Indwelling needle assembly

Abstract

To provide an indwelling needle assembly which facilitates separation of an inner needle unit from an outer needle unit and has a novel structure.SOLUTION: In an indwelling needle assembly 10 in which an inner needle unit 14 and an outer needle unit 12 are coupled to be separated from each other, and which has a protector 128 for protecting an inner needle after removal of a needle 44, a storage housing 84 of the inner needle unit 14 includes a connecting part 96, 116 inserted into an outer needle hub 18 and a coupling part 104 locked to an outer peripheral surface of the outer needle hub 18. A part 116 of the connecting part is a movable member 112 which can be displaced and separated from the coupling part 104. As the movable member 112 engages the protector 128 and is retained in a proximity position to the coupling part 104, the coupling part 104 is locked to the outer needle hub 18. The movable member 112 and the protector 128 are disengaged by deformation of the protector 128 at the actuation, and the movable member 112 is separated from the outer needle hub 18. Consequently, the separation of the inner needle unit 14 from the outer needle unit 12 is allowed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an indwelling needle assembly that is inserted into a body when performing transfusion, blood sampling, hemodialysis, or the like. [Background technology]

[0002] Conventionally, indwelling needle assemblies equipped with an inner needle unit and an outer needle unit have been known as medical tools for use in treatments such as infusion, blood collection, and hemodialysis. In some cases, the indwelling needle assembly is equipped with a protector that protects the inner needle that has been pulled out in order to prevent accidental puncture with the inner needle that has been pulled out after puncturing. An indwelling needle assembly equipped with a protector is disclosed, for example, in Japanese Patent Application Laid-Open No. 2004-24622 (Patent Document 1). After the indwelling needle assembly punctures the patient with the inner needle inserted into the outer needle, the inner needle is pulled out while the outer needle is still puncturing the patient, and the inner needle unit is separated from the outer needle unit, thereby leaving the outer needle unit (indwelling needle) indwelling in the punctured state in the patient.

[0003] In addition, as shown in JP 2022-513285 A (Patent Document 2), the indwelling needle assembly may also be provided with a valve body that switches between communication and blocking of the inner cavity of the outer needle hub in order to prevent blood, etc. from leaking from the base end side of the outer needle hub after the inner needle is removed. As shown in Patent Document 2, the valve body is, for example, a disk-shaped elastic body with a slit that penetrates through, and the inner cavity of the outer needle hub is switched from a blocked state to a communicating state by pushing the slit wide by a pusher arranged on the base end side of the valve body. The pusher is, for example, pushed toward the tip side by a connector connected to the outer needle hub to push the slit of the valve body wide, so that the inner cavity of the outer needle hub is in a communicating state in a state in which blood, etc. are unlikely to leak out to the outside when the connector is connected.

[0004] Furthermore, conventionally, a protective cap is attached to a puncture unit such as an indwelling needle assembly to protect the puncture needle before use in order to prevent accidental punctures. The protective cap has a generally cylindrical shape with a bottom, and the peripheral wall covers the periphery of the puncture needle and the bottom wall covers the tip side of the needle tip, thereby preventing accidental punctures by the puncture needle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-24622 A [Patent Document 1] JP 2022-513285 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, it has been found that there is some room for improvement in the indwelling needle assembly of the conventional structure.

[0007] For example, when the inner needle unit is detached after puncturing, the outer needle unit may be pulled by the inner needle unit and removed from the site to be punctured, and there is still room for improvement in operability for the practitioner. In the indwelling needle assembly described in Patent Document 1, the tip of the second telescopic pipe 21 is firmly fitted into the engagement hole 11B of the hemostatic adapter 11, so the outer needle unit may be pulled by the inner needle unit and removed from the site to be punctured. Therefore, the practitioner must hold the outer needle unit with one hand while pulling out the inner needle unit with the other hand, requiring a special operation.

[0008] Furthermore, in the indwelling needle assembly described in Patent Document 2, the tip portion of the inner needle hub that is inserted into the base end opening of the outer needle hub is extrapolated onto the plunger, so that the tip portion of the inner needle hub is likely to be thin-walled, making it difficult to ensure the deformation rigidity of the tip portion of the inner needle hub. Therefore, there is a problem that tilting of the inner needle hub and the outer needle hub is not sufficiently prevented. If the inner needle hub is made sufficiently thick to protect the deformation rigidity, it becomes necessary to increase the diameter of the outer needle hub, but the inner diameter dimension of the outer needle hub is standardized for connection with a connector, etc., and it is not easy to increase the diameter.

[0009] On the other hand, it is possible to ensure the thickness of the tip portion of the inner needle hub by arranging the tip portion of the inner needle hub facing the pusher in the axial direction, but in this case, the insertion length of the tip portion of the inner needle hub into the base end opening of the outer needle hub is likely to be short, which makes it easy for the inner needle hub and the outer needle hub to become tilted. If the insertion length of the tip portion of the inner needle hub into the outer needle hub is increased in order to solve this, the pusher will be positioned far away from the base end opening of the outer needle hub toward the tip side, which shortens the movement stroke of the pusher toward the tip side when connecting the connector to the outer needle hub, and there is a risk of impairing the stability of the opening and closing operation of the valve body.

[0010] Furthermore, with conventional protective caps, after removing them from the needle unit by holding the needle unit in one hand and the protective cap with the other, it was necessary to re-grip the needle unit, and so a structure was needed that would make it easier to remove the protective cap and return the needle unit to a usable state.

[0011] An object of the present invention is to provide an indwelling needle assembly and a protective cap having a novel structure that can solve at least one of the above-mentioned problems that need to be solved by the conventional art. [Means for solving the problem]

[0012] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely illustrative and may be combined with one another as appropriate, and the multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0013] In a first aspect, in an indwelling needle assembly in which an inner needle unit including an inner needle hub and an outer needle unit including an outer needle hub are separably connected, an inner needle with a protector attached is inserted removably into an outer needle, and the protector moves toward the needle tip as the inner needle is withdrawn, thereby deforming the protector to protect the needle tip, the inner needle unit is provided with a storage housing for storing the protector, and the storage housing is provided with a connecting part inserted into the inner circumference of the outer needle hub and a coupling part engaged with the outer peripheral surface of the outer needle hub in the needle axial direction, The connection portion is composed of a movable member whose portion located opposite the inner circumference of the connecting portion is capable of being displaced radially relative to the connecting portion, and the movable member is held in a position close to the connecting portion by engagement with the protector, thereby holding the connecting portion in an engaged state with the outer peripheral surface of the outer needle hub, and deformation accompanying the needle tip protection operation of the protector releases the engagement between the movable member and the protector, and the movable member moves away from the outer needle hub, allowing separation of the inner needle unit and the outer needle unit.

[0014] With an indwelling needle assembly constructed in accordance with this embodiment, the inner needle unit and the outer needle unit can be easily separated by utilizing the deformation that accompanies the needle tip protection operation of the protector when the inner needle is pulled out from the outer needle.

[0015] Since the movable member moves away from the outer needle hub and toward the inner circumference, there is no need to secure space for the movable member to move on the outer circumference side, as opposed to when the movable member moves toward the outer circumference, and the diameter can be reduced when the movable member moves to a separation-allowing state.

[0016] In a second aspect, in the indwelling needle assembly described in the first aspect, a part of the peripheral wall of the storage housing is formed of a cover member which is separate from the other part, the housing main body, and is attached from the side, the cover member is provided with the connecting portion, and the tip surface of the connecting portion is a tapered tip surface which slopes inwardly towards the tip.

[0017] According to the indwelling needle assembly constructed according to this embodiment, for example, by attaching the cover member to the housing body from the side while the housing body is connected to the outer needle hub, the connecting part of the cover member can be engaged with the outer peripheral surface of the outer needle hub. As a result, the shape of the tip surface of the connecting part is not limited to a shape that takes into consideration the connection between the housing body and the outer needle hub, and can be designed with a large degree of freedom. Therefore, if the tip surface of the connecting part is made a tapered surface, the connecting part can be made smaller, thereby improving ease of holding.

[0018] In the third aspect, in the indwelling needle assembly described in the first or second aspect, an engagement groove is formed on the outer surface of the outer needle hub, into which the connecting portion is inserted to be engaged in the axial direction, and the engagement groove is annular and extends circumferentially.

[0019] An indwelling needle assembly constructed according to this aspect can provide a large engagement allowance between the connecting part and the outer needle hub while preventing an increase in diameter at the engagement portion between the connecting part and the outer needle hub.

[0020] A fourth aspect is an indwelling needle assembly described in any one of the first to third aspects, wherein the base end of the outer needle hub is provided with a locking protrusion that protrudes laterally toward the outer periphery and engages with the connecting portion, and the connecting portion is provided with a rotation prevention portion that engages with the locking protrusion in the circumferential direction.

[0021] With an indwelling needle assembly constructed in accordance with this embodiment, for example, by utilizing a locking protrusion that is screwed into a connector or the like as an engaging part with the connecting part, it is possible to ensure an axial engaging allowance for the connecting part with the outer needle hub without providing a special protrusion or the like.

[0022] Furthermore, the inner needle unit and the outer needle unit can be positioned in the circumferential direction by the anti-rotation portion provided on the connecting portion.

[0023] A fifth aspect is an indwelling needle assembly described in any one of the first to fourth aspects, wherein the inner circumference of the outer needle hub accommodates a valve body that switches the inner cavity of the outer needle hub between open and closed, and the inner circumference of the outer needle hub accommodates a pusher that is positioned base end side of the valve body and switches the valve body to a connected state when pushed toward the tip side, and the tip portion of the storage housing is the connecting part that is fitted into the base end opening of the outer needle hub, and the tip surface of the connecting part and the base end surface of the pusher are opposed to each other in the axial direction, and the tip of the connecting part is located tip end side of the base end of the pusher.

[0024] With an indwelling needle assembly constructed in accordance with the present embodiment, even if the connection portion of the pusher and the inner needle hub are arranged opposite each other in the axial direction, the base end position of the pusher can be set to a position close to the base end opening of the outer needle hub, while ensuring a sufficient fitting length of the connection portion with respect to the base end opening of the outer needle hub, thereby preventing relative tilting (axial misalignment) between the inner needle unit and the outer needle unit.

[0025] Furthermore, by increasing the length of the connecting portion, for example, contact between the connecting portion and the outer needle hub is more easily maintained when the arms of the protector gradually deform inward along the outer surface of the inner needle.

[0026] A sixth aspect is an indwelling needle assembly comprising an inner needle unit having an inner needle hub attached to the base end of an inner needle equipped with a needle tip, and an outer needle unit having an outer needle hub attached to the base end of an outer needle that is inserted onto the inner needle, wherein a valve body that switches the inner cavity of the outer needle hub between communication and blockage is provided on the inner circumference of the outer needle hub, and a pusher is housed on the inner circumference of the outer needle hub, positioned base side of the valve body and switching the valve body to a communicating state when pushed toward the tip side, and the inner needle unit is provided with a connecting portion that is fitted into the base end opening of the outer needle hub, and the tip surface of the connecting portion and the base end surface of the pusher are opposed to each other in the axial direction, and the tip of the connecting portion is located tip side of the base end of the pusher.

[0027] With an indwelling needle assembly constructed in accordance with the present embodiment, even if the connection portion of the pusher and the inner needle hub are arranged opposite each other in the axial direction, the base end position of the pusher can be set to a position close to the base end opening of the outer needle hub, while ensuring a sufficient fitting length of the connection portion with respect to the base end opening of the outer needle hub, thereby preventing relative tilting (axial misalignment) between the inner needle unit and the outer needle unit.

[0028] In addition, by increasing the length of the connection portion, it is easier to maintain contact between the connection portion and the outer needle hub, for example, when the arm of the protector that protects the needle tip after the inner needle is removed gradually deforms inward along the outer surface of the inner needle.

[0029] In a seventh aspect, in the indwelling needle assembly described in the sixth aspect, the pusher is partially provided with an insertion piece protruding toward the base end side in the circumferential direction, and the connection portion of the inner needle unit is formed with an insertion recess that opens to the tip surface and into which the insertion piece of the pusher is inserted.

[0030] With an indwelling needle assembly constructed in accordance with the present embodiment, the base end position of the pusher is set to a position close to the base end opening of the outer needle hub by the insertion piece, while a recess is provided in the connection portion of the inner needle hub into which the insertion piece is inserted, thereby ensuring the fitting length of the connection portion with the outer needle hub in a portion circumferentially outside the recess.

[0031] The eighth aspect is a bottomed, cylindrical protective cap that is attached to a needle unit equipped with a needle hub at the base end of a puncture needle having a needle tip to protect the puncture needle before use, and has a large-diameter base portion whose base end portion has a larger diameter than the tip end portion, and the base end portion of the large-diameter base is provided with an operating surface that slopes inwardly towards the base end.

[0032] With an indwelling needle assembly constructed according to this embodiment, the protective cap can be easily removed from the needle unit, for example, with the fingers of the hand holding the needle unit, by pushing the operating surface toward the tip side (needle tip side) with the fingers. The operating surface is formed on the large-diameter base of the proximal end portion of the protective cap, which allows a large area to be secured, making it easier to press with the fingers and reducing pain and discomfort when pressing. Moreover, the operating surface is an inclined surface that slopes toward the tip side toward the outer periphery, so the operating surface can be easily pressed with the fingers of the hand holding the needle unit.

[0033] In a ninth aspect, in the indwelling needle assembly described in the eighth aspect, a positioning portion is provided which positions the circumferential orientation relative to the needle hub, and the pair of operating surfaces are positioned on the tip side in the same circumferential orientation relative to a pair of gripping surfaces provided on either side of the needle hub by the positioning portion.

[0034] With the indwelling needle assembly constructed according to this aspect, while the needle hub is being gripped by pinching the pair of gripping surfaces between the fingers, the operating surface located at the tip side of the gripping surfaces can be pressed with the fingers. Moreover, since the operating surface is located at the tip side of both gripping surfaces, the operating surface can be pressed with the fingers in the same way regardless of whether the needle unit is held in the left or right hand. Effect of the Invention

[0035] According to one aspect of the present invention relating to the indwelling needle assembly, the inner needle unit and the outer needle unit can be easily separated. According to another aspect of the present invention relating to the indwelling needle assembly, the base end position of the plunger can be set to a position close to the base end opening of the outer needle hub, while preventing relative tilting (axial misalignment) between the inner needle hub and the outer needle hub.

[0036] Furthermore, according to the present invention relating to the protective cap, it can be easily removed from the needle unit to make the needle unit ready for use. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a perspective view showing an indwelling needle assembly according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a plan view of the indwelling needle assembly shown in FIG. [Diagram 3] FIG. 2 is a left side view of the indwelling needle assembly shown in FIG. [Figure 4] FIG. 2 is a right side view of the indwelling needle assembly shown in FIG. [Diagram 5] VV cross section of Figure 2 [Figure 6] VI-VI cross section of Figure 4 [Figure 7] FIG. 2 is a perspective view of an outer needle unit constituting the indwelling needle assembly shown in FIG. [Figure 8] FIG. 8 is a perspective view of a pusher constituting the outer needle unit shown in FIG. [Figure 9] FIG. 2 is a perspective view of an inner needle unit constituting the indwelling needle assembly shown in FIG. [Figure 10] FIG. 5 is a cross-sectional view of the indwelling needle assembly shown in FIG. 1, which corresponds to XX in FIG. [Figure 11] FIG. 10 is a perspective view of a movable member constituting the inner needle unit shown in FIG. [Figure 12] FIG. 12 is a perspective view showing the movable member shown in FIG. 11 from a different angle. [Figure 13] FIG. 10 is a perspective view of a needle tip protector constituting the inner needle unit shown in FIG. [Figure 14] FIG. 2 is an enlarged perspective view showing a main part of the indwelling needle assembly shown in FIG. [Figure 15] FIG. 17 is a cross-sectional view of the indwelling needle assembly shown in FIG. 1, which corresponds to XV-XV in FIG. 16. [Figure 16] Sectional view of XVI-XVI in Fig. 4 [Figure 17] FIG. 7 is a longitudinal cross-sectional view showing the indwelling needle assembly shown in FIG. 6 in a state where the inner needle has been pulled out from the outer needle. [Figure 18A] FIG. 2 is an enlarged cross-sectional view of a main part illustrating a process of separating the outer needle unit and the inner needle unit in the indwelling needle assembly shown in FIG. 1, and illustrates a protector in an activated state in which the inner needle has been pulled out. [Figure 18B] FIG. 2 is an enlarged cross-sectional view of a main portion illustrating a process of separating the outer needle unit and the inner needle unit in the indwelling needle assembly shown in FIG. 1, and illustrating a relative displacement state of a movable member with respect to a housing main body. [Figure 18C] FIG. 2 is an enlarged cross-sectional view of a main portion illustrating a process of separating an outer needle unit and an inner needle unit in the indwelling needle assembly illustrated in FIG. 1, showing the separated state of the outer needle unit and the inner needle unit. [Figure 19] FIG. 11 is a perspective view showing an indwelling needle assembly with a protective cap according to a second embodiment of the present invention. [Figure 20] FIG. 27 is a longitudinal cross-sectional view of the indwelling needle assembly shown in FIG. 19, which corresponds to the line XX-XX in FIG. 26. [Figure 21] FIG. 20 is a perspective view of a protective cap constituting the indwelling needle assembly shown in FIG. 19 . [Figure 22] 22 is a plan view of the protective cap shown in FIG. 21. [Diagram 23] Bottom view of the protective cap shown in Figure 21 [Figure 24] Right side view of the protective cap shown in Figure 21 [Diagram 25] Enlarged rear view of the protective cap shown in Figure 21 [Figure 26] XXVI-XXVI cross section of Figure 20 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0039] 1 to 6 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 outer needle unit 12 and an inner needle unit 14 are separably combined. In the following description, as a general rule, the up-down direction refers to the up-down direction in Fig. 3, the front-rear direction refers to the up-down direction in Fig. 2 which is the needle axial direction, and the left-right direction refers to the left-right direction in Fig. 2. In addition, as a general rule, the tip side refers to the front side which is the side of a needle tip 48 described later, and the base side refers to the rear side which is the opposite side to the needle tip 48.

[0040] 7, the outer needle unit 12 has a structure in which an outer needle hub 18 is fixed to the base end of an outer needle 16. The outer needle 16 is in the form of a hollow tube made of resin or the like, and has a tapered tip. It is desirable that the outer needle 16 has a degree of flexibility that allows the outer needle hub 18 to be fixed (taped) to the body surface of a patient when, for example, the outer needle 16 is inserted into a blood vessel of the patient.

[0041] The outer needle hub 18 has a hollow, generally cylindrical shape, and the tip portion of the outer peripheral surface has a smaller diameter than the base portion. The smaller-diameter tip portion of the outer needle hub 18 is fitted onto the base end portion of the outer needle 16 and fixed to the outer needle 16 by means of welding, adhesion, or the like. The inner cavity of the outer needle hub 18 is in communication with the inner cavity of the outer needle 16.

[0042] An upwardly protruding pusher piece 24 is integrally formed at the base end portion of the large-diameter outer needle hub 18. The pusher piece 24 is plate-shaped extending approximately perpendicular to the needle axial direction, and is located in the middle in the axial direction of the base end portion of the outer needle hub 18. Furthermore, the left and right side surfaces of the base end portion of the outer needle hub 18 form a pair of flat surfaces 26, 26.

[0043] A pair of locking protrusions 28a, 28b protruding outwardly are integrally formed at the base end of the outer needle hub 18. The locking protrusions 28 protrude outwardly in the left-right direction and have a tapered shape that narrows in the circumferential direction toward the protruding tip. One of the locking protrusions 28a has a notch 30 formed in the approximate center in the circumferential direction and is divided into two circumferential sides with the notch 30 in between.

[0044] A locking groove 32 that opens onto the outer circumferential surface and extends in the circumferential direction is formed in the base end portion of the outer needle hub 18. The locking groove 32 is an annular recessed groove that is formed continuously around the entire circumference and extends without inclining in the axial direction. The locking groove 32 is located close to the tip sides of the pair of locking protrusions 28a, 28b, which effectively lengthens the radial length of the front surfaces of the pair of locking protrusions 28a, 28b.

[0045] As shown in Figs. 5 and 6, a valve body 34 is housed in the inner cavity of the outer needle hub 18. The valve body 34 is made of rubber, resin elastomer, or the like, and is elastically deformable. The valve body 34 is substantially disk-shaped, and has slits 36 extending radially from the center, and the opening and closing of the slits 36 switches between communication and blocking of the inner cavity of the outer needle hub 18. The outer peripheral portion of the valve body 34 is positioned relative to the outer needle hub 18 by clamping the outer peripheral end between a step provided on the inner peripheral surface of the outer needle hub 18 and a support member 38 that is press-fitted and fixed to the outer needle hub 18 on the proximal side of the valve body 34. When the valve body 34 is attached to the outer needle hub 18, a pressing force acts toward the inner circumference, so that the inner surfaces of the slits 36 are in close contact with each other to block the slits 36, and the inner cavity of the outer needle hub 18 is blocked by the valve body 34.

[0046] A plunger 40 is disposed on the base end side of the valve body 34 in the inner cavity of the outer needle hub 18. As shown in FIG. 8, the plunger 40 has a generally cylindrical shape, and the outer circumferential surface of the tip portion is tapered to a point. The plunger 40 is provided with a pair of insertion pieces 42, 42 that protrude toward the base end side. The insertion pieces 42 are provided partially in the circumferential direction of the plunger 40, and in this embodiment, are provided on both the left and right sides of the plunger 40 and face each other in the left-right direction. The base end of the insertion piece 42 protrudes outward to the left and right, ensuring a large area for the base end face.

[0047] The plunger 40 is held on the inner circumferential side of the support member 38 in a state in which movement towards the base end side is restricted and movement towards the tip end side is permitted. When the plunger 40 is pushed and moved towards the tip end side, the plunger 40 is inserted into the slit 36 ​​of the valve body 34, the valve body 34 is brought into an open state, and the inner cavity of the outer needle hub 18 is switched to a communicated state.

[0048] As shown in Fig. 9, the inner needle unit 14 has a structure in which an inner needle hub 46 is attached to the base end of an inner needle 44. The inner needle 44 is formed of a known metal material such as stainless steel, aluminum, titanium or an alloy thereof, and is a tube with a lumen penetrating in the axial direction as shown in Figs. 5 and 6, and is provided with a sharp needle tip 48 at its tip. The needle tip 48 is formed by forming the tip surface of the inner needle 44 into a blade surface 50 that widens and is inclined with respect to the needle axis. The tip portion of the inner needle 44 may have a through hole that penetrates the needle wall.

[0049] The inner needle hub 46 includes a hub body 52 fixed to the base end of the inner needle 44. The hub body 52 includes a fixed tube portion 54 fixed to the inner needle 44 in an externally fitted state, and a housing tube portion 56 surrounding the outer periphery of the fixed tube portion 54. The fixed tube portion 54 and the housing tube portion 56 are integrated with each other at the tip side, and a tube-shaped portion 58 protruding from the fixed tube portion 54 and the housing tube portion 56 toward the tip side is provided. A filter 60 that allows air to pass and restricts blood to pass is provided at the base end opening of the housing tube portion 56. When the inner needle 44 punctures a blood vessel, blood that has flowed into the lumen of the hub body 52 through the lumen of the inner needle 44 is retained in the lumen of the hub body 52 by the filter 60 without leaking out to the outside. It is preferable that at least a part of the housing tube portion 56 of the hub body 52 is transparent or semi-transparent so that blood that has flowed into the lumen can be visually observed from the outside.

[0050] The inner needle unit 14 includes an inner needle storage section 62. In this embodiment, the inner needle storage section 62 has a multi-tube structure in which a plurality of (three) axially extending tubular bodies are inserted inside and outside the inner needle storage section 62 approximately concentrically, and includes a first tubular body 64 located on the outermost side, a second tubular body 66 located in the middle in the radial direction, and a third tubular body 68 located on the innermost side. The first to third tubular bodies 64, 66, 68 are combined in a telescopic structure inserted inside and outside the inner needle storage section 62 so as to be expandable and contractible in the axial direction. In this embodiment, the inner needle hub 46 fixed to the base end side of the inner needle 44 is composed of the hub body 52 and the first tubular body 64.

[0051] The first cylindrical body 64 has a generally cylindrical shape overall. A pair of plate-shaped gripping portions 70, 70 are provided on both the left and right sides of the front half of the first cylindrical body 64. The plate-shaped gripping portion 70 extends generally perpendicular to the left-right direction, and its vertical width dimension is larger than the outer diameter dimension of the cylindrical portion of the first cylindrical body 64. A user of the indwelling needle assembly 10 can easily grip the first cylindrical body 64 by pinching the plate-shaped gripping portions 70, 70 between their fingertips.

[0052] The plate-shaped gripping portion 70, 70 has gripping surfaces 74, 74 whose left and right outer surfaces extend substantially perpendicular to the left and right direction, making it easier to pinch and grip with fingertips than the cylindrical portion. The gripping surface 74 is, for example, a flat surface or a concave curved surface to make it easier to grip. The gripping surface 74 can also be provided with a slip-proof surface such as fine unevenness, or with a shape or mark indicating that it is a part to be gripped. The gripping surface 74 of this embodiment has a plurality of protrusions 76 extending in the vertical direction and spaced apart from each other in the front-rear direction, making it difficult for the fingers to slip in the front-rear direction when inserting or removing the needle while holding the gripping surface 74 with the fingers.

[0053] The upper surface of the tip portion of the first cylindrical body 64 is a pressing surface 78 that is approximately perpendicular to the up-down direction. The pressing surface 78 is provided between a pair of plate-shaped gripping parts 70, 70, and at the axial position where the pressing surface 78 is provided, the outer peripheral surface of the first cylindrical body 64 has three surfaces, the left and right sides and the upper surface, that are approximately flat. Therefore, for example, by pinching the pair of gripping surfaces 74, 74 with fingertips from both the left and right sides and placing another fingertip on the pressing surface 78 from above, it is easy for the practitioner to stably hold the three surfaces excluding the surface located on the patient's body surface by placing his / her fingertips on each of them. In addition, when puncturing, the needle tip 48 side can be tilted downward by pressing the pressing surface 78 with the fingers while pinching the pair of gripping surfaces 74, 74 with the fingertips, making it easier to press the needle tip 48 against the patient's skin and puncture it. In this embodiment, the axial distance between the cylindrical outer peripheral surface of the first cylindrical body 64 and the pressing surface 78 is an inclined curved surface that slopes downward toward the tip, reducing the discomfort felt when placing the fingertips on the pressing surface 78.

[0054] The second cylindrical body 66 has a substantially constant diameter dimension over substantially the entire axial length, and has an axial dimension that is shorter than that of the first cylindrical body 64. A base end of the second cylindrical body 66 is provided with a base end engagement claw 80 that protrudes outwardly, and a tip end engagement claw 82 that protrudes inwardly is provided at the tip of the second cylindrical body 66.

[0055] The third cylindrical body 68 has a generally stepped cylindrical shape with a diameter dimension that varies in the axial direction as a whole. That is, the third cylindrical body 68 has a distal end portion that is generally rectangular in shape and has a large diameter to serve as a storage housing 84 for storing a protector 128 (described later), and a small-diameter cylindrical portion 86 that is generally cylindrical and has a smaller diameter than the storage housing 84 on the proximal side of the storage housing 84 is formed. The inner needle 44 is inserted through the lumen of the third cylindrical body 68, and the inner needle 44 protrudes further toward the distal side than the distal end of the third cylindrical body 68.

[0056] The storage housing 84 includes a housing main body 88 that is integrally formed with the third cylindrical body 68, and a cover member 90 that is a separate part that is attached to the housing main body 88. The housing main body 88 is shaped like a rectangular box that opens forward (toward the tip) and to the left as a whole. A window 92 that has a substantially rectangular cross section and penetrates in the left-right direction is provided in the right wall of the housing main body 88. Hooks 94 that protrude outward in the vertical direction are formed integrally on both the upper and lower side surfaces of the housing main body 88, respectively.

[0057] The storage housing 84 also includes a first connection piece 96 as a connection part that protrudes from the right wall of the housing main body 88 toward the tip side. The first connection piece 96 is plate-shaped and extends in a direction intersecting the left-right direction, and has an outer peripheral surface (right side) with an arc-shaped cross section that curves in the circumferential direction, and a flat inner peripheral surface (left side) that extends approximately perpendicular to the left-right direction. As shown in FIG. 6, the outer peripheral surface of the first connection piece 96 has a luer taper that inclines toward the inner peripheral side toward the tip side. A first insertion recess 98 is formed at the tip of the first connection piece 96 as an insertion recess that opens on the tip surface. The first insertion recess 98 opens on the tip surface at the center part of the first connection piece 96 in the up-down direction, and penetrates the first connection piece 96 in the left-right direction. The first insertion recess 98 has an open end toward the tip side that expands up and down toward the tip, making it easy to insert the insertion piece 42 of the plunger 40.

[0058] The cover member 90 is integrally provided with a plate-shaped cover body 100 shown in FIG. 6 and a pair of mounting parts 102, 102 (see FIG. 5) extending rightward from both upper and lower ends of the cover body 100. The cover member 90 is made of, for example, resin or metal, and at least the mounting part 102 is flexible. The cover body 100 is made in a substantially rectangular plate shape, and is sized and shaped to cover the left opening of the housing body 88. As shown in FIG. 10, the left opening of the housing body 88 is covered with the cover body 100, so that a storage space for a protector 128 (described later) extending in the front-rear direction with a substantially rectangular cross section is formed inside the storage housing 84. The cover body 100 is made in a stepped plate shape with a step provided midway in the front-rear direction, and the tip side is located leftward and outward from the base end side.

[0059] A connecting portion 104 is integrally provided on the tip side of the cover body 100 of the cover member 90. The connecting portion 104 protrudes leftward and forward from the tip of the cover body 100 and extends in the circumferential direction to have a predetermined width in the vertical direction. The connecting portion 104 has a tapered tip surface 106 whose tip surface (front end surface) is inclined toward the tip side as it approaches the right side, which is the inner periphery side. As shown by the dashed line in FIG. 6, the connecting portion 104 has a hollow structure in which a locking recess 108 that opens on the right side surface is provided. Furthermore, the connecting portion 104 is integrally provided with a positioning piece 110 that protrudes into the locking recess 108 at the center in the vertical direction. The positioning piece 110 is in the shape of a plate that extends approximately perpendicular to the vertical direction and protrudes rightward from the inner surface of the locking recess 108. As shown in FIG. 6, the positioning piece 110 is positioned within the locking recess 108 without protruding from the opening of the locking recess 108 .

[0060] The mounting portions 102 of the cover member 90 extend rightward from the upper and lower ends at both the front and rear ends of the cover body 100, and are frame-shaped and interconnected in the front-rear direction at the right end.

[0061] The cover member 90 is attached to the housing main body 88 from the side by hooking a pair of upper and lower mounting portions 102, 102 onto the latch portions 94 of the housing main body 88. When the cover member 90 is attached to the housing main body 88, the window portions 92 of the housing main body 88 are covered by the cover main body 100, thereby forming the storage housing 84 having a recessed storage space that opens toward the tip side.

[0062] A movable member 112 is disposed at the tip portion of the storage housing 84. As shown in Figures 11 and 12, the movable member 112 includes a protector engagement portion 114 and a second connection piece 116 as a connection portion that protrudes from the protector engagement portion 114 toward the tip side.

[0063] The protector engagement portion 114 is a hard member made of resin or metal. The protector engagement portion 114 is generally in the shape of a rectangular box that opens toward the base end, and includes a protector insertion recess 118 that opens toward the base end side. A circular needle insertion hole 120 that penetrates in the front-rear direction is formed in the front wall of the protector insertion recess 118. A tapered relief surface 122 that expands leftward toward the opening side is provided in the opening portion on the inner wall of the left side of the protector insertion recess 118. In this embodiment, the right side surface of the protector engagement portion 114 is curved in a substantially arc shape when viewed in the front-rear direction, and includes an inclined surface that inclines rightward toward the tip side, so that the protector engagement portion 114 is less likely to protrude rightward from the storage housing 84 after the movable member 112 described later moves.

[0064] The second connection piece 116 is substantially symmetrical to the first connection piece 96, with the outer circumferential surface (left side surface) being a curved surface with a substantially arc-shaped cross section with a lure taper set, and the inner circumferential surface (right side surface) being a flat surface that spreads perpendicularly to the left-right direction. In addition, a second insertion recess 124 is formed at the tip of the second connection piece 116 as an insertion recess. The second insertion recess 124 has substantially the same shape and size as the first insertion recess 98, and is a groove-like shape that penetrates in the left-right direction while opening at the tip surface of the second connection piece 116. The second connection piece 116 protrudes from the left end of the protector engagement part 114 toward the tip side. In this embodiment, a rectangular block-shaped base 126 that protrudes toward the tip side is provided at the left end of the protector engagement part 114, and the second connection piece 116 protrudes from the base 126 toward the tip side.

[0065] The movable member 112 is attached to the storage housing 84 as shown in FIG. 6. That is, the protector engagement portion 114 of the movable member 112 is inserted into the storage space of the storage housing 84, and the right end portion of the protector engagement portion 114 is inserted into the window portion 92 of the storage housing 84, thereby setting the relative position of the movable member 112 in the front-rear direction with respect to the storage housing 84. By attaching the movable member 112 to the storage housing 84, the opening to the tip side of the storage housing 84 is covered by the movable member 112, and the internal space of the storage housing 84 is opened to the tip side through the needle insertion hole 120 of the movable member 112. In a state in which the movable member 112 is attached to the storage housing 84, the first connection piece 96 of the storage housing 84 and the second connection piece 116 of the movable member 112 are arranged to face each other in the left-right direction. The second connection piece 116 is positioned to face the inner periphery side of the connection portion 104 of the cover member 90 in the left-right direction.

[0066] A protector 128 is stored in the internal space (storage space) of the storage housing 84. As shown in FIG. 13, the protector 128 includes a pair of elastic pieces 132, 132 extending from a bottom wall portion 130 toward the tip side. The bottom wall portion 130 is a rectangular plate, and a circular needle insertion hole 134 is formed penetrating the bottom wall portion 130 in the front-rear direction. The pair of elastic pieces 132, 132 are rectangular plates that are elongated in the front-rear direction, extend toward the tip side at both left and right ends of the bottom wall portion 130, and face each other in the left-right direction. The elastic pieces 132, 132 of this embodiment have different length dimensions in the front-rear direction. At the tips of the pair of elastic pieces 132, 132, a needle tip protection piece 136 that protrudes toward the inside in the opposing direction is provided. The needle tip protection piece 136 is a rectangular plate, and an arc-shaped notch 138 is formed on the protruding tip surface. The needle tip protection piece 136 is disposed facing the bottom wall portion 130 at a distance from the tip side, and is inclined toward the base end side toward the protruding tip. The protector 128 of this embodiment is formed of a pressed metal plate, and is integrated as a whole. Note that Fig. 13 shows a state in which the inner needle 44 is inserted and the pair of elastic pieces 132, 132 are pushed open, but in the protector 128 in a single state, the pair of elastic pieces 132, 132 are inclined inward in the opposing direction toward the tip side, and the needle tip protection pieces 136 provided on each elastic piece 132 overlap each other when projected in the front-rear direction (see Figs. 17 and 18A described later).

[0067] The protector 128 is attached in an outer fitted state to the inner needle 44 and is stored in the storage space of the storage housing 84. The inner needle 44 is inserted through a needle insertion hole 134 in a bottom wall portion 130 of the protector 128. The inner needle 44 is also inserted between a pair of needle tip protection pieces 136, 136 of the protector 128, and the needle tip protection pieces 136, 136 contact the outer circumferential surface of the inner needle 44 at each notch 138. As a result, the pair of elastic pieces 132, 132 of the protector 128 are pushed outward to the left and right by the inner needle 44, and the tip portions are elastically deformed in directions separating them from each other, and are urged in directions approaching each other.

[0068] The protector 128 has a bottom wall portion 130 overlapped on the inner rear wall surface of the housing main body 88, and a tip portion equipped with a pair of needle tip protection pieces 136, 136 is inserted into the protector insertion recess 118 of the movable member 112. The tip portions of the protector 128 are overlapped on the left and right inner surfaces of the protector insertion recess 118 in a state separated from each other by the insertion of the inner needle 44. In this manner, the tip portion of the protector 128 engages with the left and right inner surfaces of the protector insertion recess 118, thereby positioning the movable member 112 in the left and right direction relative to the storage housing 84. In addition, when the storage housing 84 and the movable member 112 are positioned, the inner cavity of the first tubular body 64, the needle insertion hole 134 of the bottom wall portion 130 of the protector 128, and the needle insertion hole 120 of the movable member 112 are arranged in series and aligned in approximately the same straight line in the front-to-back direction, and the inner needle 44 is inserted through the inner cavity of the first tubular body 64, the needle insertion hole 134 of the protector 128, and the needle insertion hole 120 of the movable member 112.

[0069] The movable member 112 is positioned relative to the storage housing 84 by engagement with the protector 128, and is therefore close to the cover member 90 in the left-right direction. As a result, the second connection piece 116 of the movable member 112 is held in a position close to the coupling portion 104 of the cover member 90 in the left-right direction. In addition, the protector engagement portion 114 of the movable member 112 is overlapped and abuts against the cover main body 100 of the cover member 90 in the left-right direction.

[0070] In addition, in Figure 6, the protector 128 has a pair of elastic pieces 132, 132 extending in the front-to-rear direction approximately parallel to the needle axis of the inner needle 44, and the left and right outer surfaces of the pair of elastic pieces 132, 132 are overlapped against the left and right inner surfaces of the storage housing 84 and the protector insertion recess 118 of the movable member 112. However, the pair of elastic pieces 132, 132 may, for example, be inclined relatively to the needle axis direction of the inner needle 44, abutting the left and right inner surfaces of the storage housing 84 at the base end and abutting the left and right inner surfaces of the protector insertion recess 118 of the movable member 112 at the tip end, and being separated from the storage housing 84 and the movable member 112 at the middle portion.

[0071] The indwelling needle assembly 10 of this embodiment is constructed by combining the outer needle unit 12 and the inner needle unit 14 structured as described above. That is, the inner needle 44 fitted with the protector 128 is inserted from the base end opening of the outer needle hub 18 and passes through the inner cavities of the outer needle hub 18 and the outer needle 16, and the needle tip 48 of the inner needle 44 protrudes from the tip opening of the outer needle 16. The inner needle 44 is inserted through the outer needle 16 and the outer needle hub 18 so as to be retractable toward the base end side. The inner needle 44 is inserted through the slit 36 ​​of the valve body 34, but since the valve body 34, which has had the slit 36 ​​pushed open by the inner needle 44, is pressed against the outer peripheral surface of the inner needle 44, the spaces on both the front and rear sides of the valve body 34 in the inner cavity of the outer needle hub 18 are not communicated with each other and are liquid-tightly separated.

[0072] The first and second connecting pieces 96, 116 of the inner needle unit 14 are fitted into the proximal end opening of the outer needle hub 18. This causes the inner needle unit 14 and the outer needle unit 12 to be connected to each other.

[0073] The distal end surfaces of the first and second connecting pieces 96, 116 fitted into the proximal end opening of the outer needle hub 18 and the proximal end surface of the pusher 40 housed in the outer needle hub 18 face each other in the axial direction. This makes it possible to prevent the inner diameter of the outer needle hub 18 from becoming larger than when the first and second connecting pieces 96, 116 are extrapolated onto the pusher 40, for example, while ensuring the wall thickness of the first and second connecting pieces 96, 116 and obtaining sufficient deformation rigidity. Note that the first and second connecting pieces 96, 116 and the pusher 40 may face each other at a distance in the axial direction, but are preferably overlapped facing each other in an abutting state.

[0074] Furthermore, the pair of insertion pieces 42, 42 provided at the base end of the pusher 40 are inserted into the first and second insertion recesses 98, 124 of the first and second connecting pieces 96, 116, and the tip of the first and second connecting pieces 96, 116 at a portion outside the first and second insertion recesses 98, 124 is located on the tip side of the base end of the pair of insertion pieces 42, 42 of the pusher 40. As a result, while the base end position of the pusher 40 is set to a predetermined position close to the base end opening of the outer needle hub 18 in the pair of insertion pieces 42, 42, a large fit margin of the first and second connecting pieces 96, 116 with the outer needle hub 18 in the axial direction is secured in a portion circumferentially outside the pair of insertion pieces 42, 42 (first and second insertion recesses 98, 124), and relative inclination (axial misalignment) of the inner needle unit 14 and the outer needle unit 12 is prevented.

[0075] 14 and 15 , the connecting part 104 of the cover member 90 of the inner needle unit 14 is locked in the front-to-rear direction to one locking protrusion 28a of the outer needle hub 18. The locking protrusion 28a is inserted into a locking recess 108 of the connecting part 104, and the rear inner surface of the locking recess 108 is superimposed on the base end surface of the locking protrusion 28a and the front inner surface of the locking recess 108 is superimposed on the front surface of the locking protrusion 28a, thereby locking the connecting part 104 to the locking protrusion 28a in the axial direction. Movement of the inner needle unit 14 towards the base end side relative to the outer needle unit 12 is restricted by the engagement between the locking protrusion 28a and the connecting part 104. Since the second connecting piece 116 of the movable member 112 is located close to the connecting portion 104, the movement of the locking protrusion 28a of the outer needle hub 18 toward the inner circumference is restricted by the second connecting piece 116, and the engaged state between the locking protrusion 28a and the connecting portion 104 is maintained.

[0076] The tip of the connecting part 104 is inserted into a locking groove 32 that opens into the outer peripheral surface of the outer needle hub 18, and is locked in the axial direction against the inner surface of the locking groove 32. As a result, a large locking margin for the connecting part 104 with the outer needle hub 18 is ensured by cooperation between the inner surface of the locking groove 32 and the front surface of the locking projection 28a, and the connected state of the outer needle unit 12 and the inner needle unit 14 is stabilized.

[0077] In this embodiment, the cover member 90 having the connecting portion 104 is a separate part from the housing main body 88 formed integrally with the third cylindrical body 68, and can be easily attached by approaching the housing main body 88 from the left. Therefore, the inner needle unit 14 without the cover member 90 is inserted into the outer needle unit 12 in the needle axial direction from the base end side to the tip end side, and then the cover member 90 is assembled to the housing main body 88 of the inner needle unit 14 from the left, so that the connecting portion 104 of the cover member 90 covers the entire surface of the locking protrusion 28a of the outer needle hub 18. In this manner, the locking structure formed by the connecting portion 104 and the locking protrusion 28a is configured by attaching the cover member 90 from the side after the inner needle 44 has been inserted into the outer needle 16, and inserting the locking protrusion 28a into the locking recess 108 of the connecting portion 104. Therefore, the tip surface of the connecting portion 104 does not need a tapered surface for axially climbing over the locking protrusion 28a, i.e., a tapered surface that slopes toward the base end toward the inner circumference, and a tapered tip surface 106 is set on the tip surface of the connecting portion 104, thereby preventing the connecting portion 104 from protruding toward the outer periphery.

[0078] The cover member 90 is attached to the housing main body 88 in a state in which the third cylindrical body 68 is pulled out from the first cylindrical body 64 toward the distal end and the housing main body 88 is exposed further toward the distal end than the first cylindrical body 64. Then, by contracting the inner needle storage section 62 after the attachment of the cover member 90 is complete, the cover member 90 is placed in a state in which the connecting section 104 is exposed close to the distal end side of the first cylindrical body 64 and the cover main body 100 is housed within the inner periphery of the first cylindrical body 64.

[0079] 16, the positioning piece 110 protruding into the locking recess 108 of the connecting part 104 is inserted into the notch 30 of the locking projection 28a, and the inner needle unit 14 and the outer needle unit 12 are positioned relative to each other in the circumferential direction by engagement of the positioning piece 110 with the upper and lower inner surfaces of the notch 30 in the locking projection 28a. In this embodiment, the inner needle unit 14 and the outer needle unit 12 are also positioned in the circumferential direction by components of the upper and lower wall parts of the locking recess 108 in the connecting part 104 engaging with both the upper and lower end faces of the locking projection 28a. Thus, in the connecting part 104 of this embodiment, the positioning piece 110 and the upper and lower wall parts of the locking recess 108 form a rotation prevention part.

[0080] The indwelling needle assembly 10 of this embodiment thus constructed is inserted into a blood vessel in the patient's arm, etc., with the inner needle 44 inserted through the outer needle 16 and protruding toward the tip side. When inserting the blood vessel, as described above, the pair of gripping surfaces 74, 74 of the inner needle hub 46 is pinched between the fingertips while the pressing surface 78 provided on the upper surface of the inner needle hub 46 is pressed downward with the index finger, thereby pressing the needle tip 48 against the patient's skin.

[0081] Then, by removing the inner needle 44 from the outer needle 16, the outer needle unit 12 is left indwelling with the outer needle 16 punctured into a blood vessel, and by connecting a blood circuit or an infusion circuit (not shown) to the left outer needle unit 12, the outer needle unit 12 is used as an indwelling needle that constitutes a blood removal port or blood return port of a blood circuit, or an infusion administration port of an infusion circuit, etc. When removing the inner needle 44 from the outer needle 16 toward the base end, the inner needle 44 can be pulled toward the base end while pushing out the pushing piece 24 provided on the outer needle hub 18 toward the tip end with the tip of the index finger, thereby preventing the outer needle 16 from coming out of the blood vessel.

[0082] When the inner needle 44 is removed from the outer needle 16, the inner needle 44 is stored in the inner needle storage section 62 of the inner needle unit 14. That is, since the base end of the inner needle 44 is fixed to the first cylindrical body 64 via the hub body 52, the first cylindrical body 64 having the gripping surfaces 74, 74 is pulled toward the base end when the inner needle 44 is removed. Then, when the first cylindrical body 64 is pulled toward the base end, the first to third cylindrical bodies 64, 66, 68 having a telescopic structure are relatively displaced, as shown in Fig. 17, and the inner needle storage section 62 is deformed into an extended state. More specifically, when the first cylindrical body 64 is pulled toward the base end, the first cylindrical body 64 moves toward the base end relative to the second cylindrical body 66, and when the tip portion of the first cylindrical body 64 and the base end portion (base end engaging claw 80) of the second cylindrical body 66 are locked in the axial direction, the second cylindrical body 66 moves toward the base end relative to the third cylindrical body 68. This causes the inner needle storage section 62 to enter an extended state, and the entire inner needle 44 is stored in the inner circumference of the inner needle storage section 62. This makes it possible to prevent accidental touching of the inner needle 44 that has been removed after puncturing, thereby preventing accidental puncturing, contamination due to blood splashing, and the like.

[0083] 18A, the needle tip 48 of the inner needle 44 after withdrawal is covered and protected by the protector 128. That is, when the first cylindrical body 64 is pulled toward the base end when the inner needle 44 is withdrawn, the protector 128 stored in the storage housing 84 of the third cylindrical body 68 moves relatively toward the needle tip 48 with respect to the inner needle 44. Then, as shown in FIG. 18B, when the needle tip 48 of the inner needle 44 moves toward the base end beyond the pair of needle tip protection pieces 136, 136 of the protector 128 and the abutment state between the pair of needle tip protection pieces 136, 136 and the outer circumferential surface of the inner needle 44 is released, the elasticity of the pair of elastic pieces 132, 132 causes the pair of needle tip protection pieces 136, 136 to move in a direction approaching each other and are positioned on an extension line toward the tip side of the inner needle 44. As a result, the distal end side of the needle tip 48 of the inner needle 44 is covered by the pair of needle tip protection pieces 136, 136, preventing the inner needle 44 from re-protruding toward the distal end side, thereby avoiding problems such as erroneous puncture.

[0084] Incidentally, the protector 128 before the above-mentioned needle tip protection activation has the function of relatively positioning the housing main body 88 and the cover member 90 of the third cylindrical body 68 in the left-right direction in the inner needle unit 14. When the tip ends of the pair of elastic pieces 132, 132 of the protector 128 are displaced closer to each other by the needle tip protection activation, the left-right lock between the tip end of the protector 128 and the protector engagement portion 114 of the movable member 112 is released, as shown in Figure 18B, and displacement of the movable member 112 to the right relative to the housing main body 88 is permitted.

[0085] 18B, when the movable member 112 is displaced to the right relative to the housing main body 88, the second connecting piece 116 of the movable member 112 is displaced toward the first connecting piece 96 of the housing main body 88 in the left-right direction, and the first and second connecting pieces 96, 116 are released from the engagement with the outer needle hub 18. Then, since the inner needle unit 14 including the first and second connecting pieces 96, 116 can be displaced leftward relative to the outer needle hub 18, when the connecting part 104 of the inner needle unit 14 is displaced leftward relative to the locking projection 28a of the outer needle hub 18, as shown in Figure 18C, the connecting part 104 moves away to the left relative to the locking projection 28a, and the locking of the connecting part 104 and the locking projection 28a in the front-rear direction is released. This releases the connection between the inner needle unit 14 and the outer needle unit 12, which is formed by the engagement between the connecting portion 104 and the locking protrusion 28a, making it possible to separate the inner needle unit 14 from the outer needle unit 12.The inner needle unit 14 can then be removed while leaving the outer needle unit 12 in a punctured state in the patient's blood vessel.

[0086] 18B, the movable member 112 does not protrude significantly outward when moved relative to the housing main body 88, preventing the movable member 112 from becoming larger in diameter when displaced. As a result, even if a user holds the connection portion between the inner needle unit 14 and the outer needle unit 12, changes in ease of holding due to displacement of the movable member 112 can be avoided.

[0087] Furthermore, when releasing the engagement of the connecting part 104 with the locking protrusion 28a, the entire storage housing 84 only needs to be displaced to the right, and there is no significant change in the external shape or size of the storage housing 84. Therefore, even if the operation of separating the inner needle unit 14 from the outer needle unit 12 is performed while holding the storage housing 84, there is little change in ease of holding, etc.

[0088] Furthermore, by increasing the length of the first and second connecting pieces 96, 116, for example, when the elastic pieces 132, 132 of the protector 128 gradually deform inwardly to the left and right along the outer shape of the blade surface 50 of the inner needle 44 due to withdrawal of the inner needle 44, the abutment between the first and second connecting pieces 96, 116 and the outer needle hub 18 is more easily maintained, making it less likely that the engagement will come loose.

[0089] 19 and 20 show an indwelling needle assembly 140 with a protective cap as a second embodiment of the present invention. The indwelling needle assembly 140 with a protective cap has a structure in which a protective cap 142 that protects the inner needle 44 as a puncture needle is attached to the indwelling needle assembly 10 as a needle unit. In the following explanation, the same reference numerals are used to designate members and parts that are substantially the same as those in the first embodiment, and explanations thereof will be omitted.

[0090] A wing member 144 is attached to the outer needle hub 18 of this embodiment. The wing member 144 is fixed to the outer peripheral surface of the outer needle hub 18 and protrudes to both the left and right sides from the lower end of the outer needle hub 18. Therefore, the outer needle unit 12 of this embodiment is a winged needle.

[0091] 21 to 25, the protective cap 142 is generally cylindrical with a bottom, with the front wall serving as the bottom wall. The protective cap 142 is made of, for example, a hard resin, and is preferably transparent or semi-transparent so that the inside can be seen. The peripheral wall of the protective cap 142 is a tapered cylindrical needle accommodating section 146 whose tip portion becomes slightly smaller in diameter toward the tip side, and a hub accommodating section 148 whose base end portion is larger in diameter than the needle accommodating section 146.

[0092] 25, four locking ribs 150a, 150b, 150c, and 150d are provided inside the needle accommodating portion 146. The locking ribs 150 are provided at 90° intervals in the circumferential direction, with the upper locking rib 150a being provided continuously over substantially the entire length of the protective cap 142 to the base end of the hub accommodating portion 148, and the other three locking ribs 150b, 150c, and 150d being provided continuously up to the tip portion of the hub accommodating portion 148, but not reaching the base end of the hub accommodating portion 148. The protective cap 142 is attached to the indwelling needle assembly 10 in a detachable manner by fitting the outer needle hub 18 of the indwelling needle assembly 10 into the locking ribs 150a, 150b, 150c, and 150d, and the inner needle 44 and the outer needle 16 are accommodated in the needle accommodating portion 146.

[0093] Hub accommodating portion 148 is provided integrally with needle accommodating portion 146 on the rear side via tapered tube portion 152. Side surfaces 154, 154 that extend approximately perpendicularly to the left-right direction on both left and right sides are formed on the outer circumferential surface of hub accommodating portion 148. Side surfaces 154 may be, for example, flat surfaces, or curved surfaces that curve outwardly to the left and right on both sides in the up-down direction.

[0094] An open window 156 penetrating in the up-down direction is formed in the lower wall of the hub accommodating portion 148. The open window 156 is formed over approximately the entire length of the hub accommodating portion 148 in the front-rear direction, and the internal space of the protective cap 142 is open downward through the open window 156. A protrusion 158 that protrudes toward the base end toward the open window 156 is provided in approximately the center in the left-right direction in front of the open window 156. The left-right width dimension of the open window 156 is increased at the base end where a large diameter base portion 160 (described later) is formed.

[0095] A large diameter base 160 is provided at the base end of the hub housing 148. The large diameter base 160 has a tapered shape with a tip end having a larger diameter toward the base end, and the base end extends in the front-rear direction with a substantially constant outer diameter dimension. A pair of operation surfaces 162, 162 is formed on the outer circumferential surface of the base end of the large diameter base 160. The operation surfaces 162, 162 are provided on both the left and right sides of the large diameter base 160, and as shown in FIG. 22, are inclined surfaces that incline inwardly to the left and right toward the base end. It is desirable that the operation surfaces 162 are formed so as to reach the base end of the large diameter base 160.

[0096] The protective cap 142 is provided with a positioning portion 164 that protrudes toward the inner circumference of the large diameter base portion 160. The positioning portion 164 protrudes leftward from the right wall portion of the large diameter base portion 160 toward the inner circumference of the protective cap 142, and extends a predetermined length in the axial direction. As shown in FIG. 26, the positioning portion 164 is inserted into a positioning groove 166 that opens into the outer circumferential surface of the tip portion of the first cylindrical body 64, and the positioning portion 164 is engaged with the circumferential inner surface of the positioning groove 166, whereby the protective cap 142 is positioned in the circumferential direction with respect to the first cylindrical body 64. As a result, the protective cap 142 is attached to the indwelling needle assembly 10 with its circumferential orientation specified.

[0097] 20, when the protective cap 142 is attached to the indwelling needle assembly 10, the protective cap 142 is positioned in the circumferential direction so that the open window 156 is located downward, and the blade surface 50 of the inner needle 44, which is formed facing upward, faces opposite the open window 156. Therefore, when the protective cap 142 is attached, the user can easily ascertain the orientation of the blade surface 50 by checking the orientation of the open window 156. In addition, because the pair of side surfaces 154, 154 of the protective cap 142 are positioned in the left-right direction, the orientation of the blade surface 50 can also be ascertained from the orientation of the pair of side surfaces 154, 154.

[0098] Furthermore, since the wing members 144, 144 attached to the outer needle hub 18 of the indwelling needle assembly 10 are exposed to the outside through the open window 156 of the protective cap 142, the protective cap 142 can be attached without any problem to the indwelling needle assembly 10 equipped with the wing members 144. When the protective cap 142 is attached to the indwelling needle assembly 10, the open window 156 is located on the base end side relative to the tip of the outer needle hub 18, and the outer needle 16 is covered all around with the protective cap 142 without being exposed to the outside through the open window 156.

[0099] The protective cap 142 can be easily removed from the indwelling needle assembly 10. That is, when the user holds the pair of gripping surfaces 74, 74 of the inner needle hub 46 (first cylindrical body 64) between fingers (e.g., thumb, middle finger, and ring finger) and presses the operating surface 162 of the protective cap 142 toward the tip side with the other fingers (e.g., index finger), the protective cap 142 can be detached toward the tip side from the indwelling needle assembly 10. In this manner, the protective cap 142 can also be removed with one hand.

[0100] The user (doctor, etc.) can remove the protective cap 142 while gripping the gripping surfaces 74, 74 of the indwelling needle assembly 10 in the same manner as during puncturing. Therefore, there is no need to re-hold the indwelling needle assembly 10 after removing the protective cap 142, and the operations from removing the protective cap 142 to puncturing can be performed quickly and easily.

[0101] The operation surfaces 162, 162 are positioned on both the left and right sides of the indwelling needle assembly 10 by positioning the protective cap 142 in the circumferential direction by engagement between the positioning portion 164 and the inner surface of the positioning groove 166, and are located on the distal end side of the gripping surfaces 74, 74. This allows the operation surfaces 162, 162 to be easily pushed toward the distal end side while the gripping surfaces 74, 74 are gripped with fingers. Moreover, since the operation surfaces 162 are provided on both the left and right sides, the protective cap 142 can be removed with the same ease regardless of whether the user is right-handed or left-handed.

[0102] Since the operation surface 162 is provided on the large diameter base 160 of the protective cap 142, it is located on the outer periphery side and is easy to press with a finger. Moreover, by providing it on the large diameter base 160, it is easy to ensure the area of ​​the operation surface 162, and in particular, it is possible to obtain a large projected area in the axial direction, so that it is easy to perform a pressing operation toward the tip side. In addition, since the tapered operation surface 162 is provided on the base end of the large diameter base 160, the edge of the base end outer periphery of the large diameter base 160 is obtuse at the portion where the operation surface 162 is formed, and even if a finger touches the edge, pain or discomfort is reduced.

[0103] Furthermore, the operation surfaces 162, 162 are provided on both the left and right sides of the large diameter base 160 of the protective cap 142, and are arranged close to the tip sides of the gripping surfaces 74, 74. Therefore, if the fingers of the hand holding the gripping surfaces 74, 74 are pressed against the operation surface 162 in a bent state and the fingers are stretched forward, a forward force can be efficiently applied to the protective cap 142.

[0104] Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the specific description. For example, the indwelling needle assembly of the above embodiment is provided with a full-cover type needle tip protection mechanism in which the entire inner needle 44 is housed in the inner needle storage section 62 after removal of the needle, but it is also possible to adopt a needle tip protection mechanism in which only the tip portion including the needle tip 48 is housed and the other portion is exposed to the outside. The needle tip protection mechanism may be composed of only the protector 128.

[0105] In the indwelling needle assemblies according to the first to fourth aspects, it is not essential that the insertion pieces 42, 42 constituting the base end of the plunger 40 are inserted into the first and second insertion recesses 98, 124 opening at the tips of the first and second connecting pieces 96, 116. Moreover, in the indwelling needle assemblies according to the first to fourth aspects, the valve body 34 and the plunger 40 may be omitted.

[0106] In the indwelling needle assemblies according to the sixth to eighth aspects, it is not essential to provide a mechanism for releasing the connection between the inner needle unit 14 and the outer needle unit 12 by movement of the movable member 112 when the inner needle 44 is withdrawn. In this case, for example, the tip portion of the third cylindrical body 68 does not need to be equipped with the movable member 112, and the connecting part can be provided integrally with the third cylindrical body 68 as a continuous cylindrical part around the entire circumference.

[0107] When adopting the protective cap 142 according to the eighth embodiment, there is no particular limitation on the structure of the needle unit to which the protective cap 142 is attached. Specifically, for example, it is not necessarily limited to a structure in which an outer needle unit and an inner needle unit are separably combined, and may be a needle assembly consisting of only an inner needle unit, or may be constituted by an outer needle unit and an inner needle unit without a valve or plunger.

[0108] In the storage housing, the structure in which the cover member is separate from the housing body is not essential, and for example, the connecting part may be provided integrally with the housing body. In addition, the tip surface of the connecting part is not limited to the tapered tip surface 106 shown in the above embodiment, and may be, for example, an orthogonal surface that spreads approximately perpendicular to the needle axial direction, or an inverse tapered surface that slopes toward the base end toward the inner circumference. [Explanation of symbols]

[0109] 10 Indwelling needle assembly (first embodiment needle unit) 12 Outer needle unit 14 Inner needle unit 16 Outer needle 18 Outer needle hub 24 Push piece 26 Flat surface 28 Lock protrusion 28a Lock protrusion 28b Lock protrusion 30 Cutting 32 Locking groove 34 Valve body 36 Slit 38 Support member 40 Pusher 42 Insert 44 Inner needle (puncture needle) 46 Inner needle hub 48 Needle tip 50 Blade surface 52 Hub body 54 Fixed cylinder part 56 Storage tube 58 Cylindrical part 60 Filters 62 Inner needle storage section 64 First cylindrical body 66 Second Cylinder 68 Third Cylinder 70 Plate gripping part 74 Gripping surface 76 protrusion 78 Pressing surface 80 Base end engagement claw 82 Tip side engagement claw 84 Storage Housing 86 Small diameter cylinder part 88 Housing body 90 Cover material 92 Window 94 Latch part 96 First connecting piece (connecting part) 98 First insertion recess (insertion recess) 100 Cover body 102 Mounting part 104 Connection part 106 Tapered tip surface 108 Locking recess 110 Positioning piece (anti-rotation part) 112 Movable parts 114 Protector engagement part 116 Second connecting piece (connecting part) 118 Protector insertion recess 120 Needle insertion hole 122 Relief surface 124 Second insertion recess (insertion recess) 126 Base 128 Protector 130 Bottom wall 132 Elastic piece 134 Needle insertion hole 136 Needle tip protection piece 138 Notch 140 Indwelling needle assembly with protective cap (second embodiment) 142 Protective Cap 144 Wing components 146 Needle storage unit 148 Hub housing 150 Locking rib 150a Locking rib 150b Locking rib 150c locking rib 150d Retaining rib 152 Tapered cylinder 154 Side 156 Open Window 158 Protrusion 160 Large diameter base 162 Operation surface 164 Positioning part 166 Positioning groove

Claims

1. An indwelling needle assembly in which an inner needle unit including an inner needle hub and an outer needle unit including an outer needle hub are separably connected, an inner needle having a protector attached thereto is inserted removably into an outer needle, and the protector is deformed by moving toward the needle tip as the inner needle is withdrawn, thereby protecting the needle tip. the inner needle unit includes a storage housing that stores the protector, the storage housing comprises a connection portion inserted into the inner periphery of the outer needle hub, and a coupling portion engaged with the outer periphery of the outer needle hub in the needle axis direction, the connection portion is configured with a movable member, the portion of the connection portion being opposed to the inner circumferential side of the coupling portion, and being capable of being displaced in a radial direction relative to the coupling portion, the movable member is held in a position close to the connecting portion by engagement with the protector, and the connecting portion is held in an engaged state with respect to the outer circumferential surface of the outer needle hub, An indwelling needle assembly in which the engagement between the movable member and the protector is released by deformation accompanying the needle tip protection operation of the protector, and the movable member moves away from the outer needle hub, allowing separation of the inner needle unit and the outer needle unit.

2. A part of the peripheral wall of the storage housing is constituted by a cover member which is separate from the housing main body, which is the other part, and is attached from the side, The cover member is provided with the connecting portion, 2. The indwelling needle assembly according to claim 1, wherein the distal end surface of the connecting portion is a tapered distal end surface that is inclined inwardly toward the distal end.

3. 3. The indwelling needle assembly according to claim 1 or 2, wherein an engagement groove is formed on the outer peripheral surface of the outer needle hub, into which the connecting portion is inserted to be engaged in the axial direction, and the engagement groove is annular and extends circumferentially.

4. A locking protrusion that protrudes laterally toward the outer periphery and engages with the connecting portion is provided at the base end of the outer needle hub, 3. The indwelling needle assembly according to claim 1, wherein the connecting portion is provided with a rotation prevention portion that is engaged with the locking protrusion in the circumferential direction.

5. A valve body that switches between communication and blocking of the inner cavity of the outer needle hub is accommodated on the inner circumference of the outer needle hub, a pusher is accommodated on the inner periphery of the outer needle hub, the pusher being disposed on the base end side of the valve body and configured to switch the valve body to a communicating state by being pushed toward the tip end side; a tip portion of the storage housing is the connection portion that is fitted into a base end opening of the outer needle hub, a tip end surface of the connection portion and a base end surface of the pusher are opposed to each other in the axial direction, 3. The indwelling needle assembly according to claim 1, wherein the tip of the connecting portion is located distal to the base end of the plunger.

6. the needle unit includes an inner needle unit having an inner needle hub provided at a base end of an inner needle having a needle tip, and an outer needle unit having an outer needle hub provided at a base end of an outer needle that is fitted onto the inner needle, The indwelling needle assembly includes an inner periphery of the outer needle hub provided with a valve body for switching between communication and blocking of an inner cavity of the outer needle hub, a pusher is accommodated on the inner periphery of the outer needle hub, the pusher being disposed on the base end side of the valve body and configured to switch the valve body to a communicating state by being pushed toward the tip end side; the inner needle unit is provided with a connecting portion that is fitted into a proximal end opening of the outer needle hub, a tip end surface of the connection portion and a base end surface of the pusher are opposed to each other in the axial direction, The tip of the connection portion is located distal to the base end of the plunger.

7. The pusher is partially provided with an insertion piece protruding toward a base end side in a circumferential direction, The indwelling needle assembly according to claim 6, wherein the connecting portion of the inner needle unit is formed with an insertion recess that opens to a distal end surface and into which the insertion piece of the pusher is inserted.

8. A bottomed, cylindrical protective cap is attached to a needle unit having a needle hub at a base end of a puncture needle having a needle tip, and protects the puncture needle before use, The base end portion has a larger diameter than the tip end portion, The protective cap has an operating surface at the base end of the large diameter base portion, the operating surface inclining inwardly toward the base end side.

9. A positioning portion is provided for positioning the needle in a circumferential direction relative to the needle hub, 9. The protective cap according to claim 8, wherein the pair of operating surfaces are positioned by the positioning portion on the tip side and in the same circumferential direction with respect to a pair of gripping surfaces provided on both sides of the needle hub.

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