Indwelling needle assembly

Abstract

To provide an indwelling needle assembly of a new structure, the assembly that enables air from being hard to remain more distally than a valve body in the inside of an outer needle hub.SOLUTION: An indwelling needle assembly 10 is provided in which a hollow inner needle 14 having an inner needle hub 20 in the base end side is removably inserted into an outer needle 18 having an outer needle hub 42 in the base end side, and a valve body 70 for switching between communication and interception of the outer needle hub 42 is arranged in the inside of the outer needle hub 42. In the circumferential wall of the inner needle 14, an outlet opening 28 and a reflux opening 30 are penetrated and formed, and the reflux opening 30 provided more proximally than the outlet opening 28 is opened in the inside of the outer needle hub 42 at the position more distal than the valve body 70.SELECTED DRAWING: Figure 1

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. 2007-136246 (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 withdrawable, 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 and pulling out the inner needle from the outer needle, 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, a valve body for switching the communication and blockage of the outer needle hub is provided inside the outer needle hub. The valve body blocks the inside of the outer needle hub in a state where the inner needle is inserted into the outer needle. Then, when a syringe or the like is connected to the outer needle hub left in a state of being punctured into the blood vessel, the valve body is opened and the outer needle hub is switched to a communicating state.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the structure of Patent Document 1, since the inner lumen of the outer needle is substantially blocked by the inner needle when the inner needle is inserted through the outer needle, even if the outer needle inserted over the inner needle is punctured into a blood vessel, it is difficult for blood to be introduced into the space distal to the valve body inside the outer needle hub, and air is likely to remain in the space. Therefore, when pulling out the inner needle from the outer needle and administering infusion fluid, a drug solution, etc. into the blood vessel through the indwelling outer needle and outer needle hub, it was considered that the amount of air mixed into the infusion fluid or drug solution would be relatively large.

[0006] Further, in Patent Document 1, even when the inner lumen of the outer needle is opened by removing the inner needle from the outer needle, the space distal to the valve body inside the outer needle hub is not opened to the outside other than the inner lumen of the outer needle, and the discharge of air to the outside is not considered. Therefore, when the valve body is closed, the introduction of blood into the outer needle hub is restricted by air pressure, and air is likely to remain in the space distal to the valve body inside the outer needle hub.

[0007] The problem to be solved by the present invention is to provide an indwelling needle assembly with a novel structure that can make it difficult for air to remain distal to the valve body inside the outer needle hub.

Means for Solving the Problem

[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 adopted in appropriate combinations with each other, but also for the plurality of components described in each embodiment, they can be recognized and adopted independently as much as possible, and can also be adopted in combination with any of the components described in another embodiment as appropriate. Thereby, 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 a hollow inner needle having an inner needle hub on the proximal side is inserted into an outer needle having an outer needle hub on the proximal side so as to be retractable, and a valve body for switching between communication and blockage of the outer needle hub is disposed inside the outer needle hub. An outflow opening and a reflux opening are formed through the peripheral wall of the inner needle, and the reflux opening provided proximal to the outflow opening opens inside the outer needle hub distal to the valve body.

[0010] According to the indwelling needle assembly having the structure according to this aspect, by guiding the blood flowing into the inside of the inner needle to the inside of the outer needle at the outflow opening, the blood can be guided to the space distal to the valve body inside the outer needle hub. Further, since the reflux opening of the inner needle opens distal to the valve body inside the outer needle hub, when the air inside the outer needle hub is pushed out by the blood, the air flows into the inside of the inner needle from the reflux opening, and the air is discharged from the proximal opening of the inner needle. Thereby, air can be discharged from the space distal to the valve body inside the outer needle hub, and the amount of air remaining in the space can be reduced. As a result, when infusing a transfusion, a chemical solution, or the like into a blood vessel through the inside of the outer needle hub, the mixing of air is suppressed, and the safety is improved.

[0011] A second aspect is the indwelling needle assembly according to the first aspect, in which the distance between the reflux opening and the valve body is closer than the distance between the reflux opening and the distal end of the outer needle hub.

[0012] According to the indwelling needle assembly having the structure according to this aspect, since the reflux opening is provided at a position closer to the valve body, when blood is introduced into the inside of the outer needle hub from the distal side, the reflux opening is less likely to be blocked by the blood, and the air is easily discharged into the inside of the inner needle through the reflux opening.

[0013] A third aspect is the indwelling needle assembly according to the first or second aspect, in which a constriction for partially reducing the cross-sectional area of the inner cavity of the inner needle is provided between the outflow opening and the reflux opening.

[0014] According to the indwelling needle assembly having a structure according to this aspect, since the blood flowing into the inner needle is blocked by the constriction portion, it becomes easier for the blood to flow out to the outer needle at the outflow opening. Therefore, the blood can be efficiently introduced into the outer needle hub. Further, since the constriction portion is provided between the outflow opening and the reflux opening, the constriction portion does not prevent the air entering the inner needle from the reflux opening from being discharged to the proximal end side.

[0015] A fourth aspect is an indwelling needle assembly in which a hollow 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 valve body for switching the communication and blocking of the outer needle hub is disposed inside the outer needle hub. An outflow opening and a reflux opening are formed through the peripheral wall of the inner needle, the reflux opening is located closer to the proximal end than the outflow opening and farther from the valve body, and a crushed portion where the inner needle is crushed is provided between the outflow opening and the reflux opening in the axial direction. A protector locking portion that is locked to a needle tip protector that protects the needle tip of the inner needle by pulling out the inner needle from the outer needle is provided on the inner needle due to a radial bulge accompanying the crushing of the inner needle at the crushed portion.

[0016] According to the indwelling needle assembly having a structure according to this aspect, by allowing the blood flowing into the inner needle to flow out to the outer needle or the outer needle hub at the outflow opening, the blood can be guided to the space distal to the valve body inside the outer needle hub. Further, when the air inside the outer needle hub is pushed out by the blood, the air flows into the lumen of the inner needle from the reflux opening, and the air is discharged from the proximal end opening of the inner needle. As a result, the air can be discharged from the space distal to the valve body inside the outer needle hub, and the amount of air remaining in the space can be reduced. As a result, when infusing a liquid medicine or the like into a blood vessel through the inside of the outer needle hub, the mixing of air is suppressed, and the safety is improved.

[0017] A crushing portion is provided between the outflow opening and the reflux opening, and the lumen of the inner needle is narrowed at the crushing portion. Therefore, the blood flowing through the inner needle is blocked by the crushing portion and easily flows out through the outflow opening to the outer needle or the outer needle hub. Therefore, blood can be efficiently introduced into the interior of the outer needle hub. Further, since the crushing portion is provided between the outflow opening and the reflux opening, the crushing portion does not prevent the discharge of air that has entered the inner needle from the reflux opening to the proximal end side.

[0018] Since the crushing portion is formed by partially crushing the inner needle, the inner needle bulges in a direction perpendicular to the crushing direction at the crushing portion. By using this bulging portion as a protector locking portion that is locked to the needle tip protector when the inner needle is withdrawn, the crushing portion and the protector locking portion can be formed simultaneously, and the number of manufacturing processes can be reduced.

[0019] A fifth aspect is the indwelling needle assembly according to any one of the first to fourth aspects, wherein the outflow opening and the reflux opening are continuously opened over at least a half circumference in the circumferential direction of the inner needle.

[0020] According to the indwelling needle assembly having the structure according to this aspect, since the outflow opening is a wide opening that opens over at least a half circumference in the circumferential direction of the inner needle, the amount of blood flowing out into the outer needle or the outer needle hub can be ensured. Since the reflux opening is a wide opening that opens over at least a half circumference in the circumferential direction of the inner needle, air is easily guided to the reflux opening, and the air in the outer needle hub can be discharged more efficiently.

[0021] A sixth aspect is an indwelling needle assembly in which a hollow 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 withdrawable, and a valve body that switches the communication and interruption of the outer needle hub is disposed inside the outer needle hub. A needle insertion hole through which the inner needle is inserted is formed in the valve body, and an exhaust hole penetrating the valve body is formed between the inner needle and the needle insertion hole in a state where the inner needle is inserted into the needle insertion hole.

[0022] According to the indwelling needle assembly having the structure according to this aspect, since the exhaust hole is formed in the valve body, the internal region distal to the valve body and the proximal internal region in the outer needle hub are communicated by the exhaust hole. Therefore, when blood or the like is introduced into the outer needle hub, the air in the region distal to the valve body in the outer needle hub is discharged to the proximal region through the exhaust hole, and the internal region distal to the valve body can be filled with blood or the like. As a result, when infusing a transfusion, a chemical solution, or the like into a blood vessel through the inside of the outer needle hub, the mixing of air is suppressed and the safety is improved.

[0023] In order to suppress the passage of blood, it is desirable that the hole cross-sectional area and the minimum width dimension of the exhaust hole are small. However, in the hole formed during the molding of the valve body, the hole cross-sectional area and the minimum width dimension cannot be made as small as required for the exhaust hole. Therefore, paying attention to the fact that the needle insertion hole is narrowed by the insertion of the inner needle, by forming the exhaust hole using the narrowed region between the inner needle and the inner surface of the needle insertion hole, it is possible to realize an exhaust hole that is so small that it cannot be formed during the molding of the valve body.

[0024] A seventh aspect is the indwelling needle assembly described in the sixth aspect, wherein the valve body includes a needle arrangement portion in which the inner needle is arranged and a concave groove that opens on the inner peripheral surface of the needle arrangement portion and penetrates in the needle axis direction, and the groove cross-sectional area of the concave groove is smaller than the hole cross-sectional area of the needle arrangement portion.

[0025] According to the indwelling needle assembly having the structure according to this aspect, by forming a concave groove that opens on the inner peripheral surface of the needle arrangement portion, for example, even if the outer peripheral surface of the inner needle is in contact with the inner peripheral surface of the needle arrangement portion at a portion where the opening of the concave groove is disengaged, an exhaust hole is formed in the formed portion of the concave groove. Therefore, the inner needle can be brought into contact with the valve body on the inner surface of the needle arrangement portion, and while suppressing the rattling of the inner needle, an exhaust hole using the needle insertion hole can be provided.

[0026] An eighth aspect is the indwelling needle assembly described in the seventh aspect, wherein a plurality of the concave grooves are formed in the circumferential direction of the needle arrangement portion.

[0027] According to the indwelling needle assembly structured according to this aspect, for example, when the inner needle contacts the valve body between the circumferential directions of a plurality of concave grooves, a plurality of exhaust holes are independently formed by the plurality of concave grooves. Thereby, while restricting the passage of blood by reducing the hole cross-sectional area and the minimum width dimension of each exhaust hole, it is possible to ensure a large sum of the hole cross-sectional areas of the plurality of exhaust holes and efficiently discharge air.

[0028] A ninth aspect is an indwelling needle assembly in which a hollow inner needle having an inner needle hub on the proximal end side is inserted through a outer needle having an outer needle hub on the proximal end side so as to be retractable, and a valve body that switches between communication and cutoff of the outer needle hub is disposed inside the outer needle hub. An opening penetrating in the axial direction of the inner needle is formed in the valve body, the valve body is disposed inside the outer needle hub in a state of being compressed in the radial direction by the outer needle hub, and the opening is reduced due to the radial compression of the valve body, and an exhaust hole penetrating the valve body is formed by the reduced opening.

[0029] According to the indwelling needle assembly structured according to this aspect, since an exhaust hole is formed in the valve body, the internal region distal to the valve body and the proximal internal region in the outer needle hub are communicated by the exhaust hole. Therefore, when blood or the like is introduced into the outer needle hub, the air in the region distal to the valve body in the outer needle hub is discharged to the proximal region through the exhaust hole, and it becomes possible to fill the internal region distal to the valve body with blood or the like. As a result, when infusing or administering a chemical solution or the like into a blood vessel through the inside of the outer needle hub, the mixing of air is suppressed and the safety is improved.

[0030] The exhaust hole is formed by reducing an opening formed in the valve body due to deformation caused by compression of the valve body. Therefore, it is possible to form an exhaust hole smaller than the minimum opening that can be formed in the valve body, and leakage of blood through the exhaust hole can be suppressed. Moreover, the reduction of the opening is realized by radially compressing the valve body when the valve body is attached to the outer needle hub. Therefore, there is no need to provide a special component for reducing the opening or to perform a special operation for reducing the opening, and a valve body provided with an exhaust hole can be easily obtained.

[0031] Aspect 10 is the indwelling needle assembly according to Aspect 9, wherein the opening includes a main opening and a groove-shaped secondary opening that opens on the inner peripheral surface of the main opening and penetrates the valve body in the axial direction of the inner needle. The main opening is closed by radial compression of the valve body, and the exhaust hole is constituted by the secondary opening.

[0032] According to the indwelling needle assembly having the structure according to this aspect, since the main opening of the opening is closed by radial compression due to the attachment of the valve body to the outer needle hub, it is easier to obtain a smaller exhaust hole. Even in a state where the main opening is closed, since a communicating exhaust hole is ensured by the groove-shaped secondary opening that opens on the inner peripheral surface of the main opening, the discharge of air through the exhaust hole is effectively realized. Since the secondary opening is in the shape of a groove, the secondary opening can be formed with a smaller cross-sectional area than a through-hole, and the hole cross-sectional area of the exhaust hole constituted by the secondary opening can be made smaller.

[0033] Aspect 11 is the indwelling needle assembly according to Aspect 9 or 10, wherein the valve body is in a single-piece state and has an elliptical plate shape, and the valve body is arranged inside the outer needle hub having a circular cross-section and is compressed in the major axis direction, whereby the opening of the valve body is reduced.

[0034] According to the indwelling needle assembly having the structure according to this aspect, it is easy to specify the compression direction due to the attachment of the valve body to the outer needle hub, and since the stabilization of the reduced deformation mode of the opening is achieved, it is easy to obtain a uniform exhaust hole.

[0035] A 12th aspect is an indwelling needle assembly in which a hollow 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 valve body that switches between communication and blockage of the outer needle hub is disposed inside the outer needle hub. The valve body includes a first valve member and a second valve member that are stacked in the axial direction of the inner needle. A first through hole is formed in the first valve member, and a second through hole is formed in the second valve member. The first through hole and the second through hole are located apart from each other in the axial direction view. On at least one of the overlapping surfaces of the first valve member and the second valve member, a constriction groove extending across the first through hole and the second through hole is formed. An exhaust hole passing through the valve body is constituted by the first through hole, the second through hole, and the constriction groove. The groove cross-sectional area of the constriction groove is smaller than the hole cross-sectional areas of the first through hole and the second through hole.

[0036] According to the indwelling needle assembly having the structure according to this aspect, since the exhaust hole is formed in the valve body, the inner region distal to the valve body and the proximal inner region in the outer needle hub are communicated by the exhaust hole. Therefore, when blood or the like is introduced into the outer needle hub, the air in the region distal to the valve body in the outer needle hub is discharged to the proximal region through the exhaust hole, and the inner region distal to the valve body can be filled with blood or the like. As a result, when infusing a liquid medicine or the like into a blood vessel through the inside of the outer needle hub, the mixing of air is suppressed, and the safety is improved.

[0037] The flow resistance of the exhaust hole can be adjusted so as to allow the passage of air and restrict the passage of blood according to the groove cross-sectional area and the minimum width dimension of the constriction groove extending between the overlapping surfaces of the first valve member and the second valve member.

Effects of the Invention

[0038] According to the present invention, it is possible to make it difficult for air to remain distal to the valve body inside the outer needle hub.

Brief Description of the Drawings

[0039]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0040] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0041] In FIG. 1, 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 slidably 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 direction perpendicular to the paper surface of FIG. 1. Further, 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.

[0042] 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 in this embodiment, it is a hollow needle having a lumen 21. The tip of the inner needle 14 has a tip surface cut into an inclined shape, and as shown in FIGS. 1 and 2, a sharp needle tip 22 is formed.

[0043] As shown in FIG. 1, a constriction 24 that partially constricts the lumen 21 is provided at the tip portion of the inner needle 14. The constriction 24 of this embodiment is a crushed portion formed by partially crushing the hollow inner needle 14 in the needle axis direction. Further, in the constriction 24 of this embodiment, the inner surface of the inner needle 14 is pressed in the vertical direction, and the lumen 21 of the inner needle 14 is blocked by the constriction 24 so that blood does not pass through. However, the constriction 24 only needs to constrict the lumen 21 so that the cross-sectional area of the hole is reduced to limit the passage of blood, and it is not necessarily required to block the lumen 21 so that blood does not pass through. The structure of the constriction 24 is not limited as long as it constricts the lumen 21 of the inner needle 14. For example, a separate plug member may be disposed in the lumen 21 to form the constriction with the plug member.

[0044] As shown in FIG. 2, 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 as protector locking portions protrude in the left-right direction (the vertical direction in FIG. 2). In this embodiment, when the inner needle 14 is crushed in the vertical direction to form the constriction 24, the crushed inner needle 14 bulges to both sides in the left-right direction at the constriction 24, thereby forming the locking protrusions 26, 26. However, the locking protrusions 26 can also be provided independently of the constriction 24. For example, they can be formed by crushing the left and right ends of the hollow portion of the inner needle 14 vertically to such an extent that the lumen 21 of the inner needle 14 is not constricted.

[0045] The inner needle 14 is formed with a distal outflow opening 28 and a proximal reflux opening 30. The outflow opening 28 and the reflux opening 30 are formed to penetrate the peripheral wall of the inner needle 14 at the upper part. The outflow opening 28 and the reflux opening 30 communicate the inner cavity 21 of the inner needle 14 with the outside with respect to the inner cavity 21. The outflow opening 28 and the reflux opening 30 of the present embodiment have substantially the same opening shape and size, but for example, the shapes and sizes of the outflow opening 28 and the reflux opening 30 can be made different from each other. The outflow opening 28 and the reflux opening 30 preferably open over at least half of the circumferential direction of the inner needle 14 respectively, and in the present embodiment, they open in the upper half over half of the circumference of the inner needle 14. The reflux opening 30 is arranged further proximally away from the outflow opening 28. The outflow opening 28 is formed on the tip side of the constriction 24 of the inner needle 14, and in the present embodiment, the distance from the constriction 24 is made closer than the distance from the needle tip 22. The reflux opening 30 is formed on the proximal side of the constriction 24 of the inner needle 14 and is located on the tip side of a valve body 70 to be described later in the state where the inner needle 14 is inserted into the outer needle 18. In the state where the inner needle 14 is inserted into the outer needle 18, the distance of the reflux opening 30 from the valve body 70 is made closer than the distance from the tip of the outer needle hub 42.

[0046] As shown in FIG. 1, the inner needle hub 20 includes a hub body 32. The hub body 32 has a tip portion with a substantially rectangular cylindrical shape and a base end portion with a substantially cylindrical shape. The outer peripheral surface of the tip portion of the hub body 32 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 axially when pinched by a finger and axially moved. The hub body 32 integrally includes a substantially cylindrical inner needle holding portion 34 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 34 is fixed to the outer peripheral surface of the inner needle 14, and the hub body 32 is fixed to the inner needle 14. A flange-like portion 36 protruding toward the outer periphery is provided at the tip of the hub body 32, and the inner diameter of the tip surface of the hub body 32 is made smaller and the outer diameter is made larger than the base end surface of an outer needle hub 42 to be described later. In the inner needle unit 12, both the outflow opening 28 and the reflux opening 30 of the inner needle 14 are located on the tip side of the inner needle hub 20 and are exposed to the outside.

[0047] A cap member 38 is attached to the proximal opening portion of the hub body 32. The cap member 38 is generally in a substantially cylindrical shape. The cap member 38 has a tapered outer peripheral surface whose diameter decreases toward the tip at the distal end portion, and the distal end portion is fitted into the proximal opening portion of the hub body 32, whereby the cap member 38 is attached to the hub body 32. A breathable filter 40 is attached to the proximal opening portion of the cap member 38, and the air inside the cap member 38 can be discharged to the outside through the breathable filter 40. On the other hand, for example, blood that enters the inside of the cap member 38 through the inner needle 14 due to flashback during puncture does not pass through the breathable filter 40 and does not leak from the inside of the cap member 38. Note that the cap member 38 is preferably transparent or translucent in order to facilitate visual recognition of the flashback during puncture of the inner needle 14 into the blood vessel.

[0048] The indwelling needle 16 has a structure in which an outer needle hub 42 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 distal end portion of the outer needle 18 is a tapered surface whose diameter becomes smaller toward the tip. The inner diameter dimension of the tip of the outer needle 18 may be larger than the outer diameter dimension of the inner needle 14, or may be the same, but preferably, it is made smaller than the outer diameter dimension of the inner needle 14. With the inner needle 14 inserted through the outer needle 18, the tip of the outer needle 18 is fitted to the inner needle 14, and the inner needle 14 and the outer needle 18 are positioned to some extent.

[0049] The proximal end portion of the outer needle 18 is inserted into the inner circumference of the tubular outer needle hub 42 and fixed to the outer needle hub 42. The outer needle hub 42 is, for example, a tubular body made of resin. The outer needle hub 42 of the present embodiment has a structure in which a needle fixing member 44 constituting the tip portion and a luer connecting member 46 constituting the proximal end portion are combined. However, the outer needle hub 42 may be composed of a single part as a whole, or may be composed of a combination of three or more parts. Further, when the outer needle hub 42 is constituted by combining a plurality of parts, those parts may be fixed by being fitted non-adhesively, or may be fixed by means such as adhesion or welding.

[0050] The needle fixing member 44 is cylindrical as a whole and has a tapered portion 48 that becomes larger in diameter toward the proximal end in the middle of the axial direction. The proximal end side of the tapered portion 48 has a larger diameter than the distal end side. Engagement holes 50, 50 penetrating in the vertical direction are formed in the needle fixing member 44, and the inner peripheral surface of the proximal end side of the engagement hole 50 has 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 44 having a small diameter, and the outer needle 18 is fixed to the needle fixing member 44 by a cylindrical pin.

[0051] The luer connecting member 46 is cylindrical as a whole, and a step is provided in the middle of the axial direction. The portion on the distal end side of the step is a hub connecting portion 54 having a larger diameter, and the proximal end side is a luer insertion portion 56 having a smaller diameter. A pair of engagement claws 58, 58 are provided on the outer peripheral surface of the hub connecting portion 54, and the needle fixing member 44 and the luer connecting member 46 are connected by engaging the engagement claws 58, 58 with the inner surfaces of the engagement holes 50, 50 provided in the needle fixing member 44 to constitute the outer needle hub 42. The inner peripheral surface of the luer insertion portion 56 has a luer taper that expands toward the proximal end.

[0052] The outer needle hub 42 has a luer connecting member 46 that houses a pusher 60. The pusher 60 is generally in a substantially stepped cylindrical shape and has a protector housing portion 62 penetrating axially therein. The pusher 60 has an input portion 64 with a small-diameter small cylindrical portion at the proximal end and an acting portion 66 with a larger diameter than the input portion 64 at the distal end. The input portion 64 and the acting portion 66 are continuously integrally formed with a stepped shape. The inner peripheral surface shape of the pusher 60 is a quadrilateral corresponding to the needle insertion portion 80 of the needle tip protector 78 described later in the input portion 64 and is circular in the acting portion 66. Note that the inner peripheral surface shape of the input portion 64 is not limited to a quadrilateral, but is preferably a shape such as an ellipse or a polygon in which the inner diameter dimension changes in the circumferential direction so as to be able to prevent the rotation of the needle tip protector 78. The pusher 60 may be appropriately provided with slits (holes) penetrating the peripheral wall. Further, by making the inner peripheral surface shape of the acting portion 66 flat in the left-right direction, the needle tip protector 78 with an outer dimension in the up-down direction larger than that in the left-right direction can be efficiently accommodated in the protector housing portion 62 formed on the inner periphery of the acting portion 66.

[0053] For the pusher 60, the input portion 64 is housed in the luer insertion portion 56 of the luer connecting member 46, and the acting portion 66 is housed in the hub connecting portion 54 of the luer connecting member 46. The pusher 60 is positioned in a direction perpendicular to the axis with respect to the outer needle hub 42 by the outer peripheral surface of the acting portion 66 being overlapped with the inner peripheral surface of the hub connecting portion 54 of the outer needle hub 42. Further, the outer diameter dimension of the acting portion 66 is made larger than the inner diameter dimension of the luer insertion portion 56, and the pusher 60 is positioned axially with respect to the outer needle hub 42 by the proximal end surface of the acting portion 66 being overlapped with the step of the luer connecting member 46. The proximal end of the pusher 60 is located on the distal end side of the proximal end of the outer needle hub 42 (luer connecting member 46), and the pusher 60 is housed without protruding from the outer needle hub 42 toward the proximal end.

[0054] A valve body 70 is disposed on the tip side of the pusher 60 inside the outer needle hub 42. The valve body 70 is formed of a resin elastomer or rubber having rubber-like elasticity. The valve body 70 has a substantially disc shape, and is arranged so as to block the inside of the outer needle hub 42 by being sandwiched in the thickness direction between a needle fixing member 44 and a luer connecting member 46 that constitute the outer needle hub 42 at its outer peripheral end. Thereby, the inside of the outer needle hub 42 is divided into a first region 72 on the tip side of the valve body 70 and a second region 74 on the base end side of the valve body 70.

[0055] As shown in FIG. 1, the valve body 70 is provided with a slit 76 penetrating the inner peripheral portion. The slit 76 extends radially, for example, from the center of the valve body 70, and penetrates the valve body 70 in the left-right direction in FIG. 1, which is the axial direction of the inner needle 14. The slit 76 of the present embodiment has a substantially Y shape extending radially in three directions from the center of the valve body 70 to the outer periphery. However, for example, it may be a linear shape extending to both sides in the radial direction, a cross shape extending in four directions, or the like. And, the inside of the outer needle hub 42 is switched between a communication state in which the first region 72 and the second region 74 communicate with each other through the slit 76 and a blocking state in which the first region 72 and the second region 74 are separated by the valve body 70 when the slit 76 of the valve body 70 is opened and closed.

[0056] As shown in FIG. 1, the tip outer peripheral edge of the acting portion 66 of the pusher 60 is located on the outer peripheral side of the outer peripheral end of the slit 76 of the valve body 70. Thereby, at least the outer peripheral end of the tip surface of the pusher 60 is located on the outer periphery of the slit 76. More preferably, the tip inner peripheral edge of the acting portion 66 is located on the outer peripheral side of the outer peripheral end of the slit 76, and the entire tip surface of the acting portion 66 is located outside the slit 76 at the outer periphery. The tip of the pusher 60 may be in contact with the valve body 70 supported by the outer needle hub 42, but in the present embodiment, it is located away from the valve body 70 toward the base end.

[0057] In a protector housing portion 62 provided inside the pusher 60, a needle tip protector 78 is accommodated. The needle tip protector 78 is formed of, for example, an elastically deformable metal plate material. The needle tip protector 78 has a needle insertion portion 80 that extends substantially orthogonally to the axial direction of the inner needle 14 at the base end. The needle insertion portion 80 has a rectangular plate shape, and a circular hole 82 corresponding to the outer shape of the inner needle 14 penetrates in the thickness direction at the center. The diameter of the circular hole 82 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 formation portion of the locking protrusions 26, 26.

[0058] The needle tip protector 78 includes a pair of needle tip protection portions 84a, 84b. The pair of needle tip protection portions 84a, 84b face each other vertically and extend from the upper and lower end portions of the needle insertion portion 80 toward the tip.

[0059] The needle tip protector 78 is accommodated inside the pusher 60. That is, the needle insertion portion 80 and the base end portions of the pair of needle tip protection portions 84a, 84b are inserted into the tip portion of the input portion 64 of the pusher 60. Further, the tip portions of the pair of needle tip protection portions 84a, 84b are inserted into the acting portion 66 of the pusher 60. By inserting the base end portion of the needle tip protector 78 into the input portion 64 having a small diameter with a quadrangular inner peripheral cross-sectional shape, the needle tip protector 78 is positioned in the direction perpendicular to the axis and in the circumferential direction with respect to the pusher 60, and rattling and displacement are prevented. Further, since the tip portion of the needle tip protector 78 is accommodated in the acting portion 66 having a large internal space, the pair of needle tip protection portions 84a, 84b are accommodated in the pusher 60 while maintaining the initial shape in which they are separated from each other.

[0060] 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 so as to be withdrawable from the proximal end side, and penetrates the indwelling needle 16 such 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 base end surface of the outer needle hub 42 from the proximal end side in the axial direction, thereby defining the amount of protrusion of the inner needle 14 from the outer needle 18 toward the tip.

[0061] The inner needle 14 penetrates through the needle tip protector 78. That is, the inner needle 14 inserted from the proximal end side into the indwelling needle 16 is inserted through the circular hole 82 of the needle insertion portion 80 of the needle tip protector 78 and penetrates between the tip portions of the pair of needle tip protection portions 84a, 84b toward the tip side. The pair of needle tip protection portions 84a, 84b are separated from each other in the vertical direction with respect to the inner needle 14. When the inner needle 14 moves axially with respect to the needle tip protector 78, 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 84a, 84b. Further, since the pair of needle tip protection portions 84a, 84b are arranged at a separation distance larger than the vertical width dimension of the inner needle 14 in the initial shape, when the inner needle 14 is inserted through the needle tip protector 78 from the proximal end side, it is not necessary to expand the space between the pair of needle tip protection portions 84a, 84b, and the insertion operation of the inner needle 14 is facilitated.

[0062] The inner needle 14 is inserted through the slit 76 of the valve body 70 and penetrates the valve body 70 in the needle axis direction. The outflow opening 28 of the inner needle 14 is located on the distal side of the outer needle hub 42 and on the proximal side of the tip of the outer needle 18, and opens in the inner cavity of the outer needle 18. At the axial position where the outflow opening 28 is formed, the outer needle 18 is separated from the inner needle 14 on the outer periphery, so that the outflow opening 28 is not blocked by the outer needle 18 in close contact therewith. On the proximal side of the outflow opening 28, the outer needle 18 is separated from the inner needle 14 on the outer periphery. The reflux opening 30 of the inner needle 14 is located on the distal side, which is farther from the valve body 70, and opens in the first region 72 inside the outer needle hub 42. The distance of the reflux opening 30 from the valve body 70 is closer than the distance from the tip of the outer needle hub 42. In the present embodiment, the reflux opening 30 is located on the proximal side of the tapered portion 48 of the outer needle hub 42.

[0063] In the indwelling needle assembly 10 having such a structure, first, the inner needle 14 and the outer needle 18 are punctured into the patient's blood vessel. When the inner needle 14 is punctured into the blood vessel, blood flows from the tip opening of the inner needle 14 into the inner cavity 21 of the inner needle 14. The blood flowing into the inner cavity 21 flows toward the proximal end of the inner cavity 21, but the flow is restricted and blocked by the constriction 24, so that it flows out of the inner cavity 21 through the outflow opening 28 and into the inner cavity of the outer needle 18. The blood that has entered the inner cavity of the outer needle 18 flows between the inner needle 14 and the outer needle 18 toward the proximal end side and into the first region 72 inside the outer needle hub 42.

[0064] As blood flows into the first region 72, the air in the first region 72 is pushed out by the blood and discharged to the outside. That is, the air in the first region 72 flows into the lumen 21 of the inner needle 14 through the reflux opening 30, is discharged from the proximal opening of the inner needle 14 into the inside of the cap member 38, passes through the breathable filter 40, and is discharged to the outside. The reflux opening 30 allows not only air but also blood to pass through. Blood also flows into the inside of the cap member 38 through the lumen 21 of the inner needle 14. However, the breathable filter 40 provided at the proximal end of the cap member 38 prevents blood from leaking to the outside and allows air to be discharged to the outside. Also, when blood flows into the lumen 21 of the inner needle 14, it can be expected that the air in the first region 72 is entrained and guided into the lumen 21.

[0065] In this way, the air in the first region 72 provided inside the outer needle hub 42 is discharged to the outside by the introduction of blood into the outer needle hub 42 through the outflow opening 28 and the exhaust to the proximal end side through the reflux opening 30. In this way, by effectively performing priming to fill the first region 72 with blood, the mixing of air during the use of the indwelling needle 16 described later is suppressed, and the safety is improved.

[0066] After the inner needle 14 and the outer needle 18 are punctured into the blood vessel, the inner needle 14 is pulled out from the outer needle 18, and the indwelling needle 16 is left in the state of being punctured into the blood vessel. As shown in FIG. 3, when the inner needle 14 is removed from the outer needle 18, the tip opening of the outer needle 18 is opened, and the amount of blood flowing into the first region 72 of the outer needle hub 42 increases. However, since the first region 72 is pre-filled with blood and the air in the first region 72 has been discharged, even if, for example, a turbulent flow is generated due to an increase in the flow rate, the mixing of air into the blood is suppressed.

[0067] 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 parts 84a and 84b of the needle tip protector 78. Then, the locking protrusions 26, 26 of the inner needle 14 are axially locked to the needle insertion part 80. When the inner needle 14 is further pulled out toward the proximal end, the needle tip protector 78 moves toward the proximal end side together with the inner needle 14, and the needle tip protector 78 passes through the input part 64 of the pusher 60. When the needle tip protector 78 passes through the input part 64, the pair of needle tip protection parts 84a and 84b contact the stepped part of the pusher 60, and the pair of needle tip protection parts 84a and 84b deform and approach each other and are locked to each other. The mutually approaching needle tip protection parts 84a and 84b are positioned to cover and protect the distal end side of the needle tip 22 of the inner needle 14 as shown in FIG. 3, and the exposure of the distal end side of the needle tip 22 is prevented by the needle tip protector 78.

[0068] Note that the pair of needle tip protection parts 84a and 84b in the needle tip protector 78 only needs to be deformed from an initial position where they are separated from each other to a closed position where they approach each other by contacting the stepped part of the pusher 60 so as to cover the needle tip 22. For example, the pair of needle tip protection parts 84a and 84b that are elastically held in the initial position may be locked in the closed position to prevent elastic restoration to the initial position. Preferably, for example, by giving spring characteristics to the proximal end portions of the pair of needle tip protection parts 84a and 84b with 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 be stably held in either the initial position or the protection position. However, in order to prevent the re-exposure of the needle tip due to the pair of needle tip protection parts 84a and 84b of the closed needle tip protector 78 being deliberately or unintentionally widened when the inner needle 14 is pulled out, even when the pair of needle tip protection parts 84a and 84b are held in the protection position, it is desirable to provide a locking mechanism or the like for preventing the deformation of the pair of needle tip protection parts 84a and 84b in the mutually separating direction.

[0069] The inner needle 14 with the needle tip 22 protected by the needle tip protector 78 is pulled proximally with respect to the outer needle hub 42 and separated from the outer needle hub 42. Even when separated from the outer needle hub 42, the needle tip protector 78 is held in a protected position where the needle tip protection portions 84a and 84b approach each other and continues to protect the needle tip 22.

[0070] The indwelling needle 16 separated from the inner needle unit 12 is indwelled with the outer needle 18 puncturing the patient's blood vessel. For the indwelled indwelling needle 16, for example, an infusion line, a connector, a syringe (not shown) or the like is connected to the proximal end portion of the outer needle hub 42. The male luer of the connector or syringe connected to the outer needle hub 42 is inserted into the luer insertion portion 56 of the outer needle hub 42 and pressed against the proximal end of the input portion 64 of the pusher 60, whereby an external force for moving the pusher 60 toward the distal end side is exerted on the input portion 64, and the pusher 60 is pushed toward the distal end. Then, as the pusher 60 moves toward the distal end side, the acting portion 66 of the pusher 60 presses against the valve body 70. As a result, the valve body 70 is elastically deformed, the slit 76 of the valve body 70 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 76, and infusion and medication through the indwelling needle 16 become possible.

[0071] FIG. 4 and FIG. 5 show a valve body 90 constituting an indwelling needle assembly as a second embodiment of the present invention. The valve body 90 can be employed, for example, in place of the valve body 70 in the indwelling needle assembly 10 of the first embodiment. In the following description, members and parts that are substantially the same as those in the above embodiment are denoted by the same reference numerals in the drawings and the description thereof is omitted. Also, parts not shown in the drawings in the indwelling needle assembly are the same as those in the first embodiment.

[0072] The valve body 90 is provided with a needle insertion hole 92 that penetrates the central portion in the radial direction in the axial direction, which is the thickness direction. As shown in FIG. 5, the needle insertion hole 92 is composed of a needle arrangement portion 94 corresponding to the inner needle 14 and a plurality of concave grooves 96 that open on the inner peripheral surface of the needle arrangement portion 94. Thereby, the needle insertion hole 92 has an inner diameter dimension larger than the outer diameter dimension of the inner needle 14 at the formed portion of the concave groove 96, and has an inner diameter dimension substantially the same as the outer diameter dimension of the inner needle 14 at the portion where the concave groove 96 is disengaged in the circumferential direction. The number of formed concave grooves 96 constituting the needle insertion hole 92 and their circumferential arrangement are not particularly limited, but in this embodiment, eight concave grooves 96 are provided side by side at substantially equal intervals in the circumferential direction.

[0073] As shown in FIG. 5, the inner needle 14 is inserted into the needle insertion hole 92 of the valve body 90. When the inner needle 14 is inserted, the needle insertion hole 92 is narrowed by the inner needle 14, and an exhaust hole 98 that penetrates the valve body 90 in the axial direction is formed between the inner peripheral surface of the needle insertion hole 92 and the outer peripheral surface of the inner needle 14. The exhaust hole 98 is formed to extend in the axial direction between the inner peripheral surface of the valve body 90 and the outer peripheral surface of the inner needle 14 when the opening of the concave groove 96 is covered by the inner needle 14. The groove cross-sectional area of the concave groove 96 is sufficiently smaller than the hole cross-sectional area of the needle arrangement portion 94, and the hole cross-sectional area of the exhaust hole 98 is sufficiently smaller than that of the needle insertion hole 92. The hole shape and hole cross-sectional area of the exhaust hole 98 are set so that the passage of air is allowed and the passage of blood is restricted by the flow resistance. In this embodiment, on both sides in the circumferential direction of the exhaust hole 98, the outer peripheral surface of the inner needle 14 is in contact with the inner peripheral surface of the valve body 90, and the needle arrangement portion 94 is substantially blocked by the inner needle 14. For example, the inner needle 14 and the valve body 90 may be separated from each other not only at the formed portion of the concave groove 96 but also at the portion where the concave groove 96 is disengaged in the circumferential direction.

[0074] According to the indwelling needle assembly provided with the valve body 90 having such a structure according to this embodiment, a first region on the distal side of the valve body 90 in the outer needle hub and a second region on the proximal side of the valve body 90 in the outer needle hub communicate with each other through the exhaust hole 98. Therefore, when the outer needle punctures a blood vessel and blood flows into the first region of the outer needle hub, the air in the first region is discharged to the second region through the exhaust hole 98 and then discharged to the outside from the proximal opening of the outer needle hub or the like. Thereby, the remaining air in the first region is reduced, and when administering a drug solution or the like into the blood vessel through the inside of the outer needle hub, it is possible to suppress the mixing of air into the drug solution or the like.

[0075] In addition, when the inner needle 14 is pulled out from the valve body 90, the entire needle insertion hole 92 formed in the center of the valve body 90 is in an open state, and the flow of blood from the first region to the second region through the needle insertion hole 92 is allowed. Therefore, if the male Luer is connected to the outer needle hub before the blood leaks to the outside from the proximal opening of the outer needle hub, the leakage of blood can be prevented. In particular, if the outer needle is bent or the like so that the proximal opening of the outer needle hub faces upward, the leakage of blood from the outer needle hub can be more effectively prevented.

[0076] In this embodiment, an example of the structure is shown in which the needle insertion hole 92 is provided with a concave groove 96 that opens on the inner peripheral surface, and the exhaust hole 98 is formed in the enlarged diameter portion of the needle insertion hole 92 by the concave groove 96. For example, the needle insertion hole may be larger in diameter than the outer diameter of the inner needle 14, and the inner needle 14 is inserted into the needle insertion hole with a gap, and the exhaust hole may be formed using the gap. In this case, the inner needle 14 may be inserted into the central portion of the needle insertion hole, and the exhaust holes may be continuously provided over the entire circumference. Alternatively, the inner needle 14 may be in contact with a part of the inner peripheral surface of the needle insertion hole in the circumferential direction, and the exhaust holes may be provided in a portion excluding the contact portion between the inner needle and the inner peripheral surface of the needle insertion hole.

[0077] FIG. 6 shows a valve body 100 that constitutes an indwelling needle assembly as a third embodiment of the present invention. The valve body 100 can be employed, for example, in place of the valve body 70 in the indwelling needle assembly 10 of the first embodiment. The valve body 100 is in the shape of an elliptical plate, and the vertical direction in FIG. 6 is the major axis direction. The valve body 100 is provided with an opening 102 that penetrates the central portion in the thickness direction. The opening 102 is a substantially elliptical hole that is flattened in the vertical direction as a whole, and the left-right direction is the major axis direction in the hole cross-section. The opening 102 includes a main opening 104 that is an elliptical hole, and groove-shaped sub-openings 106, 106 that open on the inner peripheral surface of the main opening 104 and extend in the thickness direction of the valve body 100.

[0078] The sub-opening 106 has a substantially semicircular cross-section. Opposing sub-openings 106, 106 are formed at corresponding positions in the vertical direction, and are arranged at positions where the openings of the opposing sub-openings 106, 106 are joined together by elastic deformation of the valve body 100 described later. In the present embodiment, opposing sub-openings 106, 106 are provided at three positions separated from each other in the left-right direction in FIG. 6.

[0079] The valve body 100 is attached to the outer needle hub 42. The valve body 100, which is in the shape of an oval plate with the vertical direction as the major axis, is fitted onto the inner peripheral surface of the cylindrical outer needle hub 42, and is thus greatly compressed in the vertical direction and arranged inside the outer needle hub 42 in a state of being elastically deformed into a substantially circular shape as shown in FIG. 7.

[0080] When the valve body 100 is compressed in the vertical direction by being attached to the outer needle hub 42, the opening width dimension of the main opening 104 of the opening 102 becomes smaller. In the present embodiment, in the valve body 100 after being attached to the outer needle hub 42, the inner peripheral surfaces of the main opening 104 are in contact with each other in the vertical direction, and the main opening 104 is closed. In the valve body 100 of the present embodiment, a slit that linearly extends in the left-right direction is formed using the main opening 104 whose inner surface is in contact with each other and closed in the vertical direction.

[0081] By setting the vertical opening width dimension of the main opening 104 to be approximately zero, the opening edge portions of the pair of sub-openings 106, 106 that are opposed in the vertical direction are abutted against each other, and the exhaust holes 108 having a substantially circular cross-section are formed by these sub-openings 106, 106. In the present embodiment, three exhaust holes 108 are formed side by side in the left-right direction. The exhaust holes 108 have a hole cross-sectional area smaller than the hole cross-sectional area of the opening 102, and the hole shape, hole cross-sectional area, etc. are set so as to allow the passage of air and restrict the passage of blood. In the present embodiment, the central exhaust hole 108 is blocked by the inner needle in the state where the inner needle is inserted, and is opened by pulling out the inner needle from the outer needle. However, the central exhaust hole 108 may be formed to have a diameter larger than the outer diameter of the inner needle, for example, and be narrowed by the insertion of the inner needle so as to form an exhaust hole on the outer peripheral surface of the inner needle.

[0082] According to the valve body 100 of such a present embodiment, the air in the first region, which is on the tip side of the valve body 100 inside the outer needle hub 42, is discharged to the second region, which is on the base end side of the valve body 100, through the exhaust holes 108. Therefore, it is difficult for air to remain in the first region, and the amount of air injected into the blood vessel together with the chemical solution or the like can be reduced, thereby improving safety.

[0083] In FIGS. 6 and 7, the opening 102 having the main opening 104 provided in the middle portion without opening to the outer peripheral surface of the valve body 100 is illustrated. However, for example, the main opening may be in the shape of an inverted V-shaped groove that opens to the outer peripheral surface on either the left or right side of the valve body 100. In this case, the sub-openings 106 are formed to open to the inner surface of the main opening, and the exhaust holes 108 are formed by the sub-openings 106 when the main opening is closed by compression accompanying the attachment of the valve body 100 to the outer needle hub.

[0084] Figure 8 shows a valve body 110 that constitutes an indwelling needle assembly as a fourth embodiment of the present invention. The valve body 110 can be adopted, for example, in place of the valve body 70 in the indwelling needle assembly 10 of the first embodiment. The valve body 110 is in an elliptical plate shape, and the vertical direction in FIG. 8 is the major axis direction. The valve body 110 is provided with a pair of openings 112, 112 that penetrate in the thickness direction. The openings 112 are substantially circular holes and are provided on both sides in the vertical direction at the center in the left-right direction. In this embodiment, a slit 76 that linearly extends in the left-right direction is illustrated, but the shape, size, etc. of the slit 76 are not particularly limited.

[0085] The valve body 110 is attached to the outer needle hub 42. The valve body 110 in an oval plate shape with the vertical direction as the major axis is fitted to the inner peripheral surface of the cylindrical outer needle hub 42, and is greatly compressed in the vertical direction, and is arranged inside the outer needle hub 42 in a state of being elastically deformed into a substantially circular shape as shown in FIG. 9.

[0086] When the valve body 110 is compressed in the vertical direction by being attached to the outer needle hub 42, the opening widths in the vertical direction of the openings 112, 112 become smaller. In the valve body 110 attached to the outer needle hub 42 shown in FIG. 9, the inner peripheral surfaces of the openings 112, 112 are separated in the vertical direction and are held in an open state. Therefore, in the valve body 110 attached to the outer needle hub 42, the width dimension in the vertical direction of the opening 112 becomes smaller, the opening 112 has an opening shape that is flat in the vertical direction, and the hole cross-sectional area of the opening 112 becomes smaller. Thus, an exhaust hole 114 that penetrates the valve body 110 is formed by the opening 112 that is reduced and deformed due to the elastic deformation caused by the attachment of the valve body 110 to the outer needle hub 42. In the valve body 110 attached to the outer needle hub 42, the exhaust hole 114 is set in terms of hole cross-sectional area, hole shape, etc. so as to allow the passage of air and restrict the passage of blood.

[0087] According to the valve body 110 of such an embodiment of the present invention, air in the first region, which is on the tip side of the valve body 110 inside the outer needle hub 42, is discharged through the exhaust hole 114 to the second region, which is on the proximal side of the valve body 110. Therefore, it is difficult for air to remain in the first region, and the amount of air injected into the blood vessel together with the chemical solution or the like can be reduced, improving safety.

[0088] FIGS. 10 and 11 show a valve body 120 that constitutes an indwelling needle assembly as a fifth embodiment of the present invention. The valve body 120 can be adopted, for example, in place of the valve body 70 in the indwelling needle assembly 10 of the first embodiment. The valve body 120 is composed of a first valve member 122 and a second valve member 124 that are axially overlapped.

[0089] The first valve member 122 is an elastic body having a substantially disc shape. The first valve member 122 is provided with a pair of upper and lower first through holes 126, 126. The first through hole 126 is a substantially circular hole that penetrates the first valve member 122 in the thickness direction. The first valve member 122 is provided with a linear first slit 128 that extends in the left-right direction at the central portion in the up-down direction.

[0090] The second valve member 124 is an elastic body having a substantially disc shape. The second valve member 124 is provided with a circular second through hole 130 that penetrates the center in the thickness direction. The second through hole 130 may be formed with a different shape and size from the first through hole 126, or may be formed with the same shape and size as the first through hole 126. In this embodiment, the first through hole 126 and the second through hole 130 are the smallest holes that can be formed during the molding of the first valve member 122 and the second valve member 124, and are substantially the same shape and size.

[0091] The second valve member 124 is formed with a constriction groove 132. The constriction groove 132 extends in the vertical direction with a groove cross-sectional area smaller than the hole cross-sectional area of the second through-hole 130. The constriction groove 132 opens to one surface of the second valve member 124 and extends in the vertical direction. The constriction groove 132 passes through the center of the second valve member 124, and the second through-hole 130 penetrating the center of the second valve member 124 opens into the constriction groove 132. In other words, the constriction groove 132 is formed to linearly extend from the opening of the second through-hole 130 radially outward on one surface of the second valve member 124.

[0092] As shown in FIG. 11, the second valve member 124 is formed with a second slit 134. The second slit 134 is linear and extends in the vertical direction through the center of the second valve member 124. One opening of the second slit 134 is located within the constriction groove 132 on one surface of the second valve member 124.

[0093] The first valve member 122 and the second valve member 124 are overlapped in the thickness direction to form the valve body 120. It is desirable that the first valve member 122 and the second valve member 124 are positioned relative to each other. They may be fixed to each other, or may be positioned relative to each other by another member such as an outer needle hub (not shown).

[0094] In the valve body 120, the first through-holes 126, 126 and the second through-hole 130 are provided at positions separated from each other in the axial direction view, and are arranged so as not to be aligned in series in the axial direction (the left-right direction in FIG. 11). In the present embodiment, the first through-holes 126, 126 are arranged at positions vertically separated from the second through-hole 130 located at the center.

[0095] The narrow groove 132 of the second valve member 124 has an opening covered by the first valve member 122. As a result, a narrow flow path 136 that linearly extends in the vertical direction is formed between the overlapping surfaces of the first valve member 122 and the second valve member 124. The narrow groove 132 extends across the first through holes 126, 126 and the second through hole 130. The narrow flow path 136 communicates with the first through holes 126, 126 at both ends in the vertical direction and communicates with the second through hole 130 at the central portion in the vertical direction. Then, an exhaust hole 138 passing through the valve body 120 is formed by the first through holes 126, 126, the narrow flow path 136, and the second through hole 130. The flow path cross-sectional area of the intermediate portion formed by the narrow flow path 136 is smaller than that of both ends formed by the first through holes 126, 126 and the second through hole 130, and the flow resistance of the exhaust hole 138 is mainly set by the narrow flow path 136. The flow resistance of the exhaust hole 138 is set to allow the passage of air and restrict the passage of blood.

[0096] According to the valve body 120 of this embodiment, a narrow flow path 136 formed by the narrow groove 132 is provided between the first valve member 122 and the second valve member 124, and the exhaust hole 138 is configured to include the narrow flow path 136. As a result, it becomes possible to set a flow resistance that cannot be achieved by merely a simple through hole such as the first through hole 126 or the second through hole 130 in the exhaust hole 138, and it is possible to discharge the air in the outer needle hub while suppressing the leakage of blood.

[0097] Note that the shapes, numbers, arrangements, etc. of the first through-hole 126 and the second through-hole 130 are not particularly limited and can be changed as appropriate. Further, the constriction groove 132 is provided across the first through-hole 126 and the second through-hole 130, and when the first valve member 122 and the second valve member 124 are combined to form the valve body 120, it is only necessary to form a constricted flow path 136 connecting the first through-hole 126 and the second through-hole 130, and the arrangement, shape, etc. of the constriction groove 132 can also be changed. Further, for example, when there are a plurality of the first through-holes 126 and the second through-holes 130, it is also possible to provide a plurality of constriction grooves 132, and in that case, a plurality of independent exhaust holes 138 can be formed. Further, three or more valve members may be stacked to form the valve body, and in that case, the constriction groove may be formed only on one side of one valve member, may be formed on both sides of one valve member, or may be formed on one side or both sides of two or more valve members.

[0098] Note that the valve bodies 90, 100, 110, and 120 shown in the second to fifth embodiments may be employed in combination with the inner needle 14 having the exhaust structure by the outflow opening 28 and the reflux opening 30 shown in the first embodiment, or may be employed in combination with a conventional inner needle having no exhaust structure.

[0099] As described above, the embodiments of the present invention have been described in detail, but the present invention is not limited by the specific description. For example, in the above embodiments, the indwelling needle assembly including the needle tip protector is exemplified, but the needle tip protector is not essential. Further, when providing the needle tip protector, the structure of the needle tip protector is not particularly limited, and various structures including conventionally known structures can be adopted.

[0100] The specific shape of the pusher 60 shown in the above embodiments and the structure in which the needle tip protector is housed in the pusher 60 are not essential. For example, the pusher may have a tapered cylindrical shape, or the needle tip protector may be housed in the outer needle hub more proximally than the pusher.

[0101] As shown in the first embodiment, when providing the outflow opening 28 and the reflux opening 30 in the inner needle 14, it is desirable to provide a constriction 24 between the outflow opening 28 and the reflux opening 30, but the constriction 24 is not essential. The constriction 24 does not necessarily have to be a crushed portion formed simultaneously with the locking protrusions 26, 26. The locking protrusions 26, 26 may be provided separately from the constriction 24, or only the locking protrusions 26, 26 may be provided in the case where there is no constriction 24. Further, for example, an inner needle having a structure in which the constriction 24 is provided and the locking protrusions 26, 26 are not provided can also be adopted.

Explanation of Reference Numerals

[0102] 10 Indwelling needle assembly (first embodiment) 12 Inner needle unit 14 Inner needle 16 Indwelling needle 18 Outer needle 20 Inner needle hub 21 Lumen 22 Needle tip 24 Constriction 26 Locking protrusion (protector locking portion) 28 Outflow opening 30 Reflux opening 32 Hub body 34 Inner needle holding portion 36 Flange portion 38 Cap member 40 Breathable filter 42 Outer needle hub 44 Needle fixing member 46 Luer connection member 48 Taper portion 50 Engagement hole 54 Hub connection portion 56 Luer insertion portion 58 Engagement claw 60 Pusher 62 Protector housing portion 64 Input portion 66 Actuating portion 70 Valve body 72 First region 74 Second region 76 Slit 78 - needle tip protector 80 - needle insertion part 82 - circular hole 84 - needle tip protection part 90 - valve body (second embodiment) 92 - needle insertion hole 94 - needle arrangement part 96 - concave groove 98 - exhaust hole 100 - valve body (third embodiment) 102 - opening 104 - main opening 106 - sub - opening 108 - exhaust hole 110 - valve body (fourth embodiment) 112 - opening 114 - exhaust hole 120 - valve body (fifth embodiment) 122 - first valve member 124 - second valve member 126 - first through - hole 128 - first slit 130 - second through - hole 132 - narrow groove 134 - second slit 136 - narrow flow path 138 - exhaust hole

Claims

1. A cannula assembly in which a hollow inner needle having an inner needle hub on the proximal side is slidably inserted into an outer needle having an outer needle hub on the proximal side, and a valve body for switching between communication and blockage of the outer needle hub is disposed inside the outer needle hub, an outflow opening and a reflux opening are formed through the peripheral wall of the inner needle, the reflux opening provided more proximally than the outflow opening is initially open inside the outer needle hub distally of the valve body, the distance between the reflux opening and the valve body is made closer than the distance between the reflux opening and the distal end of the outer needle hub, blood flowing into the lumen of the inner needle by puncture flows out into the outer needle hub through the outflow opening and flows into the lumen of the inner needle from the reflux opening, while a breathable filter is provided on the inner needle hub, a cannula assembly in which air pushed into the inner needle hub by the blood flowing into the lumen of the inner needle passes through the breathable filter and is discharged to the outside.

2. A crushed portion is provided in the inner needle between the outflow opening and the reflux opening in the axial direction, and a protector locking portion that is locked to a needle tip protector that protects the needle tip of the inner needle by pulling out the inner needle from the outer needle is provided on the inner needle by a radial bulge accompanying the crushing of the inner needle at the crushed portion. The cannula assembly according to claim 1.

3. A needle insertion hole through which the inner needle is inserted is formed in the valve body, and an exhaust hole penetrating the valve body is formed between the inner needle and the needle insertion hole in a state where the inner needle is inserted into the needle insertion hole. The cannula assembly according to claim 1 or 2.

4. An opening penetrating in the needle axis direction of the inner needle is formed in the valve body, and the valve body is disposed inside the outer needle hub in a state of being radially compressed by the outer needle hub, the opening is reduced in size by the radial compression of the valve body, and an exhaust hole penetrating the valve body is formed by the reduced opening. The cannula assembly according to claim 1 or 2.

5. the opening includes a main opening and a groove-shaped sub-opening that opens on the inner peripheral surface of the main opening and penetrates the valve body in the needle axis direction of the inner needle, and the main opening is closed by the radial compression of the valve body, and the exhaust hole is constituted by the sub-opening. The cannula assembly according to claim 4.

6. The valve body includes a first valve member and a second valve member that are overlapped in the needle axis direction of the inner needle, A first through hole is formed in the first valve member, and a second through hole is formed in the second valve member. The first through hole and the second through hole are located apart from each other in the axial direction view. On at least one of the overlapping surfaces of the first valve member and the second valve member, a narrow groove extending across the first through hole and the second through hole is formed. An exhaust hole passing through the valve body is constituted by the first through hole, the second through hole, and the narrow groove. The indwelling needle assembly according to claim 1 or 2, wherein the groove cross-sectional area of the narrow groove is smaller than the hole cross-sectional areas of the first through hole and the second through hole.

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