Indwelling needle assembly

Abstract

Provided is an indwelling needle assembly having a novel structure that can solve at least one of inherent problems of indwelling needle assemblies having the conventional structure.　This indwelling needle assembly 10 comprises a needle tip protector 66. The needle tip protector 66 has needle tip protection parts 72a, 72b located laterally away from an inner needle 14. The indwelling needle assembly 10 comprises an abutting part 60 that stops at an outer needle hub 20 and abuts on the pair of needle tip protection parts 72a, 72b to displace the needle tip protection parts 72a, 72b in the direction approaching the inner needle 14, and consequently leads the needle tip protection parts 72a, 72b to a protection position at which the needle tip 22 of the inner needle 14 having been drawn is covered, when the inner needle 14 is drawn from an outer needle 18. A pusher 54 that switches a valve body 62 is disposed at a position closer to the base end than the valve body 62 within an outer needle hub 36. At least a part of the needle tip protector 66 is housed inside the pusher 54.

Description

Technical Field

[0001] The present invention relates to an indwelling needle assembly that is punctured into a blood vessel during infusion, blood sampling, hemodialysis, etc.

Background Art

[0002] Conventionally, indwelling needle assemblies that are punctured into blood vessels during infusion, blood sampling, hemodialysis, etc. are known. As shown in Japanese Patent Application Laid-Open No. 2010-088520 (Patent Document 1), the indwelling needle assembly has a structure in which an inner needle is inserted into an outer needle so as to be retractable, and an inner needle hub provided on the proximal end side of the inner needle and an outer needle hub provided on the proximal end side of the outer needle are combined with each other. Then, after puncturing the blood vessel with the outer needle together with the inner needle, the inner needle is pulled out from the outer needle, and the indwelling needle having the outer needle and the outer needle hub is left in a state of being punctured into the blood vessel.

[0003] By the way, in Patent Document 1, an indwelling needle assembly provided with a needle tip protector for protecting the needle tip of the inner needle so that the inner needle pulled out from the outer needle is not accidentally re-punctured has been proposed. That is, in Patent Document 1, a protector body disposed on the inner periphery of the outer needle hub moves to the tip of the inner needle by pulling out the inner needle from the outer needle, and the structure is such that the needle tip of the inner needle is protected. In Patent Document 1, in a state where the inner needle is inserted into the outer needle, the protector body is separated from the inner needle, and a resistance force due to friction between the inner needle and the protector body does not act when the inner needle is pulled out. Then, as the protector body moves to the proximal end side together with the inner needle, an action ring attached to the inner peripheral surface of the outer needle hub moves to the tip side of the protector body, and the action ring deforms the tip portion of the protector body and moves it to a position covering the tip side of the inner needle. Thereby, the needle tip of the inner needle is covered and protected by the protector body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, since the protector body needs to be held in a state of protecting the tip of the inner needle, the protector body needs to be deformed by the operating ring. Therefore, it was necessary to provide a separate operating ring that can be separated from the outer needle hub.

[0006] In addition, as shown in Japanese Patent Application Laid-Open No. 2007-136246, a catheter assembly provided with a valve body has also been proposed. By inserting the tip of a tapered pusher into the slit of the valve body, the slit is opened. However, in a catheter assembly having such a structure, since the diameter of the pusher is set to be insertable into the slit, the internal space of the pusher tends to be narrow, and the dimensions and shape of a needle tip protector or the like accommodated inside the pusher may be restricted.

[0007] The problem to be solved by the present invention is to provide a catheter assembly with a novel structure that can solve at least one of the problems inherent in the catheter assembly having the conventional structure as described above.

Means for Solving the Problems

[0008] Hereinafter, preferred embodiments for understanding the present invention will be described. However, each of the embodiments described below is described by way of example, and not only can they be appropriately combined and adopted with each other, but also for a plurality of components described in each embodiment, they can be recognized and adopted independently as much as possible, and can also be appropriately combined with any of the components described in other embodiments and adopted. As a result, in the present invention, various other embodiments can be realized without being limited to the embodiments described below.

[0009] A first aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and includes a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle. The needle tip protector has a needle tip protection portion located laterally away from the inner needle. When the inner needle is withdrawn from the outer needle, it stops at the outer needle hub and abuts against the needle tip protection portion, and has a contact portion for guiding the needle tip protection portion to a protection position covering the needle tip of the withdrawn inner needle by displacing the needle tip protection portion toward the approaching side of the inner needle. Inside the outer needle hub, a pusher for switching a valve body is arranged on the proximal side of the valve body, and at least a part of the needle tip protector is accommodated inside the pusher.

[0010] According to the indwelling needle assembly having the structure according to this aspect, when the inner needle is withdrawn from the outer needle, the needle tip protection portion of the needle tip protector is deformed and displaced in the direction approaching the inner needle by the contact portion, and the needle tip of the inner needle is covered and protected by the needle tip protection portion.

[0011] A second aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching a valve body inside the outer needle hub is arranged on the proximal side of the valve body. At least a part of a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle is accommodated inside the pusher. The pusher includes a small cylindrical portion and a large cylindrical portion. The large cylindrical portion is formed on the distal side of the small cylindrical portion, and the inner diameter dimension of the large cylindrical portion is larger than that of the small cylindrical portion.

[0012] According to the indwelling needle assembly having the structure according to this aspect, a large space is secured inside the large cylindrical portion of the pusher, and it is difficult to limit the dimensions and shapes of the needle tip protector and the like accommodated inside the large cylindrical portion.

[0013] A third aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching a valve body is arranged on the proximal end side of the valve body inside the outer needle hub. At least a part of a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle is accommodated inside the pusher. The pusher includes an input portion to which an external force for pressing the pusher against the valve body is input, and an action portion provided on the tip side of the input portion for pushing open the valve body. The action portion has a larger diameter than the input portion.

[0014] According to the indwelling needle assembly having the structure according to this aspect, since the input portion having a smaller diameter than the action portion is provided on the proximal end side, for example, a male Luer inserted into and connected to the proximal end opening of the outer needle hub is pressed against the proximal end surface of the pusher, and an external force for pressing the pusher against the valve body is effectively input to the pusher. Further, when the outer peripheral side of the valve body is pressed by the action portion, a force from the valve body toward the proximal end side easily acts on the pusher, and when the external force for pressing the pusher against the valve body is released, the pusher easily returns to the initial position.

[0015] A fourth aspect is the indwelling needle assembly according to the third aspect, wherein the input portion is accommodated in a Luer insertion portion on the proximal end side of the outer needle hub, and an outer diameter dimension of the action portion is made larger than an inner diameter dimension of the Luer insertion portion.

[0016] According to the indwelling needle assembly having the structure according to this aspect, the movement of the pusher toward the proximal end is restricted by the engagement between the tip of the Luer insertion portion and the proximal end of the action portion. Therefore, for example, when the needle tip protector is withdrawn toward the proximal end while sliding in contact with the pusher, it is possible to prevent the pusher from being withdrawn from the outer needle hub together with the needle tip protector.

[0017] The fifth aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching a valve body is disposed on the proximal side of the valve body inside the outer needle hub. At least a part of a needle tip protector for protecting the needle tip of the inner needle pulled out from the outer needle is accommodated inside the pusher. The pusher includes an input part to which an external force for pressing the pusher against the valve body is input, and an acting part provided on the tip side of the input part for pushing open the valve body. The acting part having a larger diameter than the input part has an outer diameter dimension larger than the inner diameter dimension of the proximal end portion of the outer needle hub.

[0018] According to the indwelling needle assembly having the structure according to this aspect, since the tip portion of the pusher is the acting part with a large diameter, a large space is secured inside the acting part, and it is difficult to limit the dimensions and shape of the needle tip protector and the like accommodated inside the acting part.

[0019] The sixth aspect is the indwelling needle assembly according to the fourth or fifth aspect, wherein a slit penetrating the inner peripheral portion in the axial direction of the inner needle is formed in the valve body, and the outer peripheral end of the acting part is located more on the outer periphery than the outer peripheral end of the slit.

[0020] According to the indwelling needle assembly having the structure according to this aspect, when the acting part is pressed against the valve body, it is possible to prevent the whole of the acting part from entering the slit of the valve body. Therefore, for example, when the opening and closing operation of the valve body by the pusher is repeatedly executed, it is possible to avoid a situation where the pusher cannot come out of the slit of the valve body and cannot return from the open position to the closed position.

[0021] The seventh aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching a valve body is disposed on the proximal end side of the valve body inside the outer needle hub. At least a part of a needle tip protector for protecting the needle tip of the inner needle pulled out from the outer needle is accommodated inside the pusher. The pusher includes a tip member attached to an opening on the tip side of a base member, and at least a part of the opening on the tip side of the base member is blocked by the tip member.

[0022] According to the indwelling needle assembly having the structure according to this aspect, for example, the internal space of the pusher can be secured by the base member. Further, since at least a part of the tip opening of the accommodation region of the needle tip protector in the pusher is blocked by the tip member, even when the needle tip protector moves toward the tip side, the amount of movement of the needle tip protector toward the tip side is restricted by the tip member, so that it is possible to prevent the needle tip protector from interfering with the valve body disposed at a position more distal than the pusher.

[0023] The eighth aspect is the indwelling needle assembly according to the seventh aspect, wherein the tip member includes an insertion portion having a smaller diameter than the tip opening of the base member. According to the indwelling needle assembly having the structure according to this aspect, when the pusher is pressed against the valve body to push open the slit of the valve body, the insertion portion with a smaller diameter is easily inserted into the slit of the valve body, and the insertion of the insertion portion makes it easier to open the slit, thereby stabilizing the opening operation of the valve body.

[0024] The ninth aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching a valve body is disposed on the proximal end side of the valve body inside the outer needle hub. The opening portion at the tip of the pusher is formed in a flat cylindrical shape, and the pusher is formed with insertion protrusions that protrude toward the tip on both sides in the flat direction and can be inserted into slits formed in the valve body.

[0025] According to the indwelling needle assembly structured according to this aspect, when the insertion protruding portion of the pusher is inserted into the slit of the valve body, the slit is effectively widened, and a stable opening operation of the valve body is realized. Further, since the large-diameter portion of the pusher orthogonal to the flat direction is not inserted into the slit of the valve body, for example, when the opening and closing operation of the valve body by the pusher is repeatedly executed, it becomes easier for the insertion protruding portion to return from the open position where it is inserted into the slit to the initial closed position. In particular, since the large-diameter portion of the pusher orthogonal to the flat direction is not inserted into the slit but is pressed against the outer peripheral portion of the valve body, the elastic restoring force of the valve body acts in the direction of moving the pusher to the closed position, and the movement of the pusher from the open position to the closed position is realized more stably.

[0026] The tenth aspect is an indwelling needle assembly in which an inner needle having an inner needle hub on the proximal end side is inserted into an outer needle having an outer needle hub on the proximal end side so as to be retractable, and a pusher for switching the valve body is arranged on the proximal end side of the valve body inside the outer needle hub, and the indwelling needle assembly is provided with a needle tip protector for protecting the needle tip of the inner needle pulled out from the outer needle, the opening portion at the tip of the pusher is formed in a flat cylindrical shape, and a protector accommodating portion for accommodating at least a part of the needle tip protector is provided inside the pusher formed in a flat cylindrical shape.

[0027] According to the indwelling needle assembly structured according to this aspect, the unnecessary space inside the pusher when the needle tip protector is accommodated can be particularly reduced in the flat direction, and the pusher and the outer needle hub can be miniaturized without restricting the dimensions of the needle tip protector or the like. Note that the flat cylindrical shape refers to a cylindrical shape in which the outer dimensions in the cross-sectional shape perpendicular to the axis are different from each other in two orthogonal directions.

[0028] The eleventh aspect is the indwelling needle assembly according to the tenth aspect, wherein the pusher is provided with insertion protruding portions that protrude toward the tip on both sides in the flat direction and can be inserted into a slit formed in the valve body.

[0029] According to the indwelling needle assembly structured according to this aspect, when the insertion protrusion of the pusher is inserted into the slit of the valve body, a stable opening operation of the valve body is realized.

Effect of the Invention

[0030] According to the present invention, at least one of the problems inherent in the indwelling needle assembly having the conventional structure as described above can be solved.

Brief Description of the Drawings

[0031]

Figure 1

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Mode for Carrying Out the Invention

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

[0033] In FIGS. 1 to 3, an indwelling needle assembly 10 as the first embodiment of the present invention is shown. The indwelling needle assembly 10 has a structure in which an inner needle 14 constituting an inner needle unit 12 is inserted into an outer needle 18 constituting an indwelling needle 16, and the inner needle unit 12 and the indwelling needle 16 are combined. In the following description, in principle, the vertical direction refers to the vertical direction in FIG. 1, and the horizontal direction refers to the vertical direction in FIG. 3. Also, the distal side refers to the left side in FIG. 1 that is distal, and the proximal side refers to the right side in FIG. 1 that is proximal.

[0034] The inner needle unit 12 has a structure in which an inner needle hub 20 is fixed to an inner needle 14. The inner needle 14 is a rigid member formed of metal or the like, and is a hollow needle in this embodiment. The tip of the inner needle 14 has a tip surface cut into an inclined shape, and a sharp needle tip 22 is formed. As shown in FIG. 4, a closing portion 24 that blocks the inner cavity is provided at the tip portion of the inner needle 14. A pair of locking protrusions 26, 26 protruding from the outer peripheral surface are formed at the tip portion of the inner needle 14. The locking protrusions 26 protrude in the left-right direction (the up-down direction in FIGS. 3 and 4), and are formed, for example, by partially crushing the inner needle 14 in the up-down direction. In this embodiment, the locking protrusions 26 are provided on the closing portion 24 of the inner needle 14, but the locking protrusions 26 may be provided in the hollow portion of the inner needle 14 outside the closing portion 24. Further, the inner needle 14 may not include the closing portion 24. For example, the inner cavity of the inner needle 14 may be formed to penetrate from the tip to the base end.

[0035] As shown in FIGS. 1 to 3, the inner needle hub 20 includes a hub body 28. The tip portion of the hub body 28 has a substantially rectangular cylindrical shape, and the base end portion has a substantially cylindrical shape. The outer peripheral surface of the tip portion of the hub body 28 is curved in the axial direction and has a smaller diameter from both ends in the axial direction toward the center, making it difficult for a finger to slip when it is pinched by a finger and moved axially. The hub body 28 integrally includes a substantially cylindrical inner needle holding portion 30 that protrudes from the inner peripheral surface of the tip portion and extends toward the base end. The inner peripheral surface of the inner needle holding portion 30 is adhered to the outer peripheral surface of the inner needle 14, and the hub body 28 is fixed to the inner needle 14. A flange-like portion 32 protruding toward the outer periphery is provided at the tip of the hub body 28, and the inner diameter of the tip surface of the hub body 28 is smaller and the outer diameter is larger than the base end surface of an outer needle hub 36 described later.

[0036] A cap member 34 is attached to the proximal opening portion of the hub body 28. The cap member 34 is generally in a substantially cylindrical shape. The cap member 34 has a tapered outer peripheral surface whose tip portion with a small diameter tapers toward the tip, and the tip portion is fitted into the proximal opening portion of the hub body 28, whereby it is attached to the hub body 28. A breathable filter 35 is attached to the proximal opening portion of the cap member 34. While the air inside the cap member 34 can be discharged to the outside through the breathable filter 35, for example, blood that enters the inside of the cap member 34 through the inner needle 14 due to flashback during puncture does not pass through the breathable filter 35 and does not leak from the inside of the cap member 34. Note that the cap member 34 is preferably transparent or translucent in order to facilitate visual recognition of flashback during puncture of the inner needle 14 into a blood vessel.

[0037] The indwelling needle 16 has a structure in which an outer needle hub 36 is provided at the proximal end of the outer needle 18. The outer needle 18 is a hollow needle formed of resin or metal. It is desirable that the outer peripheral surface of the tip portion of the outer needle 18 is a tapered surface whose diameter becomes smaller toward the tip.

[0038] The proximal end portion of the outer needle 18 is inserted into the inner circumference of the tubular outer needle hub 36 and fixed to the outer needle hub 36. The outer needle hub 36 is, for example, a tubular body made of resin. The outer needle hub 36 of the present embodiment has a structure in which a needle fixing member 38 constituting the tip portion and a luer connecting member 40 constituting the proximal end portion are combined. However, the outer needle hub 36 may be entirely composed of one part, or may be composed of a combination of three or more parts. Further, when the outer needle hub 36 is constituted by combining a plurality of parts, those parts may be fixed by being non-adhesively fitted or the like, or may be fixed by means such as adhesion or welding.

[0039] The needle fixing member 38 is generally cylindrical and has a tapered portion 42 that becomes larger in diameter toward the proximal end in the middle of the axial direction. The proximal end side of the tapered portion 42 is larger in diameter than the distal end side. Engagement holes 44, 44 penetrating in the vertical direction are formed in the needle fixing member 38, and the proximal end side of the engagement holes 44 has an inner peripheral surface with a tapered shape that expands toward the proximal end. Then, the outer needle 18 is inserted into the distal end portion of the needle fixing member 38 with a small diameter, and the outer needle 18 is fixed to the needle fixing member 38 by a cylindrical pin.

[0040] The luer connection member 40 is generally cylindrical and has a step 46 provided in the middle of the axial direction. The distal end side of the step 46 is a hub connection portion 48 with a large diameter, and the proximal end side is a luer insertion portion 50 with a small diameter. A pair of engagement claws 52 are provided on the outer peripheral surface of the hub connection portion 48. By engaging these engagement claws 52 with the inner surface of the engagement hole 44 provided in the needle fixing member 38, the needle fixing member 38 and the luer connection member 40 are connected to form the outer needle hub 36. The inner peripheral surface of the luer insertion portion 50 is a luer taper that expands in diameter toward the proximal end.

[0041] The luer connecting member 40 of the outer needle hub 36 houses a pusher 54. The pusher 54 has a generally stepped cylindrical shape as a whole and is provided internally with a protector housing portion 55 that penetrates in the axial direction. The pusher 54 has an input portion 56 that is a small cylindrical portion with a small diameter at the proximal end and an acting portion 58 that is a large cylindrical portion with a larger diameter than the input portion 56 at the distal end. The input portion 56 and the acting portion 58 are integrally and continuously provided by a stepped contact portion 60 that protrudes toward the inner circumferences of the outer needle hub 36 and the pusher 54 at the proximal end of the acting portion 58 located inside the outer needle hub 36. The shape of the inner circumferential surface of the pusher 54 is a quadrilateral corresponding to the first needle insertion portion 68 of the needle tip protector 66 to be described later in the input portion 56 and is circular in the acting portion 58. As a result, the protruding dimension of the contact portion 60 from the acting portion 58 varies in the circumferential direction. The inner normal dimension of the acting portion 58 in the direction perpendicular to the axis is made larger than the inner normal dimension of the input portion 56 in the direction perpendicular to the axis. Therefore, the protector housing portion 55 provided on the inner circumference of the pusher 54 has a larger diameter at the distal end portion than at the proximal end portion. Note that the shape of the inner circumferential surface of the input portion 56 is not limited to a quadrilateral, but is preferably a shape in which the inner diameter dimension varies in the circumferential direction, such as an ellipse or a polygon, so as to be able to prevent the rotation of the needle tip protector 66. The pusher 54 may be appropriately provided with slits (holes) that penetrate the peripheral wall and the like.

[0042] The pusher 54 has the input portion 56 housed in the lure insertion portion 50 of the lure connecting member 40, and the acting portion 58 housed in the hub connecting portion 48 of the lure connecting member 40. The input portion 56 of the pusher 54 extends with a substantially constant outer diameter dimension, and a gap is formed between the inner peripheral surface of the lure insertion portion 50 having a lure taper and the outer peripheral surface of the input portion 56. The pusher 54 is positioned in a direction perpendicular to the axis with respect to the outer needle hub 36 by overlapping the outer peripheral surface of the acting portion 58 with the inner peripheral surface of the hub connecting portion 48 of the outer needle hub 36. Further, the outer diameter dimension of the acting portion 58 of the pusher 54 is made larger than the inner diameter dimension of the lure insertion portion 50 that constitutes the proximal end portion of the outer needle hub 36, and the proximal end surface of the acting portion 58 is overlapped with the step 46 of the outer needle hub 36, whereby the pusher 54 is positioned in the axial direction with respect to the outer needle hub 36. The proximal end of the pusher 54 is located on the distal end side with respect to the proximal end of the outer needle hub 36 (lure connecting member 40), and the pusher 54 is housed without protruding from the outer needle hub 36 toward the proximal end.

[0043] A valve body 62 is disposed on the distal end side of the pusher 54 inside the outer needle hub 36. The valve body 62 is formed of a resin elastomer or rubber having rubber-like elasticity. The valve body 62 has a substantially disc shape, and is arranged to block the inner cavity of the outer needle hub 36 by being sandwiched in the thickness direction between the needle fixing member 38 and the lure connecting member 40 that constitute the outer needle hub 36 at the outer peripheral end portion. The valve body 62 is provided with a slit 64 penetrating the inner peripheral portion. The slit 64 extends radially, for example, from the center of the valve body 62, and penetrates the valve body 62 in the left-right direction in FIG. 2, which is the axial direction of the inner needle 14. Then, the inner cavity of the outer needle hub 36 is switched between a communication state through the slit 64 and a blocked state by opening and closing the slit 64 of the valve body 62.

[0044] The pusher 54 is arranged on the proximal side of the valve body 62, and the outer peripheral edge of the tip of the working portion 58 of the pusher 54 is located on the outer peripheral side of the outer peripheral end of the slit 64 of the valve body 62. Thereby, at least the outer peripheral end of the tip surface of the pusher 54 is located on the outer periphery of the slit 64. More preferably, the inner peripheral edge of the tip of the working portion 58 is located on the outer peripheral side of the outer peripheral end of the slit 64, and the entire tip surface of the working portion 58 is located outside the outer periphery of the slit 64. The tip of the pusher 54 may be in contact with the valve body 62 supported by the outer needle hub 36, but in the present embodiment, it is located away from the valve body 62 toward the proximal end.

[0045] A needle tip protector 66 as shown in FIGS. 5 to 9 is accommodated in a protector accommodation portion 55 provided inside the pusher 54. The entire needle tip protector 66 is located inside the pusher 54, preventing the outer needle hub 36 from becoming larger. The needle tip protector 66 is formed of, for example, an elastically deformable metal plate material. The needle tip protector 66 has a first needle insertion portion 68 that extends substantially orthogonally to the axial direction of the inner needle 14 at the proximal end. The first needle insertion portion 68 is in the shape of a rectangular plate, and a first circular hole 70 corresponding to the outer shape of the inner needle 14 is formed to penetrate in the thickness direction at the center. The diameter of the first circular hole 70 is larger than the outer diameter dimension of the inner needle 14 at the portion where the locking protrusions 26, 26 are disengaged and smaller than the outer diameter dimension of the inner needle 14 at the portion where the locking protrusions 26, 26 are formed.

[0046] The needle tip protector 66 includes a pair of needle tip protection portions 72a, 72b. The pair of needle tip protection portions 72a, 72b extend from the upper and lower end portions of the first needle insertion portion 68 toward the tip. The needle tip protection portion 72a includes an elastic plate portion 74a that extends from the upper end portion of the first needle insertion portion 68 toward the tip. The elastic plate portion 74a has a first portion 76a that is the proximal end portion orthogonal to the vertical direction, a second portion 78a that is the intermediate portion inclined upward toward the tip, and a third portion 80a that is the tip portion inclined downward toward the tip. Further, the needle tip protection portion 72a includes a folded-back portion 82a in which the tip end portion of the third portion 80a is folded back downward toward the proximal end.

[0047] At the tip portion of the needle tip protection part 72a, a pair of side wall parts 84, 84 are provided so as to face each other in the left - right direction. The side wall parts 84 extend from the third part 80a of the elastic plate part 74a. The side wall parts 84 are tapered such that the protruding dimension from the needle tip protection part 72a toward the tip becomes smaller in the side view shown in FIG. 7. Since a notch 85 is formed between the folded - back part 82a of the needle tip protection part 72a and the side wall part 84, the side wall part 84 is allowed to flex - deform in the thickness direction without being excessively restricted by the folded - back part 82a. Locking pieces 86 are integrally provided on the pair of side wall parts 84, 84 of the needle tip protection part 72a, respectively. The locking piece 86 extends along the protruding tip of the side wall part 84 and protrudes toward the inner side in the facing direction of the pair of side wall parts 84, 84. As shown in FIG. 9, the locking piece 86 is inclined toward the elastic plate part 74a side in the thickness direction toward the protruding tip.

[0048] The needle tip protection part 72b includes an elastic plate part 74b that extends from the lower end part to the tip of the first needle insertion part 68. The elastic plate part 74b has a first part 76b, which is the base end part, orthogonal to the vertical direction, a second part 78b, which is the middle part, inclined downward toward the tip, and a third part 80b, which is the tip part, inclined upward toward the tip. Further, the needle tip protection part 72b includes a folded - back part 82b in which the tip part of the third part 80b is folded upward toward the base end. The folded - back part 82a of the needle tip protection part 72a and the folded - back part 82b of the needle tip protection part 72b are separated from each other in the vertical direction in the projection in the needle axis direction.

[0049] The length of the needle tip protection part 72b from the first needle insertion part 68 to the tip is shorter than that of the needle tip protection part 72a. The tip of the needle tip protection part 72b reaches the locking piece 86 of the needle tip protection part 72a as shown in FIG. 8 and does not reach the folded - back part 82a of the needle tip protection part 72a. Also, the width dimension of the third part 80b of the needle tip protection part 72b is smaller than the width dimension in the left - right direction of the third part 80a of the needle tip protection part 72a. The width dimension of the third part 80b is smaller than the opposing distance between the pair of side wall parts 84, 84 and larger than the distance between the pair of locking pieces 86, 86.

[0050] The needle tip protector 66 is provided with a positioning portion 88 positioned between the opposing pair of needle tip protection portions 72a and 72b. The positioning portion 88 includes a support portion 90 extending from the first needle insertion portion 68 toward the tip, and a second needle insertion portion 92 facing substantially parallel to the first needle insertion portion 68 on the tip side. The first needle insertion portion 68 and the second needle insertion portion 92 are integrally connected by the support portion 90. A second circular hole 94 is formed to penetrate through the second needle insertion portion 92 in the thickness direction. The second circular hole 94 has a larger diameter than the first circular hole 70, and has a diameter that allows the locking protrusions 26, 26 of the inner needle 14 to easily pass through when the inner needle 14 is withdrawn.

[0051] As shown in FIGS. 2 and 3, the needle tip protector 66 is accommodated in the protector accommodation portion 55 of the pusher 54. That is, the first needle insertion portion 68, the first portions 76a and 76b of the pair of needle tip protection portions 72a and 72b, and the proximal end portion of the positioning portion 88 are inserted into the tip portion of the input portion 56 of the pusher 54. Further, the second portions 78a and 78b and the third portions 80a and 80b of the pair of needle tip protection portions 72a and 72b, and the tip portion of the positioning portion 88 including the second needle insertion portion 92 are inserted into the acting portion 58 of the pusher 54. Since the proximal end portion of the needle tip protector 66 is inserted into the input portion 56 having a small diameter with a quadrangular inner peripheral cross-sectional shape, the needle tip protector 66 is positioned with respect to the pusher 54 in a direction perpendicular to the axis, and rattling and displacement are prevented. Further, since the tip portion of the needle tip protector 66 is accommodated in the acting portion 58 having a large internal space, the pair of needle tip protection portions 72a and 72b are accommodated in the pusher 54 while maintaining an initial shape in which they are separated from each other.

[0052] In a state where the needle tip protector 66 is accommodated in the protector accommodation portion 55 of the pusher 54 inside the outer needle hub 36, the second portions 78a and 78b of the pair of needle tip protection portions 72a and 72b and the contact portion 60 of the pusher 54 are arranged at positions overlapping in the needle axis direction projection. In other words, the outer ends (the boundary portions between the second portion 78 and the third portion 80) in the vertical direction of the pair of needle tip protection portions 72a and 72b are located outside in the vertical direction with respect to the inner ends in the vertical direction of the contact portion 60.

[0053] The inner needle unit 12 and the indwelling needle 16 are combined with each other to form the indwelling needle assembly 10. That is, the inner needle 14 is inserted into the indwelling needle 16 from the proximal end side, and penetrates the indwelling needle 16 so that the needle tip 22 protrudes from the tip opening of the outer needle 18. The inner needle hub 20 of the inner needle unit 12 abuts against the proximal end face of the outer needle hub 36 in the axial direction from the proximal end side, thereby defining the amount of protrusion of the inner needle 14 from the outer needle 18 toward the tip.

[0054] The inner needle 14 penetrates the needle tip protector 66. That is, the inner needle 14 inserted into the indwelling needle 16 from the proximal end side is inserted into the first circular hole 70 of the first needle insertion portion 68 and the second circular hole 94 of the second needle insertion portion 92 of the needle tip protector 66, and penetrates between the folded portions 82a and 82b of the pair of needle tip protection portions 72a and 72b toward the tip side. By inserting the inner needle 14 into the first circular hole 70 of the first needle insertion portion 68 and the second circular hole 94 of the second needle insertion portion 92, the needle tip protector 66 is restricted from moving and tilting in a direction perpendicular to the axis of the inner needle 14, and is positioned with respect to the needle tip protector 66. The pair of needle tip protection portions 72a and 72b are laterally separated from the inner needle 14 in the vertical direction in the initial shape of the needle tip protector 66 when no external force is acting. When the inner needle 14 moves axially with respect to the needle tip protector 66, the inner needle 14 can move smoothly without generating frictional resistance due to contact between the inner needle 14 and the pair of needle tip protection portions 72a and 72b (folded portions 82a and 82b). Further, since the pair of needle tip protection portions 72a and 72b are arranged at a separation distance larger than the vertical width dimension of the inner needle 14 in the initial shape, when inserting the inner needle 14 into the needle tip protector 66 from the proximal end side, it is not necessary to spread the space between the pair of needle tip protection portions 72a and 72b, and the insertion operation of the inner needle 14 is facilitated.

[0055] In the indwelling needle assembly 10 having such a structure, after the inner needle 14 and the outer needle 18 are punctured into the patient's blood vessel, the inner needle 14 is withdrawn from the outer needle 18, so that the indwelling needle 16 is left in a state of being punctured into the blood vessel.

[0056] The inner needle 14 pulled out from the outer needle 18 has its needle tip 22 protected by the needle tip protector 66. That is, as shown in FIG. 10, the inner needle 14 pulled out from the outer needle 18 moves until the needle tip 22 reaches between a pair of needle tip protection portions 72a, 72b of the needle tip protector 66. Then, the locking projections 26, 26 of the inner needle 14 are axially locked with respect to the first needle insertion portion 68. The inner needle 14 is kept in an inserted state without passing through the second circular hole 94 with the needle tip 22 positioned on the tip side of the second needle insertion portion 92, and the swing of the needle tip 22 is suppressed.

[0057] When the inner needle 14 is further pulled out toward the proximal end, the needle tip protector 66 moves toward the proximal end together with the inner needle 14, and the needle tip protector 66 passes through the input portion 56 of the pusher 54. When the needle tip protector 66 passes through the input portion 56, the second portions 78a, 78b of the pair of needle tip protection portions 72a, 72b abut against the contact portion 60 of the pusher 54, and the elastic plate portions 74a, 74b of the pair of needle tip protection portions 72a, 72b deform and approach each other. As a result, the needle tip protection portion 72b is pressed against the needle tip protection portion 72a by the locking pieces 86, 86. Since the locking pieces 86, 86 are inclined toward the needle tip protection portion 72a toward the inner side in the width direction, when the needle tip protection portion 72a is pressed against the locking pieces 86, 86, a force that pushes and spreads them in a direction away from each other acts on the locking pieces 86, 86. As a result, the side wall portions 84, 84 that support the locking pieces 86, 86 are elastically deformed, the space between the locking pieces 86, 86 is pushed and spread, and the needle tip protection portion 72b moves through the space between the locking pieces 86, 86 to the side of the needle tip protection portion 72a beyond the locking pieces 86, 86 (see FIGS. 11 and 12).

[0058] The locking pieces 86, 86 return to their initial positions due to the elasticity of the side wall portions 84, 84 when the force that allows the needle tip protection portion 72b to pass through and expand is released. Then, both end portions in the width direction of the needle tip protection portion 72b are locked to the locking pieces 86, 86, and the needle tip protection portion 72b is held at the approaching position where the needle tip protection portion 72a and the needle tip protection portion 72b approach each other without passing between the locking pieces 86, 86 again. Thus, in the present embodiment, a holding mechanism for holding the needle tip protection portion 72a and the needle tip protection portion 72b at positions where they approach each other is configured by the locking between the elastic plate portion 74b of the needle tip protection portion 72b and the locking pieces 86, 86 of the needle tip protection portion 72a. Therefore, in the present embodiment, the locking pieces 86, 86 of the needle tip protection portion 72a and the end portions in the width direction of the elastic plate portion 74b of the needle tip protection portion 72b are locking portions that are locked to each other, and the holding mechanism is configured by the locking portions. The holding mechanism is provided integrally with the needle tip protector 66. Note that when the needle tip protection portion 72a and the needle tip protection portion 72b are displaced in the approaching direction, a biasing force may be generated in the approaching direction, or conversely, a biasing force may be generated in the separating direction, or no biasing force may be generated. Further, the needle tip protection portion is not limited to the structure of the embodiment, and a needle tip protection portion having a known structure can be appropriately selected and adopted.

[0059] The tip portion of the needle tip protection part 72b that has moved to the approaching position with respect to the needle tip protection part 72a by pulling out the inner needle 14 covers the needle tip 22 of the inner needle 14 on the tip side. In short, the tip portion of the needle tip protection part 72b that has moved to the approaching position shown in FIG. 11 is located on the extension line of the inner needle 14 toward the tip side. Thus, even if a force is applied to push the inner needle unit 12 toward the tip side, the inner needle 14 will not penetrate the needle tip protector 66 and re-project toward the tip side, and the used inner needle 14 will not be accidentally punctured. In this way, the needle tip protection parts 72a and 72b are configured to protect the needle tip 22 of the inner needle 14 at the approaching position where they are close to each other, and the approaching position of the needle tip protection parts 72a and 72b is the protection position for protecting the needle tip 22. Since the needle tip protection parts 72a and 72b of the present embodiment are provided with folding parts 82a and 82b at the tip parts, even if the needle tip 22 moves along the elastic plate parts 74a and 74b by any chance, the movement of the needle tip 22 is restricted by being received by the folding parts 82a and 82b, and the needle tip 22 will not re-project.

[0060] The side walls 84, 84 of the needle tip protection part 72a at the protection position are arranged on both the left and right sides with respect to the needle tip 22 of the inner needle 14, and the exposure of the needle tip 22 is prevented not only on the tip side and both the upper and lower sides by the elastic plate parts 74a and 74b but also on both the left and right sides. In short, in the state where the needle tip protection parts 72a and 72b move to the protection position to protect the needle tip 22, the tip portion of the needle tip protector 66 is in a bag shape, and the needle tip 22 is inserted into the bag-shaped tip portion, and both the outer peripheral side and the tip side of the needle tip 22 are covered by the needle tip protector 66. Therefore, even if the needle tip 22 swings in the vertical direction or the horizontal direction, the movement of the needle tip 22 remains within the bag-shaped tip portion of the needle tip protector 66, and it is possible to prevent the needle tip 22 from touching the patient or medical staff.

[0061] Incidentally, the pair of needle tip protection portions 72a and 72b in the needle tip protector 66 may be configured to cover the needle tip 22 by deforming from an initial position where they are separated from each other to a closed position where they approach each other by contacting the stepped portion (contact portion 60) of the pusher 54. For example, by locking the pair of needle tip protection portions 72a and 72b that are elastically held in the initial position in the closed position, elastic restoration to the initial position may be prevented. Preferably, for example, by giving spring characteristics to the base end portions of the pair of needle tip protection portions 72a and 72b by using a curved cross-sectional shape or the like, at the boundary position between the initial position where they are separated from each other and the protection position where they approach and close, they are elastically deformed alternatively between the initial position and the protection position, and are set to stably hold the shape at either the initial position or the protection position. However, in order to prevent the needle tip from being re-exposed by deliberately or inadvertently spreading the pair of needle tip protection portions 72a and 72b of the closed needle tip protector 66 when the inner needle 14 is withdrawn, even when the pair of needle tip protection portions 72a and 72b are held in the protection position, it is desirable to provide a locking mechanism or the like for preventing the pair of needle tip protection portions 72a and 72b from deforming in the direction of separating from each other.

[0062] The inner needle 14 with the needle tip 22 protected by the needle tip protector 66 is pulled proximally with respect to the outer needle hub 36 and separated from the outer needle hub 36 as shown in FIG. 13. Since the holding mechanism is provided in the needle tip protection portions 72a, 72b of the needle tip protector 66, even when the needle tip protector 66 is separated from the outer needle hub 36, the needle tip protection portions 72a, 72b are held in the protection position where they approach each other, and the needle tip 22 is protected by the needle tip protector 66. Thus, since the holding mechanism for holding the needle tip protection portions 72a, 72b in the protection position is provided in the needle tip protector 66 itself, there is no need to separately provide a separate component such as a ring for holding the needle tip protection portions 72a, 72b of the needle tip protector 66 separated from the outer needle hub 36 in a separable manner with respect to the outer needle hub 36. When separating the needle tip protector 66 from the outer needle hub 36, a guide portion may be provided to accommodate the needle tip protector 66 in a close state and guide it during pulling out so that it can be smoothly pulled out. The guide portion may be, for example, the contact portion 60 of the pusher 54. However, for example, since it is provided in a close state where it can be guided with respect to the needle tip protector 66, it does not have to be in contact with the needle tip protector 66.

[0063] The indwelling needle 16 separated from the inner needle unit 12 is indwelled with the outer needle 18 punctured into the patient's blood vessel. For the indwelled indwelling needle 16, for example, an infusion line, a connector, a syringe, etc. (not shown) are connected to the proximal end portion of the outer needle hub 36. The male luer of the connector or syringe connected to the outer needle hub 36 is inserted into the luer insertion portion 50 of the outer needle hub 36 and pressed against the proximal end of the input portion 56 of the pusher 54, whereby an external force for moving the pusher 54 toward the distal end side is exerted on the input portion 56, and the pusher 54 is pushed toward the distal end. Then, as the pusher 54 moves toward the distal end side, the acting portion 58 of the pusher 54 presses against the valve body 62. As a result, the valve body 62 is elastically deformed, the slit 64 of the valve body 62 is pushed open, the inside of the patient's blood vessel and the infusion line, syringe, etc. are communicated with each other through the opened slit 64, and infusion and drug administration through the indwelling needle 16 become possible.

[0064] In the pusher 54 of the present embodiment, the outer peripheral end of the acting portion 58 is located outside the outer peripheral end of the slit 64, and the acting portion 58 presses the outer peripheral portion of the valve body 62 without being inserted into the slit 64. Therefore, for example, when the infusion line or the syringe is removed from the outer needle hub 36 and the pushing of the pusher 54 by the male luer is released, the pusher 54 moves toward the proximal end side based on the elastic restoring force of the valve body 62, and the closing operation of the valve body 62 is realized. Thereby, in the indwelling needle 16 that can be frequently used in the indwelling state, the valve body 62 can be stably opened and closed.

[0065] FIGS. 14 and 15 show a part of the indwelling needle assembly 100 as the second embodiment of the present invention. In the following description, members and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted. Further, in the indwelling needle assembly 100 of the present embodiment, parts not shown in FIGS. 14 to 18 are the same as those in the first embodiment.

[0066] The indwelling needle assembly 100 includes a pusher 102. As shown in FIGS. 16 to 18, the proximal end portion of the pusher 102 is a small-diameter cylindrical input portion 56 having a cylindrical outer peripheral surface and a square cross-sectional inner peripheral surface, and the distal end portion is a flat cylindrical working portion 104 in which the cylinder is crushed by a predetermined amount in a specific axis-perpendicular direction (the left-right direction in FIG. 18). The working portion 104 has a substantially oval inner shape and outer shape in which the left-right direction is the minor axis direction and the up-down direction is the major axis direction. Thereby, the opening portion at the tip of the pusher 102 formed by the working portion 104 has a flat shape in which the minimum and maximum diameter portions are set in two orthogonal directions. Thereby, the protector accommodation portion 55 formed inside the pusher 102 has a flat shape in which the tip portion whose wall portion is formed by the working portion 104 has an inner dimension in the up-down direction larger than the inner dimension in the left-right direction. The outer peripheral surface of the working portion 104 in the minor axis direction is a plane that extends substantially orthogonally to the minor axis direction. The outer peripheral surface of the working portion 104 in the major axis direction is a curved surface that curves in an arc shape in the circumferential direction. The inner peripheral surface of the working portion 104 has a cross-sectional shape corresponding to the outer peripheral surface, and the width dimension in the minor axis direction is substantially the same as the width dimension in the same direction of the input portion 56. Note that the flat shape of the tip opening portion of the pusher 102 is not limited to an elliptical or oval shape as illustrated, and may be, for example, a rectangular cylindrical shape or the like.

[0067] On the tip surface of the working part 104, a pair of insertion protrusions 106, 106 are formed. The insertion protrusions 106 are respectively provided on both sides of the flat direction (minor axis direction) of the working part 104. The cross-sectional shape of the insertion protrusion 106 is not particularly limited, but it has a shape and dimensions that can be inserted into the slit 64 of the valve body 62. Preferably, the width dimension in the vertical direction, which is the opening and closing direction of the slit 64 of the valve body 62, is made larger than the width dimension in the left-right direction. The insertion protrusion 106 of the present embodiment extends in the axial direction with a substantially oval cross-section in which both end surfaces in the vertical direction are curved surfaces, and the vertical direction, which is the opening and closing direction of the slit 64, is the major axis direction in the axial cross-section. The tip surface of the insertion protrusion 106 is a plane that extends orthogonally to the axial direction. However, for example, in order to improve the ease of insertion into the slit 64, it may have a tapered shape or the like in which the width becomes narrower in the vertical direction toward the tip. Each insertion protrusion 106 is arranged in the radial direction on the tip surface of the working part 104 where the separation distance becomes smaller, so that a predetermined part of the valve body 62 can be strongly pressed. Note that each insertion protrusion 106 may be provided above and below (up and down in FIG. 16) the tip surface of the working part 104 where the separation distance becomes larger. The insertion protrusion 106 may be only one instead of a plurality. The insertion protrusion 106 may not be provided. The insertion protrusion 106 may be continuously provided in a circumferential shape on the inner edge of the tip surface of the working part 104 so that the inner side of the valve body 62 that contacts the tip surface of the working part 104 is displaced more greatly.

[0068] As shown in FIGS. 14 and 15, the pusher 102 is housed inside the outer needle hub 36 and houses the needle tip protector 66 inside. In the initial shape before protecting the needle tip 22, the needle tip protector 66 includes second portions 78a and 78b where the needle tip protection portions 72a and 72b incline outward in the vertical direction toward the tip. Therefore, in the vertical direction, which is the direction in which the needle tip protection portions 72a and 72b are separated and opposed, the outer dimension is larger than that in the left-right direction. Therefore, when the tip portion of the needle tip protector 66 is housed in the protector housing portion 55 of the operation portion 104 that is flattened in the left-right direction, the gap between the needle tip protector 66 and the inner surface of the operation portion 104 is reduced. As a result, it is possible to reduce the size of the pusher 102 provided with the protector housing portion 55 and the outer needle hub 36 that houses the pusher 102. In particular, in the left-right direction, which is the flattened direction of the operation portion 104, it is easier to reduce the size of the pusher 102 and the like.

[0069] Then, when a male Luer (not shown) is inserted into the indwelling needle 16 indwelled in a blood vessel or the like and the pusher 102 is pushed toward the tip side, the pair of insertion protrusions 106, 106 of the pusher 102 are inserted into the slit 64 while expanding the slit 64 of the valve body 62. As a result, as virtually shown by the two-dot chain line in FIG. 18, the slit 64 of the valve body 62 is greatly expanded by the insertion protrusions 106, 106 of the pusher 102, and the slit 64 is brought into an open state. Since the insertion protrusion 106 of the present embodiment has a vertically long cross-sectional shape, by being inserted into the slit 64, the slit 64 can be expanded more and reliably opened. In FIG. 18, the slit 64 is formed as a single line extending in the left-right direction and is opened in the vertical direction, but it can also be a slit extending radially in a plurality of directions such as a Y shape or a cross shape.

[0070] Also, the portion of the distal end surface of the pusher 102 where the insertion protrusions 106, 106 are removed is pressed against the base end surface of the valve body 62 on the outer periphery rather than the slit 64. As a result, in the open state of the valve body 62, the valve body 62 is pushed into the distal end side by the pusher 102 and is in an elastically deformed state. When the male luer is removed from the outer needle hub 36 and the external force for pushing the pusher 102 into the distal end side is released, the pusher 102 is pushed back to the proximal end side based on the elasticity of the valve body 62. In particular, the working portion 104 has a larger outer diameter than the input portion 56, and since the working portion 104 presses the outer peripheral side of the valve body 62, a force directed from the valve body 62 toward the proximal end direction is easily transmitted to the pusher 102, and the pusher 102 is stably pushed back to the proximal end side. In this way, when the pusher 102 moves toward the proximal end by the elasticity of the valve body 62, the insertion protrusions 106, 106 inserted into the slit 64 come out of the slit 64. As a result, the slit 64 closes, and the communication between the inside of the blood vessel and the outside is blocked. Therefore, according to the attachment and detachment of an external line such as an infusion line or a syringe to the indwelling needle 16, the valve body 62 is opened and closed, and it is possible to prevent the once-opened valve body 62 from failing to close.

[0071] FIG. 19 shows a part of an indwelling needle assembly 110 as a third embodiment of the present invention. The indwelling needle assembly 110 includes a pusher 112. In the indwelling needle assembly 110 of the present embodiment, the portions not shown in FIGS. 19 and 20 are the same as those in the first embodiment.

[0072] As shown in FIG. 20, the pusher 112 includes a pusher main body 114 as a base end member and an opening and closing member 116 as a tip member attached to the opening at the tip side of the pusher main body 114. The pusher main body 114 and the opening and closing member 116 are formed independently as separate members, and for example, the pusher 112 is configured by being fixed to each other by means such as adhesion, welding, fitting, caulking, etc. The pusher main body 114 has the same structure as the pusher 54 of the first embodiment and includes an input portion 56 and a working portion 58.

[0073] The opening and closing member 116 includes a mounting portion 118 having a substantially disc shape with an outer diameter dimension substantially the same as that of the operating portion 58, and the mounting portion 118 covers the tip opening of the plunger body 114. The opening and closing member 116 includes a through hole 120 penetrating in the thickness direction at the central portion, and the peripheral edge portion of the opening of the through hole 120 is formed as an insertion cylinder portion 122 as an insertion portion protruding from the mounting portion 118 toward the tip. The insertion cylinder portion 122 has a substantially cylindrical shape with a smaller diameter than the mounting portion 118, and is insertable into the slit 64 of the valve body 62. The insertion cylinder portion 122 of the present embodiment has a cylindrical shape extending with a substantially constant outer diameter dimension. However, for example, the insertion cylinder portion can be formed as a tapered cylinder portion that tapers toward the tip in order to facilitate insertion and removal with respect to the slit 64.

[0074] As shown in FIG. 19, the plunger 112 is accommodated inside the outer needle hub 36 and accommodates the needle tip protector 66 inside. Then, when a male luer (not shown) is inserted into the indwelling catheter 16 and the plunger 112 is pushed toward the tip side, the insertion cylinder portion 122 provided at the tip of the plunger 112 is inserted into the slit 64 while expanding the slit 64 of the valve body 62. As a result, the slit 64 of the valve body 62 is expanded by the insertion cylinder portion 122 of the plunger 112, and the slit 64 is brought into an open state.

[0075] Further, the front end surface of the mounting portion 118 from which the insertion cylinder portion 122 has come off to the outer periphery is pressed against the base end surface of the valve body 62 on the outer periphery rather than the slit 64. As a result, the valve body 62 in the open state is pushed toward the tip side by the plunger 112 and is in an elastically deformed state. Then, when the male luer is removed from the outer needle hub 36 and the external force for pushing the plunger 112 toward the tip side is released, the plunger 112 is pushed back toward the base end side based on the elasticity of the valve body 62. In this way, when the plunger 112 moves toward the base end by the elasticity of the valve body 62, the insertion cylinder portion 122 inserted into the slit 64 comes out of the slit 64. As a result, the slit 64 closes, and the communication between the inside of the blood vessel and the outside is blocked. Therefore, according to the attachment and detachment of an external line such as an infusion line or a syringe to the indwelling catheter 16, the valve body 62 is opened and closed, and it is possible to prevent the once-opened valve body 62 from failing to close.

[0076] Since the pusher 112 has a structure in which two components, a pusher body 114 and an opening / closing member 116, are combined, the performance required for the proximal end portion of the pusher 112 and the performance required for the distal end portion of the pusher 112 can be highly realized respectively. For example, if the pusher 112 according to the present embodiment is adopted, while ensuring an internal space necessary for accommodating the needle tip protector 66 by the pusher body 114 constituting the proximal end portion of the pusher 112, the opening operation of the slit 64 of the valve body 62 can be stably realized by the opening / closing member 116 constituting the distal end portion of the pusher 112.

[0077] As described above, the embodiments of the present invention have been described in detail, but the present invention is not limited by its specific description. For example, in the above embodiment, an example in which the holding mechanism is constituted by the engagement between the locking pieces 86, 86 protruding from the side wall portions 84, 84 and the side edge portions of the elastic plate portion 74b of the needle tip protection portions 72a, 72b has been shown, but the position where the holding mechanism is provided is not particularly limited. Specifically, for example, the holding mechanism can also be constituted by the tip of the needle tip protection portion 72b being locked to the folded-back portion 82a of the needle tip protection portion 72a. Further, for example, the holding mechanism can also be constituted by providing a locking structure between the needle tip protection portions 72a, 72b and the positioning portion 88.

[0078] In the above embodiment, the contact portion 60 for shifting the needle tip protector 66 to the needle tip protection state is provided in a stepped shape protruding from the acting portion 58 of the pusher 54 to the inner circumference, but for example, it may be a ridge protruding further from the input portion 56 of the pusher 54 to the inner circumference.

[0079] Further, the contact portion 60 does not necessarily have to be provided on the pusher 54. For example, a notch may be formed on the proximal end side of the pusher 54, and the contact portion 60 may be provided on the inner circumferential surface of the outer needle hub 36. When the contact portion 60 is provided on the inner circumferential surface of the outer needle hub 36, for example, a contact portion protruding radially inward may be formed on the inner surface of the luer connection member, or the contact portion may be realized by assembling a member different from the luer connection member to the luer connection member. Further, the contact portion may not be provided.

[0080] When adopting the pushers 54, 102, and 112 of the first to third embodiments, the structure of the needle tip protector 66 is not limited, and needle tip protectors with various known structures can be combined and adopted. Also, when there is no needle tip protector 66 or when the needle tip protector 66 is not housed in the pushers 54, 102, 112, the pushers 54, 102, 112 of the above embodiments can be adopted.

[0081] The pusher 112 of the third embodiment has a two-component structure formed by combining a pusher body 114 as a base end member and an opening / closing member 116 as a tip end member. However, for example, the operating portion 58 and the input portion 56 of the pusher body 114 can be made into separate components, and the pusher can be composed of three or more components.

[0082] In the above embodiments, the needle tip protector is housed inside the pusher, but components other than the needle tip protector may be housed inside the pusher. Specifically, for example, a coil spring externally inserted into the needle tip protector can be arranged inside the operating portion of the pusher. According to this, for example, when pulling out the inner needle, the tip end portion of the needle tip protector can pass through the inner circumference of the coil spring, and the needle tip protection portion of the needle tip protector can be moved to the protection position. Also, if the coil spring is compressed when the pusher is pressed against the valve body, when the force for pushing the pusher is released, the pusher can be moved to the base end side by the elasticity of the coil spring, and the valve body can be quickly shifted to the closed state.

[0083] When the needle tip protector is housed inside the pusher, it is not necessarily required that the entire needle tip protector be housed inside the pusher. For example, the tip end portion of the needle tip protector may be housed inside the pusher, and the base end portion may be exposed more basally than the pusher, that is, the needle tip protector may be partially housed inside the pusher.

[0084] The working part of the pusher was made larger not only in inner diameter but also in outer diameter than the input part. However, for example, the working part may have an inner diameter larger than that of the input part and an outer diameter the same as that of the input part.

Explanation of Signs

[0085] 10 Indwelling needle assembly (First Embodiment) 12 Inner needle unit 14 Inner needle 16 Indwelling needle 18 Outer needle 20 Inner needle hub 22 Needle tip 26 Locking projection 28 Hub body 30 Inner needle holding part 32 Flange part 34 Cap member 35 Breathable filter 36 Outer needle hub 38 Needle fixing member 40 Luer connection member 42 Taper part 44 Engagement hole 46 Step 48 Hub connection part 50 Luer insertion part 52 Engagement claw 54 Pusher 55 Protector housing part 56 Input part (small cylinder part) 58 Working part (large cylinder part) 60 Contact part 62 Valve body 64 Slit 66 Needle tip protector 68 First needle insertion part 70 First circular hole 72 Needle tip protection part 74 Elastic plate part 76 First part 78 Second part 80 Third part 82 Folding part 84 Side wall part 85 Notch 86 Locking piece 88 Positioning part 90 Support section 92 Second needle insertion section 94 Second circular hole 100 Indwelling needle assembly (second embodiment) 102 Pusher 104 Actuating section 106 Insertion protrusion 110 Indwelling needle assembly (third embodiment) 112 Pusher 114 Pusher body (base end member) 116 Opening / closing member (tip member) 118 Mounting section 120 Through hole 122 Insertion cylinder section

Claims

1. An indwelling needle assembly comprising an inner needle having an inner needle hub on the proximal end side, which is slidably inserted into an outer needle having an outer needle hub on the proximal end side, and a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle, wherein the needle tip protector has a needle tip protection portion located laterally away from the inner needle, and the indwelling needle assembly further comprises a contact portion that abuts against the needle tip protection portion when the inner needle is withdrawn from the outer needle and stops at the outer needle hub, and guides the needle tip protection portion to a protection position covering the needle tip of the inner needle withdrawn by displacing the needle tip protection portion toward the approaching side of the inner needle, wherein a pusher for switching the valve body is arranged on the proximal end side of the valve body inside the outer needle hub, and at least a part of the needle tip protector is accommodated inside the pusher.

2. An indwelling needle assembly comprising an inner needle having an inner needle hub on the proximal end side, which is slidably inserted into an outer needle having an outer needle hub on the proximal end side, and a pusher for switching the valve body is arranged on the proximal end side of the valve body inside the outer needle hub, wherein at least a part of a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle is accommodated inside the pusher, wherein the pusher comprises a small cylindrical portion and a large cylindrical portion, wherein the large cylindrical portion is formed on the distal end side of the small cylindrical portion, and the inner diameter dimension of the large cylindrical portion is larger than that of the small cylindrical portion.

3. An indwelling needle assembly comprising an inner needle having an inner needle hub on the proximal end side, which is slidably inserted into an outer needle having an outer needle hub on the proximal end side, and a pusher for switching the valve body is arranged on the proximal end side of the valve body inside the outer needle hub, wherein at least a part of a needle tip protector for protecting the needle tip of the inner needle withdrawn from the outer needle is accommodated inside the pusher, wherein the pusher comprises an input portion to which an external force for pressing the pusher against the valve body is input, and an acting portion provided on the distal end side of the input portion for pushing open the valve body, wherein the acting portion has a larger diameter than the input portion.

4. A slit penetrating the inner peripheral portion in the axial direction of the inner needle is formed in the valve body, wherein the outer peripheral end of the acting portion is located on the outer periphery rather than the outer peripheral end of the slit, according to the indwelling needle assembly of claim 3.

5. An indwelling needle assembly comprising an inner needle having an inner needle hub on the proximal end side, which is slidably inserted into an outer needle having an outer needle hub on the proximal end side, and a pusher for switching the valve body is arranged on the proximal end side of the valve body inside the outer needle hub, At least a part of a needle tip protector that protects the needle tip of the inner needle withdrawn from the outer needle is accommodated inside the pusher, The pusher includes a tip member attached to an opening on the tip side of a base end member, A cannula assembly in which at least a part of the opening on the tip side of the base end member is blocked by the tip member.

6. An inner needle having an inner needle hub on the base end side is inserted into an outer needle having an outer needle hub on the base end side so as to be withdrawable, and a pusher for switching a valve body is arranged on the base end side of the valve body. A cannula assembly, Comprising a needle tip protector that protects the needle tip of the inner needle withdrawn from the outer needle, The opening portion at the tip of the pusher is formed in a flat cylindrical shape, Inside the pusher having a flat cylindrical shape, a protector accommodating portion for accommodating at least a part of the needle tip protector is provided, The pusher is provided with insertion protrusions that protrude toward the tip on both sides in the flat direction and can be inserted into slits formed in the valve body. A cannula assembly.

Images