Catheter Assembly

Abstract

A catheter assembly (10) includes a catheter (12), a catheter hub (20) anchored to the catheter (12), an inner needle (14) inserted in the catheter (12), and a grip (18) that anchors and holds the inner needle (14). The catheter assembly (10) also includes a supporting structure (62) that contacts the outer circumferential surface of the catheter (12) and supports the outside of the catheter (12) when the assembly is in an assembled state. If viewed from a direction orthogonal to the extension direction of the catheter (12) in the assembled state, the supporting structure (62), without clamping therebetween the same position of the catheter (12) in the extension direction, compresses the catheter (12), causing the catheter (12) to bend along the extension direction.

Description

[Technical field]

[0001] The present invention relates to a catheter assembly having a structure capable of supporting the outside of a catheter when the catheter and inner needle are inserted. [Background technology]

[0002] When constructing an introduction portion for infusion or blood transfusion in a treatment subject (patient), a catheter assembly such as that disclosed in U.S. Patent Application Publication No. 2016 / 0256667 is used. This catheter assembly has a multi-needle in which an inner needle is inserted into a catheter (outer needle). In using this catheter assembly, a user inserts the multi-needle into the body of a treatment subject, then advances the catheter into a blood vessel, and further removes the inner needle from the catheter to leave the catheter in place.

[0003] In use, this type of catheter assembly is prone to bending when the multiple needle comes into contact with a treatment target, and this bending makes it difficult to insert the multiple needle into the body. For this reason, the catheter assembly disclosed in U.S. Patent Application Publication No. 2016 / 0256667 has a structure in which the tip of the grip that fixes the inner needle is positioned near the outer periphery of the catheter to support the catheter when it is inserted. Summary of the Invention

[0004] However, if the support structure of the catheter assembly tightly grips the outside of the catheter to suppress bending of the catheter, the sliding resistance on the catheter increases, making it difficult for the user to move the catheter. For this reason, the conventional support structure is formed so as to create a clearance between the catheter and the support structure when the catheter assembly is assembled.

[0005] However, when the catheter is manufactured to be thin within the range of dimensional tolerances, the support structure thus formed has a large clearance with the outer circumferential surface of the catheter, which causes the support structure to be unable to effectively support the catheter when multiple needles are inserted.

[0006] The present invention relates to the above-mentioned catheter assembly technology, and aims to provide a catheter assembly that properly supports the catheter to suppress bending during puncture, and allows the catheter to be easily moved when the user performs a movement operation.

[0007] In order to achieve the above-mentioned object, one aspect of the present invention comprises a catheter, a catheter hub fixed to the catheter, an inner needle inserted into the catheter, a grip for fixing and holding the inner needle, and a support structure that, in an assembled state, contacts the outer surface of the catheter to support the outside of the catheter, and when viewed from a direction perpendicular to the extension direction of the catheter in the assembled state, the support structure presses the catheter without clamping the same position in the extension direction of the catheter, thereby bending the catheter along the extension direction.

[0008] The catheter assembly described above appropriately supports the catheter to suppress bending during puncture, and allows the catheter to be easily moved when moved by the user. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a catheter assembly according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the catheter assembly of FIG. 1. [Diagram 3] FIG. 2 is a perspective view of the catheter manipulation member as seen obliquely from below. [Figure 4] FIG. 2 is a side cross-sectional view showing the distal end portion of the catheter assembly. [Diagram 5] FIG. 2 is a partial front cross-sectional view showing the distal end portion of the catheter assembly. [Figure 6] 6A and 6B are side cross-sectional views each showing a schematic assembly of a catheter and a support structure, respectively, and FIG 6B is a side cross-sectional view showing a schematic assembly of a conventional catheter and a support structure. [Figure 7]Fig. 7A is a side cross-sectional view showing an assembled state of a catheter and a support structure according to a first modified example, Fig. 7B is a side cross-sectional view showing an assembled state of a catheter and a support structure according to a second modified example, and Fig. 7C is a side cross-sectional view showing an assembled state of a catheter and a support structure according to a third modified example. [Figure 8] FIG. 13 is a side cross-sectional view showing, in outline, the assembled state of a catheter and a support structure according to a fourth modified example. [Figure 9] Fig. 9A is a side view showing the catheter assembly during puncture, and Fig. 9B is a side view showing the catheter manipulation member advanced after puncture. [Figure 10] Fig. 10A is a side cross-sectional view showing a schematic diagram of a supported state of the catheter during puncture, and Fig. 10B is a side cross-sectional view showing a schematic diagram of a supported state of the catheter when the catheter is largely bent. [Figure 11] FIG. 11 is a partial front cross-sectional view showing a tip portion of a catheter assembly according to a second embodiment. [Figure 12] FIG. 12 is a plan cross-sectional view taken along the axis of a catheter in the catheter assembly of FIG. 11. [Figure 13] Fig. 13A is a plan sectional view showing an assembled state of the catheter and the support structure, Fig. 13B is a plan sectional view showing an assembled state of the catheter when the catheter is largely bent, and Fig. 13C is a plan sectional view showing an assembled state of the catheter and the support structure according to a fifth modified example. [Figure 14] Fig. 14A is a plan sectional view showing an assembled state of a catheter and a support structure according to a sixth modified example, and Fig. 14B is a plan sectional view showing an operation of a support member when the catheter of Fig. 14A moves. [Figure 15] FIG. 11 is a perspective view showing a tip portion of a catheter assembly according to a third embodiment. [Figure 16] Fig. 16A is a plan sectional view showing, in a simplified manner, the assembled state of the catheter and the support structure of Fig. 15. Fig. 16B is a plan sectional view showing, in a simplified manner, the supported state of the catheter when the catheter of Fig. 16A is subjected to a large bending motion. [Figure 17] Fig. 17A is a plan sectional view showing an assembled state of a catheter and a support structure according to a seventh modified example, and Fig. 17B is a plan sectional view showing an assembled state of the catheter when the catheter of Fig. 17A is largely bent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to preferred embodiments thereof and accompanying drawings.

[0011] [First embodiment] As shown in Fig. 1, a catheter assembly 10 according to a first embodiment of the present invention is a medical device used when infusing fluid, transfusing blood, or collecting blood from a treatment target (living body), and a catheter 12 is inserted and placed in the body of the treatment target to establish electrical continuity between the inside and outside of the body. This catheter assembly 10 allows the insertion of a catheter 12 (e.g., a central venous catheter, PICC, midline catheter, etc.) that is longer than a peripheral venous catheter. The catheter assembly 10 may be configured to allow the insertion of a peripheral venous catheter. Furthermore, the catheter assembly 10 is not limited to a venous catheter, and may also be one into which an arterial catheter such as a peripheral arterial catheter is inserted.

[0012] 1 and 2, the catheter assembly 10, in an assembled state prior to use (before puncture), comprises an inner / outer needle assembly 16 comprising a catheter 12, an inner needle 14, a catheter hub 20, an inner needle hub 30, a safety member 40, and a catheter operating member 60. Furthermore, the catheter assembly 10 comprises a grip 18 (housing) that houses the inner / outer needle assembly 16 and is held by the user.

[0013] In the assembled internal / external needle assembly 16, the inner needle 14 penetrates the catheter 12 and the catheter hub 20, and the needle tip 15 of the inner needle 14 protrudes beyond the tip of the catheter 12 to form a multiple needle 11. A safety member 40 through which the inner needle 14 is inserted is disposed on the proximal side of the catheter hub 20, and an inner needle hub 30 holding the inner needle 14 is disposed on the proximal side of the safety member 40. A catheter operating member 60 is disposed above the catheter 12, the catheter hub 20, and the safety member 40, and moves these members forward and backward under the user's operation. The internal / external needle assembly 16 including the proximal portion of the multiple needle 11 is housed in the grip 18, and the inner needle hub 30 is fixed to the grip 18.

[0014] The catheter 12 according to this embodiment is a tube having moderate flexibility, and is configured as a multi-lumen type having a plurality of lumens 12a, 12b therein (see also FIG. 5). Each of the lumens 12a, 12b extends in the axial direction (direction of arrow A) of the catheter 12, and communicates with a tip opening 12a1 and a tip opening 12b1 at the tip of the catheter 12, respectively. For example, the lumen 12a is formed in a circular shape capable of accommodating the inner needle 14, and the lumen 12b is formed in an arc-shaped ellipse above the lumen 12a. The length of the catheter 12 is set within a range of about 14 to 500 mm, preferably within a range of 30 to 400 mm, and more preferably within a range of 76 to 200 mm.

[0015] The catheter 12 is preferably made of a soft resin material, for example, fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroalkoxy fluororesin (PFA), etc., olefin resins such as polyethylene and polypropylene, or mixtures thereof, polyurethane, polyester, polyamide, polyether nylon resin, mixtures of olefin resins and ethylene-vinyl acetate copolymer, etc. In the present invention, the catheter 12 is not limited to a multi-lumen type, and may of course be a single-lumen type consisting of only the lumen 12a through which the inner needle 14 is inserted.

[0016] The base end of the catheter 12 is fixed to the tip end inside the catheter hub 20 by an appropriate fixing means such as crimping, fusion, adhesion, etc. The catheter hub 20 is exposed on the skin of the subject with the catheter 12 inserted into the blood vessel of the subject, and is left indwelling together with the catheter 12 by being affixed with tape or the like.

[0017] The catheter hub 20 has two separate hubs (main hub 21 and sub-hub 22) to accommodate the multi-lumen type catheter 12. The main hub 21 is a member that is directly connected to the catheter 12, and the sub-hub 22 is a member that is connected to the main hub 21 via a tube 23.

[0018] The material of construction of the catheter hub 20 (main hub 21, sub-hub 22) is not particularly limited, but it is preferable to use thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

[0019] The main hub 21 is a cylinder extending parallel to the axis of the proximal end side of the catheter 12, and a tube 23 is connected to a predetermined position on the outer circumferential surface. An internal space 21a communicating with the lumen 12a and an internal space 21b communicating with the lumen 12b are provided inside the main hub 21. The proximal end of the internal space 21a communicates with a proximal end opening 21a1 of the main hub 21. Meanwhile, the internal space 21b is separated from the internal space 21a and communicates with an inner cavity 23a of a tube 23 inserted and fixed in the main hub 21.

[0020] In the assembled state, the valve member 24 is inserted into the main hub 21 from the base end opening 21a1 toward the back side (arrow A1 side) of the internal space 21a. A valve hole 24a that can be elastically opened and closed is provided at the axis of the valve member 24. In the assembled state, the inner surface of the valve hole 24a and the outer surface of the safety member 40 are tightly attached to each other by inserting the inner needle 14 and the tip of the safety member 40 into the valve hole 24a. In this way, the valve member 24 brings the catheter hub 20 and the safety member 40 into an engaged state, and prevents blood from leaking from the base end opening 21a1 of the main hub 21 when the inner needle 14 is inserted.

[0021] Sub-hub 22 is formed in a cylindrical shape with a thickness similar to that of main hub 21, with the base end of tube 23 inserted and fixed from the tip end. An internal space 22a that communicates with lumen 23a of tube 23 is formed inside sub-hub 22. The base end of internal space 22a communicates with a base end opening (not shown) of sub-hub 22. In the assembled state, a blocking member 25 that blocks the base end opening is connected to sub-hub 22.

[0022] The tube 23 is configured to be flexible, similar to the catheter 12. A clamp 26 capable of opening and closing a lumen 23a of the tube 23 is attached in advance to a midpoint of the tube 23 in the extending direction.

[0023] On the other hand, the inner needle 14 of the catheter assembly 10 is configured as a hollow tube having enough rigidity to puncture the skin of a living body. A sharp needle tip 15 is formed at the tip of the inner needle 14. The needle tip 15 has a blade surface 15a that is inclined toward the tip side and upward. In other words, the blade surface 15a faces upward (the arrow C1 side, the catheter operating member 60 side). A hollow portion 14a is formed inside the inner needle 14 along the direction of arrow A, and this hollow portion 14a communicates with a tip opening 14a1 provided on the blade surface 15a.

[0024] Examples of materials constituting the inner needle 14 include metal materials such as stainless steel, aluminum or an aluminum alloy, titanium or a titanium alloy, or hard resins, ceramics, etc. The inner needle 14 is firmly fixed to the inner needle hub 30 by an appropriate fixing means such as fusion, adhesion, or insert molding.

[0025] The inner needle hub 30 is a member for directly holding the inner needle 14, and is fixed to the grip 18 via a grip fixing part 31 (lower wall) formed on the side of arrow C2. A plurality of fixing protrusions 34 are provided on the lower surface of the grip fixing part 31, which protrude slightly downward and constitute an attachment mechanism 33 between the grip 18 and the grip fixing part 31.

[0026] The safety member 40 is configured to follow the moving catheter hub 20 by being inserted into and fitted into the main hub 21 and the valve member 24 of the catheter hub 20. This safety member 40 includes a cover body 41 that covers the outside of the inner needle 14 as it advances, a blunt needle 50 that protrudes from the needle tip 15 of the inner needle 14 after puncture, and a blunt needle hub 51 that holds the blunt needle 50.

[0027] The cover body 41 has a cylindrical distal end cover part 42 that houses and protects the inner needle 14 after puncture, a base end flat plate part 43 that extends from the upper part of the distal end cover part 42 to the side of arrow A2, and a pair of protruding pieces 44 that protrude outward in the width direction from the base end flat plate part 43. In addition, an engagement protrusion 45 with which the blunt needle hub 51 engages is provided at the location where the base end flat plate part 43 and the distal end cover part 42 are connected.

[0028] The tip side of the tip cover part 42 is inserted into and tightly attached to the valve member 24, so that it is frictionally fitted into the catheter hub 20 including the valve member 24. In addition, in the assembled state, the base end of the tip cover part 42 faces the tip of the inner needle hub 30. The base end flat plate part 43 connected to the tip cover part 42 extends along the upper part of the inner needle hub 30 to the base end inside the grip 18 in the assembled state.

[0029] The pair of protruding pieces 44 protrude outward in the width direction (arrow B direction) beyond the inner needle hub 30, and extend up to the vicinity of the side wall 77 of the grip 18 (onto rail walls 96, 98 described below). Each protruding piece 44 constitutes a guide mechanism 46 that cooperates with the grip 18 to guide the movement of the safety member 40 in the direction of arrow A. In addition, an interlocking protrusion 48 is provided on the side edge of the protruding piece 44 on the arrow B1 side. The interlocking protrusion 48 constitutes one side of a safety movement limiting mechanism 49 that limits the advancement and retreat of the cover body 41 by being interlocked with an interlocking portion 100 of the grip 18 at the advanced position where the safety member 40 is advanced.

[0030] The blunt needle 50 of the safety member 40 is a rod member (round bar) for preventing the inner needle 14 from erroneously pricking the catheter 12 or a living body, and is movably housed in the hollow portion 14a of the inner needle 14. The tip of the blunt needle 50 is formed into a shape (e.g., a polished flat surface) that is blunter than the needle tip 15, and in the assembled state is disposed in a position near the base end of the tip opening 14a1 of the inner needle 14. The tip of the blunt needle 50 is exposed from the needle tip 15 (tip opening 14a1) as the safety member 40 advances.

[0031] The blunt needle hub 51 holds the blunt needle 50, and is configured to be movable relative to the inner needle 14, the inner needle hub 30, and the grip 18 by engaging with the engaging protrusion 45 of the cover body 41. The blunt needle hub 51 has a blunt needle holding portion 52 that holds the blunt needle 50 on the side of arrow A2, and an arm portion 53 extending from the blunt needle holding portion 52 to the side of arrow A1.

[0032] The blunt needle holding portion 52 is disposed in a space on the proximal side of the location where the inner needle 14 is fixed in the inner needle hub 30. When the distal end surface of the blunt needle holding portion 52 comes into contact with an inner needle fixing block (not shown) of the inner needle hub 30 as the blunt needle hub 51 advances, further advancement of the blunt needle hub 51 is prevented.

[0033] The arm portion 53 is configured so that the entire extending portion can be elastically deformed in the width direction, and an engagement end portion 54 is provided at its tip, which engages with the engagement protrusion 45 in the assembled state. When the movement of the blunt needle hub 51 is prevented and the cover body 41 advances further, the engagement end portion 54 appropriately elastically deforms and releases the engagement with the engagement protrusion 45.

[0034] The safety member 40 is not limited to the above configuration as long as it can prevent erroneous sticking of the needle tip 15 of the inner needle 14. For example, the safety member 40 may be configured only with the cover body 41 without including the blunt needle 50 or the blunt needle hub 51.

[0035] 2 and 3, the catheter manipulation member 60 constitutes an operation section 61 that is operated by the user in the catheter assembly 10. The catheter manipulation member 60 according to this embodiment also serves as a first support section 62a of a support structure 62 that supports the outside of the catheter 12 (multiple needles 11) when the multiple needles 11 are inserted. The material constituting the catheter manipulation member 60 is not particularly limited, and may be appropriately selected from the materials listed for the catheter hub 20, for example.

[0036] Specifically, the catheter operating member 60 has an operating plate portion 63 (extension portion) extending in the direction of arrow A, a hub engagement portion 64 connected to the base end of the operating plate portion 63 and engaging with the catheter hub 20, and an operating portion cylinder portion 65 connected to the base end of the hub engagement portion 64 and accommodating the safety member 40. In addition, the catheter operating member 60 has a cover member 66 extending in the base end direction from the hub engagement portion 64 to cover the safety member 40.

[0037] The operation plate portion 63 is a portion where the user's finger is placed to perform the forward / backward operation. The operation plate portion 63 is formed thin, and thus has flexibility that allows it to bend in a direction away from the multiple needle 11. Side edges 63a extending in the direction of arrow A are formed on both sides of the width direction of the operation plate portion 63. A plurality of tabs 67 are provided on the upper surface of the operation plate portion 63. Among the plurality of tabs 67, the most distal tab 67a protrudes further than the other tabs 67. Furthermore, a plurality of ribs 68 protrude short from the lower surface of the operation plate portion 63. The catheter 12 is disposed below the plurality of ribs 68.

[0038] An operation unit support region 110 for supporting the catheter 12 is provided on the tip side of the operation plate 63. The operation unit support region 110 constitutes a portion of the operation plate 63 where bending is restricted. The operation unit support region 110 has an upper support portion 111 that covers the catheter 12 (multiple needles 11) from above on the lower surface of the operation plate 63.

[0039] The upper support part 111 is provided at the center in the width direction of the catheter operating member 60, and extends a predetermined length (over the range of the operating part support region 110) from the tip toward the arrow A2 side. The base end of the upper support part 111 is located on the arrow A2 side of the tab 67a. The upper support part 111 includes a base part 112 that can come into contact with the arrow C1 side of the catheter 12, and a pair of protrusions 113 that can come into contact with the catheter 12 in the arrow B direction.

[0040] The base 112 protrudes from the operation plate 63 at a position offset downward (toward the arrow C2 side) and extends along the extension direction (arrow A direction) of the catheter 12. The tip surface of the base 112 is flush with the edges of the pair of protrusions 113. The base 112 is formed thicker than the operation plate 63, and suppresses bending of the operation unit support region 110 in the up-down direction (arrow C direction).

[0041] 4, the base 112 is formed in a stepped shape having a plurality of different lower surface positions (tip protrusion 112a, base extension 112b) along the direction of arrow A. That is, the tip protrusion 112a is located at a position protruding downward (toward arrow C2) from the base extension 112b. The difference in the protruding amount of the tip protrusion 112a relative to the base extension 112b is slight, and is set to, for example, 1 / 10 or less of the protruding amount from the operation plate 63 to the tip protrusion 112a.

[0042] A lower surface 112a1 of the tip projection 112a and a lower surface 112b1 of the base end extension 112b each extend linearly in the direction of arrow A. The length of the tip projection 112a in the direction of arrow A is shorter than the length of the base end extension 112b in the direction of arrow A. The tip projection 112a is provided in an area that just overlaps with a tip projection piece 113a of each protrusion 113 described below in side view.

[0043] The above-mentioned tip projection 112a is positioned further distal than the grip 18 (the support member 120 described below) when the catheter assembly 10 is in an assembled state. The lower surface 112a1 of the tip projection 112a constitutes a portion that contacts the outer circumferential surface of the catheter 12 and presses the catheter 12. On the other hand, the base end extension portion 112b faces the outer circumferential surface of the catheter 12 without contacting the outer circumferential surface of the catheter 12 (forming a clearance with the catheter 12).

[0044] 3 and 4, the pair of protrusions 113 of the upper support part 111 are configured to sandwich the base 112 therebetween, and protrude in the direction of arrow C2 from the lower surface of the operation plate part 63. The amount of protrusion of each protrusion 113 from the operation plate part 63 is sufficiently greater than the amount of protrusion of the base 112. When the catheter assembly 10 is in an assembled state, each protrusion 113 is designed at a position and interval such that it does not contact the outer peripheral surface of the catheter 12 (or contacts the catheter 12 to the extent that it does not deflect the catheter 12).

[0045] Each protrusion 113 is formed to have a step along the direction of arrow A, similar to the stepped shape of the base 112 (tip protrusion 112a, base extension 112b). The tip side (tip projection 113a) of each protrusion 113 is sufficiently long toward the arrow C2 side from the arrangement position of the catheter 12. The edge of each tip projection 113a curves from the tip connected to the operation plate 63 toward the base end (arrow A2 side) toward the arrow C2 side, and extends linearly toward the arrow C1 side at the protruding apex on the arrow C2 side.

[0046] The lower edge of the base end side (base end projection 113b) of each protrusion 113 extends linearly in the direction of arrow A2 from the point where it connects to the edge of the tip projection 113a. Each base end projection 113b protrudes from the base 112 by a length approximately equal to the outer diameter of the catheter 12. Several ribs 68a on the tip side of the multiple ribs 68 provided on the underside of the operation plate 63 are connected to each base end projection 113b. These ribs 68a are connected to side ribs 114 that extend short in the direction of arrow A on the outer side in the width direction. The side ribs 114 protrude further toward the direction of arrow C2 than the ribs 68a and have the function of guiding the advancement and retreat of the catheter operation member 60 relative to the grip 18.

[0047] In the assembled state, the upper support part 111 described above places the catheter 12 in a support space 111a formed by the base part 112 and the pair of protrusions 113. That is, the catheter 12 is covered from above by the base part 112, and is covered in the left-right width direction by the pair of protrusions 113.

[0048] The operation unit support region 110 also has a pair of lower protruding blocks 115 that protrude in the direction of arrow C2 on the lower surface side of the operation plate 63 and on the outer side in the width direction of the upper support unit 111. Each of the lower protruding blocks 115 is provided with a predetermined gap 117 from the upper support unit 111.

[0049] The pair of downward protruding blocks 115 also protrude toward the arrow C2 side by the same amount as the tip protrusions 113a of the pair of protrusions 113. The width (thickness) of each downward protruding block 115 is greater than the width (thickness) of the protrusions 113. The tip surface 115a of each downward protruding block 115 is curved toward the arrow A2 side as it approaches the arrow C2 side.

[0050] That is, the tip protrusions 113a and the lower protrusion blocks 115 are positioned to overlap each other in a side view, and are formed to have approximately the same shape. As a result, the tip side and lower side (the arrow A1 side and the arrow C2 side) of the catheter manipulation member 60 are guided so that the catheter manipulation member 60 moves away from the catheter 12 when the catheter manipulation member 60 is advanced to a certain extent from the grip 18 and comes into contact with the body surface of the treatment target.

[0051] Furthermore, the operation unit support region 110 has a pair of upper protruding blocks 118 that protrude slightly toward the arrow C1 side at the same widthwise position as the lower protruding blocks 115 on the upper surface side of the operation plate portion 63. The width of each upper protruding block 118 matches the width of each lower protruding block 115. A tip surface 118a of each upper protruding block 118 is continuous with the upper end of the tip surface 115a of the lower protruding block 115 and is flush with each other.

[0052] Furthermore, a pair of reinforcing pieces 119 (reinforcing parts) are provided on the widthwise inner sides of the pair of upper protruding blocks 118. Each reinforcing piece 119 is provided at the same widthwise position as each protruding part 113, and protrudes on the opposite side (arrow C1 side) of each protruding part 113. Each reinforcing piece 119 protrudes at its tip from the upper surface of the operation plate part 63 to the same extent as the upper protruding block 118, and is formed so as to gradually lower while curving from this tip toward the arrow A2 side, and contacts the tab 67a. Since the operation plate part 63 is not present between each reinforcing piece 119, a groove part 119a is formed in which the upper surface of the base part 112 of the upper support part 111 is exposed.

[0053] Meanwhile, the hub engagement portion 64 connected to the base end of the operation plate portion 63 has a storage chamber 64a that stores the main hub 21, but is configured with a wall portion 64b on the arrow B1 side and a cutout shape on the arrow B2 side (a shape in which the storage chamber 64a is opened). This shape is for exposing the sub-hub 22 and tube 23 of the catheter hub 20 configured as a multi-lumen type. At the tip side of the hub engagement portion 64, the wall portion 64b on the arrow B1 side extends so as to go around the storage chamber 64a. This wall portion 64b on the tip side is provided with a gap 64b1 that is narrower than the diameter of the catheter hub 20 and allows only the catheter 12 (multiple needles 11) to extend therethrough.

[0054] The operation part tubular portion 65 is formed in a cylindrical shape that protrudes slightly from the base end of the hub engagement portion 64 toward the base end. A communication space 65a through which the safety member 40 (cover body 41) is inserted and disposed is provided inside the operation part tubular portion 65. A slit 65b that communicates with the accommodation chamber 64a and the communication space 65a is formed in the lower portion of the operation part tubular portion 65. An arc-shaped rib 65c that protrudes in the circumferential direction and restricts the movement of the cover member 66 is provided on the outer circumferential surface of the operation part tubular portion 65.

[0055] Returning to Fig. 2, the covering member 66 is attached to the catheter operating member 60 and is provided to prevent the user from directly contacting the safety member 40. The covering member 66 has a main body portion 66a that covers the upper side of the safety member 40 (the side where the user's hands are positioned when gripping it), and a pair of mounting legs 66b that are provided at the tip of the main body portion 66a and attached to the operating part tube portion 65. The pair of mounting legs 66b engage between the base end surface of the hub engaging portion 64 and the arc-shaped rib 65c.

[0056] The grip 18 of the catheter assembly 10 is formed to an appropriate thickness so that it is easy for the user to hold, and extends in the direction of arrow A. A storage space 18a is formed within the grip 18, into which the catheter 12, the catheter hub 20, the safety member 40, and the catheter operating member 60 can advance and retreat. The storage space 18a is in communication with a tip open portion 18b of the grip 18. The grip 18 is constructed by assembling an upper grip 70, which can be separated in the direction of arrow C, and a lower grip 90.

[0057] The upper grip 70 has a ceiling wall 71, a pair of upper side walls 72, and an upper rear wall 73, and is formed in a downwardly open concave (bowl-like) shape. The pair of upper side walls 72, together with a lower side wall 92 of the lower grip 90, constitute side walls 77 on both sides in the width direction of the grip 18.

[0058] The ceiling wall 71 also has an operation unit exposing notch 75 in the center in the direction of arrow B, closer to the tip side than the intermediate portion in the direction of arrow A. The operation unit exposing notch 75 is open at the tip and communicates with the accommodation space 18a, exposing the tube 23 of the catheter hub 20 and the tab 67 of the catheter operating member 60 so that they can be advanced and retreated. Furthermore, the upper grip 70 has a pair of upper protrusions 78 at its tip, and fixing hooks 80 that constitute a fixing mechanism 79 for the upper grip 70 and the lower grip 90 are provided on the underside of each upper protrusion 78 and on the upper rear wall 73, respectively.

[0059] The lower grip 90 has a bottom wall 91, a pair of lower side walls 92, and a lower rear wall 93, and is formed in an upwardly open concave (bowl-like) shape. A predetermined range on the arrow A2 side of the bottom wall 91 serves as a mounting portion onto which the inner needle hub 30 is mounted, and is provided with a plurality of mounting holes 94 (part of the attachment mechanism 33) (three in this embodiment) into which the fixing protrusions 34 of the inner needle hub 30 can be fitted.

[0060] Further, the pair of lower side walls 92 have rail walls 96, 98 at their upper parts, and in the assembled state, the upper side wall 72 of the upper grip 70 is disposed on the widthwise outer side of these rail walls 96, 98. In the assembled state, the pair of side edges 63a of the catheter operating member 60 and the protruding piece 44 of the safety member 40 are slidably disposed on the pair of rail walls 96, 98. In addition, the locked protrusion 48 of the cover body 41 is disposed between the upper side wall 72 on the arrow B1 side and the rail wall 98.

[0061] The lower side wall 92 on the side of arrow B1 is provided with a locking portion 100 that, when the cover body 41 of the safety member 40 advances, engages with the locked protrusion 48 to determine the advancement limit of the cover body 41 and restrict the retraction of the cover body 41. That is, the locking portion 100, together with the locked protrusion 48, constitutes a safety movement restriction mechanism 49. By restricting the release of the safety member 40 from the grip 18, the catheter assembly 10 can reliably cover (protect) the inner needle 14 with the cover body 41 after puncture.

[0062] A pair of protrusions 101 are provided at the tip of the lower grip 90, protruding outward in the width direction from a pair of lower side walls 92. The protrusion 101 on the arrow B1 side has a first fixing hole 103a that is part of the fixing mechanism 79. The protrusion 101 on the arrow B2 side has a second fixing hole 105a that is part of the fixing mechanism 79. In addition, the protrusion 101 on the arrow B2 side has a movement space 107 in which the support member 120 can rotate.

[0063] 2, 4 and 5, the support member 120 is rotatably attached to the grip 18, and in the assembled state constitutes the second support portion 62b of the support structure 62 that supports the catheter 12 (multiple needles 11) extending below the catheter manipulation member 60. The support member 120 also rotates in response to contact with the wall portion 64b of the hub engagement portion 64 when the catheter manipulation member 60 advances, enabling the catheter manipulation member 60 (and the catheter hub 20 and safety member 40) to be delivered from the accommodation space 18a.

[0064] The support member 120 has a shaft portion 122 extending in the direction of arrow C, and a lower support portion 124 protruding in a direction perpendicular to the axis of the shaft portion 122. The upper portion of the shaft portion 122 is provided with a guide plane 122a continuing to the upper end of the rail wall 96, and a pair of small projections 123 flush with the guide plane 122a. In the assembled state, the side edge 63a of the catheter manipulation member 60 comes close to the guide plane 122a. As a result, the rotation of the support member 120 is restricted with the side edge 63a in place.

[0065] The lower support part 124 has an appropriate thickness in the direction of arrow C, and is connected to the shaft part 122 below the middle position in the direction of arrow C (the side of arrow C2). The lower support part 124 is formed, for example, to be thicker than the thickness of the bottom wall 91 of the lower grip 90. The lower support part 124 is configured by connecting part 125 connected to the shaft part 122, central part 126 located in the center in the width direction, and protruding end part 127 located at the position furthest from the shaft part 122, all of which are connected to each other from the side of arrow B2 to the side of arrow B1.

[0066] In order to improve the molding accuracy of the lower support part 124, the connecting part 125 and the central part 126 are provided with a lightening hole 128 penetrating in the direction of the arrow A. The central part 126 protrudes somewhat upward (toward the arrow C1 side) further than the connecting part 125 and the protruding end part 127, and has the greatest thickness among the lower support part 124. The lower support part 124 basically supports the lower side of the catheter 12 at this central part 126. The upper surface of the protruding end part 127 gradually slopes downward from the central part 126 toward the arrow B1 side.

[0067] The support member 120 is inserted from above the lower grip 90 along the bearing notch 105b with the lower support portion 124 facing the arrow B1 side. At this time, the vicinity of the connecting portion of the lower support portion 124 passes through the open portion of the bearing notch 105b on the housing space 18a side, so that the support member 120 is smoothly inserted into the bearing notch 105b. Then, when the upper grip 70 and the lower grip 90 are attached, the upper end of the shaft portion 122 supported by the lower grip 90 is pivotally supported by the upper grip 70.

[0068] In the assembled state, the support member 120 waits to support the catheter 12 with the side edge 63a of the catheter manipulation member 60 on the guide plane 122a, restricting rotation of the lower support portion 124. As a result, the lower support portion 124 supports the catheter 12 and suppresses bending of the catheter 12. When the catheter manipulation member 60 advances from the grip 18, the side edge 63a of the support member 120 comes out of the guide plane 122a, making it rotatable, thereby allowing the catheter hub 20, the catheter manipulation member 60, and the safety member 40 to be delivered.

[0069] When assembling the above catheter assembly 10, the inner / outer needle assembly 16 (catheter 12, inner needle 14, catheter hub 20, inner needle hub 30, safety member 40, catheter operating member 60) is assembled first. Thereafter, the inner / outer needle assembly 16 is placed in the lower grip 90 incorporating the support member 120, and further the upper grip 70 is attached to the inner / outer needle assembly 16 and the lower grip 90.

[0070] 5, in the assembled state of the catheter assembly 10, the catheter operating member 60 has a side edge 63a disposed in a guide space 99 of the grip 18 (between the upper grip 70 and the lower grip 90). This prevents the catheter operating member 60 from moving or bending in the direction of arrow C (up and down) within the grip 18. The support space 111a of the support structure 62 is surrounded by the base 112, the pair of protrusions 113, and the lower support part 124, forming a rectangular shape (approximately square shape) in a front cross-sectional view.

[0071] 4 and 6A, the support structure 62 presses (contacts) a position shifted in the extension direction of the catheter 12 in a side cross-sectional view (when viewed from a direction perpendicular to the extension direction of the catheter 12), causing the catheter 12 (multiple needles 11) to bend. Note that Fig. 6A (and the following Figs. 6B to 8, 10A and 10B) are side cross-sectional views that roughly show the catheter 12 and the support structures 62, 62A to 62D.

[0072] The support structure 62 sandwiches the outside of the catheter 12 in the direction of arrow C, with the base 112 of the upper support part 111 pressing against a first position 13a on the upper side of the catheter 12, and the central part 126 of the lower support part 124 pressing against a second position 13b on the lower side of the catheter 12. The base 112 (first position 13a) presses against the catheter 12 on the arrow A1 side relative to the central part 126 (second position 13b) of the lower support part 124. That is, the stepped base 112 has a tip projection 112a in contact with the catheter 12, while a base end extension 112b is not in contact with the catheter 12.

[0073] Here, as shown in Fig. 6B, in the conventional catheter assembly 10', the inner needle 14 extending inside the catheter 12 (multiple needles 11) causes the catheter 12 to extend linearly in the direction of arrow A. A support structure 62' (e.g., a support point 19 formed at the tip of a grip 18) is disposed in the vicinity of the outer circumferential surface of the catheter 12 with a slight clearance 19a therebetween. In other words, the support structure 62' is configured to be able to clamp the same position in the extension direction of the catheter 12.

[0074] In contrast, in the support structure 62 of the present invention, the lower surface 112a1 of the tip protrusion 112a is positioned on the arrow C2 side of the top position of the linearly extending outer circumferential surface of the catheter 12. Meanwhile, the upper surface 126a of the central portion 126 of the support member 120 is at the same height as the bottom position of the outer circumferential surface of the catheter 12. That is, the length L1 of the support space 111a of the support structure 62 in the direction of the arrow C is smaller than the outer diameter of the catheter 12 when viewed from the front (see FIG. 5).

[0075] In the assembled state, the support structure 62 configured as described above suppresses bending of the catheter 12 in the direction of the arrow C2 by the lower support part 124 in the grip 18, while deliberately bending the catheter 12 in the direction of the arrow C2 by the distal protrusion 112a on the distal side of the grip 18. Therefore, the support structure 62 makes it difficult for the catheter 12 to bend in the direction of the arrow C1. Note that the support structure 62 only bends the catheter 12 slightly in the direction of the arrow C2, and the radius of curvature of the curved portion of the catheter 12 is sufficiently larger than the length of the catheter 12 in the extending direction (for example, set to three times or more the length of the catheter 12 in the extending direction). Therefore, the user recognizes that the catheter 12 exposed on the distal side of the support structure 62 extends parallel to the extending direction of the grip 18, and can perform a puncture operation or the like without any discomfort.

[0076] Furthermore, in the support structure 62, the first position 13a pressed by the tip projection 112a and the second position 13b pressed by the lower support part 124 are offset in the axial direction of the catheter 12. Therefore, the support structure 62 can reduce the sliding resistance applied from the lower support member 120 to the catheter 12 when the catheter manipulation member 60 is advanced, thereby facilitating the movement of the catheter 12.

[0077] The support structure 62 of the catheter assembly 10 is not limited to the above and may have various configurations. Some modified examples of the support structure 62 will be described below.

[0078] 7A is configured such that, in an assembled state, the upper support portion 111 (tip projection 112a) of the catheter operating member 60 presses the outer circumferential surface on the arrow C1 side of the catheter 12, while the lower support portion 124 does not contact the catheter 12. In other words, the catheter 12 is internally supported by the inner needle 14, the base end side of which is fixed by the inner needle hub 30, and is supported by the upper support portion 111 so as to bend toward the arrow C2 side.

[0079] In this way, even in a configuration in which the catheter 12 is deflected by support from the inner needle 14 and pressure from the catheter operating member 60, the support structure 62A firmly supports the catheter 12 and allows the catheter 12 to slide stably. The lower support part 124, which does not contact the catheter 12, supports the lower side of the catheter 12 when, for example, the multiple needle 11 is deflected toward the arrow C2 side during puncture. The support structure 62A may be configured without including the lower support member 120 (lower support part 124).

[0080] 7B is configured such that, in an assembled state, the lower support part 124 of the support member 120 presses the outer peripheral surface on the arrow C2 side of the catheter 12, while the upper support part 111 does not contact the catheter 12. In other words, the catheter 12 is internally supported by the inner needle 14, the base end side of which is fixed by the inner needle hub 30, and the tip side is supported by the lower support part 124 so as to bend toward the arrow C1 side.

[0081] In this way, even in a configuration in which the catheter 12 is deflected by support from the inner needle 14 and pressure from the support member 120, the support structure 62B firmly supports the catheter 12 and allows the catheter 12 to slide stably. The upper support part 111, which does not contact the catheter 12, supports the upper side of the catheter 12 when, for example, the multiple needle 11 is deflected toward the side of arrow C1 during puncture.

[0082] A support structure 62C according to a third modified example shown in Fig. 7C does not include a lower support member 120, and a tip portion (projection 108) of the lower grip 90 serves as a lower support portion 124 that directly contacts and presses the catheter 12. As a result, like the support structure 62B described above, the catheter 12 is internally supported by the inner needle 14 whose base end side is fixed by the inner needle hub 30, and the tip side is supported by the projection 108 so as to bend in the direction of arrow C1.

[0083] The support structure 62C also has an upper support portion 111 (protrusion 82 of the upper grip 70) that faces the outer circumferential surface of the catheter 12 without contacting it, at a position facing the protrusion 108 of the lower grip 90. In this manner, the support structure 62C that supports the catheter 12 can also be formed by the grip 18. In this case, the catheter 12 and the catheter hub 20 can be moved by a catheter operating member (not shown) that protrudes from the inside to the outside of the grip 18.

[0084] A support structure 62D according to a fourth modified example shown in Fig. 8 extends the catheter 12 parallel to the extending direction of the grip 18 (arrow A direction) on the tip side (arrow A1 side) of the upper support part 111 of the catheter manipulation member 60. The support structure 62D bends the catheter 12 in the grip 18 to assume a curved position. That is, the inner needle hub 30 fixes the inner needle 14 so that it is tilted slightly obliquely upward, and the base end side of the catheter 12 through which the inner needle 14 is inserted also extends at an oblique upward angle. This catheter 12 is corrected to a state in which it is elastically deformed (bent) along the arrow A direction by being pressed by the upper support part 111 and the lower support part 124 (support member 120).

[0085] The support structure 62D configured as above can also facilitate movement of the catheter 12 while firmly supporting the catheter 12 through the support of the upper support portion 111 and the lower support portion 124. Furthermore, the support structure 62D has an exposed portion of the catheter 12 extending parallel to the extension direction of the grip 18, thereby further improving operability by the user during puncture.

[0086] The catheter assembly 10 according to this embodiment is basically constructed as described above, and its operation will be described below.

[0087] As described above, the catheter assembly 10 is used when infusing fluid, transfusing blood, or drawing blood from a treatment target (living body). As shown in Fig. 9A, when using the catheter assembly 10, a user grasps the grip 18 to insert the multiple needles 11 into the treatment target P.

[0088] During puncture, the upper support part 111 of the catheter manipulation member 60 and the lower support part 124 of the support member 120 press against positions (first position 13a, second position 13b) that are offset in the extending direction of the catheter 12 (multiple needle 11) in a side view perpendicular to the extending direction of the catheter 12. The first position 13a and the second position 13b are opposite positions to each other across the axis of the catheter 12, and the pressing direction of the catheter 12 connecting the first position 13a and the second position 13b is along the direction of arrow C (the direction in which the blade surface 15a of the inner needle 14 faces). Therefore, as shown in FIG. 10A, the support structure part 62 firmly supports the catheter 12 up to the tip of the catheter manipulation member 60, while extending the catheter 12 exposed from the tip of the catheter manipulation member 60 in a state in which it is bent in advance in the direction of arrow C2.

[0089] This allows the user to stably insert the multiple needle 11 (catheter 12), which is firmly supported by the support structure 62, into the body of the treatment subject P. Furthermore, since the pair of tip projections 113a of the catheter manipulation member 60 protrude farther toward the arrow C2 side than the upper surface of the lower support part 124, each tip projection 113a prevents the catheter 12 from moving in the width direction (arrow B direction) during puncture.

[0090] Furthermore, even if the catheter 12 is significantly curved when the multiple needle 11 is inserted as shown in Fig. 10B, the support structure 62 brings the outer circumferential surface of the catheter 12 into contact with the base end extension 112b. That is, when the catheter 12 is about to bend more than in the assembled state, the support structure 62 comes into contact with multiple different points on the axial direction of the catheter 12. Therefore, the support structure 62 can more effectively suppress the bending (curving) of the catheter 12 during insertion.

[0091] As shown in Fig. 9B, when the multiple needle 11 is inserted into the treatment target P and the needle tip 15 reaches the inside of the blood vessel, the user advances the catheter manipulation member 60, and advances the catheter 12 beyond the inner needle 14 and inserts it into the blood vessel. At this time, the catheter manipulation member 60 advances relative to the lower support member 120. The support structure 62 presses against a position offset in the axial direction of the catheter 12, thereby reducing the sliding resistance applied from the lower support part 124. This allows the user to move the catheter 12 smoothly.

[0092] The support member 120 becomes rotatable when the base end of the side edge 63a of the catheter manipulation member 60 (manipulation plate portion 63) comes out of the grip 18. The support member 120 comes into contact with the hub engagement portion 64 (wall portion 64b) of the catheter manipulation member 60 in the process of advancing and is pushed out, thereby rotating relatively to the grip 18. As a result, the members (catheter hub 20, safety member 40) on the base end side from the hub engagement portion 64 come out of the tip open portion 18b.

[0093] Then, by the user's advancing operation, the catheter 12 and catheter hub 20 come out of the tip of the grip 18, and then the safety member 40 protrudes from the tip of the grip 18. When the catheter operating member 60 is advanced further, the locked protrusion 48 of the safety member 40 moves to the locking portion 100 (advanced position) of the grip 18. At this time, the tip of the safety member 40 is exposed from the grip 18 and advances beyond the tip of the inner needle 14 to cover the inner needle 14, thereby activating the puncture prevention function.

[0094] At the advanced position, the safety member 40 does not come out of the grip 18 and is in an engaged state where movement in the distal and proximal directions is stopped. As a result, when the catheter 12, the catheter hub 20, and the catheter operating member 60 are advanced further, the safety member 40 is detached from these members. In the catheter assembly 10, the catheter operating member 60 and the safety member 40 are separated from each other, so that the engagement between the catheter operating member 60 and the catheter hub 20 can be released. As a result, the catheter 12 and the catheter hub 20 are detached from below the catheter operating member 60.

[0095] The catheter 12 and the catheter hub 20 are detached from the catheter operating member 60 and placed in the treatment subject P. After placement, a connector (not shown) of another medical device is connected to the catheter hub 20. Meanwhile, the inner needle 14, the inner needle hub 30, the safety member 40, and the grip 18 are appropriately discarded by the user while remaining integrated.

[0096] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. For example, the support structures 62, 62D may be configured so that the first position 13a and the second position 13b for pressing the catheter 12 are not necessarily opposite positions (positions with a phase difference of 180°) in the circumferential direction of the catheter 12, but are instead configured to press appropriate positions in the circumferential direction.

[0097] Second Embodiment Next, a catheter assembly 10A according to a second embodiment will be described with reference to Figures 11 and 12. In the following description, elements having the same configurations or functions as those in the above embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0098] The catheter assembly 10A differs from the above-mentioned catheter assembly 10, which bends the catheter 12 in the up-down direction (arrow C direction), in that it has a support structure 200 that supports the catheter 12 (multiple needles 11) by bending it in the width direction (arrow B direction). That is, the support structure 200 is composed of a catheter operating member 201 and a lower support member 210, and the upper support member 202 presses the arrow B1 side of the catheter 12, while the lower support member 211 presses the arrow B2 side of the catheter 12.

[0099] In detail, the upper support portion 202 has a base portion 203 located on the arrow C1 side of the catheter 12, a first protrusion portion 204 located on the arrow B1 side of the catheter 12, and a second protrusion portion 206 located on the arrow B2 side of the catheter 12. When the catheter assembly 10 is in an assembled state, the base portion 203 is not in contact with the outer circumferential surface of the catheter 12 (or is in contact to the extent that it does not deflect the catheter 12).

[0100] On the other hand, the first protrusion 204 is formed to be thicker than the second protrusion 206, and serves as a first support 205 that presses against the outer circumferential surface of the catheter 12. The first protrusion 204 has a widthwise thickness on the tip end side that is thicker than the widthwise thickness on the base end side, and in a planar cross-sectional view, the inside (arrow B2 side) facing the second protrusion 206 presents a stepped shape. That is, on the arrow B2 side of the first protrusion 204, a tip protrusion 204a that contacts the outer circumferential surface of the catheter 12 in an assembled state and a base end extension 204b that does not contact the outer circumferential surface of the catheter 12 are provided.

[0101] The tip projection 204a is provided in a range overlapping with the downward protruding block 115 in side view, and is formed in approximately the same shape as the downward protruding block 115. A side surface 204a1 on the arrow B2 side of the tip projection 204a is located slightly toward the arrow B2 side of the outer circumferential surface of the catheter 12 on the arrow B1 side supported by the inner needle 14 in the assembled state. On the other hand, the base end extension 204b extends parallel to the extension direction of the catheter 12 (arrow A direction) over a longer range than the tip projection 204a. The base end extension 204b has a side surface 204b1 that extends in a non-contact manner near the outer circumferential surface of the catheter 12.

[0102] The second protrusion 206 is also provided in a range overlapping with the lower protrusion block 115, and is formed in substantially the same shape as the lower protrusion block 115. However, the second protrusion 206 does not have a portion facing the base end extension 204b of the first protrusion 204. In addition, of the pair of reinforcing pieces 119, the reinforcing piece 119 on the arrow B1 side is formed to have the same thickness at the same widthwise position of the first protrusion 204.

[0103] The lower support member 210 has a lower support part 211 disposed on the side of the catheter 12 indicated by the arrow C2, but the catheter 12 is not pressed by this lower support part 211, but by a protrusion 212 (second support part 213) connected to the lower support part 211. The protrusion 212 protrudes slightly toward the side of the arrow C1 at the boundary between the connecting part 125 and the central part 126 of the lower support part 211.

[0104] In the assembled state of the catheter assembly 10A, the protruding end of the projection 212 is located in the vicinity of the lower surface of the base 203 of the catheter operating member 201. In the assembled state, the side surface 212a on the arrow B1 side of the projection 212 is located on the arrow B1 side of the side surface of the second protrusion 206 on the arrow B1 side.

[0105] 12 and 13A, the support structure 200 described above presses (contacts) a position shifted in the extension direction of the catheter 12 in a planar cross-sectional view (when viewed from a direction perpendicular to the extension direction of the catheter 12), causing the catheter 12 (multiple needles 11) to bend. Note that Fig. 13A (and the following Figs. 13B to 14B) are planar cross-sectional views that generally show the catheter 12 and the support structures 200, 200A, and 200B.

[0106] That is, the support structure 200 pinches the outside of the catheter 12 in the direction of arrow B, with the tip projection 204a pressing against the first position 13a on the arrow B1 side of the catheter 12 and the projection 212 pressing against the second position 13b on the arrow B2 side of the catheter 12. The tip projection 204a (first position 13a) presses against the catheter 12 on the arrow A1 side more than the projection 212 (second position 13b). In other words, the width (width in the direction of arrow B) of the support space 200a of the support structure 200 is determined by the tip projection 204a and the projection 212 in a front view, and the length L2 is set to be smaller than the outer diameter of the catheter 12.

[0107] Therefore, the support structure 200 according to the second embodiment can also firmly support the catheter 12 (multiple needles 11) while facilitating movement of the catheter 12. Furthermore, as shown in Fig. 13B, even if the catheter 12 is significantly curved when the multiple needles 11 are inserted, the support structure 200 can restrict further bending of the catheter 12 by bringing the outer circumferential surface of the catheter 12 into contact with the base end extension part 204b.

[0108] Various modified examples can also be adopted for the support structure 200. For example, since the catheter 12 is supported on the inside by the inner needle 14, the support structure 200 does not need to have one of the configurations for pressing the catheter 12 at two points (the tip protrusion 204a and the protrusion 212).

[0109] 13C, the support structure 200A according to the fifth modified example is configured such that the width (wall thickness) of the second protrusion 206 is increased in the direction of arrow B. As a result, when the catheter 12 bends significantly during puncture, the support structure 200A can suppress the bending of the catheter 12 by the first protrusion 204 (tip protrusion 204a) and the second protrusion 206.

[0110] 14A and 14B, the support structure 200B according to the sixth modified example has the base end (forming range) of the protrusion 212 on the lower support part 211 located on the tip side (arrow A1 side) of the axis of the shaft part 122 of the support member 210. This prevents the protrusion 212 from interfering with the catheter 12 when the support member 210 rotates. In other words, the support structure 200B allows the support member 210 to rotate smoothly by contact with the wall part 64b of the hub engagement part 64 when the catheter 12 advances, thereby allowing the catheter 12 and the catheter hub 20 to be smoothly delivered from the grip 18.

[0111] Third Embodiment Next, a catheter assembly 10B according to a third embodiment will be described with reference to Fig. 15 to Fig. 16B. This catheter assembly 10B differs from the catheter assemblies 10 and 10A described above in that the catheter 12 is supported at the tip portion of the grip 300 by a support structure 301A provided on the grip 300 itself.

[0112] In detail, the tip of the grip 300 includes a first section 302 (first support section 303) and a second section 304 (second support section 305) that are separable in the width direction (arrow B direction). As shown in FIG. 15, the first section 302 has a first lateral protrusion 302a (tip protrusion) that protrudes in the direction of arrow B2 at the tip. A first support groove 302a1 that supports the catheter 12 is provided on the side surface of the first lateral protrusion 302a on the arrow B2 side. On the other hand, the second section 304 has a second lateral protrusion 304a that protrudes in the direction of arrow B1 at the tip. A second support groove 304a1 that supports the catheter 12 is provided on the side surface of the second lateral protrusion 304a on the arrow B1 side.

[0113] The support structure 301A also has a clamping portion 306 that holds the first and second portions 302, 304 together outside the first and second portions 302, 304. The clamping portion 306 is formed in a concave shape that opens downward, and has a space 306a on the inside that accommodates the first and second portions 302, 304. The clamping portion 306 constitutes, for example, a part of the grip 300 (a part that covers the upper surface of the grip 300), and moves upward or toward the tip based on the advancement operation of the catheter 12 and the catheter hub 20 to release the clamping of the first and second portions 302, 304.

[0114] Alternatively, the clamping portion 306 may be formed of a member different from the grip 18. For example, the clamping portion 306 may be formed of the catheter operating member 60, or may be formed of an operating member for allowing the user to operate the blunt needle 50 or a guide wire (not shown).

[0115] 15 and 16A, the support structure 301A supports the catheter 12 (multiple needles 11) by bending it in the direction of arrow B through the assembly of the first portion 302, the second portion 304, and the clamping portion 306. Specifically, the first portion 302 has a first lateral projection 302a projecting in the direction of arrow B2 at the tip side, and a base end extension portion 302b extending (without contact) near the outer circumferential surface of the catheter 12 on the base end side of the first lateral projection 302a. The first lateral projection 302a presses the outer circumferential surface of the catheter 12 on the arrow B1 side (first position 13a), while the second lateral projection 304a of the second portion 304 presses the outer circumferential surface of the catheter 12 on the arrow B2 side (second position 13b).

[0116] Furthermore, the first lateral protrusion 302a protrudes further toward the tip side (arrow A1 side) than the second lateral protrusion 304a, and the first position 13a and the second position 13b are offset from each other in the extension direction of the catheter 12. As a result, the first support groove 302a1 and the second support groove 304a1 form a support space (not shown) having a length L2 smaller than the outer diameter of the catheter 12 in a front view.

[0117] Therefore, the catheter assembly 10B can, by the support structure 301A, firmly support the catheter 12 at the tip side of the grip 18 during puncture, while reducing the sliding resistance during movement of the catheter 12. Furthermore, if the catheter 12 bends significantly during puncture as shown in Fig. 16B, the bending of the catheter 12 can be suppressed at the side surface of the base end extension portion 302b located on the base end side relative to the first lateral protrusion 302a.

[0118] On the other hand, the support structure 301B according to the seventh modification shown in Fig. 17A and Fig. 17B is configured to have a distal extension 304b extending further toward the distal end (arrow A1 side) than the second lateral protrusion 304a in the second portion 304. The distal extension 304b extends to the same position as the distal end of the first portion 302 and faces the first lateral protrusion 302a of the first portion 302. The distal extension 304b is located on the arrow B2 side of the second lateral protrusion 304a (as it does not protrude toward the arrow B1 side), and a relatively large clearance is formed between the distal extension 304b and the first lateral protrusion 302a. That is, in the assembled state, the distal extension 304b is not in contact with the catheter 12.

[0119] In this manner, since the support structure 301B has the tip extension 304b, when the catheter 12 is significantly bent during puncture, the catheter 12 comes into contact with the side surface of the tip extension 304b (the tip side of the second portion 304). This allows the support structure 301B to more effectively suppress bending of the catheter 12.

[0120] The technical ideas and effects that can be understood from the above-described embodiments will be described below.

[0121] A catheter assembly 10, 10A, 10B according to one embodiment of the present invention comprises a catheter 12, a catheter hub 20 fixed to the catheter 12, an inner needle 14 inserted into the catheter 12, a grip 18, 300 for fixing and holding the inner needle 14, and support structures 62, 62A-62D, 200, 200A, 200B, 301A, 301B which contact the outer surface of the catheter 12 to support the outside of the catheter 12 in the assembled state, and when viewed from a direction perpendicular to the extension direction of the catheter 12 in the assembled state, the support structures 62, 62A-62D, 200, 200A, 200B, 301A, 301B press the catheter 12 without clamping the same position in the extension direction of the catheter 12, thereby bending the catheter 12 along the extension direction.

[0122] According to the above, in the assembled state, the catheter assemblies 10, 10A, 10B support the catheter 12 so that it bends along the extension direction by pressing the catheter 12 with the support structures 62, 62A-62D, 200, 200A, 200B, 301A, 301B. This allows the catheter assemblies 10, 10A, 10B to suppress bending of the catheter 12 during puncture. In addition, the support structures 62, 62A-62D, 200, 200A, 200B, 301A, 301B support the catheter 12 without clamping it, thereby reducing the sliding resistance of the catheter 12 and allowing the catheter 12 to be easily moved when moved by the user. In other words, the catheter assemblies 10, 10A, 10B can significantly improve the operability of the user.

[0123] Further, in the assembled state, the support structures 62, 62D, 200, 200A, 200B, 301A, and 301B are configured to support the catheter 12 by contacting a first position 13a and a second position 13b on the outer circumferential surface of the catheter 12, the first position 13a and the second position 13b being on opposite sides of the axis of the catheter 12 and being offset in the axial direction of the catheter 12. In this manner, the support structures 62, 62D, 200, 200A, 200B, 301A, and 301B support the catheter 12 at offset positions in the extension direction, thereby making it possible to both suppress bending of the catheter 12 during puncture and facilitate the movement of the catheter 12.

[0124] Furthermore, in the support structure 62, 200, 200A, 200B, the first support portion 62a, 205 that contacts the first position 13a and the second support portion 62b, 213 that contacts the second position 13b are configured as separate members. This allows the support structure 62, 200, 200A, 200B to support the catheter 12 with the first support portion 62a, 205 and the second support portion 62b, 213, while easily releasing the support of the catheter 12 by the relative movement of the first support portion 62a, 205 and the second support portion 62b, 213.

[0125] Additionally, the first support parts 62a, 205 are an operation part 61 for operating the relative movement of the catheter 12 with respect to the grip 18, and the second support parts 62b, 213 are the grip 18 or a support member (support member 120, 210) rotatably attached to the grip 18. This allows the user to move the operation part 61 relatively to the grip 18, thereby releasing the support of the catheter 12 and allowing the catheter 12 to move smoothly.

[0126] Furthermore, the first position 13a where the first support portion 62a, 205 contacts the catheter 12 is located further distal than the second position 13b where the second support portion 62b, 213 contacts the catheter 12. This enables the support structure portions 62, 200, 200A, 200B to stably move the first support portion 62a, 205 without interfering with the second support portion 62b, 213 when the catheter 12 moves.

[0127] Furthermore, in a front view of the catheter assembly 10, the pressing direction of the catheter 12 connecting the first position 13a and the second position 13b is along the facing direction of the blade surface 15a of the inner needle 14. As a result, the support structures 62, 62D can effectively suppress bending of the catheter 12 along the facing direction of the blade surface 15a of the inner needle 14 during puncture.

[0128] Furthermore, in a front view of the catheter assembly 10, the pressing direction of the catheter 12 connecting the first position 13a and the second position 13b is perpendicular to the facing direction of the blade surface 15a of the inner needle 14. As a result, the support structures 200, 200A, 200B, 301A, 301B can effectively suppress bending of the catheter 12 in a direction perpendicular to the facing direction of the blade surface 15a of the inner needle 14 during puncture.

[0129] Additionally, the catheter 12 is supported on the inside by the inner needle 14 that extends linearly within the grip 18, and the support structures 62A-62C, in the assembled state, press the outer circumferential surface of the catheter 12 from one direction, thereby bending the catheter 12 along the extension direction. In this way, by pressing from one direction the outer circumferential surface of the catheter 12, the inner side of which is supported by the inner needle 14, the support structures 62A-62C can simultaneously suppress bending of the catheter 12 during puncture and facilitate movement of the catheter 12.

[0130] In addition, the support structures 62, 62D, 200, 200A, 200B, 301A, 301B are formed in a stepped shape having distal projections 112a, 204a (and first lateral projection 302a) that press the outer circumferential surface of the catheter 12 in the assembled state, and proximal extensions 112b, 204b, 302b that extend in a non-contact manner near the outer circumferential surface of the catheter 12 on the proximal side of the distal projections 112a, 204a (and first lateral projection 302a). As a result, even if the catheter 12 bends significantly during puncture, the support structures 62, 62D, 200, 200A, 200B, 301A, 301B can suppress bending of the catheter 12 by the proximal extensions 112b, 204b, 302b.

[0131] Furthermore, the support structures 301A and 301B have a clamping portion 306 that supports the outside of the catheter 12 and holds in a clamped state a plurality of separable portions. In this manner, by having the clamping portion 306, the support structures 301A and 301B can more stably maintain the support state of the catheter 12.

Claims

1. A catheter; a catheter hub secured to the catheter; an inner needle inserted into the catheter; a grip for fixing and holding the inner needle; a support structure that contacts a first position and a second position on an outer circumferential surface of the catheter in an assembled state before use to support an outside of the catheter, the portions of the support structure that come into contact with the first position and the second position are located on opposite sides of an axial center of the catheter and are shifted in the axial direction of the catheter so as to press the catheter without clamping the same position in the extension direction of the catheter and to bend the catheter along the extension direction, when viewed in a direction perpendicular to the extension direction of the catheter in the assembled state; In the assembled state before use, the catheter and the inner needle are deflected by the support structure pressing against the first position and the second position. Catheter assembly.

2. The catheter assembly according to claim 1, The support structure includes a first support portion that contacts the first position and a second support portion that contacts the second position, the first support portion being formed of separate members. Catheter assembly.

3. A catheter, a catheter hub secured to the catheter; an inner needle inserted into the catheter; a grip for fixing and holding the inner needle; a support structure that supports the outside of the catheter in contact with an outer circumferential surface of the catheter in an assembled state; when viewed in a direction perpendicular to the extension direction of the catheter in the assembled state, the support structure presses the catheter without clamping the same position in the extension direction of the catheter, thereby bending the catheter along the extension direction, the support structure is configured to support the catheter by contacting a first position and a second position on an outer circumferential surface of the catheter in the assembled state, the first position and the second position are located on opposite sides of an axis of the catheter and are offset from each other in the axial direction of the catheter; The support structure includes a first support portion that contacts the first position and a second support portion that contacts the second position, the first support portion being formed of separate members, the first support portion is an operation portion for operating a relative movement of the catheter with respect to the grip, The second support portion is the grip or a support member rotatably attached to the grip. Catheter assembly.

4. The catheter assembly according to claim 3, The first position where the first support part contacts the catheter is located on the distal side of the second position where the second support part contacts the catheter. Catheter assembly.

5. The catheter assembly according to any one of claims 1 to 4, When viewed from the front of the catheter assembly, the pushing direction of the catheter connecting the first position and the second position is along the direction in which the blade surface of the inner needle faces. Catheter assembly.

6. A catheter, a catheter hub secured to the catheter; an inner needle inserted into the catheter; a grip for fixing and holding the inner needle; a support structure that supports the outside of the catheter in contact with an outer circumferential surface of the catheter in an assembled state, when viewed in a direction perpendicular to the extension direction of the catheter in the assembled state, the support structure presses the catheter without clamping the same position in the extension direction of the catheter, thereby bending the catheter along the extension direction, the support structure is configured to support the catheter by contacting a first position and a second position on an outer circumferential surface of the catheter in the assembled state, the first position and the second position are located on opposite sides of an axis of the catheter and are offset from each other in the axial direction of the catheter; When viewed from the front of the catheter assembly, a pressing direction of the catheter connecting the first position and the second position is perpendicular to a direction in which a blade surface of the inner needle faces. Catheter assembly.

7. The catheter assembly according to claim 1, The catheter is supported on the inside by the inner needle that extends linearly within the grip, In the assembled state, the support structure presses an outer circumferential surface of the catheter from one direction, thereby bending the catheter along the extension direction. Catheter assembly.

8. The catheter assembly according to any one of claims 1 to 7, The support structure is formed in a stepped shape having a tip projection that presses against the outer circumferential surface of the catheter in the assembled state, and a base end extension that extends in a non-contact manner in the vicinity of the outer circumferential surface of the catheter on the base end side of the tip projection. Catheter assembly.

9. The catheter assembly according to any one of claims 1 to 8, The support structure has a clamping portion that supports the outside of the catheter and holds a plurality of separable portions in a clamped state. Catheter assembly.

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