Indwelling needle assembly

Abstract

To provide a new indwelling needle assembly whose relative movement of an inner needle with respect to an outer needle is restricted even when the puncture is performed by holding an outer needle hub side.SOLUTION: In an indwelling needle assembly 10 in which an inner needle 14 having an inner needle hub 46 on a proximal end side is removably inserted into an outer needle 12 having an outer needle hub 16 on a proximal end side, a clip 74 that can releasably engage with an engagement part 100 on an outer needle hub 16 side is provided in the inner needle hub 46, and a pair of lateral support faces 60,60 supported by fingers are provided on the two lateral faces in the inner needle hub 46 while the engagement part 100 on the outer needle hub 16 side is provided in a connection member 88 provided on a proximal end side of the outer needle hub 16.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an indwelling needle assembly having a structure in which an inner needle having an inner needle hub on its proximal end is removably inserted through an outer needle having an outer needle hub on its proximal end. [Background technology]

[0002] Conventionally, indwelling needle assemblies used for transfusions, blood collection, hemodialysis, and the like have been known. As shown in, for example, Japanese Patent Application Laid-Open Publication No. 2011-206609 (Patent Document 1), an indwelling needle assembly has a structure in which an inner needle having an inner needle hub at its proximal end is removably inserted into an outer needle having an outer needle hub at its proximal end. With the inner needle inserted into the outer needle, the inner and outer needles of the indwelling needle assembly are inserted into a patient's blood vessel or the like, and the inner needle is removed from the outer needle, thereby leaving the outer needle in the blood vessel or the like. An external flow path is then connected to the outer needle hub, and transfusions, blood collection, hemodialysis, and the like are performed through the lumen of the outer needle and the outer needle hub and the external flow path.

[0003] In an indwelling needle assembly, the inner needle, which has a sharp needle tip, is inserted into a body lumen such as a blood vessel, and the outer needle, which is fitted onto the inner needle, is inserted into the blood vessel or the like at the puncture site of the inner needle. Therefore, it is desirable to perform the puncture operation by holding the inner needle hub fixed to the inner needle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-206609 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it has become clear that in practice, when puncturing an indwelling needle assembly, the puncturing operation may be performed by holding the outer needle hub, which is closer to the needle tip than the inner needle hub. Because the inner needle is inserted into the outer needle so as to be removably toward the proximal end, there is a risk that the inner needle may move toward the proximal end of the outer needle if the puncturing operation is performed by holding the outer needle hub. As a result, for example, the tip of the outer needle may cover the tip of the inner needle, reducing the sharpness of the tip of the inner needle and increasing the pain experienced by the patient during puncturing.

[0006] An object of the present invention is to provide a novel indwelling needle assembly in which relative movement of the inner needle with respect to the outer needle is limited even when puncturing is performed by holding the outer needle hub side. [Means for solving the problem]

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] In the first aspect, in an indwelling needle assembly in which an inner needle having an inner needle hub on its base end is removably inserted into an outer needle having an outer needle hub on its base end, a clip is provided on the inner needle hub that is releasably engaged with an engaging portion on the outer needle hub, the clip is provided on the same top surface side of the inner needle hub as the cutting surface of the needle tip of the inner needle, and a pair of lateral support surfaces that can be supported by fingers are provided on both sides of the inner needle hub circumferentially away from the clip.

[0009] According to this aspect, the engagement between the engaging portion on the outer needle hub and the clip on the inner needle hub limits the amount of movement of the inner needle toward the proximal end relative to the outer needle. Therefore, the tip of the inner needle is maintained in a state where it protrudes further toward the distal end than the outer needle, preventing the sharpness of the inner needle from being reduced due to the outer needle contacting the tip of the inner needle. As a result, the pain inflicted on the patient during puncture can be reduced.

[0010] By providing the clip on the same top surface as the cutting surface of the inner needle tip, the clip is positioned on the opposite side of the patient's body surface during puncture, making it easy to operate the clip when releasing the clip engagement and preventing the clip from accidentally releasing the engagement due to the clip hitting the patient's body.

[0011] Since the lateral support surfaces that the user holds with their fingers are provided on both sides of the inner needle hub that are spaced apart from the clip in the circumferential direction, handling is easy with the orientation of the blade face of the needle tip of the inner needle positioned, making puncture easier. Moreover, unintended forces are less likely to act on the clip, and unintended release of the clip engagement can be prevented.

[0012] In a second aspect, in an indwelling needle assembly in which an inner needle having an inner needle hub on its base end is removably inserted into an outer needle having an outer needle hub on its base end, the outer needle hub is provided with a needle joint portion to which the outer needle is fixed, a flow path connection portion connected to an external flow path, and a soft tube connecting the needle joint portion and the flow path connection portion, and the inner needle hub is provided with a clip that can be releasably engaged with an engagement portion provided on the outer needle hub.

[0013] According to this aspect, since the outer needle hub is equipped with a soft tube, when, for example, an external flow path is connected to the flow path connection portion while the outer needle is inserted into a blood vessel or the like, it is easy to connect the flow path connection portion to the external flow path by bending the soft tube.

[0014] The engagement between the engaging portion on the outer needle hub and the clip on the inner needle hub limits the amount of movement of the inner needle toward the proximal end relative to the outer needle. This keeps the tip of the inner needle protruding further toward the distal end than the outer needle, preventing a decrease in the sharpness of the inner needle and reducing the pain felt by the patient when the needle is inserted.

[0015] The indwelling needle assembly of this embodiment is equipped with a soft tube, which means that the outer needle hub is likely to be long. When attempting to puncture by grasping the inner needle hub, the needle tip is far from the grasping position, making it difficult to position the needle tip. Statistical information has shown that there are an increasing number of cases where the outer needle hub is held during puncture. In the indwelling needle assembly of this embodiment, the relative movement of the inner needle and outer needle is prevented by the engagement of the clip. Therefore, even if puncture is performed by holding the outer needle hub, problems such as the outer needle moving toward the distal end of the inner needle and covering the tip of the inner needle with the outer needle are avoided. Therefore, it is possible to satisfactorily perform stable puncture, for example, by holding the needle joint close to the needle tip.

[0016] In a third aspect, in the indwelling needle assembly described in the first or second aspect, the engaging portion is provided on a connecting member attached to the base end side of the outer needle hub.

[0017] According to this aspect, by providing an engagement portion on the connecting member that is closer to the base end than the outer needle hub, there is no need to extend the clip far toward the tip end, and the size of the inner needle hub equipped with the clip can be reduced in the axial direction.

[0018] In a fourth aspect, in an indwelling needle assembly in which an inner needle having an inner needle hub on its base end side is removably inserted into an outer needle having an outer needle hub on its base end side, a clip is provided on the inner needle hub that is releasably engageable with an engaging portion provided on the outer needle hub side, a needle tip protector is provided that covers the needle tip of the inner needle when the inner needle is pulled out from the outer needle toward the base end side, and a connecting member is provided on the base end side of the outer needle hub that detachably connects the needle tip protector to the outer needle hub, and the engaging portion is provided on the connecting member.

[0019] According to this aspect, the amount of movement of the inner needle toward the proximal end relative to the outer needle is limited by the engagement between the engaging portion on the outer needle hub and the clip on the inner needle hub. As a result, the tip of the inner needle is maintained in a state where it protrudes further toward the distal end than the outer needle, preventing a decrease in the sharpness of the inner needle and reducing pain to the patient when the needle is inserted.

[0020] Since the engagement portion that engages with the clip is provided on a connecting member that connects the outer needle hub and the needle tip protector at the base end side of the outer needle hub, the extension length of the clip toward the tip side can be shortened compared to when the clip is engaged with the outer needle hub, and the inner needle hub equipped with the clip can be made smaller in the axial direction.

[0021] The fifth aspect is an indwelling needle assembly described in any one of the first to fourth aspects, wherein the engaging portion provided on the outer needle hub is an engaging recess into which an engaging claw provided on the clip engages.

[0022] According to this aspect, the diameter of the outer needle hub does not increase at the portion where the engagement portion is formed. Furthermore, for example, if the engagement claws are made to engage with the inner wall surface of the engagement recess not only in the axial direction but also in the circumferential direction, relative rotation between the inner needle hub and the outer needle hub is restricted, and the inner needle and outer needle can be positioned circumferentially.

[0023] In a sixth aspect, in the indwelling needle assembly described in any one of the first to fifth aspects, the clip comprises a fulcrum portion connected to the inner needle hub and protruding toward the outer periphery, an external force acting piece extending from the fulcrum portion toward the base end, and an engaging piece extending from the fulcrum portion toward the tip end and equipped with an engaging claw that engages with the engaging portion on the outer needle hub side.

[0024] According to this aspect, for example, by a simple operation such as pressing the external force application piece, the engagement claw provided on the engagement piece can be moved to release the engagement of the engagement claw with the engagement portion.

[0025] In a seventh aspect, in an indwelling needle assembly in which an inner needle having an inner needle hub at its base end is removably inserted into an outer needle having an outer needle hub at its base end, the outer needle hub comprises a needle joint to which the outer needle is fixed, a flow path connection part connected to an external flow path, and a soft tube connecting the needle joint and the flow path connection part, and an anti-slip member is provided between the outer surface of the portion of the inner needle that is inserted into the soft tube and the inner surface of the soft tube.

[0026] According to this aspect, for example, when the soft tube is pinched and crushed with the fingers during puncturing, causing the inner circumferential surface of the soft tube to come into contact with the outer circumferential surface of the inner needle, the anti-slip feature provided between the inner circumferential surface of the soft tube and the outer circumferential surface of the inner needle makes it difficult for the soft tube to slip relative to the inner needle, thereby making it possible to prevent the relative positions of the inner needle and outer needle from shifting in the axial direction.

[0027] The anti-slip feature is preferably provided by roughening the outer peripheral surface of the inner needle or by forming concaves and convexes on the outer peripheral surface of the inner needle. In this way, when the soft tube is pressed against the anti-slip feature of the inner needle, the inner peripheral portion of the soft tube deforms in accordance with the concaves and convexes on the anti-slip feature of the inner needle, and the soft tube is mechanically locked in the axial direction against the concaves and convexes on the anti-slip feature, and the anchor effect makes it more difficult for the soft tube to slip in the axial direction relative to the inner needle.

[0028] In the eighth aspect, in an indwelling needle assembly in which an inner needle having an inner needle hub on its base end side is removably inserted into an outer needle having an outer needle hub on its base end side, a needle tip protector is provided that covers the needle tip of the inner needle when the inner needle is pulled out from the outer needle toward the base end side, a connecting member is provided on the base end side of the outer needle hub that detachably connects the needle tip protector to the outer needle hub, and a positioning portion is provided that generates resistance to relative movement between the connecting member and the inner needle hub in the direction of separation of the needle tip protector and the outer needle hub.

[0029] According to this aspect, unintended relative movement between the outer needle hub and the inner needle hub is prevented by the resistance force exerted by the positioning portion, so it is possible to prevent the inner needle from moving toward the proximal end relative to the outer needle and the needle tip of the inner needle from being covered by the outer needle. This avoids a decrease in the sharpness of the inner needle and reduces pain to the patient when puncturing. Furthermore, because unintended relative movement between the connecting member and the inner needle hub in the separation direction is prevented by the positioning portion, unnecessary movement of the needle tip protector relative to the inner needle is also prevented. [Effects of the Invention]

[0030] According to the present invention, even when puncturing is performed by holding the outer needle hub side, movement of the inner needle relative to the outer needle is limited. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view showing an indwelling needle assembly according to a first embodiment of the present invention; [Figure 2] FIG. 2 is a front view of the indwelling needle assembly shown in FIG. [Figure 3] FIG. 3 is a longitudinal cross-sectional view of the indwelling needle assembly shown in FIG. [Figure 4] FIG. 3 is an enlarged perspective cross-sectional view of a main part of the indwelling needle assembly of FIG. 2, showing an initial state in which the inner needle is inserted into the outer needle. [Figure 5] FIG. 3 is an enlarged perspective cross-sectional view of a main part of the indwelling needle assembly of FIG. 2, showing a state in which the needle tip of the inner needle is positioned closer to the base end than the needle tip protector. [Figure 6] FIG. 3 is an enlarged perspective cross-sectional view of a main part of the indwelling needle assembly of FIG. 2, showing a state in which the needle tip protector has been separated from the outer needle hub side. [Figure 7] FIG. 1 is a perspective view showing an indwelling needle assembly according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0033] 1 to 3 show an indwelling needle assembly 10 as a first embodiment of the present invention. The indwelling needle assembly 10 has a structure in which an inner needle 14 is inserted through an outer needle 12 in a manner that allows it to be removed. In the following description, the axial direction generally refers to the left-right direction in FIG. 2, which is the needle axial direction of the outer needle 12 and the inner needle 14. Furthermore, the distal end side refers to the left side in FIG. 2, which is the side of a needle tip 44 described below, and the proximal end side refers to the right side in FIG. 2.

[0034] The outer needle 12 is in the form of a small diameter tube made of synthetic resin etc. The tip portion of the outer needle 12 is tapered so that the diameter gradually decreases towards the tip side.

[0035] An outer needle hub 16 is provided on the proximal end side of the outer needle 12. The outer needle hub 16 is cylindrical overall, and has a structure in which a needle joint 18 and a flow path connection 20 are connected by a soft tube 22.

[0036] The needle joint 18 is made of a hard synthetic resin. The needle joint 18 has a tapered cylindrical shape that decreases in diameter toward the tip. The base end portion of the outer needle 12 is inserted into and fitted into the inner periphery of the needle joint 18. As a result, the needle joint 18 is fixed to the base end portion of the outer needle 12, and extends from the needle joint 18 toward the tip side.

[0037] The flow path connecting portion 20 has a cylindrical structure having a connecting portion at its base end that is connected to an external flow path, which will be described later, and in this embodiment, has a structure in which a hemostatic valve 26 and a plunger 28 are housed in a cylindrical valve housing 24. The valve housing 24 is constructed by inserting the tip portion of a cylindrical plunger guide 32 into the base end portion of a cylindrical cover member 30, and connecting the cover member 30 and the plunger guide 32 in the axial direction. The base end portion of the plunger guide 32 extends in the axial direction with a substantially constant cross-sectional shape, and a male thread portion 34 that protrudes toward the outer periphery is integrally formed at the base end.

[0038] The hemostatic valve 26 has a generally circular disk shape overall and is made of an elastic material such as a resin elastomer or rubber. The hemostatic valve 26 has radial notches 36 formed in the center of the disk shape, and the notches 36 are opened and closed by elastic deformation of the center. The outer periphery of the hemostatic valve 26 is axially sandwiched between the tip of the plunger guide 32 and a valve support member 38 held on the inner periphery of the cover member 30. As a result, the hemostatic valve 26 is supported by the valve housing 24, and the inner cavity of the valve housing 24 is blocked by the hemostatic valve 26.

[0039] The plunger 28 is cylindrical and inserted into the inner periphery of the plunger guide 32. The plunger 28 has a base end portion with a substantially constant outer diameter, and a tip portion with an outer peripheral surface that tapers toward the tip.

[0040] The soft tube 22 connecting the needle joint 18 and the flow path connecting portion 20 is made of a resin elastomer, rubber, or the like, and is capable of being bent and deformed, and its cross-sectional shape is also allowed to change. The provision of the soft tube 22 makes it easier to connect an external flow path (described later) to the outer needle hub 16, for example, while the outer needle hub 16 is fixed to the skin. The distal end portion of the soft tube 22 is inserted between the needle joint 18 and the outer needle 12 and fixed thereto. The proximal end portion of the soft tube 22 is inserted into and fixed to the inner periphery of a tube connecting member 40 attached in an inserted state to the cover member 30 of the flow path connecting portion 20. This connects the needle joint 18 and the flow path connecting portion 20 via the soft tube 22, and the lumen of the needle joint 18 and the lumen of the flow path connecting portion 20 are mutually communicated via the lumen of the soft tube 22.

[0041] The soft tube 22 of this embodiment has an outer diameter that is approximately constant in the axial direction, and an inner diameter that is smaller in the axial central portion than in both end portions. Therefore, the axial central portion of the soft tube 22 has a thick-walled portion 41 that is thicker than the end portions. As a result, the inner circumferential surface of the thick-walled portion 41, which is the axial central portion of the soft tube 22, is located close to the outer circumferential surface 42 of the inner needle 14 when the inner needle 14 is inserted through the outer needle 12. Therefore, for example, when the soft tube 22 is pinched, the soft tube 22 is pressed strongly against the inner needle 14 at the thick-walled portion 41, making it difficult for slippage to occur between the soft tube 22 and the inner needle 14. The soft tube 22 may have an approximately constant thickness in the axial direction, or the axial central portion may be thin-walled.

[0042] The outer peripheral surface 42 of the portion of the inner needle 14 that is inserted into the soft tube 22 can be provided with a non-slip surface that makes it less likely to slip against the inner peripheral surface of the soft tube 22, for example, by roughening the surface with unevenness or texture, or by coating with an elastomer, rubber, synthetic resin, or the like that has high frictional resistance. In this way, when the soft tube 22 is grasped, slippage between the soft tube 22 and the inner needle 14 is less likely to occur, and the relative positions of the inner needle 14 and the outer needle 12 are less likely to shift. Note that it is not necessary to provide the outer peripheral surface of the inner needle 14 with a structure (non-slip surface) that makes it less likely to slip against the inner peripheral surface of the soft tube 22. Furthermore, a non-slip surface may be provided on the inner peripheral surface of the soft tube 22, and it is sufficient that it is provided between the inner needle 14 and the soft tube 22, in other words, on at least one of the outer peripheral surface of the inner needle 14 and the inner peripheral surface of the soft tube 22.

[0043] The inner needle 14 is inserted from the proximal end into each of the lumens of the outer needle 12, the needle joint 18, the soft tube 22, and the flow path connecting part 20. The inner needle 14 is a hollow metal needle, and has a beveled cutting edge 43 on its distal end, thereby forming an acute-angled needle tip 44. In Figures 2 and 3, the cutting edge 43 of the inner needle 14 is located on the upper side in the figures.

[0044] An inner needle hub 46 is provided on the proximal end side of the inner needle 14. The inner needle hub 46 has a base portion 48 to which the proximal end portion of the inner needle 14 is fixed in an inserted state, and a connecting portion 50 is provided on the proximal end side of the base portion 48, and a protector accommodating portion 52 is provided on the distal end side of the base portion 48.

[0045] The connecting part 50 is cylindrical, and the inner needle cap 54 is removably inserted and attached. The inner needle cap 54 has a roughly stepped cylindrical shape with a step provided in the middle part in the needle axial direction. A breathable filter 56 is provided at the tip part of the inner needle cap 54. The breathable filter 56 has the property of allowing gas to pass through but not liquid, and by providing the breathable filter 56 in the lumen of the inner needle cap 54, backflow blood is prevented from leaking to the outside through the inner needle 14. If the inner needle hub 46 and the inner needle cap 54 are transparent or translucent, it is easy to confirm that a blood vessel has been punctured by backflow blood (flashback).

[0046] The protector housing portion 52 is cylindrical. A puncturing operation portion 58 is provided on the distal end side of the protector housing portion 52. The puncturing operation portion 58 is generally cylindrical and has a larger diameter than the protector housing portion 52. The puncturing operation portion 58 extends from the protector housing portion 52 toward the distal end side, and is disposed so as to surround the outer periphery of the base end of the flow path connecting portion 20 in the outer needle hub 16 when the inner needle 14 is inserted into the outer needle 12. Note that the puncturing operation portion 58 may reach, for example, the outer periphery of the soft tube 22, which makes it possible to hold the inner needle hub 46 closer to the distal end and makes it difficult to hold the soft tube 22 during puncturing.

[0047] As shown in FIGS. 1 and 2 , a pair of side support surfaces 60, 60 are provided on the outer surface of the puncturing operation unit 58. The side support surfaces 60 are provided on opposing sides of the outer peripheral surface of the puncturing operation unit 58 and extend in the axial direction. When the blade surface 43 of the needle tip 44 of the inner needle 14 faces upward as shown in FIG. 2 , the side support surfaces 60, 60 are provided so as to be located on both sides perpendicular to the up-down direction. The side support surfaces 60, 60 do not reach the tip of the puncturing operation unit 58, and their tip portions are inclined outwardly toward the tip. Because the side support surfaces 60, 60 do not reach the tip of the puncturing operation unit 58, the tip portion of the puncturing operation unit 58 is thickened, thereby improving the shape stability of the tip portion of the puncturing operation unit 58. Furthermore, each side support surface 60 may be provided with anti-slip features such as protrusions, recesses, or textures, or may simply be a curved surface.

[0048] A protector housing 62 is disposed on the inner periphery of the protector accommodating portion 52. As shown in FIGS. 3 and 4 , the protector housing 62 includes a cylindrical accommodating tube portion 64 and a lid 66 that closes the opening on the distal end side of the accommodating tube portion 64. The lid 66 has a plate-like portion on the distal end side and a plate-like portion on the proximal end side that are spaced apart in the axial direction, and a needle tip protector 68 is disposed between these plate-like portions. The needle tip protector 68 is constituted by a shielding member 70 and a fixing member 72 that are housed in the protector housing 62. The shielding member 70 and the fixing member 72 are disposed apart from each other with the inner needle 14 sandwiched between them in the direction perpendicular to the axis. One of the shielding member 70 and the fixing member 72 is a magnet, and the other is a magnet or a ferromagnetic material, and a magnetic attractive force acts between the shielding member 70 and the fixing member 72. In this embodiment, the shielding member 70 is made of a ferromagnetic material such as metal, and the fixed member 72 is made of a permanent magnet. The fixed member 72 is fixed to the tip of the tubular housing portion 64. The shielding member 70 is displaceable in a direction approaching the fixed member 72, and when the inner needle 14 is inserted between the shielding member 70 and the fixed member 72, movement of the shielding member 70 toward the fixed member 72 is prevented by the inner needle 14.

[0049] More specifically, the puncturing operation part 58 has an upper portion that is not formed on the top surface, and has a substantially C-shaped cross section that opens upward. A clip 74 is provided between the circumferential ends of the puncturing operation part 58 on the inner needle hub 46.

[0050] The clip 74 is provided on the top surface side (upper side in Figure 2) of the inner needle hub 46, which is the same side as the blade surface 43 of the needle tip 44 of the inner needle 14. Side support surfaces 60, 60 are formed on the inner needle hub 46 on both sides circumferentially spaced from the clip 74. As shown in Figures 1, 3, 4, etc., the clip 74 has a fulcrum part 76 that extends upward from the tip end of the puncture operation section 58, and is integrally provided with an external force application piece 78 that extends from the protruding end of the fulcrum part 76 toward the base end, and an engagement piece 80 that extends from the protruding end of the fulcrum part 76 toward the tip side.

[0051] The external force application piece 78 is shaped like a plate that is curved in the circumferential direction. Two recesses 82, 82 extending in the circumferential direction are formed on the upper surface of the external force application piece 78, and these recesses 82, 82 make it difficult for the fingertips to slip when pressing the external force application piece 78, which will be described later.

[0052] The engagement piece 80 is located between both circumferential ends of the puncturing operation section 58, and like the external force application piece 78, the engagement piece 80 is formed in the shape of a plate that is curved in the circumferential direction. The axial length of the engagement piece 80 is greater than that of the external force application piece 78. The tip of the engagement piece 80 reaches approximately the same position in the axial direction as the tip of the puncturing operation section 58. A through-hole 83 that passes through in the vertical direction is formed in the central part of the engagement piece 80.

[0053] The engagement piece 80 is provided with an engagement claw 84. The engagement claw 84 is provided on the tip side of the through hole 83 in the engagement piece 80. The engagement claw 84 protrudes downward from the engagement piece 80. The protruding dimension of the engagement claw 84 gradually increases toward the base end side. In this embodiment, the surface on the base end side of the engagement claw 84 is an engagement plane 86 that extends in the axis-perpendicular direction, and the surface on the tip side is a guide plane 87 that is inclined with respect to the engagement plane 86, and has a substantially right-angled triangular cross section in the longitudinal section shown in FIG. 3.

[0054] When a downward force is applied to the external force acting piece 78 of the clip 74, the engaging piece 80 tilts around the fulcrum portion 76, and the engaging claw 84 provided at the tip of the engaging piece 80 moves upward.

[0055] The protector housing 62 is connected to the outer needle hub 16 by a connector cap 88 serving as a connecting member. The connector cap 88 has a bottom wall portion 90 that extends in the axially perpendicular direction. The bottom wall portion 90 is in the shape of an annular plate, and a tubular projection 92 that protrudes toward the distal end is integrally formed at the inner peripheral end. A circumferential wall portion 94 that extends toward the distal end and a pair of elastic pieces 96, 96 that extend toward the base end are integrally formed at the outer peripheral end of the bottom wall portion 90.

[0056] The circumferential wall portion 94 is cylindrical. An internal thread 98 is provided on the inner peripheral surface of the circumferential wall portion 94. The base end portion of the plunger guide 32 that constitutes the outer needle hub 16 is inserted into the inner periphery of the circumferential wall portion 94, and the external thread portion 34 of the plunger guide 32 and the internal thread 98 of the circumferential wall portion 94 are threadedly engaged, thereby attaching the connector cap 88 to the base end portion of the outer needle hub 16.

[0057] An engagement recess 100 serving as an engagement portion that opens onto the upper surface is formed at the tip portion of the connector cap 88. The engagement recess 100 is a recess that opens onto the upper surface and tip surface of the circumferential wall portion 94, and has a shape that corresponds to the engagement claw 84 provided on the clip 74 of the inner needle hub 46. In short, the engagement recess 100 allows the engagement claw 84 to be inserted from above, and the inner wall surface on the base end side of the engagement recess 100 is a flat surface that extends in the axis-perpendicular direction and corresponds to the engagement flat surface 86 of the engagement claw 84.

[0058] The elastic pieces 96, 96 are plate-shaped and are allowed to elastically flex and deform in the thickness direction. Each of the elastic pieces 96, 96 is provided with a locking protrusion 102 that protrudes toward the inner periphery at its protruding tip. The locking protrusion 102 has a tapered cross-sectional shape in which the axial width dimension decreases toward the inner periphery, which is the protruding tip. The tip portion of the protector housing 62 is inserted between the opposing elastic pieces 96, 96, and the locking protrusions 102 of the elastic pieces 96, 96 are locked in the axial direction with respect to the protector housing 62. In this way, the connector cap 88 is attached to the protector housing 62, and the outer needle hub 16 and the protector housing 62 are connected via the connector cap 88. In addition, by pulling the protector housing 62 toward the base end, the protector housing 62 pushes the elastic pieces 96, 96 outward and overcomes the locking protrusions 102, 102, making it possible to separate the protector housing 62 and therefore the needle tip protector 68 from the connector cap 88.

[0059] The puncturing operation section 58 of the inner needle hub 46 is fitted onto the connector cap 88. As a result, the puncturing operation section 58 restricts the deformation of the elastic pieces 96, 96 toward the outer periphery, and the connection between the connector cap 88 and the protector housing 62 by the pair of locking protrusions 102, 102 is stably maintained.

[0060] The engaging claws 84 of the clip 74 are inserted into engaging recesses 100 of the connector cap 88, and the two are engaged with each other in the axial direction, thereby restricting movement of the inner needle hub 46 toward the proximal end relative to the connector cap 88. That is, by inserting the engaging claws 84 into the engaging recesses 100, the engaging flat surfaces 86 of the engaging claws 84 and the inner wall surface of the proximal end side of the engaging recess 100 are positioned so as to overlap each other when projected in the axial direction. As a result, when the inner needle hub 46 attempts to move toward the proximal end relative to the connector cap 88, the engaging flat surfaces 86 of the engaging claws 84 engage with the inner wall surface of the proximal end side of the engaging recess 100, restricting the amount of relative movement of the inner needle hub 46 with the connector cap 88. Therefore, the engagement between the engaging claws 84 of the clip 74 and the connector cap 88 prevents the inner needle 14 from coming off the outer needle 12 toward the proximal end. In this way, by connecting the inner needle hub 46 to the connector cap 88 attached to the base end side of the outer needle hub 16, the inner needle 14 is positioned axially relative to the outer needle 12, preventing the inner needle 14 from moving toward the base end side relative to the outer needle 12.

[0061] As described above, movement of the inner needle hub 46 in the separation direction (proximal end side) relative to the outer needle hub 16 is restricted by engagement between the engaging claws 84 of the clip 74 and the inner wall surface of the engagement recess 100. Therefore, in the present embodiment, the positioning part that generates resistance to relative movement in the separation direction between the outer needle hub 16 and the inner needle hub 46 is composed of the engaging claws 84 of the clip 74 provided on the inner needle hub 46 side, and the engagement recess 100 provided on the connector cap 88 on the outer needle hub 16 side. The separation direction between the outer needle hub 16 and the inner needle hub 46 is approximately the same as the separation direction between the outer needle hub 16 and the needle tip protector 68.

[0062] When the puncture operation section 58 and the engagement piece 80 of the inner needle hub 46 are brought close to the connector cap 88 from the proximal end side, the guide surface 87 of the engagement claw 84 provided on the engagement piece 80 comes into axial contact with the proximal end of the upper elastic piece 96 of the connector cap 88. As a result, when the inner needle hub 46 is moved further toward the distal end side relative to the connector cap 88, the engagement claw 84 is pushed upward by the upper elastic piece 96, and the engagement claw 84 moves toward the distal end side while making sliding contact with the outer circumferential surface of the connector cap 88. When the engagement claw 84 moves to an engagement recess 100 provided at the distal end of the connector cap 88, the elasticity of the engagement piece 80 causes the engagement claw 84 to be inserted into the engagement recess 100 of the connector cap 88. In this way, in the present embodiment, the engagement claw 84 can be inserted into the engagement recess 100 of the connector cap 88 by moving the inner needle hub 46 from the proximal end side to the distal end side relative to the connector cap 88 without operating the clip 74.

[0063] In this embodiment, the engagement portion provided on the connector cap 88 on the outer needle hub 16 side is a concave engagement recess 100 that opens to the outer peripheral surface, thereby preventing the external dimensions of the connector cap 88 from increasing due to the formation of the engagement portion.

[0064] The engagement recess 100 is provided in a connector cap 88 that is attached to the base end side of the outer needle hub 16. Therefore, there is no need for the engagement piece 80 of the clip 74 to be long enough to reach further toward the tip side than the connector cap 88, making it possible to reduce the size of the clip 74. Furthermore, since it is no longer necessary to provide an engagement recess 100 in the outer needle hub 16, the shape of the outer needle hub 16 can be designed more freely.

[0065] The engagement recess 100 is provided on the tip side of the connector cap 88. As a result, the length of the engagement piece 80 is longer than the external force application piece 78, and the amount of movement of the tip portion of the engagement piece 80 where the engagement claw 84 is provided is greater than the amount of movement of the external force application piece 78 due to input. Therefore, the engagement claw 84 can be moved sufficiently without moving the external force application piece 78 significantly, and the insertion state of the engagement claw 84 in the engagement recess 100 can be released.

[0066] The engaging recess 100 extends in the axial direction and is provided in a portion of the circumferential direction. The engaging claw 84 inserted into the engaging recess 100 engages with the inner wall surface on the base end side of the engaging recess 100, and also engages with the inner wall surfaces on both circumferential sides of the engaging recess 100. As a result, a rotation limiting portion that positions the outer needle 12 and the inner needle 14 in the circumferential direction is formed by the circumferential engagement between the engaging claw 84 and the inner wall surface of the engaging recess 100. In short, the engagement between the engaging claw 84 and the inner wall surface of the engaging recess 100 not only restricts the movement of the inner needle 14 toward the base end side relative to the outer needle 12, but also restricts the relative rotation of the inner needle 14 with respect to the outer needle 12.

[0067] In the indwelling needle assembly 10 constructed as described above, the inner needle 14 is inserted into a blood vessel in a patient's arm (not shown), etc. The healthcare professional (user) performing the blood vessel puncture inserts the inner needle 14 into the patient's arm, etc., while properly holding the puncturing operation portion 58 of the inner needle hub 46 with their fingers. The healthcare professional places their fingertips against the lateral support surfaces 60, 60 and holds the puncturing operation portion 58 so as to pinch the sides of the puncturing operation portion 58. This allows the healthcare professional to stably insert the inner needle 14 into the patient, needle tip 44 first. By holding the lateral support surfaces 60, 60, which are provided on the sides offset from the clip 74 in the circumferential direction, it is less likely that force will be applied inadvertently to the clip 74 provided on the upper surface of the inner needle hub 46. This prevents unintentional release of the connection between the connector cap 88 on the outer needle hub 16 and the clip 74 of the inner needle hub 46.

[0068] In this way, by having the medical professional hold the puncture operation part 58 provided on the inner needle hub 46 and perform the puncture operation, the medical professional can precisely control the inner needle 14 and achieve accurate puncture.

[0069] The puncturing operation unit 58 has side support surfaces 60, 60 at the portions that the medical professional holds with their fingertips, making it easy to hold the puncturing operation unit 58 in a circumferentially positioned state. Furthermore, the tip portions of the side support surfaces 60, 60 are inclined, making it difficult for the fingertips to slip distally from the side support surfaces 60, 60, allowing for more reliable application of force in the puncturing direction. Furthermore, the puncturing operation unit 58 may be provided with wing-like portions, which can be held for operation. The wing-like portions have a structure in which, for example, a plate-shaped connecting portion is provided protruding in a tangential direction of a fitting cylindrical portion that is attached to the puncturing operation unit 58 in an externally inserted state, and a wing main body is provided at each of the protruding tip ends of the connecting portion from the fitting cylindrical portion.

[0070] By having the puncturing operation part 58 provided on the inner needle 14 side, unnecessary external force is less likely to be applied to the outer needle 12 side, and unintended relative displacement of the outer needle 12 and the inner needle 14 is less likely to occur compared to when puncturing is performed by holding the outer needle hub 16. Therefore, relative movement of the outer needle 12 and the inner needle 14 due to deformation of the soft tube 22 is prevented, reducing puncture pain and achieving more accurate puncturing.

[0071] Incidentally, in an outer needle hub 16 equipped with a soft tube 22, the outer needle hub 16 tends to be long due to the inclusion of the soft tube 22. When attempting to perform puncture by grasping the inner needle 14 side, the grasping position is far from the needle tip 44, making it difficult to position the needle tip 44, and therefore users are increasingly likely to hold the outer needle hub 16 during puncture. When a healthcare professional performs puncture by holding the outer needle hub 16 side, which is closer to the needle tip 44 than the puncture operation part 58, the indwelling needle assembly 10 prevents the inner needle 14 from moving proximally relative to the outer needle 12 due to resistance during puncture. That is, the clip 74 restricts the inner needle hub 46 from moving proximally relative to the connector cap 88 attached to the outer needle hub 16. As a result, even if puncture is performed by holding the outer needle hub 16 side, the inner needle hub 46 will not move proximally relative to the outer needle hub 16 side, and the inner needle 14 will not move proximally relative to the outer needle 12. As a result, the needle tip 44 of the inner needle 14, which has the cutting surface 43, is kept exposed further forward than the outer needle 12, preventing the sharpness of the needle tip 44 from decreasing, thereby reducing the pain felt by the patient.

[0072] After the inner needle 14 and the outer needle 12 have punctured the patient's blood vessel, the inner needle 14 is removed from the outer needle 12, leaving the outer needle 12 and the outer needle hub 16 inserted in the patient's blood vessel.

[0073] The inner needle 14 can be removed from the outer needle 12 by releasing the connection of the clip 74 to the connector cap 88. That is, by applying a downward external force to the external force application piece 78, which extends proximally beyond the fulcrum 76 of the clip 74, for example by pressing the external force application piece 78 with a fingertip, the engagement claw 84 provided on the engagement piece 80 extending distally beyond the fulcrum 76 moves upward. This causes the engagement claw 84 to move upward beyond the opening of the engagement recess 100 of the connector cap 88, allowing movement of the inner needle hub 46 proximally relative to the connector cap 88, in other words, separation of the inner needle hub 46 from the outer needle hub 16, without being restricted by the engagement of the engagement claw 84 with the inner wall surface of the proximal side of the engagement recess 100. In this way, the engagement of the clip 74 to the connector cap 88 can be released by the simple operation of pushing the external force application piece 78 downward. The outer needle 12 and outer needle hub 16 and the inner needle 14 and inner needle hub 46 are separably combined as described above, and after the inner needle 14 and outer needle 12 have punctured the patient's blood vessel, they are separated and the inner needle 14 and inner needle hub 46 are removed.

[0074] When the inner needle 14 and the outer needle 12 have punctured the patient's blood vessel, the clip 74 is located on the top surface (upper surface) of the indwelling needle assembly 10, facing away from the patient. This allows the puncture operation to be performed by grasping the lateral support surface 60 with the thumb and middle finger, and then the clip can be pressed with the index finger while still grasping the lateral support surface 60, eliminating the need to change hands or use both hands. Therefore, the operation of pushing in the clip 74 as described above and withdrawing the inner needle 14 toward the proximal end relative to the outer needle 12 can be easily performed with one hand.

[0075] 5 and 6, the needle tip 44 of the inner needle 14 that has been pulled out from the outer needle 12 is protected by the needle tip protector 68. That is, when the inner needle 14 is pulled out toward the base end, the inner needle 14 is displaced toward the base end relative to the protector housing 62 that is engaged with the connector cap 88. Then, as shown in FIG. 5, the tip of the inner needle 14 moves to the base end side beyond the shielding member 70, allowing the shielding member 70 to move closer to the fixing member 72, and the shielding member 70 is positioned so as to block the tip side of the inner needle 14. As a result, movement of the inner needle 14 toward the tip side relative to the needle tip protector 68 is restricted, and the needle tip 44 of the inner needle 14 housed in the protector housing 62 is not exposed to the outside.

[0076] Furthermore, a protrusion (not shown) provided on the inner needle 14 is engaged in the axial direction with the base end of the tubular accommodating portion 64 of the protector housing 62, thereby transmitting a pulling force from the inner needle 14 to the protector housing 62. Then, when the protector housing 62 is pulled toward the base end relative to the connector cap 88, the engagement between the protector housing 62 and the engaging protrusion 102 of the connector cap 88 is released, and the protector housing 62 is separated from the connector cap 88, as shown in Figure 6. This allows the inner needle 14 to be separated from the outer needle 12 and removed.

[0077] The connector cap 88 of the outer needle 12 that has been separated from the inner needle 14 and placed in place is removed from the outer needle hub 16, and a connector of a tube or syringe (not shown) that constitutes an external flow path is attached to the male thread portion 34 provided on the flow path connecting portion 20 of the outer needle hub 16. This connects the inner lumens of the outer needle 12 and the outer needle hub 16 to the external flow path. In this way, the male thread portion 34 of the outer needle hub 16 is used both to connect the connector cap 88 to the outer needle hub 16 and to connect the external flow path to the outer needle hub 16.

[0078] The protector housing 62 may be fixed to the connector cap 88, and the inner needle 14 and the protector housing 62 may be positioned circumferentially. In this case, by rotating the inner needle 14 and the inner needle hub 46, the rotational force is transmitted to the connector cap 88 via the protector housing 62, and the connector cap 88 is removed from the outer needle hub 16. The protector housing 62 and the connector cap 88 may be fixed as separate bodies, but can also be integrated.

[0079] When an external flow path (not shown) is connected to the outer needle hub 16, the plunger 28 is pushed toward the tip side by the external flow path. The pushed-in plunger 28 is pressed against the hemostatic valve 26, deforming the hemostatic valve 26 and opening the notch 36 in the hemostatic valve 26. This connects the patient's blood vessel to the external flow path through the lumen of the outer needle 12 and the outer needle hub 16, allowing treatment such as hemodialysis, blood sampling, and administration of medicinal solutions to be performed.

[0080] 7 shows an indwelling needle assembly 110 as a second embodiment of the present invention. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

[0081] The indwelling needle assembly 110 has an outer needle hub 112 which is entirely formed integrally from a hard synthetic resin, and does not include a soft tube 22 .

[0082] Furthermore, an engagement portion (not shown) is provided on the outer peripheral surface of the outer needle hub 112, and the clip 74 of the inner needle hub 46 engages with the outer needle hub 112 without the intervention of any other member. The engagement portion provided on the outer needle hub 112 may be an engagement recess 100 as in the above embodiment, or may be an engagement protrusion that protrudes from the outer peripheral surface.

[0083] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to those specific descriptions. For example, the engagement recess 100 may extend circumferentially around the entire circumference, and the configuration of the above-described embodiment in which the outer needle 12 and the inner needle 14 are positioned circumferentially by engagement between the engagement claws 84 and the inner wall surfaces of the engagement recess 100 is not essential.

[0084] The needle tip protector 68 is not essential, and the connector cap 88 connecting the outer needle hub 16 and the protector housing 62 may also be omitted.

[0085] For example, the connector cap and protector housing may be configured so that they do not separate when the inner needle is pulled out, and the connector cap and outer needle hub may be configured so that they separate when the inner needle is pulled out, so that the connector cap separates from the outer needle hub together with the inner needle. In this case, since the fixing force between the outer needle hub and connector cap is small and positioning is likely to be insufficient, it is desirable that the clip engage with a member other than the outer needle hub or the connector cap fixed to the outer needle hub.

[0086] The surface that abuts and engages with the engaging claw in the axial direction of the engaging portion may extend at an angle relative to the axis-perpendicular direction.

[0087] The clip 74 may be separate from the protector housing portion 52 and the puncture operation portion 58, and may be made of, for example, a different material. The specific structure of the clip is not particularly limited. For example, in the clip 74 of the above embodiment, when the external force acting on the external force application piece 78 is released, the clip 74 returns to its initial shape based on the elasticity of the fulcrum portion 76, etc. However, a spring may be provided between the external force application piece 78 and the protector housing portion 52 to assist the clip 74 in returning to its initial shape with the elasticity of the spring. It is also possible to employ a separate clip that is pin-supported and swingable, or a clip in which a locking claw that retracts and moves inward when pressed engages with an engaging recess provided on the inner circumferential surface. Furthermore, particularly in an embodiment with a soft tube such as the first embodiment, at least one clip may be provided on the side or bottom surface instead of or in addition to the top surface. For example, it is also possible to provide a pair of clips on both side surfaces that engage with engaging portions provided on the outer needle hub, respectively. Furthermore, the portion of the clip 74 to which the operating force is applied may have a structure such as the external force acting piece 78, or may be configured so that the clip is held in a disengaged state without the need for a continuous application of an external force to the clip, or may be configured so that the clip can be switched between an engaged state and a disengaged state multiple times by operating a button.

[0088] The clip 74 may be provided on the outer periphery of the needle tip protector 68 and the connector cap 88 to prevent separation of the needle tip protector 68 and the connector cap 88. The clip 74 may also be provided on the outer periphery of the needle tip protector 68 and the outer needle hub 16 to prevent separation of the needle tip protector 68 and the outer needle hub 16.

[0089] In the above embodiment, a connector cap 88 that covers the base end of the outer needle hub 16 is provided at the base end of the outer needle hub 16, and the connector cap 88 is used as a connecting member, but the outer needle hub 16 and the needle tip protector 68 may be assembled together without providing the connector cap 88. In this case, the clip 74 may be provided so as to be releasably engaged with the needle tip protector 68, for example.

[0090] In the above embodiment, the positioning portion that generates a resistance force against relative movement of the outer needle hub 16 and the inner needle hub 46 in the separation direction was constituted by the engaging claws 84 of the clip 74 and the engaging recesses 100 of the connector cap 88, but the structure of the positioning portion is not limited to the specific example of the above embodiment. For example, the inner needle hub 46 may be provided with a tubular portion (corresponding to the puncture operation portion 58) that is fitted onto the connector cap 88, and the positioning portion may be constituted by a convex portion that protrudes from the inner peripheral surface of the tubular portion engaging with a convex portion that protrudes from the outer peripheral surface of the connector cap 88 in the axial direction. In this case, the convex portion of the tubular portion and the convex portion of the connector cap 88 may be provided continuously around the entire circumference, or may be provided partially in the circumferential direction. When the convex portions are partially provided in the circumferential direction, for example, the inner needle hub 46 and the outer needle hub 16 are combined in a circumferential orientation such that the convex portions do not interfere with each other, and then the inner needle hub 46 and the outer needle hub 16 are rotated to move the convex portions to a position where they engage in the axial direction, thereby facilitating the task of combining the inner needle hub 46 and the outer needle hub 16 while providing a positioning portion.

[0091] As another embodiment of the positioning section, for example, the cylindrical portion of the inner needle hub 46 can be fitted into the connector cap 88, utilizing the frictional resistance acting between the cylindrical portion of the inner needle hub 46 and the connector cap 88. As yet another embodiment of the positioning section, for example, a convex portion protruding from the outer peripheral surface of the connector cap 88 can be fitted into a slit portion formed in the cylindrical portion of the inner needle hub 46 that is fitted onto the connector cap 88, utilizing the frictional resistance acting between the convex portion and the inner surface of the slit portion. As yet another embodiment of the positioning section, for example, a rubber-like body such as a rubber valve that the inner needle 14 passes through and that comes into contact with the outer peripheral surface of the inner needle 14 can be provided separately from the hemostatic valve 26, and the inner needle hub 46 and the outer needle hub 16 can be positioned using the frictional resistance acting between the rubber body and the inner needle 14.

[0092] Furthermore, the positioning of the outer needle hub 16 and the inner needle hub 46 by the positioning portion may be released simply by pulling the inner needle hub 46 toward the base end relative to the outer needle hub 16 with a force greater than the resistance exerted by the positioning portion, without requiring any special operation such as pressing the external force acting piece 78 of the clip 74. [Explanation of symbols]

[0093] 10 Indwelling needle assembly (first embodiment) 12 Outer needle 14 Inner needle 16 Outer needle hub 18 Needle joint 20 Flow path connection 22 Soft tube 24 Valve housing 26 Hemostasis valve 28 Pusher 30 Cover member 32 Pusher guide 34 Male thread 36 Cutting 38 Valve support member 40 Tube connecting member 41 Thick wall part 42 Outer surface 43 Blade surface 44 Needle tip 46 Inner needle hub 48 Base 50 Connection part 52 Protector housing 54 Inner needle cap 56 Ventilated filter 58 Puncture operation part 60 Lateral support surface 62 Protector housing 64 Storage tube 66 Lid 68 Needle Tip Protector 70 Shielding material 72 Fixing member 74 clips 76 Fulcrum 78 External force acting piece 80 Engagement piece 82 Recess 83 Through Hole 84 Engagement claw (positioning part) 86 Engagement plane 87 Guide surface 88 Connector cap (connecting member) 90 Bottom wall 92 Tubular process 94 Circumferential wall 96 Elastic piece 98 Female thread 100 Engagement recess (engagement portion, positioning portion) 102 Locking protrusion 110 Indwelling needle assembly (second embodiment) 112 outer needle hub

Claims

1. In an indwelling needle assembly in which an inner needle having an inner needle hub on its proximal end side is removably inserted into an outer needle having an outer needle hub on its proximal end side, a clip that is releasably engaged with the engaging portion on the outer needle hub to connect the inner needle hub to the outer needle hub in the axial direction is formed directly on the inner needle hub and extends forward from the inner needle hub toward the outer needle hub; A pair of lateral support surfaces are provided on both side surfaces of the inner needle hub to be supported by fingers when the needle is inserted into a patient. the engaging portion on the outer needle hub side is provided on a connecting member provided on the base end side of the outer needle hub, When an external force is applied to the clip, the clip is elastically deformed and the engagement of the clip with the engaging portion is released.

2. The indwelling needle assembly according to claim 1, wherein at least one clip is provided on a side surface of the inner needle hub.

Images