Catheter assembly

Abstract

To provide a catheter assembly that is easy to operate, and effectively restrains deflection of an inner needle at the time of puncture.SOLUTION: A catheter assembly 10A comprises a needle supporting part 20 supporting an inner needle 16 via a catheter 12. The needle supporting part 20 has a pair of supporting arms 42 openable and closable in a left-right direction, and a binding part 44 provided displaceably with respect to the pair of supporting arms 42. The pair of supporting arms 42 each have a supporting groove 53. When the pair of supporting arms 42 are closed, a supporting hole 54 for supporting the inner needle 16 via the catheter 12 is formed by the two supporting grooves 53.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, when performing infusion on a patient or the like, 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 and the inner needle are punctured into the patient's blood vessel, and after this puncture, the inner needle is withdrawn from the catheter while the catheter remains punctured in the patient.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 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, the needle hub is provided with two retractable arms extending toward the tip. Before use, the two arms are closed to support the inner needle via the catheter and are restrained in the closed position by a restraining mechanism. During use, advancing the restraining mechanism releases the restraint. Then, opening the two arms vertically allows the catheter hub to advance. The two arms are connected via a hinge at the proximal end of the catheter assembly.

[0006] In the catheter assembly described in Japanese Patent Publication No. 10-503094, the user is required to increase or decrease the force with which they pinch the two arms in order to support and release the internal needle, making the operation cumbersome.

[0007] In the catheter assembly described in U.S. Patent Application Publication No. 2011 / 0282285, the two arms that support the inner needle open vertically, and the length of the inner needle protruding from the arms is long to avoid interference with the patient's skin, making the inner needle prone to bending. Furthermore, during puncture, the tip of the arms is held to facilitate puncture, but after the arms are released, it is necessary to switch to holding the base of the arms (the base of the catheter assembly) to open the arms, making the operation cumbersome. [Overview of the project] [Problems that the invention aims to solve]

[0008] This invention was made in consideration of these problems, and aims 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 problem]

[0009] To achieve the above objective, the present invention provides a catheter assembly comprising a catheter, a catheter hub fixed to the proximal end of the catheter, an inner needle having a needle tip and inserted into the catheter, a needle hub connected to the inner needle, and a needle support portion, wherein the needle support portion supports the inner needle via the catheter and is openable and closable in the left-right direction, and has a pair of support arms that support the catheter when closed, and a restraining portion that is displaceable relative to the pair of support arms, each of the pair of support arms having a support groove, and when the pair of support arms are closed, the two support grooves form a support hole for supporting the inner needle via the catheter. [Effects of the Invention]

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

[0011] [Figure 1] This is a perspective view of the catheter assembly relating to the first configuration. [Figure 2] Figure 1 is an exploded perspective view of the catheter assembly shown. [Figure 3] Figure 1 is a longitudinal cross-sectional view of the catheter assembly shown. [Figure 4] Figure 1 is a perspective view showing the catheter assembly with the constraints on the pair of support arms released. [Figure 5] Figure 1 is a perspective view showing the catheter assembly with the catheter member further advanced from the state shown in Figure 4. [Figure 6] Figure 1 is a perspective view showing the catheter assembly with the inner needle removed from the catheter. [Figure 7] Figure 7A is a perspective view showing the needle support portion of the first modified example, and Figure 7B is a perspective view showing the needle support portion of the second modified example. [Figure 8] This is a perspective view showing the needle support portion according to the third modified example. [Figure 9] Figure 9A is a perspective view showing the hinge structure according to the first modified example, Figure 9B is a cross-sectional view along the line IXB-IXB in Figure 9A, and Figure 9C is a perspective view showing the hinge structure according to the second modified example. [Figure 10] Figure 10A is a schematic cross-sectional view of the support hole relating to the first modification, Figure 10B is a schematic cross-sectional view of the support hole relating to the second modification, Figure 10C is a schematic cross-sectional view of the support hole relating to the third modification, and Figure 10D is a schematic cross-sectional view of the support hole relating to the fourth modification. [Figure 11] This is a perspective view showing the catheter assembly related to the second configuration. [Figure 12] Figure 11 is an exploded perspective view of the catheter assembly shown. [Figure 13] Figure 11 is a longitudinal cross-sectional view of the catheter assembly shown. [Figure 14] Figure 11 is a partially abbreviated rear view of the catheter assembly shown. [Figure 15] Figure 11 is a perspective view from the rear side of the catheter assembly, showing the state in which the first engaging portion and the first engaging projection are engaged, and the second engaging portion and the second engaging projection are engaged. [Figure 16] Figure 16A is a longitudinal cross-sectional view showing the catheter assembly shown in Figure 11 with the catheter hub partially advanced, and Figure 16B is a perspective view showing the catheter assembly shown in Figure 11 with the catheter hub partially advanced. [Figure 17] Figure 17A is a longitudinal cross-sectional view showing the catheter assembly shown in Figure 11 with the protector extended to its maximum extent, and Figure 17B is a perspective view showing the catheter assembly shown in Figure 11 with the protector extended to its maximum extent. [Figure 18] Figure 11 is a longitudinal cross-sectional view showing the catheter assembly with the catheter hub and protector separated. [Figure 19] This is a perspective view showing the catheter assembly related to the third configuration. [Figure 20]It is an exploded perspective view of the catheter assembly shown in FIG. 19. [Figure 21] It is a partial omitted longitudinal sectional view of the catheter assembly shown in FIG. 19. [Figure 22] FIG. 22A is a perspective view showing the connection state between the catheter hub and the hub operation part, and FIG. 22B is a perspective view showing the state where the catheter hub and the hub operation part are separated. [Figure 23] It is a cross-sectional view taken along line XXIII-XXIII in FIG. 21. [Figure 24] FIG. 24A is a longitudinal sectional view of the catheter assembly shown in FIG. 19 in a state where the hub operation part is advanced slightly, and FIG. 24B is a perspective view showing a part of the catheter assembly in the state of FIG. 24A. [Figure 25] It is a longitudinal sectional view of the state where the hub operation part is further advanced from the state of FIG. 24A. [Figure 26] It is a longitudinal sectional view of the state where the hub operation part is further advanced from the state of FIG. 25 and the protector is extended to the maximum. [Figure 27] It is a longitudinal sectional view of the state where the catheter member and the protector are separated in the catheter assembly shown in FIG. 19.

Embodiments for Carrying out the Invention

[0012] Hereinafter, preferred embodiments of the catheter assembly according to the present invention will be given and described while referring 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 comprises a tubular catheter 12 that functions as an outer needle, a catheter hub 14 connected to the proximal end of the catheter 12, a tubular inner needle 16 having a sharp needle tip 17 at its tip and that can be inserted into the inside of the catheter 12, a needle hub 18 connected to the inner needle 16, and a needle support part 20 for suppressing the bending of the inner needle 16 during puncture.

[0015] The catheter assembly 10A is grasped by the user (such as a doctor or nurse) via a needle hub 18, and its tip is inserted into the patient's blood vessel. In its initial state before use (before puncture), the catheter assembly 10A has a double-tube structure with the inner needle 16 inserted through the catheter 12, and the inner needle 16 protrudes from the tip of the catheter 12 by a predetermined length.

[0016] In its initial state, the catheter assembly 10A consists of a double-tube structure comprising the catheter 12 and inner needle 16, a catheter hub 14, a needle hub 18, and a needle support section 20, which are combined to form a single assembly that can be handled as a whole.

[0017] The catheter 12 is a flexible, small-diameter tubular member formed to a predetermined length. The constituent material of the catheter 12 is preferably a resin material, particularly a soft resin material. Examples include fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxy fluororesin (PFA); olefin resins such as polyethylene and polypropylene or mixtures thereof; polyurethane, polyester, polyamide, polyether nylon resin; and mixtures of the aforementioned olefin resins and ethylene-vinyl acetate copolymer. The catheter 12 may be made of a transparent resin so that the entire or partial interior can be viewed.

[0018] A catheter hub 14 is connected and fixed to the proximal end of the catheter 12. The proximal end of the catheter hub 14 is provided with a flange portion 22 that protrudes outward and extends circumferentially. 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 operating section 24 for operating the catheter hub 14. As shown in Figure 1, the hub operating section 24 in this illustrated example is a tab that protrudes upward from the tip of the catheter hub 14 and is integrally molded with the catheter hub 14. The hub operating section 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 axially by touching, grasping, or pressing the hub operating section 24. Note that the position where the hub operating section 24 is provided is not limited to the tip of the catheter hub 14, but may be between the tip and the proximal end of the catheter hub 14.

[0020] Hereinafter, the component consisting of the catheter 12, catheter hub 14, and hub operating part 24 will be referred to as the "catheter component 25".

[0021] When using the catheter assembly 10A, the catheter hub 14 is exposed on the patient's skin when the catheter 12 is punctured into a blood vessel, and is attached to the skin with a dressing or tape for placement. It is preferable that such a catheter hub 14 is made of a material that is harder than the catheter 12. The constituent material of the catheter hub 14 is not particularly limited, but thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

[0022] In Figures 1 and 2, the inner needle 16 is a tubular member with sufficient rigidity to puncture 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 a predetermined length from the tip opening of the catheter 12. Also, in the initial state, the inner needle 16 is inserted into the catheter hub 14 at a point along its longitudinal direction, and its proximal end is held by the needle hub 18.

[0023] Examples of materials that make up the inner needle 16 include metallic materials such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy.

[0024] The needle hub 18 has a hub body 36 that is initially arranged in series with the catheter hub 14, and an extension portion 38 that extends from the hub body 36 toward the tip. The hub body 36 has an inner needle holding portion 39 that fixes and holds the proximal end of the inner needle 16.

[0025] In this configuration, a pair of extensions 38 are provided on both sides of the hub body 36, facing each other along the inner needle 16 on both sides of the inner needle 16 and the catheter hub 14. In the initial state of the catheter hub 14, the extensions 38 extend beyond the proximal end of the catheter hub 14 towards the tip. That is, the tips of the extensions 38 are located towards the tip of the catheter hub 14. The extensions 38 are formed to an appropriate size (thickness and length) so that they can be easily grasped and manipulated by the user when using the catheter assembly 10A.

[0026] Guide projections 40 are provided on the opposing inner surfaces of a pair of extensions 38, each extending along the axial direction of the inner needle 16. The left and right guide projections 40 are inserted into the left and right notches 23 provided in the flange portion 22 of the catheter hub 14. As a result, in the initial state, the catheter hub 14 is stably supported by the needle hub 18, and rotation of the catheter hub 14 relative to the needle hub 18 is prevented, so the hub operating portion 24 can be held in an upward position. Furthermore, when advancing the catheter hub 14 relative to the needle hub 18, the guiding action of the guide projections 40 allows the catheter hub 14 to be smoothly advanced.

[0027] Next, the needle support portion 20 will be described. In the initial state of the catheter assembly 10A, the needle support portion 20 supports the inner needle 16 via the catheter 12 at a tip-side of the catheter hub 14. The needle support portion 20 is movably provided with respect to the needle hub 18 so as to change from a first state in which it supports the inner needle 16 to a second state in which it releases support for the inner needle 16 and allows passage through the catheter hub 14.

[0028] In this configuration, specifically, the needle support section 20 includes a pair of openable and closable support arms 42, and a restraining section 44 that can restrain the pair of support arms 42 in a closed state and release the restraint. Hereafter, when describing one of the pair of support arms 42 separately from the other, one will be referred to as "support arm 42a" and the other as "support arm 42b".

[0029] A pair of support arms 42 are rotatably connected to the extension 38 via a pair of support pins 43. In this illustrated example, the pair of support pins 43 have an axis in the vertical direction, and the pair of support arms 42 supported by them can open and close in the left and right directions. In the initial state, the connection between the pair of support arms 42 and the extension 38 is located on the tip 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 tip of the extension portion 38, and the second structure 46 is provided at the base end of the support arm 42. The first structure 45 has a plurality of connecting pieces 49 that are spaced apart in the vertical direction and facing each other, and a recess 50 formed between the connecting pieces 49. The second structure 46 has a connecting projection 51 positioned within the recess 50. On each side, a support pin 43 is inserted through the connecting projection 51 and the two connecting pieces 49. In a modified example, the first structure 45 may be provided at the base end of the support arm 42, and the second structure 46 may be provided at the tip of the extension portion 38.

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

[0032] Each support arm 42 is provided with bent engagement grooves 56a and 56b when viewed from the front in the closed state. Each engagement groove 56a and 56b penetrates the support arm 42 in the front-rear direction. One engagement groove 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") are bent in opposite directions. Specifically, the first engagement groove 56a is bent downwards, and the second engagement groove 56b is bent upwards.

[0033] Furthermore, as shown in Figure 3, the lower part of the support arm 42 should be trimmed so that it does not interfere with the skin S when puncturing the patient's skin S at a small angle.

[0034] The restraining portion 44 is slidably positioned relative to the pair of support arms 42. As the catheter hub 14 moves forward, the restraining portion 44 is pushed by the catheter hub 14, releasing its restraint from the pair of support arms 42.

[0035] Specifically, the restraining portion 44 has a first restraining projection 58a that slidably engages with the first engagement groove 56a, and a second restraining projection 58b that slidably engages with the second engagement groove 56b. In this illustrated example, the first restraining projection 58a and the second restraining projection 58b protrude in opposite directions to match the shapes of the first engagement groove 56a and the second engagement groove 56b provided on the pair of support arms 42. When the restraining portion 44 is in its initial position (retracted position), the first restraining projection 58a and the second restraining projection 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. As a result, the pair of support arms 42 are restrained in a closed state.

[0036] As the restraining portion 44 moves toward the tip, the second restraining projection 58b disengages from the second engagement groove 56b of the support arm 42 toward the tip. When the second restraining projection 58b disengages from the second engagement groove 56b, the restraining 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 restraining projection 58b disengages from the second engagement groove 56b, the engagement between the first restraining projection 58a and the first engagement groove 56a is maintained, and the restraining portion 44 is held by the support arm 42a.

[0037] When the second restraining projection 58b is disengaged from the second engagement groove 56b, the second restraining projection 58b protrudes on the side opposite to the side where the inner needle 16 is located (see Figure 4). This prevents the inner needle 16 from getting caught on the second restraining projection 58b when the support arm 42 opens with the inner needle 16 curved toward the restraining portion 44. In the modified version, the second restraining projection 58b may protrude toward the side where the inner needle 16 is located. In this case, the curved shape of the second engagement groove 56b provided on the support arm 42b is formed to match the protruding direction of the second restraining projection 58b.

[0038] A pressing portion 60 is provided at the base end of the restraining portion 44. When the catheter hub 14 advances relative to the needle hub 18, the pressing portion 60 is pressed by the tip of the catheter hub 14, causing the restraining portion 44 to advance relative to the pair of support arms 42. The surface of the pressing portion 60 facing the catheter hub 14 is provided with a taper that inclins so as it moves toward the base end, it displaces outward to the left and right.

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

[0040] As shown in Figures 1 and 3, the initial state of the catheter assembly 10A is as follows: The inner needle 16 is inserted into the catheter 12 and the needle tip 17 protrudes a predetermined length from the tip of the catheter 12. The catheter hub 14 is positioned as far as possible towards the proximal end relative to the needle hub 18, and extensions 38 are present on both the left and right sides of the catheter hub 14. The tip end of the inner needle holding portion 39 of the needle hub 18 is inserted into the proximal end of the catheter hub 14. The restraining portion 44 is in the retracted position of its range of motion, and the pair of support arms 42 are restrained in a closed state by the restraining portion 44, and the inner needle 16 is supported via the catheter 12 by the pair of support arms 42 in the closed state.

[0041] In using the catheter assembly 10A, the user (such as a doctor or nurse) grasps the needle hub 18 and inserts the catheter 12 and inner needle 16 into the patient's blood vessel. At this time, the inner needle 16 is supported via the catheter 12 by the support hole 54 formed between the pair of closed support arms 42, thereby suppressing the bending of the inner needle 16 during puncture. This enables stable puncture.

[0042] After puncture, the user places their finger on the hub operating part 24 that protrudes upward from the catheter hub 14 and pushes the hub operating part 24 toward the tip. This causes the catheter hub 14 and catheter 12 connected to the hub operating part 24 to move toward the tip relative to the needle hub 18, increasing the insertion length of the catheter 12 into the blood vessel.

[0043] As shown in Figure 4, as the catheter hub 14 advances, the hub operating section 24 pushes the restraining section 44 toward the tip. As a result, the restraining section 44 moves toward the tip relative to the pair of support arms 42, and the second restraining projection 58b disengages from the second engagement groove 56b. When the second restraining projection 58b disengages from the second engagement groove 56b, the restraining of the pair of support arms 42 by the restraining section 44 is released, and the pair of support arms 42 become able to spread apart.

[0044] As the catheter hub 14 moves further forward, the pair of support arms 42 are pushed from behind by the hub operating section 24 and the catheter hub 14, causing them to expand, as shown in Figure 5. In this way, the needle support section 20 supports the inner needle 16 in its initial state, thereby suppressing the bending of the inner needle 16 during puncture, 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 to a predetermined length, the needle hub 18 is then pulled towards the proximal end while maintaining the position of the catheter member 25. This causes the inner needle 16 to move towards the proximal end within the catheter member 25, and eventually the inner needle 16 is completely removed from the catheter member 25, as shown in Figure 5. As a result, only the catheter member 25 of the catheter assembly 10A remains in place on the patient's side.

[0046] After withdrawing the inner needle 16 from the catheter member 25, the catheter hub 14 is secured to the patient using a dressing or tape. Then, a connector for an infusion tube (not shown) is connected to the proximal end of the catheter hub 14, and the infusion solution (medicine) is supplied to the patient from the infusion tube.

[0047] As explained above, with the catheter assembly 10A, the inner needle 16 is supported by a pair of support arms 42 during puncture, which suppresses the bending of the inner needle 16 during puncture and enables stable puncture.

[0048] In particular, in this invention, the inner needle 16 is not supported and released by the user adjusting the gripping force, but rather the restraint part 44 restrains and releases the pair of support arms 42, making it easy to operate.

[0049] Furthermore, since the pair of support arms 42 that open in the left-right direction do not interfere with the patient's skin S, there is no need to make the inner needle 16 extra long to avoid interference, and the bending of the inner needle 16 can be effectively suppressed.

[0050] Furthermore, since the support arm 42 is located on the tip side of the catheter hub 14, for example, by grasping the extension 38 located on the tip side of the catheter hub 14, the puncture operation and the advancement operation of the catheter hub 14 can be performed sequentially with the same hand without changing hands. Therefore, it offers excellent operability.

[0051] In particular, with this configuration, the restraints on the pair of support arms 42 are automatically released in conjunction with the forward movement of the hub operating unit 24, eliminating the need for a separate release operation and resulting in superior operability.

[0052] Furthermore, in this configuration, the first and second restraining protrusions 58a and 58b provided on the restraining portion 44 engage with the first and second engagement grooves 56a and 56b provided on the pair of support arms 42, respectively, allowing the needle support portion 20 to be made compact.

[0053] Furthermore, in this configuration, when the restraint portion 44 is in the forward position, the restraint portion 44 is held by the support arm 42a provided with the first engagement groove 56a, and the second restraint projection 58b disengages from the second engagement groove 56b. With this configuration, after the restraint portion 44 is released from the pair of support arms 42, it moves together with one of the support arms 42, and therefore does not obstruct the forward movement of the catheter hub 14.

[0054] In particular, since the second restraining projection 58b protrudes on the side opposite to the side where the inner needle 16 is located, it is possible to prevent the second restraining projection 58b from catching on the inner needle 16 when one of the support arms 42a that holds the restraining part 44 opens.

[0055] In 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 relationship where they interlock with each other, looseness of the hinge structure 48 can be suppressed.

[0056] In the above-described configuration, the restraint portion 44 is released from the pair of support arms 42 by being pushed by the hub operating portion 24. However, instead of this configuration, the restraint portion 44 may be released from the pair of support arms 42 by being 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 operating portion 64 connected to the guide wire G for operating the guide wire G (see Figure 3). In this case, the restraint portion 44 may be released from the pair of support arms 42 by being pushed by the guide wire operating portion 64 as the guide wire operating portion 64 moves forward.

[0057] Instead of the needle support portion 20 described above, needle support portions 20a to 20c shown in Figures 7A to 8 may be used. Note that the inner needle 16, catheter 12, and catheter hub 14 are not shown in Figures 7A to 8.

[0058] In the needle support section 20a shown in Figure 7A, a pair of support arms 65 are provided that are slidable in the left-right direction relative to the left and right extensions 38. In this case, the extensions 38 are provided with, for example, slide holes 38a for holding the support arms 65 in a slidable manner in the left-right direction. Even with this configuration shown in Figure 7A, the pair of support arms 65 can be opened and closed in the left-right direction. Therefore, it is possible to change from a first state in which the inner needle 16 is supported to a second state in which the support of the inner needle 16 is released and the passage of the catheter hub 14 is permitted.

[0059] In the needle support section 20b shown in Figure 7B, a pair of support arms 66 are provided, which are rotatably supported by a pair of support pins 67 parallel to the axial direction of the inner needle 16. In this case, for example, the tips of the left and right extensions 38 are connected to each other, and the pair of support pins 67 are fixed to the connecting section 38b. Even with this configuration shown in Figure 7B, the pair of support arms 66 can be opened and closed in the left and right directions. Therefore, it is possible to change from a first state in which the inner needle 16 is supported to a second state in which the support of the inner needle 16 is released and the passage of the catheter hub 14 is permitted.

[0060] The needle support section 20c shown in Figure 8 has a pair of support arms 68 that can be opened and closed in the left and right directions, and a restraining section 69 that can restrain the pair of support arms 68 in a closed state and can also release the restraint. In Figure 8, the restraining section 69 is formed in a frame shape that surrounds the tips of the support arms 68, and can restrain the pair of support arms 68 in a closed state. A hub operating section 24a is provided instead of the hub operating section 24. The hub operating section 24a is connected to the restraining section 69. When the hub operating section 24a is moved forward, the restraining section 69 detaches from the pair of support arms 42 towards the tips, thus releasing the restraint on the pair of support arms 68. Alternatively, a guide wire operating section may be provided instead of the hub operating section 24a.

[0061] In the configuration shown in Figure 8, the restraint portion 69 is formed in a frame shape that surrounds the tip of the support arm 68, and the left and right inwardly protruding ends 69a of the restraint portion 69 fit into the stepped portion 68a provided at the lower part of the tip of the support arm 68. This configuration avoids the structure below the inner needle 16 becoming larger. In contrast, if the stepped portion 68a into which the inwardly protruding ends 69a of the restraint portion 69 fit is not provided on the support arm 68, the structure below the inner needle 16 becomes larger, making it more likely to interfere with the patient's skin.

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

[0063] As shown in Figure 9C, the hinge structure 48b may be configured such that a single connecting piece 71 provided at the base end of the support arm 42 and a single connecting piece 72 provided at the tip of the extension 38 are stacked vertically and rotatably connected by a support pin 43. Alternatively, in the hinge structure 48b, the support pin 43 may be integrally molded with the support arm 42. Furthermore, instead of using a support pin 43, the support arm 42 and the extension 38 may be integrally molded via a thin-walled portion.

[0064] In the configuration described above, each support arm 42 is provided with a support groove 53, and a support hole 54 is formed by the two support grooves 53. As a result, the left-right position of the mating surface of the support arms 42 is approximately the same as the axis of the inner needle 16 supported by the support hole 54. Therefore, if a force greater than a predetermined amount is applied to the inner needle 16 in the vertical direction, the inner needle 16 may detach from the closed pair of support arms 42. For this reason, instead of the support hole 54, support holes 54a to 54d shown in Figures 10A to 10D may be used, for example. Note that Figures 10A to 10D are schematic diagrams that mainly illustrate the structure of the support holes 54a to 54d, and therefore the restraining part 44 and the first and second engagement grooves 56a and 56b are omitted.

[0065] In the structure of the support hole 54a shown in Figure 10A, one support arm 42a does not have a support groove, while only the other support arm 42b has a support groove 53a (a groove deeper than the support groove 53). When 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 on the other support arm 42b. In this configuration, the position of the mating surfaces of the pair of support arms 42 is shifted laterally with respect to the center of the inner needle 16 supported by the support hole 54a. Therefore, even when an upward force is applied to the inner needle 16, it is difficult for the inner needle 16 to come off the closed pair of support arms 42.

[0066] In the structure of the support hole 54b shown in Figure 10B, one support arm 42a is provided with a projection 73 that protrudes inward (towards the other support arm 42b), and the other support arm 42b is provided with an even deeper support groove 53b. When the pair of support arms 42 are closed, the projection 73 is inserted into the support groove 53b, and the support hole 54b is formed by the projection 73 and the support groove 53b. In this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted in the left-right direction with respect to the center of the inner needle 16 supported by the support hole 54b, making it difficult for the inner needle 16 to come off.

[0067] In the structure of the support hole 54c shown in Figure 10C, stepped portions 74 and 75 are provided on the inner surface of one of the support arms 42a. When the pair of support arms 42 are closed, the left and right stepped portions 74 and 75 form the support hole 54c. In this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted in the left-right direction with respect to the center of the inner needle 16 supported by the support hole 54c, making it difficult for the inner needle 16 to come off.

[0068] In the structure of the support hole 54d shown in Figure 10D, multiple stair-shaped sections 76 and 77 are provided on the inner surface of each support arm 42. When the pair of support arms 42 are closed, the left and right stair-shaped sections 76 and 77 form the support hole 54d. In this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted laterally with respect to the center of the inner needle 16 supported by the support hole 54d, making it difficult for the inner needle 16 to come loose.

[0069] Figure 11 is a perspective view showing the catheter assembly 10B relating to the second configuration. Figure 12 is an exploded perspective view of the catheter assembly 10B. Figure 13 is a longitudinal cross-sectional view of the catheter assembly 10B. In the catheter assembly 10B, elements that have the same or similar functions and effects as those of the catheter assembly 10A are given the same reference numerals, and detailed explanations are omitted.

[0070] The catheter assembly 10B comprises a flexible tubular catheter 82, a catheter hub 84 connected to the proximal end of the catheter 82, a tubular inner needle 86 having a sharp needle tip 87 at its end and insertable into the inside of 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 part 20 for suppressing the bending of the inner needle 86.

[0071] The catheter assembly 10B is grasped by the user (such as a doctor or nurse) via a needle hub 88, and its tip is inserted into the patient's blood vessel. In its initial state before use (before puncture), the catheter assembly 10B has a double-tube structure with the inner needle 86 inserted through the catheter 82, and the inner needle 86 protrudes from the tip of the catheter 82 by a predetermined length. Also 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 its initial state, the catheter assembly 10B consists of a double-tube structure with a catheter 82 and an inner needle 86, a catheter hub 84, a protector 90, and a needle hub 88, all 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-right direction in their natural state. Each wing 94 is flexible and can be folded so that it overlaps with one another. As shown in Figure 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] This configuration makes it easy to bend the wing 94 upward at the first thin-walled portion 95 and easily bend it in the opposite direction to the first thin-walled portion 95 at the second thin-walled portion 96. As shown in Figure 11, in the initial state of the catheter assembly 10B, the outer ends of the wings 94 are exposed from the needle hub 88. The user can manipulate the catheter hub 84 axially by touching, grasping, or pressing the wings 94 exposed from the needle hub 88. In other words, the pair of wings 94 function as operating parts for manipulating the catheter hub 84.

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

[0077] As shown in Figure 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, its needle tip 87 protrudes a predetermined length from the tip opening of the catheter 82. Also, in the initial state, the middle portion of the inner needle 86 in the longitudinal direction is inserted into the catheter hub 84, and its proximal end is held inside the needle hub 88.

[0078] As shown in Figures 12 and 13, the needle hub 88 has an inner needle holding portion 101 that holds the proximal end of the inner needle 86 and an extension portion 100 that extends further toward the tip than the catheter hub 84. The extension portion 100 constitutes a housing that accommodates the catheter hub 84 and the protector 90 in its initial state.

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

[0080] In the initial state of the catheter assembly 10B, the catheter 82 and inner needle 86 are exposed from the tip of the needle hub 88, and the catheter hub 84 and protector 90 are housed within the needle hub 88. As a result, the tip of the needle hub 88 extends partway down the catheter 82. In this configuration, the proximal end of the catheter hub 84 is located proximal to the axial center of the needle hub 88, and the tip of the needle hub 88 is located distal to the longitudinal center of the catheter 82.

[0081] As shown in Figures 11 to 13, the needle hub 88 (specifically, the extension portion 100) has a slit 103 that extends in the axial direction of the needle hub 88 and opens towards the tip 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 folded and overlapping wings 94 protrude upward from the needle hub 88 through the slit 103.

[0082] The protector 90 covers the needle tip 87 of the inner needle 86 by accommodating the inner needle 86 when it is removed from the catheter 82. As shown in Figures 12 and 13, the protector 90 has an inner cylinder 104 that is detachably fitted to the proximal end of the catheter hub 84, and an outer cylinder 106 in which the inner cylinder 104 is positioned and which is axially displaceable relative to the inner cylinder 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 cylinder 104 has the function of covering the needle tip 87 of the inner needle 86 as the inner needle 86 is withdrawn from the catheter 82. The inner cylinder 104 has a body portion 107 and a tip fitting portion 108 that protrudes from the body portion 107 toward the tip. An axially extending notch 109 is formed in the upper wall of the body portion 107. In the initial state, the inner cylinder 104 is located inside 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 Figure 12) that extend 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 the outer diameter decreasing towards the tip. In the initial state, the tip fitting portion 108 of the inner cylinder 104 fits into the base 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 positioned 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, together with the inner cylinder 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 112.

[0086] Rail grooves 117 extending in the axial direction are provided on the left and right inner surfaces of the outer cylinder 106. Rail projections 110 provided on the inner cylinder 104 are inserted into the rail grooves 117 provided on the outer cylinder 106 (see Figure 15). Rail projections 118 extending in the axial direction are provided on the left and right outer surfaces of the outer cylinder 106. Rail projections 118 provided on the outer cylinder 106 are inserted into rail grooves 102 provided on the extension portion 100 (see Figure 15).

[0087] As shown in Figure 12, a first engaging projection 120 protruding outward (downward in the illustrated example) is provided on the outer surface of the base end of the inner cylinder 104. On the other hand, as shown in Figures 14 and 15, the outer cylinder 106 is provided with a first passage 121 that extends along the axial direction and allows axial displacement of the first engaging projection 120, and a first engaging portion 122 located on the tip side of the first passage 121. The first passage 121 extends to the base end surface of the outer cylinder 106. In the initial state of the catheter assembly 10B, the first engaging projection 120 is located at the base end of the first passage 121. In this configuration, the first passage 121 is a hole that penetrates the inside and outside of the outer cylinder 106, but it may also 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 that protrude toward the first passage 121. Slit-shaped elongated holes 124 extending in the axial direction of the outer cylinder 106 are provided on the left and right outer sides of the pair of claws 123. As a result, the pair of claws 123 can be elastically deformed in directions toward and toward each other. The first engaging portion 122 configured in this way and the first engaging projection 120 provided on the inner cylinder 104 can engage with each other.

[0089] As shown in Figures 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 projection 120 engage. Specifically, the first engaging portion 122 overcomes the pair of claws 123, and the pair of claws 123 catch on both sides of the base end of the first engaging projection 120. When the first engaging portion 122 and the first engaging projection 120 are engaged, relative axial movement between the inner cylinder 104 and the outer cylinder 106 is prevented. Therefore, the inner cylinder 104 is prevented from coming out of the outer cylinder 106 toward the tip, and the inner cylinder 104 is prevented from retracting into the outer cylinder 106.

[0090] In this way, the first engaging portion 122 and the first engaging projection 120 constitute a first locking mechanism 126 that prevents relative axial displacement between the inner cylinder 104 and the outer cylinder 106 while the protector 90 covers the needle tip 87. Furthermore, even if bending stress is applied to the inner cylinder 104 and the outer cylinder 106, the engagement between the rail projection 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 projection 120 from coming out of the first engaging portion 122. Thus, the function of the first locking mechanism 126 can be suitably maintained.

[0091] As shown in Figures 14 and 15, a second engaging projection 128 protruding outward (downward in the illustrated example) is provided on the outer surface of the base end of the outer cylinder 106. On the other hand, the needle hub 88 (specifically, the extension portion 100) is provided with a second passage 129 that extends along the axial direction and allows axial displacement of the second engaging projection 128 provided on the outer cylinder 106, and a second engaging portion 130 located 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 engaging projection 128 is located at the base end of the second passage 129. In this configuration, the second passage 129 is a hole that penetrates the inside and outside of the needle hub 88, but it may also be a groove provided on the inner surface of the needle hub 88.

[0092] The second engaging portion 130 has a pair of claws 131 that protrude toward 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. As a result, the pair of claws 131 can be elastically deformed in directions toward and toward each other. The second engaging portion 130 configured in this way and the second engaging projection 128 provided on the inner cylinder 104 can engage with each other.

[0093] As shown in Figures 14 and 15, when the outer cylinder 106 moves forward relative to the needle hub 88 to a predetermined position, the second engaging portion 130 and the second engaging projection 128 engage. Specifically, the second engaging projection 128 overcomes the pair of claws 131, and the pair of claws 131 catch on both sides of the base end of the second engaging projection 128. When the second engaging portion 130 and the second engaging projection 128 are engaged, relative axial displacement between the outer cylinder 106 and the needle hub 88 is prevented. Therefore, the outer cylinder 106 is prevented from coming out of the needle hub 88, and the outer cylinder 106 is prevented from moving backward into the needle hub 88.

[0094] In this way, the second engaging portion 130 and the second engaging projection 128 constitute a second locking mechanism 134 that prevents relative axial movement between the outer cylinder 106 and the needle hub 88 when the protector 90 covers the needle tip 87. Furthermore, even when bending stress is applied to the outer cylinder 106 and the needle hub 88, the engagement between the rail projection 118 provided on the outer surface of the outer cylinder 106 and the rail groove 102 provided on the inner surface of the needle hub 88 prevents the second engaging projection 128 from disengaging from the second engaging portion 130. Thus, the function of the second locking mechanism 134 can be suitably maintained.

[0095] As shown in Figure 14, the first locking mechanism 126 and the second locking mechanism 134 are positioned offset from each other in the circumferential direction.

[0096] The needle support portion 20 in the second configuration is configured in the same way as the needle support portion 20 in the first configuration. That is, in the initial state of the catheter assembly 10B, the needle support portion 20 supports the inner needle 86 via the catheter 82 on the tip side of the catheter hub 84. The needle support portion 20 is movably provided relative 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 between the pair of support arms 42 and the extension portion 100 is on the tip side of the catheter hub 84 than the base end. The tip of the needle hub 88 (the tip of the extension portion 100) and the support arm 42 are rotatably connected via a hinge structure 48 similar to that in the first configuration.

[0097] The restraint portion 44 in the second configuration is configured in the same way as the restraint portion 44 in the first configuration. As the catheter hub 84 moves forward, the restraint portion 44 is pushed by the catheter hub 84, releasing the restraint on the pair of support arms 42.

[0098] In addition, in the catheter assembly 10B relating to the second configuration, any component having the same name as any component of the catheter assembly 10A relating to the first configuration may be made of the materials exemplified for the constituent materials of each component of the catheter assembly 10A.

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

[0100] As shown in Figures 11 and 13, the initial state of the catheter assembly 10B is as follows: The inner needle 86 is inserted into the catheter 82 and the needle tip 87 protrudes a predetermined length from the tip of the catheter 82. The tip fitting portion 108 of the inner cylinder 104 is inserted into the proximal end of the catheter hub 84, and the outer cylinder 106 is moved to the furthest point toward the tip within its range of motion relative to the inner cylinder 104. The catheter 82 and inner needle 86 are exposed from the tip of the needle hub 88, and the catheter hub 84 and protector 90 are housed within the needle hub 88. The protector 90 is located on the proximal end side within the needle hub 88. The restraint portion 44 is in the retracted position within its range of motion, and the pair of support arms 42 are restrained in a closed state by the restraint portion 44, and the inner needle 86 is supported via the catheter 82 by the pair of support arms 42 in the closed state.

[0101] In using the catheter assembly 10B, the user (such as a doctor or nurse) grasps the needle hub 88 and inserts the catheter 82 and inner needle 86 into the patient's blood vessel. At this time, the inner needle 86 is supported via the catheter 82 by the support hole 54 formed between the closed pair of support arms 42, thereby suppressing the bending of the inner needle 86 during puncture. This enables stable puncture.

[0102] After puncture, the fingers are placed on the pair of wings 94 protruding from the needle hub 88 and the pair of wings 94 are pushed toward the tip. This causes the catheter hub 84 and catheter 82 connected to the pair of wings 94 to move toward the tip relative to the needle hub 88, increasing the insertion length of the catheter 82 into the blood vessel. Meanwhile, as the wings 94 are advanced, the protector 90 connected to the catheter hub 84 also advances within the needle hub 88.

[0103] As shown in Figures 16A and 16B, as the catheter hub 84 advances, it pushes the restraint portion 44 toward the tip. This causes the restraint portion 44 to move toward the tip relative to the pair of support arms 42, and the second restraint projection 58b disengages from the second engagement groove 56b. The disengagement of the second restraint projection 58b from the second engagement groove 56b releases the restraint of the pair of support arms 42 by the restraint portion 44, allowing the pair of support arms 42 to expand. As the catheter hub 84 advances further, the pair of support arms 42 are pushed from behind by the catheter hub 84 and expand.

[0104] After inserting the catheter 82 into the blood vessel to a predetermined length, the needle hub 88 is then pulled towards the proximal end while maintaining the position of the catheter member 98. This causes the inner needle 86 to move towards the proximal end within the catheter 82, catheter hub 84, and protector 90. In this case, the tip fitting portion 108 of the inner cylinder 104 of the protector 90 and the catheter hub 84 are fitted together by a predetermined fitting force, so the protector 90 extends as the needle hub 88 moves backward. Specifically, the inner cylinder 104 moves relative to the tip side of the outer cylinder 106, and the outer cylinder 106 moves relative to the tip side of the needle hub 88. Eventually, the protector 90 is fully extended (see Figures 17A and 17B). During the process of the protector 90 extending to its maximum extent, the inner needle 86 is withdrawn from the catheter 82, and the inner needle 86 is housed within 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 axial relative movement between the inner cylinder 104 and the outer cylinder 106 is prevented by the action of the first locking mechanism 126, and the axial relative movement between the outer cylinder 106 and the needle hub 88 is prevented by the action of the second locking mechanism 134.

[0106] Specifically, in the first locking mechanism 126, since the first engaging projection 120 is located at the very end of the first passage 121, the inner cylinder 104 cannot move any further toward the tip relative 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 toward the base end relative to the outer cylinder 106.

[0107] In the second locking mechanism 134, since the second engaging projection 128 is at the very front of the second passage 129, the outer cylinder 106 cannot move any further toward the front relative 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 toward the base relative to the needle hub 88.

[0108] As the catheter assembly 10B transitions from the state shown in Figure 16A to the state shown in Figure 17A, the pair of support arms 42 expand as they are pushed from behind by the catheter hub 84, allowing the catheter hub 84 and protector 90 to move relative to the needle hub 88 (see Figure 17B). In this way, the needle support section 20 supports the inner needle 86 in its initial state, thereby suppressing the bending of the inner needle 86 during puncture, while after puncture, the pair of support arms 42 open to prevent interference with the catheter hub 84 and protector 90.

[0109] After the protector 90 has extended to its maximum extent, if the needle hub 88 is further pulled towards the proximal end relative to the catheter member 98, the fitting between the catheter hub 84 and the tip fitting portion 108 of the inner cylinder 104 will disengage, as shown in Figure 18. 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 on the patient side.

[0110] After separating the catheter member 98 from the protector 90, the pair of wings 94 provided on the catheter hub 84 are spread to the left and right, and the catheter hub 84 is secured 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 of the catheter hub 84, and the infusion solution (medicine) is supplied to the patient from the infusion tube.

[0111] As explained above, with the catheter assembly 10B relating to the second configuration, the inner needle 86 is supported by a pair of support arms 42 during puncture, thus suppressing the bending of the inner needle 86 during puncture and enabling stable puncture. Furthermore, in the second configuration, the same functions and effects as in the first configuration are obtained for each component that is common with the first configuration.

[0112] Furthermore, in the second configuration, the catheter hub 84 is housed within the needle hub 88 in the initial state (see Figure 11). Therefore, compared to conventional catheter assemblies equipped with a protector, the exposed length of the inner needle 86 from the needle hub 88 that constitutes the housing can be shortened. Consequently, the total length of the catheter assembly 10B in the initial state, i.e., the length from the base of the needle hub 88 to the tip of the inner needle 86, can be shortened compared to conventional catheter assemblies equipped with a protector. As a result, it is compact and easy to store, and the puncture procedure is also easy. In addition, because the exposed length of the inner needle 86 from the needle hub 88 is short, the protector 90 can also be short, and therefore, the total length of the product is short even when the needle tip 87 is covered by the protector 90 (needle tip protected state). Consequently, the waste is compact and easy to dispose of.

[0113] Furthermore, in the second configuration, since the pair of wings 94 function as the operating parts of the catheter hub 84 in the initial state, there is no need to provide a dedicated operating part on the catheter hub 84, thus simplifying the configuration.

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

[0115] In the configuration described above, the restraint portion 44 is released from the pair of support arms 42 by being pushed by the catheter hub 84. However, instead of this configuration, the restraint portion 44 may be released from the pair of support arms 42 by being pushed by the wing 94. Alternatively, the catheter assembly 10B may further include a guidewire G inserted through the inner needle 86 and a guidewire operating portion 64 connected to the guidewire G for operating the guidewire G (see Figure 13). In this case, as the guidewire operating portion 64 moves forward, the restraint portion 44 may be released from the pair of support arms 42 by being pushed by the guidewire operating portion 64.

[0116] Figure 19 is a perspective view showing the catheter assembly 10C relating to the third configuration. Figure 20 is an exploded perspective view of the catheter assembly 10C. Figure 21 is a partially omitted longitudinal cross-sectional view of the catheter assembly 10C. In the catheter assembly 10C relating to the third configuration, elements that have the same or similar functions and effects as those of the catheter assembly 10B relating to the second configuration are given the same reference numerals, and detailed explanations are omitted.

[0117] The catheter assembly 10C comprises a flexible tubular catheter 152, a catheter hub 154 connected to the proximal end of the catheter 152, a tubular inner needle 156 having a sharp needle tip 157 at its end 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 grasped by a user (such as a doctor or nurse) via a needle hub 158, and its tip is inserted into the patient's blood vessel. In its initial state before use (before puncture), the catheter assembly 10C has a double-tube structure with an inner needle 156 inserted through the catheter 152, and the inner needle 156 protrudes a predetermined length from the tip of the catheter 152. Also, in the initial state of the catheter assembly 10C, the proximal end of the catheter hub 154 and the tip end of the needle hub 158 are connected via a protector 90.

[0119] In its initial state, the catheter assembly 10C consists of a double-tube structure with a catheter 152 and an inner needle 156, a catheter hub 154, a protector 90, and a needle hub 158, all combined to form a single assembly that can be handled as a single unit.

[0120] In the third configuration, catheter 152 is longer than catheters 12 and 82 in the first and second configurations. Catheter 152 may be used as a catheter longer than a peripheral venous catheter, such as a central venous catheter, PICC, or midline catheter. 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 proximal end connected to the catheter hub 154 and its tip exposed on the tip side of the needle hub 158.

[0123] The hub operating section 160 has a long main body 161 and a tab 162 provided at the tip of the main body 161 for gripping with a finger. The tab 162 protrudes upward from the tip of the main body 161.

[0124] The hub operating section 160 is rotatably connected to the catheter hub 154. In this illustrated example, outwardly projecting support protrusions 163 are provided on the outer surfaces of both the left and right sides of the catheter hub 154. Each support protrusion 163 extends in the vertical direction. On the other hand, 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 Figure 22A, each connecting groove 165 has a first groove 165a for engagement and a second groove 165b for release, which extends from the first groove 165a toward the proximal end with a narrower groove width than the first groove 165a and reaches the proximal end face of the connecting piece 164. The groove width W2 of the second groove 165b is slightly larger than the width W1 of the support projection 163 (see Figure 22B). The support projection 163 provided on the catheter hub 154 is inserted into each of the first grooves 165a provided on the hub operating section 160. As a result, the hub operating section 160 is rotatably supported relative to the catheter hub 154 with the support projection 163 as the shaft. In the initial state, the hub operating section 160 is substantially parallel to the catheter 152 and the inner needle 156, and since the support projection 163 is engaged with the first groove 165a, the hub operating section 160 is prevented from separating from the catheter hub 154.

[0126] As shown in Figure 22B, when the hub operating portion 160 is positioned substantially perpendicular to the axial direction of the catheter hub 154, the extension directions of the support projection 163 and the second groove 165b are the same, so the hub operating portion 160 can be separated from the catheter hub 154. The constituent material of the hub operating portion 160 is not particularly limited and may be the same as the constituent material of the catheter hub 154, for example.

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

[0128] As shown in Figure 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 tip opening of the catheter 152. The inner needle 156 in the third configuration is longer than the inner needles 16 and 86 in the first and second configurations.

[0129] Furthermore, in the initial state of the catheter assembly 10C, the inner needle 156 is inserted into the catheter hub 154 at an intermediate point along its longitudinal direction, 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 extension portion 170 that extends further toward the tip than the catheter hub 154. The extension portion 170 constitutes a housing that accommodates the catheter hub 154 and the protector 90 in the initial state. Also, in the initial state, the connection portion between the pair of support arms 173 and the extension portion 170 is located toward the tip than the proximal end of the catheter hub 154. The extension portion 170 in the third configuration is longer than the extension 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 down the catheter 152. In this configuration, the proximal end of the catheter hub 154 is located proximal to the axial center of the needle hub 158, and the tip of the needle hub 158 is located distal to the longitudinal center of the catheter 152.

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

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

[0134] As shown in Figures 19 and 21, in its initial state, the needle support portion 172 supports the inner needle 156 via the catheter 152 at a tip-side of the catheter hub 154. The needle support portion 172 is movably mounted relative 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 passage of the catheter hub 154.

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

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

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

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

[0139] The configuration of the pair of support arms 173 in the third configuration is the same as that of 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 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 hub operating portion 160 described above. As the hub operating portion 160 moves forward, the restraining portion 176 moves forward, releasing the restraint on the pair of support arms 173.

[0141] Specifically, the restraining 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 along the line XXIII-XXIII in Figure 21. As shown in Figure 23, the restraining portion 176 has a first restraining projection 177a that slidably engages with the first engagement groove 174a and a second restraining projection 177b that slidably engages with the second engagement groove 174b.

[0142] In this illustrated example, the first restraining projection 177a and the second restraining projection 177b protrude in the same direction to match the shapes of the first engagement groove 174a and the second engagement groove 174b provided on the pair of support arms 173. When the restraining portion 176 is in its initial position (retracted position), the first restraining projection 177a and the second restraining projection 177b of the restraining portion 176 engage with the first engagement groove 174a and the second engagement groove 174b of the pair of support arms 173, respectively, thereby restraining the pair of support arms 173 in a closed state.

[0143] As the restraining portion 176 moves toward the tip, the first restraining projection 177a and the second restraining projection 177b detach from the first engagement groove 174a and the second engagement groove 174b of the pair of support arms 173 toward the tip. When the first restraining projection 177a and the second restraining projection 177b detach from the first engagement groove 174a and the second engagement groove 174b, the restraining 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 apart.

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

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

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

[0147] As shown in Figures 19 and 21, the initial state of the catheter assembly 10C is as follows: The inner needle 156 is inserted into the catheter 152 and the needle tip 157 protrudes a predetermined length from the tip of the catheter 152. 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 is moved to the furthest point toward the tip within its range of motion relative to the inner cylinder 104. 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. 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 its range of motion, and the pair of support arms 173 are restrained in a closed state by the restraint portion 176, and the inner needle 156 is supported via the catheter 152 by the pair of support arms 173 in the closed state.

[0148] In using the catheter assembly 10C, the user (physician, nurse, etc.) grasps the needle hub 158 and inserts the catheter 152 and inner needle 156 into the patient's blood vessel. When grasping the part of the needle hub 158 closer to the tip, the needle tip 157 is stabilized, making the puncture procedure easier. During puncture, the inner needle 156 is supported via the catheter 152 by a pair of closed support arms 173, which suppresses bending of the inner needle 156 during puncture. This enables stable puncture.

[0149] After puncture, the user places their finger on the tab 162 located at the tip of the hub operating section 160 and pushes the tab 162 toward the tip. At this time, the tab 162 can be operated with the finger (for example, the index finger) of the hand that is gripping the tip of the needle hub 158, allowing for a quick transition from the puncture procedure to operating the tab 162.

[0150] When the tab 162 is pushed toward the tip, the restraining portion 176 provided on the hub operating portion 160 moves toward the tip relative to the pair of support arms 173, and the first restraining projection 177a and the second restraining projection 177b disengage from the first engagement groove 174a and the second engagement groove 174b. This disengagement releases the restraint of the pair of support arms 173 by the restraining portion 176, allowing the pair of support arms 173 to spread apart.

[0151] Then, as shown in Figures 24A and 24B, when the hub operating section 160 is advanced further, the pair of support arms 173 are pushed from the rear by the expanding projection 178 and expand. At this time, the tip of the hub operating section 160 can be bent at the thin-walled section 161a, so that the tip of the hub operating section 160 does not interfere with the patient's skin.

[0152] Next, as shown in Figure 25, when the hub operating section 160 is advanced further, the catheter hub 154 and catheter 152 connected to the hub operating section 160 move further toward the tip relative to the needle hub 158, increasing the insertion length of the catheter 152 into the blood vessel. Meanwhile, as the hub operating section 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 to a predetermined length into the blood vessel, the needle hub 158 is then pulled towards the proximal end relative to the catheter member 168. This causes the inner needle 156 to move towards the proximal end within the catheter 152, catheter hub 154, and protector 90. In this case, the tip fitting portion 108 of the inner cylinder 104 of the protector 90 and the catheter hub 154 are fitted together by a predetermined fitting force, so the protector 90 extends as the needle hub 158 moves backward. Specifically, the inner cylinder 104 moves toward the tip of the outer cylinder 106, and the outer cylinder 106 moves toward the tip of the needle hub 158. As a result, the protector 90 is extended to its maximum extent (see Figure 26). During the process of the protector 90 extending to its maximum extent, the inner needle 156 is withdrawn from the catheter 152, and the inner needle 156 is housed within the protector 90 up to the needle tip 157.

[0154] When the protector 90 is fully extended, the first locking mechanism 126 prevents axial movement between the inner cylinder 104 and the outer cylinder 106, and the second locking mechanism 134 prevents axial movement between the outer cylinder 106 and the needle hub 158.

[0155] After the protector 90 has extended to its maximum extent, if the needle hub 158 is further pulled towards the proximal end relative to the catheter member 168, the fitting between the catheter hub 154 and the tip fitting portion 108 of the inner cylinder 104 will disengage, as shown in Figure 27. As a result, the protector 90 is completely separated from the catheter member 168, and only the catheter member 168 of the catheter assembly 10C remains in place on the patient side.

[0156] After separating the catheter member 168 from the protector 90, the hub operating section 160 is separated from the catheter hub 154. Specifically, with the hub operating section 160 standing upright so that it is approximately perpendicular to the catheter hub 154, the hub operating section 160 is pulled upward to separate it from the catheter hub 154 (see Figure 22B). Then, the catheter hub 154 is secured to the patient's skin with a dressing or tape. Next, a connector for an infusion tube (not shown) is connected to the proximal end of the catheter hub 154, and the infusion fluid (medication solution) is supplied to the patient from the infusion tube.

[0157] As described above, with the catheter assembly 10C relating to the third configuration, similar to the first and second configurations, the inner needle 156 is supported by a pair of support arms 173 during puncture, thereby suppressing the bending of the inner needle 156 during puncture and enabling stable puncture. Also, similar to the second configuration, since the catheter hub 154 is housed within the needle hub 158 in the initial state, 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. Furthermore, in the third configuration, the same functions and effects as in the first and second configurations can be obtained for each component part that is the same as in the first and second configurations.

[0158] In the third configuration, the hub operating section 160 initially extends along the inner needle 156 and the catheter hub 154, with its proximal end connected to the catheter hub 154 and its tip exposed on the tip side of the needle hub 158. With this configuration, the hub operating section 160 can be operated by touching the portion of the hub operating section 160 that is exposed on the tip side of the needle hub 158. Therefore, the hub operating section 160 can be operated with the same hand that grasps the tip side of the needle hub 158 during puncture. As a result, the puncture operation and the advancement operation of the catheter 152 can be performed with the same hand, resulting in excellent operability.

[0159] In the third configuration, the restraint unit 176 is provided as part of the hub operating unit 160, and the restraint on the pair of support arms 173 is released when the hub operating unit 160 moves forward. With this configuration, the restraint on the pair of support arms 173 is automatically released in conjunction with the forward movement of the catheter hub 154 based on the operation of the hub operating unit 160, so an independent release operation is unnecessary, resulting in excellent operability.

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

[0161] The catheter assembly 10C may further include a guidewire G inserted through the inner needle 156 and a guidewire operating section 150 connected to the guidewire G for operating the guidewire G (see Figure 21). In this case, the restraint section 176 is provided as part of the guidewire operating section 150, and as the guidewire operating section 150 moves forward, the restraint section 176 is pushed by the guidewire operating section 150, thereby releasing the restraint on the pair of support arms 173.

[0162] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

Claims

1. Catheter and, A catheter hub fixed to the proximal end of the catheter, An inner needle having a needle tip and inserted into the catheter, The needle hub connected to the inner needle, It comprises a needle support section (20) and The aforementioned needle support portion is A pair of support arms (42) support the inner needle via the catheter, are openable and closable in the left-right direction, and support the catheter when closed, It has a restraining part that is displaceable with respect to a pair of support arms, Each of the pair of support arms has a support groove (53), A catheter assembly (10A) in which, when the pair of support arms are closed, the two support grooves form a support hole (54) for supporting the inner needle via the catheter.

2. In the catheter assembly according to claim 1, A catheter assembly in which, when the pair of support arms are closed, the support hole extends along the direction of extension of the inner needle.

3. In the catheter assembly according to claim 1, A catheter assembly in which, when the pair of support arms are closed, the left-right position of the mating surface of the pair of support arms is approximately the same as the axis of the inner needle supported by the support hole.

4. In the catheter assembly according to claim 1, In the initial state of the catheter assembly, the pair of support arms are constrained to a closed state by the restraint portion.

5. In the catheter assembly according to claim 1, A catheter assembly comprising a hub operating section (24) for operating the catheter hub.

6. In the catheter assembly according to claim 1, A guide wire (G) is inserted through the inner needle, A catheter assembly comprising a guidewire operating section (64) connected to the guidewire and for operating the guidewire.

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