pair of support arms 42 are closed, the support hole 54c is formed by the left - and - right stepped portions 74, 75. Also in this configuration, since the position of the mating surface of the pair of support arms 42 is displaced in the left - right direction with respect to the center of the inner needle 16 supported by the support hole 54c, the inner needle 16 is difficult to come off.

[0068] In the structure of the support hole 54d shown in FIG. 10D, a plurality of stepped shapes 76, 77 are provided on the inner surface of each support arm 42. In a state where the pair of support arms 42 are closed, the support hole 54d is formed by the left - and - right stepped shapes 76, 77. Also in this configuration, since the position of the mating surface of the pair of support arms 42 is displaced in the left - right direction with respect to the center of the inner needle 16 supported by the support hole 54d, the inner needle 16 is difficult to come off.

[0069] FIG. 11 is a perspective view showing the catheter assembly 10B according to the second configuration. FIG. 12 is an exploded perspective view of the catheter assembly 10B. FIG. 13 is a longitudinal sectional view of the catheter assembly 10B. In the catheter assembly 10B, elements having the same or similar functions and effects as those of the catheter assembly 10A are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0070] The catheter assembly 10B comprises a flexible tubular catheter 82, a catheter hub 84 connected to the base end of the catheter 82, a tubular inner needle 86 having a sharp needle tip 87 at its tip and capable of being inserted into the catheter 82, a needle hub 88 connected to the inner needle 86, a protector 90 that covers the needle tip 87 of the inner needle 86 when the inner needle 86 is removed, and a needle support portion 20 for suppressing bending of the inner needle 86.

[0071] The catheter assembly 10B is gripped by the needle hub 88 by a user (such as a doctor or nurse), and its tip is inserted into a patient's blood vessel. In the initial state before use (before the catheter is inserted into the patient), the catheter assembly 10B has a double-tube structure with an inner needle 86 inserted into the catheter 82, and the inner needle 86 protrudes a predetermined length from the tip of the catheter 82. In the initial state of the catheter assembly 10B, the catheter hub 84 and the needle hub 88 are connected via a protector 90.

[0072] In the initial state, the catheter assembly 10B comprises a double-tube structure of the catheter 82 and inner needle 86, a catheter hub 84, a protector 90 and a needle hub 88, which are combined to form a single assembly that can be handled as a single unit.

[0073] A hollow cylindrical catheter hub 84 is connected and fixed to the proximal end of the catheter 82. The proximal end of the catheter hub 84 is provided with a flange portion 92 that protrudes outward and extends in the circumferential direction.

[0074] The catheter hub 84 is provided with a pair of wings 94 that protrude in the left and right directions in a natural state. Each wing 94 is flexible and can be folded so as to overlap each other. As shown in FIG. 12, in this configuration, each wing 94 is provided with a first thin-walled portion 95 at the connection point with the catheter hub 84, and a second thin-walled portion 96 is provided outside the first thin-walled portion 95. The first thin-walled portion 95 is provided in a groove shape on the lower surface side of the wing 94, and the second thin-walled portion 96 is provided in a groove shape on the upper surface side of the wing 94.

[0075] With this configuration, the wings 94 can be easily bent upward at the first thin-walled portion 95 and easily bent in the opposite direction to the first thin-walled portion 95 at the second thin-walled portion 96. As shown in FIG. 11 , in the initial state of the catheter assembly 10B, the outer ends of the wings 94 are exposed from the needle hub 88. A user can operate the catheter hub 84 in the axial direction by touching, grasping, or pressing the wings 94 exposed from the needle hub 88. In other words, the pair of wings 94 function as an operating part for operating the catheter hub 84.

[0076] Hereinafter, the member consisting of the catheter 82, the catheter hub 84, and the pair of wings 94 will be referred to as the "catheter member 98."

[0077] 13, the inner needle 86 is formed to be sufficiently longer than the catheter 82, and in the initial state of the catheter assembly 10B, the needle tip 87 protrudes a predetermined length from the tip opening of the catheter 82. Also, in the initial state, the middle part of the inner needle 86 in the longitudinal direction is inserted into the catheter hub 84, and the base end side of the inner needle 86 is held inside the needle hub 88.

[0078] 12 and 13, the needle hub 88 has an inner needle holding portion 101 that holds the base end of the inner needle 86, and an extending portion 100 that extends further toward the distal end than the catheter hub 84. The extending portion 100 forms a housing that accommodates the catheter hub 84 and the protector 90 in the initial state.

[0079] The inner needle holding portion 101 protrudes downward from the center in the left-right direction on the base end side of the extending portion 100. On the left and right inner surfaces of the extending portion 100, rail grooves 102 extending in the axial direction are provided.

[0080] In the initial state of the catheter assembly 10B, the catheter 82 and the inner needle 86 are exposed from the tip of the needle hub 88, and the catheter hub 84 and the protector 90 are housed within the needle hub 88. As a result, the tip of the needle hub 88 extends halfway through the catheter 82. In this configuration, the base end position of the catheter hub 84 is located on the base end side of the axial center position of the needle hub 88, and the tip of the needle hub 88 is located on the tip end side of the longitudinal center position of the catheter 82.

[0081] 11 to 13, the needle hub 88 (specifically, the extension portion 100) is formed with a slit 103 that extends in the axial direction of the needle hub 88 and is open to the tip side of the needle hub 88. In this configuration, the slit 103 is formed in the upper wall of the needle hub 88. In the initial state of the catheter assembly 10B, the outer ends of the wings 94 that are folded and overlap each other protrude upward from the needle hub 88 through the slit 103.

[0082] The protector 90 accommodates the inner needle 86 and covers the needle tip 87 of the inner needle 86 as the inner needle 86 is removed from the catheter 82. As shown in Figures 12 and 13, the protector 90 has an inner tube 104 that is releasably fitted to the base end of the catheter hub 84, and an outer tube 106 inside which the inner tube 104 is disposed and which is movable axially relative to the inner tube 104 within a restricted range. When the inner needle 86 is removed from the catheter 82, the protector 90 extends to cover the entire length of the inner needle 86 (see Figure 18).

[0083] The inner tube 104 has a function of covering the needle tip 87 of the inner needle 86 as the inner needle 86 is pulled out from the catheter 82. The inner tube 104 has a body portion 107 and a tip fitting portion 108 protruding from the body portion 107 in the tip direction. A notch 109 extending in the axial direction is formed in the upper wall of the body portion 107. In the initial state, the inner tube 104 is located within the base end of the needle hub 88, and the inner needle holding portion 101 of the needle hub 88 is inserted into the notch 109 of the body portion 107. Rail projections 110 (see FIG. 12) extending in the axial direction are provided on the left and right outer surfaces of the body portion 107.

[0084] The tip fitting portion 108 of the inner cylinder 104 is formed in a tapered shape with an outer diameter decreasing toward the tip direction. In the initial state, the tip fitting portion 108 of the inner cylinder 104 fits into the proximal end of the catheter hub 84, and the inner cylinder 104 and the catheter hub 84 are connected by frictional resistance at the fitting surface.

[0085] The outer cylinder 106 is disposed between the inner cylinder 104 and the needle hub 88. An axially extending notch 112 is formed in the upper wall of the outer cylinder 106. In the initial state, the outer cylinder 106 is located inside the proximal end of the needle hub 88 together with the inner cylinder 104, and the inner needle holding portion 101 of the needle hub 88 is inserted into the notch 112.

[0086] Axially extending rail grooves 117 are provided on the left and right inner side surfaces of the outer cylinder 106. Rail protrusions 110 provided on the inner cylinder 104 are inserted into the rail grooves 117 provided on the outer cylinder 106 (see FIG. 15). Axially extending rail protrusions 118 are provided on the left and right outer side surfaces of the outer cylinder 106. The rail protrusions 118 provided on the outer cylinder 106 are inserted into the rail grooves 102 provided on the extending portion 100 (see FIG. 15).

[0087] As shown in FIG. 12, a first engaging protrusion 120 protruding outward (downward in the illustrated example) is provided on the outer surface of the proximal end portion of the inner cylinder 104. On the other hand, as shown in FIGS. 14 and 15, the outer cylinder 106 is provided with a first passage 121 extending along the axial direction and allowing axial displacement of the first engaging protrusion 120, and a first engaging portion 122 disposed on the tip side of the first passage 121. The first passage 121 extends to the proximal end surface of the outer cylinder 106. In the initial state of the catheter assembly 10B, the first engaging protrusion 120 is located at the proximal end of the first passage 121. In this configuration, the first passage 121 is a hole penetrating the inside and outside of the outer cylinder 106, but may be a groove provided on the inner surface of the outer cylinder 106.

[0088] The first engaging portion 122 has a pair of claws 123 protruding toward the first passage 121. On the left and right outer sides of the pair of claws 123, slit-shaped elongated holes 124 extending in the axial direction of the outer cylinder 106 are provided. As a result, the pair of claws 123 can be elastically deformed in directions approaching and separating from each other. The first engaging portion 122 configured in this way and the first engaging protrusion 120 provided on the inner cylinder 104 can be engaged with each other.

[0089] As shown in FIGS. 14 and 15, when the inner cylinder 104 moves forward relative to the outer cylinder 106 to a predetermined position, the first engaging portion 122 and the first engaging protrusion 120 are engaged. Specifically, the first engaging portion 122 gets over the pair of claws 123, and the pair of claws 123 are hooked on both sides of the base end of the first engaging protrusion 120. In a state where the first engaging portion 122 and the first engaging protrusion 120 are engaged, the axial relative movement between the inner cylinder 104 and the outer cylinder 106 is blocked. Therefore, it is possible to prevent the inner cylinder 104 from coming out of the outer cylinder 106 from the tip side and to prevent the inner cylinder 104 from retreating into the outer cylinder 106.

[0090] In this way, the first engaging portion 122 and the first engaging protrusion 120 constitute a first locking mechanism 126 that prevents the axial relative displacement between the inner cylinder 104 and the outer cylinder 106 in a state where the protector 90 covers the needle tip 87. Even when bending stress acts on the inner cylinder 104 and the outer cylinder 106, the engagement between the rail protrusion 110 provided on the outer surface of the inner cylinder 104 and the rail groove 117 provided on the inner surface of the outer cylinder 106 prevents the first engaging protrusion 120 from coming out of the first engaging portion 122. Therefore, the function of the first locking mechanism 126 can be suitably maintained.

[0091] As shown in Figs. 14 and 15, a second engagement protrusion 128 protruding outward (downward in the illustrated example) is provided on the outer surface of the base end of the outer tube 106. Meanwhile, the needle hub 88 (specifically, the extension portion 100) is provided with a second passage 129 that extends along the axial direction and allows the axial displacement of the second engagement protrusion 128 provided on the outer tube 106, and a second engagement portion 130 arranged on the tip side of the second passage 129. The second passage 129 extends to the base end surface of the needle hub 88. In the initial state of the catheter assembly 10B, the second engagement protrusion 128 is located at the base end of the second passage 129. In this configuration, the second passage 129 is a hole penetrating the inside and outside of the needle hub 88, but may be a groove provided on the inner surface of the needle hub 88.

[0092] The second engagement portion 130 has a pair of claws 131 that protrude into the second passage 129. Slit-shaped elongated holes 132 extending in the axial direction of the needle hub 88 are provided on the left and right outer sides of the pair of claws 131. This allows the pair of claws 131 to elastically deform in directions toward and away from each other. The second engagement portion 130 configured in this manner and the second engagement protrusions 128 provided on the inner tube 104 are engageable with each other.

[0093] As shown in Figures 14 and 15, when the outer tube 106 advances relatively to a predetermined position with respect to the needle hub 88, the second engagement portion 130 engages with the second engagement protrusion 128. Specifically, the second engagement protrusion 128 climbs over a pair of claws 131, and the pair of claws 131 hook on both sides of the base end of the second engagement protrusion 128. When the second engagement portion 130 engages with the second engagement protrusion 128, relative displacement in the axial direction between the outer tube 106 and the needle hub 88 is prevented. Therefore, the outer tube 106 is prevented from coming out of the needle hub 88, and the outer tube 106 is prevented from retracting into the needle hub 88.

[0094] In this way, the second engagement portion 130 and the second engagement protrusion 128 constitute a second lock mechanism 134 that prevents relative axial movement between the outer tube 106 and the needle hub 88 when the protector 90 covers the needle tip 87. Even if bending stress acts on the outer tube 106 and the needle hub 88, the second engagement protrusion 128 is prevented from coming out of the second engagement portion 130 by the engagement between the rail protrusion 118 provided on the outer surface of the outer tube 106 and the rail groove 102 provided on the inner surface of the needle hub 88. Therefore, the function of the second lock mechanism 134 can be appropriately maintained.

[0095] As shown in FIG. 14, the first locking mechanism 126 and the second locking mechanism 134 are disposed so as to be offset from each other in the circumferential direction.

[0096] The needle support section 20 in the second configuration is configured in the same manner as the needle support section 20 in the first configuration. That is, in the initial state of the catheter assembly 10B, the needle support section 20 supports the inner needle 86 via the catheter 82 on the distal side of the catheter hub 84. The needle support section 20 is provided movably with respect to the needle hub 88 so as to change from a first state in which it supports the inner needle 86 to a second state in which it releases support for the inner needle 86 and allows passage of the catheter hub 84. In the initial state, the connection portion between the pair of support arms 42 and the extension section 100 is located distal to the proximal end of the catheter hub 84. The distal end of the needle hub 88 (the distal end of the extension section 100) and the support arm 42 are rotatably connected via a hinge structure 48 similar to that in the first configuration.

[0097] The restraining portion 44 in the second configuration is configured similarly to the restraining portion 44 in the first configuration. As the catheter hub 84 advances, the restraining portion 44 is pushed by the catheter hub 84, and the restraint on the pair of support arms 42 is released.

[0098] In addition, in the catheter assembly 10B relating to the second configuration, components with the same names as those of the catheter assembly 10A relating to the first configuration may be made of the materials exemplified as the constituent materials of the components of the catheter assembly 10A.

[0099] The catheter assembly 10B according to the second configuration is basically configured as described above, and its operation and effects will be described below.

[0100] As shown in FIGS. 11 and 13, the catheter assembly 10B in the initial state is in the following state. The inner needle 86 is inserted into the catheter 82, and the needle tip 87 protrudes from the tip of the catheter 82 by a predetermined length. The tip fitting portion 108 of the inner cylinder 104 is inserted into the base end of the catheter hub 84, and the outer cylinder 106 has moved to the most distal side within the movable range with respect to the inner cylinder 104. The catheter 82 and the inner needle 86 are exposed from the tip of the needle hub 88, and the catheter hub 84 and the protector 90 are accommodated within the needle hub 88. The protector 90 is located on the proximal side within the needle hub 88. The restraining portion 44 is in the retracted position within the movable range, and the pair of support arms 42 are restrained in a closed state by the restraining portion 44. The inner needle 86 is supported via the catheter 82 by the pair of support arms 42 in the closed state.

[0101] In the use of the catheter assembly 10B, the user (such as a doctor or a nurse) grips the needle hub 88 and punctures the patient's blood vessel with the catheter 82 and the inner needle 86. At this time, since the inner needle 86 is supported via the catheter 82 by the support hole 54 formed between the pair of closed support arms 42, the deflection of the inner needle 86 during puncture is suppressed. Thereby, stable puncture is possible.

[0102] After puncture, place a finger on the pair of wings 94 protruding from the needle hub 88 and push the pair of wings 94 in the distal direction. Then, the catheter hub 84 and the catheter 82 connected to the pair of wings 94 move in the distal direction with respect to the needle hub 88, and the insertion length of the catheter 82 into the blood vessel increases. On the other hand, as the wings 94 are advanced, the protector 90 connected to the catheter hub 84 also advances within the needle hub 88.

[0103] 16A and 16B, as the catheter hub 84 advances, the catheter hub 84 pushes the restraining portion 44 toward the distal end. This causes the restraining portion 44 to move toward the distal end relative to the pair of support arms 42, and the second restraining projections 58b disengage from the second engagement grooves 56b. As the second restraining projections 58b disengage from the second engagement grooves 56b, the restraining of the pair of support arms 42 by the restraining portion 44 is released, and the pair of support arms 42 become able to spread. Then, as the catheter hub 84 advances further, the pair of support arms 42 are pushed from behind by the catheter hub 84 and spread apart.

[0104] After the catheter 82 is inserted into the blood vessel by a predetermined length, the needle hub 88 is pulled in the proximal direction while the position of the catheter member 98 is maintained. Then, the inner needle 86 moves in the proximal direction within the catheter 82, the catheter hub 84, and the protector 90. In this case, the distal fitting portion 108 of the inner tube 104 of the protector 90 and the catheter hub 84 are fitted with a predetermined fitting force, so that the protector 90 extends with the retraction of the needle hub 88. Specifically, the inner tube 104 moves relatively toward the distal end side of the outer tube 106, and the outer tube 106 moves relatively toward the distal end side of the needle hub 88. Eventually, the protector 90 reaches a state where it is fully extended (see Figures 17A and 17B). In the process of the protector 90 extending to its maximum, the inner needle 86 is pulled out of the catheter 82, and the inner needle 86 is housed in the protector 90 up to the needle tip 87.

[0105] When the protector 90 is fully extended, as shown in Figures 14 and 15, the first locking mechanism 126 prevents relative axial movement between the inner tube 104 and the outer tube 106, and the second locking mechanism 134 prevents relative axial movement between the outer tube 106 and the needle hub 88.

[0106] Specifically, in the first locking mechanism 126, since the first engaging projection 120 is at the foremost position of the first passage 121, the inner cylinder 104 cannot move further in the distal direction with respect to the outer cylinder 106. Also, in the first locking mechanism 126, since the first engaging projection 120 and the first engaging portion 122 are engaged, the inner cylinder 104 cannot move in the proximal direction with respect to the outer cylinder 106.

[0107] In the second locking mechanism 134, since the second engaging projection 128 is at the foremost position of the second passage 129, the outer cylinder 106 cannot move further in the distal direction with respect to the needle hub 88. Also, in the second locking mechanism 134, since the second engaging projection 128 and the second engaging portion 130 are engaged, the outer cylinder 106 cannot move in the proximal direction with respect to the needle hub 88.

[0108] In the process of the catheter assembly 10B transitioning from the state of FIG. 16A to the state of FIG. 17A, the pair of support arms 42 expand by being pushed from the rear against the catheter hub 84, allowing movement of the catheter hub 84 and the protector 90 with respect to the needle hub 88 (see FIG. 17B). Thus, the needle support portion 20 suppresses bending of the inner needle 86 during puncture by supporting the inner needle 86 in the initial state, while preventing interference with the catheter hub 84 and the protector 90 when the pair of support arms 42 open after puncture.

[0109] After the protector 90 has extended to its maximum, when the needle hub 88 is further pulled in the proximal direction with respect to the catheter member 98, as shown in FIG. 18, the fitting between the catheter hub 84 and the distal fitting portion 108 of the inner cylinder 104 becomes disengaged. As a result, the protector 90 is completely separated from the catheter member 98, and only the catheter member 98 of the catheter assembly 10B remains indwelling on the patient side.

[0110] After the separation of the catheter member 98 and the protector 90, the pair of wings 94 provided on the catheter hub 84 are spread left and right, and the catheter hub 84 is fixed by fixing the pair of wings 94 to the patient's skin with tape or the like. Then, a connector of an infusion tube (not shown) is connected to the proximal end side of the catheter hub 84, and the supply of the infusion agent (drug solution) from the infusion tube to the patient is carried out.

[0111] As described above, according to the catheter assembly 10B according to the second configuration, since the inner needle 86 is supported by the pair of support arms 42 during puncture, the deflection of the inner needle 86 during puncture is suppressed, and stable puncture is possible. In addition, in the second configuration, for each component part common to the first configuration, the same operations and effects as those of the first configuration can be obtained.

[0112] Also, in the case of the second configuration, in the initial state, the catheter hub 84 is housed in the needle hub 88 (see FIG. 11). For this reason, compared with the conventional catheter assembly provided with a protector, the exposed length of the inner needle 86 from the needle hub 88 constituting the housing can be shortened. Therefore, the overall length of the catheter assembly 10B in the initial state, that is, the length from the proximal end of the needle hub 88 to the tip of the inner needle 86 can be made shorter than that of the conventional catheter assembly provided with a protector. For this reason, it is compact and has good storability, and the puncture operation is easy. Also, since the exposed length of the inner needle 86 from the needle hub 88 is short, the protector 90 can also be short. For this reason, even in the state where the needle tip 87 is covered by the protector 90 (needle tip protection state), the overall length of the product is short. Therefore, the waste is compact and easy to dispose of.

[0113] Furthermore, in the case of the second configuration, since the pair of wings 94 function as the operation part of the catheter hub 84 in the initial state, it is not necessary to provide a dedicated operation part on the catheter hub 84, and the configuration can be simplified.

[0114] In the catheter assembly 10B, instead of the needle support portion 20, the needle support portions 20a to 20c shown in FIGS. 7A to 8 may be employed. In the catheter assembly 10B, instead of the hinge structure 48, the hinge structures 48a and 48b shown in FIGS. 9A to 9C may be employed. In the catheter assembly 10B, instead of the support hole 54, the support holes 54a to 54d shown in FIGS. 10A to 10D may be employed.

[0115] In the above-described configuration, the restraint portion 44 is pushed by the catheter hub 84, and the restraint on the pair of support arms 42 is released. Instead of such a configuration, the restraint on the pair of support arms 42 may be released by the restraint portion 44 being pushed by the wing 94. Alternatively, the catheter assembly 10B may further include a guide wire G inserted through the inner needle 86 and a guide wire operation portion 64 connected to the guide wire G for operating the guide wire G (see FIG. 13). In this case, as the guide wire operation portion 64 advances, the restraint portion 44 may be pushed by the guide wire operation portion 64, and the restraint on the pair of support arms 42 may be released.

[0116] FIG. 19 is a perspective view showing a catheter assembly 10C according to the third configuration. FIG. 20 is an exploded perspective view of the catheter assembly 10C. FIG. 21 is a partially omitted longitudinal sectional view of the catheter assembly 10C. In the catheter assembly 10C according to the third configuration, elements having the same or similar functions and effects as those of the catheter assembly 10B according to the second configuration are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0117] The catheter assembly 10C includes a flexible tubular catheter 152, a catheter hub 154 connected to the proximal end side of the catheter 152, a tubular inner needle 156 having a sharp needle tip 157 at the tip and insertable into the catheter 152, a needle hub 158 connected to the inner needle 156, a protector 90 that covers the needle tip 157 of the inner needle 156 when the inner needle 156 is removed, and a needle support portion 172 for suppressing the bending of the inner needle 156 during puncture.

[0118] The catheter assembly 10C is gripped by the needle hub 158 by a user (such as a doctor or nurse), and its tip is inserted into a patient's blood vessel. In its initial state before use (before the catheter assembly 10C is inserted into the patient), the catheter assembly 10C has a double-tube structure with an inner needle 156 inserted into the catheter 152, and the inner needle 156 protrudes a predetermined length from the tip of the catheter 152. In addition, in the initial state of the catheter assembly 10C, the base end side of the catheter hub 154 and the tip side of the needle hub 158 are connected via a protector 90.

[0119] In the initial state, the catheter assembly 10C is a single assembly that combines the double-tube structure of the catheter 152 and inner needle 156, the catheter hub 154, the protector 90, and the needle hub 158, and can be handled as a single unit.

[0120] The catheter 152 in the third configuration is longer than the catheters 12, 82 in the first and second configurations. The catheter 152 may be used as a catheter that is longer than a peripheral venous catheter, such as a central venous catheter, PICC, or midline catheter. The catheter 152 may also be used as a peripheral venous catheter.

[0121] A hollow cylindrical catheter hub 154 is connected and fixed to the proximal end of the catheter 152. The proximal end of the catheter hub 154 is provided with a flange portion 155 that protrudes outward and extends in the circumferential direction.

[0122] The catheter hub 154 is provided with a hub operating section 160 for operating the catheter hub 154. In the initial state of the catheter assembly 10C, at least a portion of the hub operating section 160 is exposed from the needle hub 158. Specifically, in the initial state, the hub operating section 160 extends along the inner needle 156 and the catheter hub 154, with its base end connected to the catheter hub 154 and its tip end exposed on the tip side of the needle hub 158.

[0123] The hub operating portion 160 has a long main body portion 161 and a tab 162 for hooking a finger, which is provided at the tip of the main body portion 161. The tab 162 protrudes upward from the tip of the main body portion 161.

[0124] The hub operating unit 160 is rotatably connected to the catheter hub 154. In this illustrated example, outwardly protruding support protrusions 163 are provided on the outer surface of both the left and right sides of the catheter hub 154. Each support protrusion 163 extends in the vertical direction. Meanwhile, a pair of left and right connecting pieces 164, each having a connecting groove 165, are provided facing each other at the base end of the main body 161.

[0125] As shown in FIG. 22A, each connection groove 165 has a first groove 165a for engagement and a second groove 165b for detachment, which has a groove width narrower than that of the first groove 165a and extends from the first groove 165a in the proximal direction to reach the proximal end surface of the connection piece 164. The groove width W2 of the second groove 165b is slightly larger than the width W1 (see FIG. 22B) of the support protrusion 163. The support protrusion 163 provided on the catheter hub 154 is inserted into each of the first grooves 165a provided on the hub operating part 160. As a result, the hub operating part 160 is rotatably supported relative to the catheter hub 154 with the support protrusion 163 as an axis. In the initial state, the hub operating part 160 is approximately parallel to the catheter 152 and the inner needle 156, and the support protrusion 163 is engaged with the first groove 165a, preventing the hub operating part 160 from separating from the catheter hub 154.

[0126] 22B, when the hub operating part 160 is positioned approximately perpendicular to the axial direction of the catheter hub 154, the extending directions of the support protrusions 163 and the second grooves 165b are the same, and therefore the hub operating part 160 can be separated from the catheter hub 154. The material of the hub operating part 160 is not particularly limited, and may be the same as the material of the catheter hub 154, for example.

[0127] Hereinafter, the member consisting of the catheter 152, the catheter hub 154, and the hub operating portion 160 will be referred to as the "catheter member 168."

[0128] 21, the inner needle 156 is formed to be sufficiently longer than the catheter 152, and in the initial state of the catheter assembly 10C, its needle tip 157 protrudes a predetermined length from the distal end opening of the catheter 152. The inner needle 156 in the third configuration is longer than the inner needles 16, 86 in the first and second configurations.

[0129] In the initial state of the catheter assembly 10 C, the inner needle 156 has a longitudinal midsection inserted into the catheter hub 154 , and its proximal end is held inside the needle hub 158 .

[0130] The needle hub 158 has an inner needle holding portion 101 that holds the proximal end of the inner needle 156, and an extending portion 170 that extends distally beyond the catheter hub 154. In the initial state, the extending portion 170 forms a housing that houses the catheter hub 154 and the protector 90. Also, in the initial state, the connection portion between the pair of support arms 173 and the extending portion 170 is located distally beyond the proximal end of the catheter hub 154. The extending portion 170 in the third configuration is longer than the extending portion 100 in the second configuration.

[0131] In the initial state of the catheter assembly 10C, the catheter 152 and inner needle 156 are exposed from the tip of the needle hub 158, and the catheter hub 154 and protector 90 are housed within the needle hub 158. As a result, the tip of the needle hub 158 extends partway through the catheter 152. In this configuration, the base end position of the catheter hub 154 is located proximally of the axial center position of the needle hub 158, and the tip of the needle hub 158 is located distally of the longitudinal center position of the catheter 152.

[0132] In the initial state of the catheter assembly 10C, most of the hub operating portion 160 is housed within the needle hub 158, and the tip portion (tab 162) of the hub operating portion 160 is exposed distal to the tip of the needle hub 158.

[0133] The protector 90 accommodates the inner needle 156 to cover the needle tip 157 of the inner needle 156 when the inner needle 156 is removed from the catheter 152. The protector 90 in the third configuration is configured similarly to the protector 90 in the second configuration, and has an inner tube 104 and an outer tube 106. In the initial state, the tip fitting portion 108 of the inner tube 104 fits inside the base end of the catheter hub 154. When the inner needle 156 is removed from the catheter 152, the protector 90 extends to cover the entire length of the inner needle 156 together with the needle hub 158 (see Figure 26). The catheter assembly 10C is also provided with the first locking mechanism 126 and second locking mechanism 134 shown in Figure 15.

[0134] 19 and 21, in an initial state, the needle support portion 172 supports the inner needle 156 via the catheter 152 on the distal side of the catheter hub 154. The needle support portion 172 is provided movably with respect to the needle hub 158 so as to change from a first state in which it supports the inner needle 156 to a second state in which it releases support for the inner needle 156 and allows the catheter hub 154 to pass through.

[0135] In the third configuration, specifically, needle support portion 172 has a pair of support arms 173 that can be opened and closed, and a restraining portion 176 that can restrain the pair of support arms 173 in a closed state and can release the restraint.

[0136] The pair of support arms 173 are rotatably connected to the extension portion 170 via a pair of support pins 43. In the initial state, the connection portion between the pair of support arms 173 and the extension portion 170 is located closer to the distal end than the proximal end of the catheter hub 154.

[0137] In this illustrated example, the pair of support pins 43 have axes in the vertical direction, and the pair of support arms 173 supported thereby can be opened and closed in the left-right direction. The pair of support arms 173 are provided with curved engagement grooves 174a, 174b when viewed from the front in the closed state. Each engagement groove 174a, 174b penetrates the support arm 173 in the front-rear direction.

[0138] In this illustrated example, one engagement groove 174a (hereinafter referred to as "first engagement groove 174a") and the other engagement groove 174b (hereinafter referred to as "second engagement groove 174b") are both bent downward. Note that the first engagement groove 174a and the second engagement groove 174b may both be bent upward, or one may be bent upward and the other bent downward.

[0139] The configuration of the pair of support arms 173 in the third configuration is the same as the pair of support arms 42 in the first configuration, except for the first engagement groove 174a and the second engagement groove 174b. The tip of the needle hub 158 (the tip of the extension portion 170) and the support arm 173 are rotatably connected via a hinge structure 48 similar to that in the first configuration.

[0140] The restraining portion 176 is slidable relative to the pair of support arms 173, and is formed as part of the above-described hub operating portion 160. When the restraining portion 176 advances as the hub operating portion 160 advances, the restraining of the pair of support arms 173 is released.

[0141] Specifically, the restraint portion 176 is provided at the tip of the main body portion 161 of the hub operating portion 160. Figure 23 is a cross-sectional view taken along line XXIII-XXIII in Figure 21. As shown in Figure 23, the restraint portion 176 has a first restraint protrusion 177a that slidably engages with the first engagement groove 174a, and a second restraint protrusion 177b that slidably engages with the second engagement groove 174b.

[0142] In this illustrated example, the first restraint protrusion 177a and the second restraint protrusion 177b protrude in the same direction so as to fit the shapes of the first engagement groove 174a and the second engagement groove 174b provided in the pair of support arms 173. When the restraint portion 176 is in the initial position (retracted position), the first restraint protrusion 177a and the second restraint protrusion 177b of the restraint portion 176 engage with the first engagement groove 174a and the second engagement groove 174b of the pair of support arms 173, respectively, and therefore the pair of support arms 173 are restrained in the closed state.

[0143] As the restraining portion 176 moves toward the tip, the first restraining protrusion 177a and the second restraining protrusion 177b move toward the tip from the first engagement groove 174a and the second engagement groove 174b of the pair of support arms 173. When the first restraining protrusion 177a and the second restraining protrusion 177b move away from the first engagement groove 174a and the second engagement groove 174b, the restraint of the pair of support arms 173 by the restraining portion 176 is released, and the pair of support arms 173 become able to spread open.

[0144] 19 and 20, in the hub operating portion 160, an opening protrusion 178 for opening the pair of support arms 173 is provided slightly closer to the base end than the restraining portion 176. The opening protrusion 178 is formed in a tapered shape, and in this illustrated example, is formed in a triangular shape.

[0145] In addition, in the catheter assembly 10C of the third configuration, components with the same names as the components of the catheter assemblies 10A and 10B of the first and second configurations may be made of the materials exemplified for the components of the catheter assemblies 10A and 10B.

[0146] The catheter assembly 10C according to the third configuration is basically configured as described above, and its operation and effects will be described below.

[0147] As shown in FIGS. 19 and 21, the catheter assembly 10C in the initial state is in the following state. The inner needle 156 is inserted into the catheter 152, and the needle tip 157 protrudes from the tip of the catheter 152 by a predetermined length. The tip fitting portion 108 of the inner cylinder 104 is inserted into the proximal end of the catheter hub 154, and the outer cylinder 106 has moved to the most distal side within the movable range with respect to the inner cylinder 104. The catheter 152 and the inner needle 156 are exposed from the tip of the needle hub 158, and the catheter hub 154 and the protector 90 are housed within the needle hub 158. The protector 90 is located on the proximal end side within the needle hub 158. The restraint portion 176 is in the retracted position within the movable range, and the pair of support arms 173 are restrained in a closed state by the restraint portion 176. The inner needle 156 is supported via the catheter 152 by the pair of support arms 173 in the closed state.

[0148] In the use of the catheter assembly 10C, a user (such as a doctor or a nurse) holds the needle hub 158 and punctures the blood vessel of a patient with the catheter 152 and the inner needle 156. At this time, when gripping the portion near the tip of the needle hub 158, the needle tip 157 is stabilized and the puncture operation is facilitated. During puncture, since the inner needle 156 is supported via the catheter 152 by the pair of closed support arms 173, the deflection of the inner needle 156 during puncture is suppressed. Thereby, a stable puncture is possible.

[0149] After puncture, place a finger on the tab 162 provided at the tip of the hub operation portion 160 and push the tab 162 in the tip direction. At this time, since the tab 162 can be operated with the finger (for example, the index finger) of the hand gripping the portion near the tip of the needle hub 158, it is possible to quickly shift to the operation of the tab 162 after the puncture operation.

[0150] When the tab 162 is pushed in the tip direction, the restraint portion 176 provided on the hub operation portion 160 moves in the tip direction with respect to the pair of support arms 173, and the first restraint protrusion 177a and the second restraint protrusion 177b disengage from the first engagement groove 174a and the second engagement groove 174b. By this disengagement, the restraint of the pair of support arms 173 by the restraint portion 176 is released, and the pair of support arms 173 can be expanded.

[0151] Then, as shown in FIGS. 24A and 24B, when the hub operation unit 160 is further advanced, the pair of support arms 173 expand by being pushed by the expanding protrusion 178 from the rear. At this time, since the tip of the hub operation unit 160 can be bent at the location of the thin-walled portion 161a, it is possible to avoid the tip of the hub operation unit 160 interfering with the patient's skin.

[0152] Next, as shown in FIG. 25, when the hub operation unit 160 is further advanced, the catheter hub 154 and the catheter 152 connected to the hub operation unit 160 move further in the distal direction with respect to the needle hub 158, and the insertion length of the catheter 152 into the blood vessel increases. On the other hand, as the hub operation unit 160 is advanced, the protector 90 connected to the catheter hub 154 also advances within the needle hub 158.

[0153] After inserting the catheter 152 into the blood vessel by a predetermined length, next, the needle hub 158 is pulled in the proximal direction with respect to the catheter member 168. Then, the inner needle 156 moves in the proximal direction within the catheter 152, the catheter hub 154, and the protector 90. In this case, since the tip fitting portion 108 of the inner cylinder 104 of the protector 90 and the catheter hub 154 are fitted with a predetermined fitting force, the protector 90 extends as the needle hub 158 moves backward. Specifically, the inner cylinder 104 moves to the distal side of the outer cylinder 106, and the outer cylinder 106 moves to the distal side of the needle hub 158. As a result, the protector 90 is in a state of being extended to the maximum (see FIG. 26). In the process of the protector 90 extending to the maximum, the inner needle 156 is withdrawn from the catheter 152, and the inner needle 156 is accommodated within the protector 90 up to the needle tip 157.

[0154] In the state where the protector 90 is extended to the maximum, the axial movement of the inner cylinder 104 and the outer cylinder 106 is blocked by the action of the first locking mechanism 126, and the axial movement of the outer cylinder 106 and the needle hub 158 is blocked by the action of the second locking mechanism 134.

[0155] After the protector 90 is fully extended, when the needle hub 158 is further pulled proximally with respect to the catheter member 168, as shown in FIG. 27, the fitting between the catheter hub 154 and the distal fitting portion 108 of the inner cylinder 104 is disengaged. As a result, the protector 90 is completely separated from the catheter member 168, and only the catheter member 168 in the catheter assembly 10C is left on the patient side.

[0156] After separating the catheter member 168 from the protector 90, the hub operating portion 160 is separated from the catheter hub 154. Specifically, with the hub operating portion 160 raised to a substantially perpendicular position with respect to the catheter hub 154, the hub operating portion 160 is pulled upward to separate the hub operating portion 160 from the catheter hub 154 (see FIG. 22B). Thereafter, the catheter hub 154 is fixed to the patient's skin with a dressing material, tape, or the like. Then, a connector of an infusion tube (not shown) is connected to the proximal side of the catheter hub 154, and an infusion agent (drug solution) is supplied from the infusion tube to the patient.

[0157] As described above, according to the catheter assembly 10C according to the third configuration, similar to the first and second configurations, since the inner needle 156 is supported by the pair of support arms 173 during puncture, the deflection of the inner needle 156 during puncture is suppressed, and stable puncture is possible. Also, similar to the second configuration, in the initial state, since the catheter hub 154 is housed within the needle hub 158, the overall length of the product can be shortened in both the initial state and the state where the needle tip is protected by the protector 90. In addition, in the third configuration, for each component similar to those in the first and second configurations, the same operations and effects as those in the first and second configurations can be obtained.

[0158] In the case of the third configuration, the hub operation portion 160 extends along the inner needle 156 and the catheter hub 154 in the initial state, with the proximal end connected to the catheter hub 154 and the distal end exposed on the distal end side of the needle hub 158. According to this configuration, since an operation on the hub operation portion 160 can be performed by touching the portion of the hub operation portion 160 that is exposed on the distal end side of the needle hub 158, the hub operation portion 160 can be operated with the same hand that holds the distal end side of the needle hub 158 during puncture. Therefore, the puncture operation and the advancement operation of the catheter 152 can be executed with the same hand, and the operability is excellent.

[0159] Also, in the case of the third configuration, the restraining portion 176 is provided as a part of the hub operation portion 160, and the restraint on the pair of support arms 173 is released when the hub operation portion 160 advances. According to this configuration, since the restraint on the pair of support arms 173 is automatically released in conjunction with the advancement of the catheter hub 154 based on the operation on the hub operation portion 160, an independent release operation is not required, and the operability is excellent.

[0160] In the catheter assembly 10C, instead of the support arms 173, the support arms 65, 66, 68 shown in FIGS. 7A to 8 may be employed. In the catheter assembly 10C, instead of the hinge structure 48, the hinge structures 48a, 48b shown in FIGS. 9A to 9C may be employed. In the catheter assembly 10C, instead of the support holes 54, the support holes 54a to 54d shown in FIGS. 10A to 10D may be employed.

[0161] The catheter assembly 10C may further include a guide wire G inserted through the inner needle 156 and a guide wire operation portion 150 connected to the guide wire G for operating the guide wire G (see FIG. 21). In this case, the restraining portion 176 is provided as a part of the guide wire operation portion 150, and as the guide wire operation portion 150 advances, the restraining portion 176 may be pushed by the guide wire operation portion 150 to release the restraint on the pair of support arms 173.

[0162] Although the present invention has been described above by citing preferred embodiments, it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the present invention.

Claims

Claim 1 a catheter; a catheter hub fixed to the proximal end portion of the catheter; an inner needle having a needle tip and inserted through the catheter; a needle hub connected to the inner needle; a needle support portion (20c); a hub operation portion for operating the catheter hub, and comprising: the needle support portion includes a pair of support arms (68) that support the inner needle via the catheter and are openable and closable in the left-right direction; a frame-shaped restraint portion (69) that can restrain the pair of support arms in a closed state and can release the restraint, and that surrounds the pair of support arms; the restraint portion releases the restraint on the pair of support arms by relatively moving in the tip direction with respect to the pair of support arms as the hub operation portion advances; A catheter assembly characterized by the above.

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