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 is inserted into a blood vessel and left indwelling when, for example, administering fluid to a patient. [Background technology]

[0002] Conventionally, catheter assemblies have been used, for example, when administering infusions to patients. 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 tip, and a needle hub fixed to the proximal end of the inner needle. When administering infusions to a patient using the catheter assembly, the catheter together with the inner needle is inserted into the patient's blood vessel. After this insertion, the inner needle is withdrawn from the catheter while the catheter remains inserted in the patient. Next, a connector provided at the end of an infusion tube is connected to the proximal end of the catheter hub, and the infusion agent is supplied into the patient's blood vessel via the infusion tube, the catheter hub, and the catheter.

[0003] Among such catheter assemblies, there are known ones that have a means for supporting the inner needle via the catheter to prevent the inner needle from bending during puncture (see, for example, Published Japanese Translation of PCT International Application No. 10-503094 and U.S. Patent Application Publication No. 2011 / 0282285).

[0004] In JP-A-10-503094, a needle hub is provided with two openable arms extending toward the tip, and the two arms are open before use and do not support the inner needle. When inserting the catheter, the user pinches the arms to prevent the inner needle from bending. After inserting the catheter, the user can loosen the force with which they pinch the two arms, causing the arms to open and allowing the catheter hub to move forward.

[0005] In U.S. Patent Application Publication No. 2011 / 0282285, a needle hub is provided with two openable and closable arms extending toward the distal end. Before use, the two arms are closed to support the inner needle via the catheter and are constrained in a 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 JP-A-10-503094, the user must increase or decrease the force with which they pinch the two arms to support or release the inner needle, which is a cumbersome operation.

[0007] In the catheter assembly of U.S. Patent Application Publication No. 2011 / 0282285, the two arms for supporting the inner needle open up and down, and so the inner needle protrudes a long distance from the arms to avoid interference with the patient's skin, making the inner needle prone to bending. Furthermore, when inserting the needle, the arm is held near its tip to facilitate insertion, but after releasing the arm, it is necessary to re-hold the arm near its base end (the base end of the catheter assembly) in order to open it, making the operation cumbersome. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of these problems, and aims to provide a catheter assembly that is easy to operate and can effectively suppress bending of the inner needle during puncture. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the present invention provides a catheter assembly comprising: a catheter; a catheter hub fixed to the base 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 part, wherein the needle support part supports the inner needle via the catheter, and is capable of opening and closing in the left-right direction, and has a pair of support arms that support the catheter in a closed state, and a restraint part 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] The catheter assembly of the present invention is easy to operate and can effectively prevent the inner needle from bending during puncture. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a catheter assembly according to a first configuration. [Figure 2] FIG. 2 is an exploded perspective view of the catheter assembly shown in FIG. [Figure 3] FIG. 2 is a longitudinal sectional view of the catheter assembly shown in FIG. [Figure 4] FIG. 2 is a perspective view showing the catheter assembly shown in FIG. 1 in a state where the constraint on the pair of support arms is released. [Figure 5] 5 is a perspective view showing the catheter assembly shown in FIG. 1 in a state where the catheter member has been further advanced from the state shown in FIG. 4. FIG. [Figure 6] 2 is a perspective view showing the catheter assembly shown in FIG. 1 in a state where the inner needle has been removed from the catheter. FIG. [Figure 7] FIG. 7A is a perspective view showing a needle support part according to a first modified example, and FIG. 7B is a perspective view showing a needle support part according to a second modified example. [Figure 8] FIG. 10 is a perspective view showing a needle support part according to a third modified example. [Figure 9] FIG. 9A is a perspective view showing a hinge structure according to a first modified example, FIG. 9B is a cross-sectional view taken along line IXB-IXB in FIG. 9A, and FIG. 9C is a perspective view showing a hinge structure according to a second modified example. [Figure 10] Figure 10A is a schematic cross-sectional view of a support hole according to a first modified example, Figure 10B is a schematic cross-sectional view of a support hole according to a second modified example, Figure 10C is a schematic cross-sectional view of a support hole according to a third modified example, and Figure 10D is a schematic cross-sectional view of a support hole according to a fourth modified example. [Figure 11] FIG. 10 is a perspective view showing a catheter assembly according to a second configuration. [Figure 12] FIG. 12 is an exploded perspective view of the catheter assembly shown in FIG. [Figure 13] FIG. 12 is a longitudinal sectional view of the catheter assembly shown in FIG. [Figure 14] FIG. 12 is a rear view, with some parts omitted, of the catheter assembly shown in FIG. [Figure 15] 12 is a perspective view from the rear side showing the catheter assembly shown in FIG. 11 in a state where the first engaging portion and the first engaging projection are engaged and the second engaging portion and the second engaging projection are engaged. FIG. [Figure 16] Figure 16A is a longitudinal cross-sectional view showing the catheter assembly shown in Figure 11 with the catheter hub advanced partway, and Figure 16B is a perspective view showing the catheter assembly shown in Figure 11 with the catheter hub advanced partway. [Figure 17] Figure 17A is a longitudinal cross-sectional view showing the catheter assembly shown in Figure 11 in a state where the protector is fully extended, and Figure 17B is a perspective view showing the catheter assembly shown in Figure 11 in a state where the protector is fully extended. [Figure 18] FIG. 12 is a longitudinal cross-sectional view showing the catheter assembly shown in FIG. 11 in a state where the catheter hub and the protector are separated. [Figure 19] FIG. 10 is a perspective view showing a catheter assembly according to a third configuration. [Figure 20]FIG. 20 is an exploded perspective view of the catheter assembly shown in FIG. 19. [Figure 21] FIG. 20 is a longitudinal sectional view of the catheter assembly shown in FIG. 19, with a portion thereof omitted. [Figure 22] FIG. 22A is a perspective view showing the catheter hub and the hub operating section in a connected state, and FIG. 22B is a perspective view showing the catheter hub and the hub operating section in a separated state. [Figure 23] FIG. 23 is a cross-sectional view taken along line XXIII-XXIII in FIG. 21. [Figure 24] 24A is a longitudinal cross-sectional view of the catheter assembly shown in FIG. 19 in a state where the hub operating portion has been slightly advanced, and FIG. 24B is a perspective view showing a portion of the catheter assembly in the state shown in FIG. 24A. [Figure 25] FIG. 24B is a vertical cross-sectional view showing a state in which the hub operating part has been further advanced from the state of FIG. 24A. [Figure 26] 26 is a vertical cross-sectional view showing a state in which the hub operating portion is further advanced from the state shown in FIG. 25 and the protector is fully extended. FIG. [Figure 27] FIG. 20 is a longitudinal cross-sectional view of the catheter assembly shown in FIG. 19, showing the catheter member and the protector separated from each other. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A catheter assembly according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

[0013] Fig. 1 is a perspective view showing the overall configuration of a catheter assembly 10A according to a 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 base end of the catheter 12, a tubular inner needle 16 that has a sharp needle tip 17 at its tip and can be inserted into the catheter 12, a needle hub 18 connected to the inner needle 16, and a needle support part 20 for suppressing bending of the inner needle 16 during puncture.

[0015] The catheter assembly 10A is gripped by the needle hub 18 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 10A is inserted into the patient's blood vessel), the catheter assembly 10A has a double-tube structure with the inner needle 16 inserted into the catheter 12, and the inner needle 16 protrudes a predetermined length from the tip of the catheter 12.

[0016] In the initial state, the catheter assembly 10A is a single assembly that combines the double-tube structure of the catheter 12 and inner needle 16, the catheter hub 14, the needle hub 18, and the needle support portion 20, and can be handled as a single unit.

[0017] The catheter 12 is a flexible, thin-diameter tubular member formed to a predetermined length. Resin materials, particularly soft resin materials, are suitable for the catheter 12. Examples of suitable materials include fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxy fluororesin (PFA); olefin resins such as polyethylene and polypropylene; mixtures of these; polyurethane; polyester; polyamide; polyether nylon resin; and mixtures of the olefin resins with ethylene-vinyl acetate copolymer. The catheter 12 may be made of a transparent resin so that all or part of its interior can be viewed.

[0018] A catheter hub 14 is connected and fixed to the proximal end of the catheter 12. A flange portion 22 that protrudes outward and extends circumferentially 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 operating unit 24 for operating the catheter hub 14. As shown in FIG. 1 , the hub operating unit 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 unit 24 may be configured as a separate part from the catheter hub 14 and may be detachable from the catheter hub 14. A user can operate the catheter hub 14 in the axial direction by touching, gripping, or pressing the hub operating unit 24. The location at which the hub operating unit 24 is provided is not limited to the tip of the catheter hub 14, but may also be between the tip and base end of the catheter hub 14.

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

[0021] When the catheter assembly 10A is used, the catheter hub 14 is exposed to the patient's skin with the catheter 12 inserted into a blood vessel, and is left in place by being attached to the skin with a dressing, tape, or the like. Such a catheter hub 14 is preferably made of a material harder than the catheter 12. The material of the catheter hub 14 is not particularly limited, but suitable examples include thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

[0022] 1 and 2, the inner needle 16 is a tubular member having sufficient rigidity to puncture the skin of a patient. 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 distal end opening of the catheter 12. Also, in the initial state, a midpoint in the longitudinal direction of the inner needle 16 is inserted into the catheter hub 14, and its proximal end side is held by the needle hub 18.

[0023] Examples of materials for 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 that is initially arranged in series with the catheter hub 14, and an extension portion 38 that extends distally from the hub body 36. 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 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 the left and right sides of the hub body 36. In the initial state of the catheter hub 14, the extension portions 38 extend distally beyond the base end of the catheter hub 14. In other words, the distal end of the extension portion 38 is located distally beyond the distal end of the catheter hub 14. The extension portions 38 are formed to an appropriate size (thickness, length) so that they can be easily grasped and manipulated by the user when using the catheter assembly 10A.

[0026] Guide protrusions 40 extending along the axial direction of the inner needle 16 are provided on the mutually opposing inner surfaces of the pair of extension portions 38. The left and right guide protrusions 40 are inserted into left and right notches 23 provided in the flange portion 22 of the catheter hub 14, respectively. 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 that the hub operating portion 24 can be held facing upward. Furthermore, when the catheter hub 14 is advanced relative to the needle hub 18, the guiding action of the guide protrusions 40 allows the catheter hub 14 to be smoothly advanced.

[0027] Next, we will explain the needle support part 20. In the initial state of the catheter assembly 10A, the needle support part 20 supports the inner needle 16 via the catheter 12, on the distal side of the catheter hub 14. The needle support part 20 is provided movably 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 the catheter hub 14 to pass through.

[0028] Specifically, in this configuration, needle support unit 20 has a pair of support arms 42 that can be opened and closed, and a restraining unit 44 that can restrain the pair of support arms 42 in a closed state and can release the restraint. Hereinafter, when one of the pair of support arms 42 is described separately, one will be referred to as "support arm 42a" and the other will be referred to 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, the pair of support pins 43 have axes in the vertical direction, and the pair of support arms 42 supported thereby can open and close 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 located closer to the distal end than 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 face each other, and recesses 50 formed between the connecting pieces 49. The second structure 46 has a connecting protrusion 51 disposed in the recess 50. On each of the left and right sides, a support pin 43 is inserted through the connecting protrusion 51 and the two connecting pieces 49. Note that 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, a support hole 54 for supporting the inner needle 16 (the inner needle 16 inserted in 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 extension direction of the inner needle 16.

[0032] Each support arm 42 is provided with bent engagement grooves 56a, 56b when viewed from the front in the closed state. Each engagement groove 56a, 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") bend in opposite directions. Specifically, the first engagement groove 56a bends downward, and the second engagement groove 56b bends upward.

[0033] As shown in FIG. 3, it is preferable that the lower portion of the support arm 42 be trimmed so that the support arm 42 does not interfere with the skin S when puncturing the patient's skin S at a small angle.

[0034] The restraining portion 44 is arranged to be slidable 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, and the restraint on the pair of support arms 42 is released.

[0035] Specifically, the restraint portion 44 has a first restraint protrusion 58a that slidably engages with the first engagement groove 56a and a second restraint protrusion 58b that slidably engages with the second engagement groove 56b. In the illustrated example, the first restraint protrusion 58a and the second restraint protrusion 58b protrude in opposite directions to fit the shapes of the first engagement groove 56a and the second engagement groove 56b provided in the pair of support arms 42. When the restraint portion 44 is in the initial position (retracted position), the first restraint protrusion 58a and the second restraint protrusion 58b of the restraint 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 the closed state.

[0036] As the restraining portion 44 moves distally, the second restraining protrusion 58b disengages distally from the second engagement groove 56b of the support arm 42. When the second restraining protrusion 58b disengages from the second engagement groove 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 open. Note that even after the second restraining protrusion 58b disengages from the second engagement groove 56b, the engagement between the first restraining protrusion 58a and the first engagement groove 56a is maintained, so that the restraining portion 44 is held by the support arm 42a.

[0037] In a state in which the second restraint projection 58b is disengaged from the second engagement groove 56b, the second restraint projection 58b protrudes on the side opposite to the side on which the inner needle 16 is present (see FIG. 4). Therefore, when the support arm 42 opens with the inner needle 16 bent toward the restraining portion 44, the inner needle 16 is prevented from being caught on the second restraint projection 58b. Note that in a modified example, the second restraint projection 58b may protrude toward the side on which the inner needle 16 is present. In this case, the curved 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 projection 58b.

[0038] A pressed portion 60 is provided at the base end of the restraint portion 44. When the catheter hub 14 advances relative to the needle hub 18, the pressed portion 60 is pressed by the tip of the catheter hub 14, causing the restraint portion 44 to advance relative to the pair of support arms 42. The surface of the pressed portion 60 facing the catheter hub 14 is tapered so as to be displaced outward to the left and right as it advances toward the base end.

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

[0040] As shown in Figures 1 and 3, the catheter assembly 10A in its initial state is as follows: The inner needle 16 is inserted into the catheter 12, and the needle tip 17 protrudes a predetermined length from the distal end of the catheter 12. The catheter hub 14 is positioned as far as possible toward the proximal end relative to the needle hub 18, and extension portions 38 are present 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 restraining portion 44 is in a retracted position within its movable range, 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] When using the catheter assembly 10A, a user (such as a doctor or nurse) grasps the needle hub 18 and inserts the catheter 12 and the inner needle 16 into a 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, so bending of the inner needle 16 during puncture is suppressed. This allows for stable puncture.

[0042] After puncture, place your finger on the hub operating part 24 that protrudes upward from the catheter hub 14 and push the hub operating part 24 toward the tip. This moves the catheter hub 14 and the catheter 12 connected to the hub operating part 24 toward the tip relative to the needle hub 18, increasing the insertion depth of the catheter 12 into the blood vessel.

[0043] 4, as the catheter hub 14 moves forward, the hub operating unit 24 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 protrusions 58b disengage from the second engagement grooves 56b. As the second restraining protrusions 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 apart.

[0044] Then, when the catheter hub 14 moves further forward, the pair of support arms 42 are pushed from behind by the hub operating unit 24 and the catheter hub 14 and spread open, as shown in Figure 5. In this way, the needle support unit 20 suppresses bending of the inner needle 16 during puncture by supporting the inner needle 16 in the initial state, and after puncture, the pair of support arms 42 open to prevent interference with the catheter hub 14.

[0045] Once the catheter 12 has been inserted a predetermined distance into the blood vessel, the needle hub 18 is then pulled in the proximal direction while the position of the catheter member 25 is maintained. This causes the inner needle 16 to move 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 Figure 5. As a result, only the catheter member 25 of the catheter assembly 10A remains indwelling on the patient side.

[0046] After the inner needle 16 is removed from the catheter member 25, the catheter hub 14 is fixed to the patient with a dressing, tape, etc. Then, a connector of an infusion tube (not shown) is connected to the base end of the catheter hub 14, and an infusion agent (medicinal liquid) is supplied to the patient from the infusion tube.

[0047] As described above, according to the catheter assembly 10A, the inner needle 16 is supported by the pair of support arms 42 during puncture, which prevents the inner needle 16 from bending during puncture, allowing for stable puncture.

[0048] In particular, in the present invention, the inner needle 16 is not supported or released by the user adjusting the gripping force, but rather the restraint on the pair of support arms 42 is restrained or released by the action of the restraining portion 44, making operation easy.

[0049] Furthermore, since the pair of support arms 42 that open left and right 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 bending of the inner needle 16 can be effectively suppressed.

[0050] Furthermore, because the support arm 42 is located closer to the distal end than the proximal end of the catheter hub 14, for example, by grasping the extension 38 located closer to the distal end than the proximal end 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 having to change hands. This provides excellent operability.

[0051] In particular, in the case of this configuration, the constraint on the pair of support arms 42 is automatically released in conjunction with the forward operation of the hub operating unit 24, so there is no need for an independent release operation, and operability is excellent.

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

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

[0054] In particular, since the second restraint protrusion 58b protrudes on the side opposite to the side on which the inner needle 16 is present, it is possible to prevent the second restraint protrusion 58b from getting caught on the inner needle 16 when one of the support arms 42a that holds the restraint portion 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. The first structure 45 and the second structure 46 are in an interlocking relationship, so that rattle of the hinge structure 48 can be suppressed.

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

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

[0058] The needle support section 20a shown in Fig. 7A is provided with a pair of support arms 65 that are slidable in the left-right direction relative to the left and right extension sections 38. In this case, the extension sections 38 are provided with, for example, slide holes 38a for holding the support arms 65 so that they can slide in the left-right direction. Even with the configuration shown in Fig. 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 support for the inner needle 16 is released and passage of the catheter hub 14 is permitted.

[0059] The needle support section 20b shown in Figure 7B is provided with a pair of support arms 66 that are rotatably supported by a pair of support pins 67 that are parallel to the axial direction of the inner needle 16. In this case, for example, the tips of the left and right extension sections 38 are connected to each other, and the pair of support pins 67 are fixed to the connecting section 38b. Even with the configuration shown in Figure 7B, the pair of support arms 66 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 support for the inner needle 16 is released and passage of the catheter hub 14 is permitted.

[0060] The needle support unit 20c shown in Figure 8 has a pair of support arms 68 that can open and close in the left-right direction, and a restraining unit 69 that can restrain the pair of support arms 68 in a closed state and can release the restraint. In Figure 8, the restraining unit 69 is formed in a frame shape that surrounds the distal ends of the support arms 68 and can restrain the pair of support arms 68 in a closed state. A hub operating unit 24a is provided in place of the hub operating unit 24. The hub operating unit 24a is connected to the restraining unit 69. When the hub operating unit 24a is operated to move forward, the restraining unit 69 disengages from the pair of support arms 42 in the distal direction, thereby releasing the restraint on the pair of support arms 68. Note that a guidewire operating unit may be provided in place of the hub operating unit 24a.

[0061] 8, the restraining 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 restraining portion 69 fit into step portions 68a provided on the lower tip of the support arm 68. This configuration makes it possible to prevent the structure present below the inner needle 16 from becoming large. In contrast, if the support arm 68 is not provided with step portions 68a into which the inwardly protruding ends 69a of the restraining portion 69 fit, the structure present below the inner needle 16 will become large, and will be more likely to interfere with the patient's skin.

[0062] 9A and 9B may be employed instead of the above-described hinge structure 48. 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, allowing the support arm 42 to rotate relative to the extension portion 38.

[0063] 9C , a configuration may be employed in which one connection piece 71 provided at the base end of support arm 42 and one connection piece 72 provided at the tip of extension portion 38 are stacked one on top of the other and rotatably connected by support pin 43. Alternatively, in hinge structure 48b, support pin 43 may be integrally molded with support arm 42. Furthermore, instead of using support pin 43, support arm 42 and extension portion 38 may be integrally molded via a thin-walled portion.

[0064] In the configuration described above, a support groove 53 is provided in each support arm 42, and a support hole 54 is formed by the two support grooves 53. Therefore, the left-right position of the mating surface of the support arm 42 is approximately the same as the axis of the inner needle 16 supported by the support hole 54. For this reason, when a force of a predetermined magnitude or greater is applied to the inner needle 16 in the vertical direction, there is a possibility that the inner needle 16 will come off from the pair of closed support arms 42. Therefore, instead of the support hole 54, for example, support holes 54a-54d shown in Figures 10A-10D may be employed. Note that Figures 10A-10D are schematic views, omitting the restraining portion 44 and the first and second engagement grooves 56a, 56b, in order to mainly illustrate the structure of the support holes 54a-54d.

[0065] 10A , no support groove is provided in one support arm 42a, and a support groove 53a (deeper than the support groove 53) is provided only in the other support arm 42b. 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 in the other support arm 42b. In this configuration, the positions of the mating surfaces of the pair of support arms 42 are shifted in the left-right direction relative to the center of the inner needle 16 supported by the support hole 54a. Therefore, even when a force is applied to the inner needle 16 in the vertical direction, the inner needle 16 is unlikely to come off from the pair of closed support arms 42.

[0066] 10B, one support arm 42a is provided with a protrusion 73 that protrudes inward (toward 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 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. In the case of this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted in the left-right direction relative to the center of the inner needle 16 supported by the support hole 54b, and therefore the inner needle 16 is less likely to become dislodged.

[0067] 10C, steps 74, 75 are provided on the inner surface of one of the support arms 42a. When the pair of support arms 42 are closed, the support hole 54c is formed by the left and right steps 74, 75. In the case of this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted in the left-right direction relative to the center of the inner needle 16 supported by the support hole 54c, and therefore the inner needle 16 is less likely to become dislodged.

[0068] 10D, a multi-step staircase shape 76, 77 is provided on the inner surface of each support arm 42. When the pair of support arms 42 are closed, the support hole 54d is formed by the left and right staircase shapes 76, 77. In the case of this configuration as well, the position of the mating surfaces of the pair of support arms 42 is shifted in the left-right direction relative to the center of the inner needle 16 supported by the support hole 54d, and therefore the inner needle 16 is less likely to become dislodged.

[0069] Fig. 11 is a perspective view showing a 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 that have the same or similar functions and effects as those in the catheter assembly 10A are designated by the same reference numerals, and detailed description thereof will be 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 that can be 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 part 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 its initial state before use (before the catheter assembly 10B 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 addition, 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 is a single assembly that combines the double-tube structure of the catheter 82 and inner needle 86, the catheter hub 84, the protector 90, and the needle hub 88, and 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 a natural state. Each wing 94 is flexible and can be folded so that it overlaps with 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 underside of the wing 94, and the second thin-walled portion 96 is provided in a groove shape on the upper 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, its needle tip 87 protrudes a predetermined length from the distal end 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 its base end side 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 proximal end of the inner needle 86, and an extending portion 100 that extends further distally 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 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 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, which 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 the function of covering the needle tip 87 of the inner needle 86 as the inner needle 86 is pulled out of the catheter 82. The inner tube 104 has a body portion 107 and a tip fitting portion 108 that protrudes 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 protrusions 110 (see Figure 12) extending in the axial direction are provided on the left and right outer surfaces of the body portion 107.

[0084] The distal fitting portion 108 of the inner tube 104 is formed in a tapered shape with an outer diameter that decreases toward the distal end. In the initial state, the distal fitting portion 108 of the inner tube 104 fits into the proximal end of the catheter hub 84, and the inner tube 104 and catheter hub 84 are connected by frictional resistance on the fitting surfaces.

[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 together with the inner cylinder 104 within the proximal 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. The 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). Rail protrusions 118 extending in the axial direction are provided on the left and right outer surfaces of the outer cylinder 106. The rail protrusions 118 provided on the outer cylinder 106 are inserted into the rail grooves 102 provided in the extension portion 100 (see FIG. 15).

[0087] As shown in Fig. 12, a first engagement protrusion 120 that protrudes outward (downward in the illustrated example) is provided on the outer surface of the proximal end of the inner tube 104. Meanwhile, as shown in Figs. 14 and 15, the outer tube 106 is provided with a first passage 121 that extends axially and allows axial displacement of the first engagement protrusion 120, and a first engagement portion 122 that is disposed on the distal side of the first passage 121. The first passage 121 extends to the proximal end surface of the outer tube 106. In the initial state of the catheter assembly 10B, the first engagement protrusion 120 is located at the proximal 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 tube 106, but it may also be a groove provided on the inner surface of the outer tube 106.

[0088] The first engagement portion 122 has a pair of claws 123 that protrude into the first passage 121. Slit-shaped elongated holes 124 that extend in the axial direction of the outer cylinder 106 are provided on the left and right outer sides of the pair of claws 123. This allows the pair of claws 123 to elastically deform in directions toward and away from each other. The first engagement portion 122 configured in this manner and the first engagement protrusions 120 provided on the inner cylinder 104 can engage with each other.

[0089] 14 and 15 , when the inner tube 104 advances relatively to a predetermined position with respect to the outer tube 106, the first engagement portion 122 engages with the first engagement protrusion 120. Specifically, the first engagement portion 122 climbs over a pair of claws 123, and the pair of claws 123 hook onto both sides of the base end of the first engagement protrusion 120. When the first engagement portion 122 engages with the first engagement protrusion 120, relative movement in the axial direction between the inner tube 104 and the outer tube 106 is prevented. Therefore, the inner tube 104 is prevented from slipping out toward the tip side from the outer tube 106, and the inner tube 104 is prevented from retracting into the outer tube 106.

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

[0091] 14 and 15, a second engagement protrusion 128 that protrudes outward (downward in the illustrated example) is provided on the outer surface of the proximal 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 axially and allows axial displacement of the second engagement protrusion 128 provided on the outer tube 106, and a second engagement portion 130 that is disposed on the distal side of the second passage 129. The second passage 129 extends to the proximal 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 proximal end of the second passage 129. In this configuration, the second passage 129 is a hole that penetrates the needle hub 88 from the inside to the outside, but it may also 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] 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 onto 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 axial displacement between the outer tube 106 and the needle hub 88 is prevented. Therefore, the outer tube 106 is prevented from slipping 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 locking 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 when bending stress acts on the outer tube 106 and the needle hub 88, 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 prevents the second engagement protrusion 128 from coming out of the second engagement portion 130. Therefore, the function of the second locking mechanism 134 can be maintained in an optimal manner.

[0095] As shown in FIG. 14, the first locking mechanism 126 and the second locking mechanism 134 are arranged at different positions 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] 11 and 13, the catheter assembly 10B is in the following initial state: The inner needle 86 is inserted into the catheter 82, and the needle tip 87 protrudes a predetermined length from the distal end of the catheter 82. The distal fitting portion 108 of the inner tube 104 is inserted into the proximal end of the catheter hub 84, and the outer tube 106 has moved to the distal endmost position within its movable range relative to the inner tube 104. The catheter 82 and inner needle 86 are exposed from the distal end 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 side within the needle hub 88. The restraining portion 44 is in a retracted position within its movable range, and the pair of support arms 42 are restrained in a closed state by the restraining 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] When using the catheter assembly 10B, a user (such as a doctor or nurse) grasps the needle hub 88 and inserts the catheter 82 and the inner needle 86 into a 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 pair of closed support arms 42, so that bending of the inner needle 86 during puncture is suppressed. This allows for stable puncture.

[0102] After puncture, the operator places his / her fingers on the pair of wings 94 protruding from the needle hub 88 and pushes the pair of wings 94 toward the distal end. This causes the catheter hub 84 and catheter 82 connected to the pair of wings 94 to move toward the distal end relative to the needle hub 88, increasing the insertion depth 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] 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 has been inserted a predetermined distance into the blood vessel, the needle hub 88 is then pulled proximally while maintaining the position of the catheter member 98. This causes the inner needle 86 to move proximally within the catheter 82, catheter hub 84, and protector 90. In this case, the distal fitting portion 108 of the inner tube 104 of the protector 90 is fitted to the catheter hub 84 with a predetermined fitting force, so that the protector 90 extends as the needle hub 88 moves backward. Specifically, the inner tube 104 moves relative to the distal end side of the outer tube 106, and the outer tube 106 moves relative to the distal end side of the needle hub 88. Eventually, the protector 90 reaches its maximum extension state (see FIGS. 17A and 17B). As the protector 90 extends to its maximum extension, the inner needle 86 is withdrawn from the catheter 82, and the inner needle 86 is housed within the protector 90 up to its 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, the first engaging protrusion 120 is at the most distal position of the first passage 121, so the inner tube 104 cannot move any further in the distal direction relative to the outer tube 106. Also, in the first locking mechanism 126, the first engaging protrusion 120 and the first engaging portion 122 are engaged with each other, so the inner tube 104 cannot move in the proximal direction relative to the outer tube 106.

[0107] In the second locking mechanism 134, the second engaging protrusion 128 is at the most distal position of the second passage 129, so the outer tube 106 cannot move any further in the distal direction relative to the needle hub 88. In addition, in the second locking mechanism 134, the second engaging protrusion 128 and the second engaging portion 130 are engaged with each other, so the outer tube 106 cannot move in the proximal direction relative to the needle hub 88.

[0108] 16A to the state of Figure 17A, the pair of support arms 42 are pushed from behind by the catheter hub 84 and spread open, 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 the initial state, thereby suppressing bending of the inner needle 86 during puncture, and after puncture, the pair of support arms 42 open, preventing interference with the catheter hub 84 and protector 90.

[0109] After the protector 90 has been fully extended, pulling the needle hub 88 further toward the proximal end relative to the catheter member 98 disengages the catheter hub 84 from the distal fitting portion 108 of the inner tube 104, as shown in Figure 18. This causes the protector 90 to be completely separated from the catheter member 98, leaving only the catheter member 98 of the catheter assembly 10B indwelling on the patient side.

[0110] After separating 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 fixed to the patient's skin with tape or the like to fix the catheter hub 84. Then, a connector of an infusion tube (not shown) is connected to the base end of the catheter hub 84, and an infusion agent (medicinal solution) is supplied to the patient from the infusion tube.

[0111] As described above, according to the catheter assembly 10B of the second configuration, the pair of support arms 42 support the inner needle 86 during puncture, thereby suppressing bending of the inner needle 86 during puncture and enabling stable puncture. In addition, in the second configuration, the components common to the first configuration provide the same actions and effects as the first configuration.

[0112] In the second configuration, the catheter hub 84 is housed within the needle hub 88 in the initial state (see FIG. 11). Therefore, compared to a conventional catheter assembly equipped 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, i.e., the length from the base end of the needle hub 88 to the tip of the inner needle 86, can be shortened compared to a conventional catheter assembly equipped with a protector. This makes the assembly compact, allowing for easy storage and facilitating puncture operations. Furthermore, because the exposed length of the inner needle 86 from the needle hub 88 is short, the protector 90 may also be short, and therefore the overall length of the product is short even when the needle tip 87 is covered by the protector 90 (needle tip protected state). Therefore, the waste product is compact and easy to dispose of.

[0113] Furthermore, in the second configuration, the pair of wings 94 function as the operating part of the catheter hub 84 in the initial state, so there is no need to provide a dedicated operating part in the catheter hub 84, and the configuration can be simplified.

[0114] In catheter assembly 10B, needle support members 20a to 20c shown in Figures 7A to 8 may be used instead of needle support member 20. In catheter assembly 10B, hinge structure 48a, 48b shown in Figures 9A to 9C may be used instead of hinge structure 48. In catheter assembly 10B, support hole 54 may be replaced by support holes 54a to 54d shown in Figures 10A to 10D.

[0115] In the configuration described above, the constraint on the pair of support arms 42 is released when the constraint portion 44 is pushed by the catheter hub 84, but instead of this configuration, the constraint on the pair of support arms 42 may be released when the constraint portion 44 is pushed by the wings 94. Alternatively, the catheter assembly 10B may further include a guidewire G that is inserted through the inner needle 86, and a guidewire operating portion 64 that is connected to the guidewire G and operates the guidewire G (see FIG. 13). In this case, the constraint on the pair of support arms 42 may be released when the constraint portion 44 is pushed by the guidewire operating portion 64 as the guidewire operating portion 64 advances.

[0116] Figure 19 is a perspective view showing a catheter assembly 10C according to the third configuration. Figure 20 is an exploded perspective view of the catheter assembly 10C. Figure 21 is a partially omitted longitudinal sectional view of the catheter assembly 10C. In the catheter assembly 10C according to the third configuration, elements that have the same or similar functions and effects as those in the catheter assembly 10B according to the second configuration are designated by the same reference numerals, and detailed description thereof will be omitted.

[0117] The catheter assembly 10C comprises a flexible tubular catheter 152, a catheter hub 154 connected to the base end of the catheter 152, a tubular inner needle 156 having a sharp needle tip 157 at its tip that can be inserted 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 part 172 for suppressing 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] 19 and 21, the catheter assembly 10C in its initial state is as follows: The inner needle 156 is inserted into the catheter 152, and the needle tip 157 protrudes a predetermined length from the distal end of the catheter 152. The distal fitting portion 108 of the inner tube 104 is inserted into the proximal end of the catheter hub 154, and the outer tube 106 has moved to the distal end-most position within its movable range relative to the inner tube 104. The catheter 152 and inner needle 156 are exposed from the distal end 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 side within the needle hub 158. The restraining portion 176 is in a retracted position within its movable range, and the pair of support arms 173 are restrained in a closed state by the restraining portion 176. The inner needle 156 is supported via the catheter 152 by the pair of support arms 173 in the closed state.

[0148] When using the catheter assembly 10C, a user (such as a doctor or nurse) grasps the needle hub 158 and inserts the catheter 152 and inner needle 156 into a patient's blood vessel. At this time, grasping the portion of the needle hub 158 near the tip stabilizes the needle tip 157, making the puncture operation easier. During puncture, the inner needle 156 is supported via the catheter 152 by the closed pair of support arms 173, which prevents the inner needle 156 from bending during puncture. This allows for stable puncture.

[0149] After puncturing, a finger is placed on tab 162 provided at the tip of hub operating part 160, and tab 162 is pushed toward the tip. At this time, tab 162 can be operated with the fingers (for example, index finger) of the hand holding the part of needle hub 158 near the tip, so that operation of tab 162 can be quickly transitioned to after the puncturing operation.

[0150] When the tab 162 is pushed in the distal direction, the restraining portion 176 provided on the hub operating portion 160 moves in the distal direction relative to the pair of support arms 173, and the first restraining protrusion 177a and the second restraining protrusion 177b are released from the first engagement groove 174a and the second engagement groove 174b. This release releases the restraint of the pair of support arms 173 by the restraining portion 176, and the pair of support arms 173 become able to spread open.

[0151] 24A and 24B, when the hub operating part 160 is moved further forward, the pair of support arms 173 are pushed from behind by the expansion protrusions 178 and expand. At this time, the tip of the hub operating part 160 can be bent at the thin-walled part 161a, so that the tip of the hub operating part 160 can be prevented from interfering with the patient's skin.

[0152] 25, when the hub operating unit 160 is further advanced, the catheter hub 154 and catheter 152 connected to the hub operating unit 160 move further toward the distal end relative to the needle hub 158, increasing the insertion depth of the catheter 152 into the blood vessel. Meanwhile, as the hub operating unit 160 is advanced, the protector 90 connected to the catheter hub 154 also moves forward within the needle hub 158.

[0153] After the catheter 152 has been inserted a predetermined distance into the blood vessel, the needle hub 158 is then pulled proximally relative to the catheter member 168. This causes the inner needle 156 to move proximally within the catheter 152, catheter hub 154, and protector 90. In this case, the distal fitting portion 108 of the inner tube 104 of the protector 90 is fitted to the catheter hub 154 with a predetermined fitting force, so that the protector 90 extends as the needle hub 158 moves backward. Specifically, the inner tube 104 moves toward the distal end of the outer tube 106, and the outer tube 106 moves toward the distal end of the needle hub 158. This causes the protector 90 to reach its maximum extended state (see Figure 26). As the protector 90 extends to its maximum, the inner needle 156 is withdrawn from the catheter 152, and the inner needle 156 is housed within the protector 90 up to its needle tip 157.

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

[0155] After the protector 90 has been fully extended, if the needle hub 158 is further pulled in the proximal direction relative to the catheter member 168, the catheter hub 154 and the tip fitting portion 108 of the inner tube 104 will be disengaged, as shown in Figure 27. This causes the protector 90 to be completely separated from the catheter member 168, leaving only the catheter member 168 of the catheter assembly 10C indwelling on the patient side.

[0156] After the catheter member 168 and the protector 90 are separated, the hub operating unit 160 is separated from the catheter hub 154. Specifically, the hub operating unit 160 is raised so that it is in a substantially vertical position relative to the catheter hub 154, and then pulled upward to separate the hub operating unit 160 from the catheter hub 154 (see FIG. 22B). The catheter hub 154 is then fixed to the patient's skin with a dressing, tape, or the like. Then, a connector for an infusion tube (not shown) is connected to the base end of the catheter hub 154, and an infusion agent (medicinal solution) is supplied to the patient through the infusion tube.

[0157] As described above, according to the catheter assembly 10C of the third configuration, as in the first and second configurations, the pair of support arms 173 support the inner needle 156 during puncture, thereby suppressing bending of the inner needle 156 during puncture and enabling stable puncture. Also, as in the second configuration, in the initial state, the catheter hub 154 is housed within the needle hub 158, so the overall length of the product can be shortened both in the initial state and in the state in which the needle tip is protected by the protector 90. In addition, in the third configuration, the same components as those in the first and second configurations provide the same actions and effects as those in the first and second configurations.

[0158] In the third configuration, in the initial state, the hub operating unit 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 at the tip side of the needle hub 158. With this configuration, the hub operating unit 160 can be operated by touching the portion of the hub operating unit 160 exposed at the tip side of the needle hub 158, and therefore the hub operating unit 160 can be operated with the same hand that grips the tip side of the needle hub 158 during puncture. Therefore, the puncture operation and the advancement operation of the catheter 152 can be performed with the same hand, providing excellent operability.

[0159] In the third configuration, the restraint unit 176 is provided as part of the hub operating unit 160, and when the hub operating unit 160 moves forward, the restraint on the pair of support arms 173 is released. With this configuration, 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 of the hub operating unit 160, so an independent release operation is not required, and operability is excellent.

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

[0161] The catheter assembly 10C may further include a guidewire G that is inserted through the inner needle 156, and a guidewire operation unit 150 that is connected to the guidewire G and that operates the guidewire G (see FIG. 21). In this case, the restraining portion 176 may be provided as part of the guidewire operation unit 150, and as the guidewire operation unit 150 advances, the restraining portion 176 may be pushed by the guidewire operation unit 150, thereby releasing 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

1. 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; a needle support portion (20); The needle support portion includes: a pair of support arms (42) that support the inner needle via the catheter, are openable and closable in the left-right direction, and support the catheter in a closed state; a restraint portion provided displaceably with respect to the 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, a support hole (54) for supporting the inner needle via the catheter is formed by the two support grooves.

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

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

4. The catheter assembly according to claim 1, A catheter assembly, wherein in an initial state of the catheter assembly, the pair of support arms are constrained in a closed state by the restraining portion.

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

6. The catheter assembly according to claim 1, a guide wire (G) inserted through the inner needle; a guidewire operating portion (64) connected to the guidewire for operating the guidewire.

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