3D needle assembly

Abstract

To provide a new needle assembly that facilitates proper operation of arm parts.SOLUTION: A needle assembly 10 comprises a puncture needle 16, a needle hub 18 for supporting a base end side of the puncture needle 16, a needle tip protector 14 for covering a needle tip 20 of the puncture needle 16 by moving in a needle axis direction with respect to the puncture needle 16, and arm parts 48, 48 provided on a base end side of the needle hub 18 and disengageably engaged with the needle tip protector 14. The needle assembly is provided with a contact part 56 with which the arm parts 48, 48 come into contact when the arm parts 48, 48 are moved in an inward direction toward the needle hub 18.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a needle assembly including a puncturing needle body provided with a needle hub on the proximal end side thereof, and a needle tip protector that covers the needle tip of the puncturing needle body by moving in the needle axis direction with respect to the puncturing needle body.

Background Art

[0002] Conventionally, puncturing needle bodies such as indwelling needles used when performing infusion, blood collection, hemodialysis, etc. are known. The indwelling needle has a structure in which a needle hub is fixed to the proximal end side of a puncturing needle having a sharp needle tip. Then, the indwelling needle is punctured and indwelt in a body lumen such as a patient's blood vessel, and an external tube is connected to the needle hub, whereby infusion, blood collection, hemodialysis, etc. are performed through the lumen of the indwelling needle and the external tube.

[0003] By the way, some puncturing needle bodies include a needle tip protector that protects the needle tip of the puncturing needle removed from the body lumen for the purpose of preventing accidental puncture after use, preventing frequent use, or facilitating disposal. As the needle tip protector and the needle assembly including the same, for example, it is disclosed in Japanese Patent Application Laid-Open No. 2017-196060 (Patent Document 1). That is, according to the medical needle with a protector of Patent Document 1, when the needle tube is pulled out from a blood vessel or the like, the protector moves toward the needle tip side with respect to the needle tube, and the needle tube removed from the patient is accommodated in the inner circumference of the protector so that the needle tip of the needle tube is not exposed to the outside.

[0004] Further, the needle tip protector is engaged with the needle hub by an arm portion provided on the proximal end side of the needle hub of the puncturing needle body when the puncturing needle punctures. Thereby, the needle tip protector is prevented from moving in the needle axis direction with respect to the puncturing needle by the input at the time of puncture, and the puncturing needle is stably held at the exposed position from the needle tip protector. The engagement with the needle tip protector is released by, for example, applying an external force with a finger or the like and moving it inward.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-196060 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, upon detailed examination by the inventors, it was found that when manipulating the arm to release its engagement with the needle tip protector, it may not always be possible to move the arm inward by the appropriate amount. In other words, if the amount of inward movement of the arm is too small, the engagement between the arm and the needle tip protector will not be released, and if the amount of inward movement of the arm is too large, the deformation of the arm will be excessive, making it prone to damage.

[0007] The problem to be solved by the present invention is to provide a novel needle assembly that facilitates proper operation of the arm portion. [Means for solving the problem]

[0008] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0009] The first aspect is a needle assembly comprising a puncture needle, a needle hub supporting the puncture needle, a needle tip protector that covers the tip of the puncture needle by moving in the axial direction relative to the puncture needle, and an arm provided on the base end side of the needle hub and releasably engaged with the needle tip protector, wherein the needle hub is provided with a contact portion that the arm abuts against when the arm is moved inward toward the needle hub, and the needle hub is provided with a conduit connection portion having a connection hole opening toward the base end, and a connection port to which an external conduit is connected is formed protruding from the bottom of the connection hole, and the arm protrudes radially outward from the conduit connection portion and extends toward the tip, and the contact portion teeth , part that forms a fluid channel but The needle hub is formed by increasing its thickness towards the base end, and the contact portion is located on the tip side of the connection hole, rather than the bottom side.

[0010] According to this embodiment, for example, when the arm is moved inward to disengage from the needle tip protector, the arm comes into contact with the contact portion, allowing the user to perceive that the amount of inward movement of the arm is sufficient through tactile feedback, and also limiting the amount of inward movement of the arm.

[0019] The 2 The manner of is, 1 In the needle assembly described in the embodiment, the contact portion is configured to include a protrusion provided on the outer surface of the needle hub.

[0020] According to this embodiment, since the contact portion includes a protrusion that projects from the outer surface of the needle hub, the distance between the contact portion and the arm portion can be easily set by the shape and size of the protrusion.

[0021] The 3 The manner of is, 1 or the 2 In the needle assembly described in the embodiment, the contact portion is configured to include a recess provided on the outer surface of the needle hub.

[0022] According to this aspect, since the contact portion includes a recess that opens to the outer surface of the needle hub, it becomes easier to ensure the distance between the arm portion and the contact portion even when the distance between the arm portion and the needle hub is small.

[0023] No. 4 of the aspect is the needle assembly described in any one of No. 1 to No. 3 in which the contact portion is configured to include a tapered portion provided on the outer surface of the needle hub.

[0024] According to this aspect, since the contact portion includes a tapered portion provided on the outer surface of the needle hub, the distance between the contact portion and the arm portion can be easily set by the inclination direction, inclination angle, etc. of the tapered portion.

[0025] No. 5 of the aspect is the needle assembly described in any one of No. 1 to No. 4 in which the contact portion is configured to include a straight portion provided on the outer surface of the needle hub.

[0026] As in this aspect, the contact portion may include a straight portion provided on the outer surface of the needle hub.

Advantages of the Invention

[0029] According to the present invention, it becomes easy to appropriately operate the arm portion.

Brief Description of the Drawings

[0030] [Figure 1] Plan view showing a needle assembly as a first embodiment of the present invention [Figure 2] Cross-sectional view of the needle assembly shown in FIG. 1, corresponding to the II-II cross-section of FIG. 3 [Figure 3] III-III cross-sectional view of FIG. 2 [Figure 4] IV-IV cross-sectional view of FIG. 3 [Figure 5] Perspective view of the needle hub constituting the needle assembly shown in FIG. 1 [Figure 6]A plan view showing an enlarged view of the needle hub in Figure 1. [Figure 7] A cross-sectional view showing the state in which the arm portion of the needle assembly in Figure 1 is in contact with the outer surface of the locking piece. [Figure 8] Figure 1 is a cross-sectional view showing the needle assembly with the arm portion in contact with the tapered portion of the needle hub. [Figure 9] A cross-sectional view showing the protection of the needle tip by the needle tip protector in the needle assembly shown in Figure 1. [Figure 10] Cross-sectional view showing the main part of a needle assembly as a second embodiment of the present invention. [Figure 11] Cross-sectional view showing the main part of a needle assembly as a third embodiment of the present invention. [Figure 12] Cross-sectional view showing the main part of a needle assembly as a fourth embodiment of the present invention. [Figure 13] Cross-sectional view showing the main part of a needle assembly as another embodiment of the present invention. [Modes for carrying out the invention]

[0031] Embodiments of the present invention will be described below with reference to the drawings.

[0032] Figures 1-4 show a needle assembly 10 as a first embodiment of the present invention. As shown in Figures 2 and 3, the needle assembly 10 has a structure in which a puncture needle body 12, such as an indwelling needle, is inserted into a needle tip protector 14 so as to be movable in the direction of the needle axis of the puncture needle 16, which will be described later. The needle tip protector 14 can cover at least the needle tip 20 (described later) of the puncture needle body 12. In the following description, as a general rule, the tip side refers to the left side in Figure 2, which is the side of the needle tip 20 of the puncture needle body 12, which will be described later, and the proximal end side refers to the right side in Figure 2, which is the rear in the direction of puncture of the puncture needle body 12. Also, as a general rule, the up and down direction refers to the up and down direction in Figure 3, which is the vertical direction, and the left and right direction refers to the up and down direction in Figure 2, which is the horizontal direction.

[0033] More specifically, the puncture needle body 12 has a structure in which a needle hub 18 is fixed to the proximal end of the puncture needle 16. The puncture needle 16 is made of a metal such as stainless steel, and has a needle tip 20 at one end that has a sharp, tapered shape.

[0034] As shown in Figures 5 and 6, the needle hub 18 is generally cylindrical in shape, and the proximal end of the puncture needle 16 is fixed to its tip in an inserted state. This connects the lumen of the needle hub 18 and the lumen of the puncture needle 16 in the direction of the needle axis.

[0035] The needle hub 18 is equipped with a tip portion 24. The tip portion 24 is substantially cylindrical in shape and has a needle fixing portion 26 into which the proximal end of the puncture needle 16 is inserted from the tip side and fixed. The tip side of the needle fixing portion 26 is provided with tip locking portions 28, 28 that protrude on both sides in the vertical direction. Furthermore, on the proximal end side of the needle fixing portion 26 beyond the tip locking portions 28, 28, there is provided with a pair of locking protrusions 30, 30 that protrude on both sides in the horizontal direction. The locking protrusions 30 have a tip-side surface that spreads perpendicular to the axis, and a proximal end surface that is inclined, with the protruding height decreasing toward the proximal end. The part of the tip portion 24 on the proximal end side of the needle fixing portion 26 is the tip portion 32 that is positioned away from the proximal end of the puncture needle 16.

[0036] The tip portion 24 is provided with a pair of guide ridges 34, 34 that protrude to both sides in the vertical direction. The guide ridges 34 are roughly rectangular in shape and extend linearly from the base end side of the tip locking portion 28 to the base end of the tip portion 24. The tip of the guide ridge 34 is connected to the tip locking portion 28, and the base end is connected to the base end portion 36, which will be described later.

[0037] A base end portion 36 is provided on the base end side of the needle hub 18, beyond the tip portion 24. In this embodiment, the base end portion 36 is integrally formed with the tip portion 24. However, the base end portion 36 may be formed separately from the tip portion 24 and fixed to the tip portion 24 by means of adhesive or other means. The outer dimensions of the base end portion 36 in the direction perpendicular to the axis are larger than those of the tip portion 24, and as a result, the outer dimensions of the needle hub 18 in the direction perpendicular to the axis are larger on the base end side than on the tip side. Recesses 38 are opened on the upper and lower outer surfaces of the base end portion 36. The recesses 38 have a substantially rectangular cross-section and are provided spanning the conduit connection portion 40 and the intermediate portion 56, which will be described later.

[0038] The base portion 36 of the needle hub 18 has a conduit connection portion 40 as a base which is roughly cylindrical in shape. The conduit connection portion 40 constitutes the base end side of the base portion 36. The outer dimensions of the conduit connection portion 40 in the direction perpendicular to the axis are larger than those of the tip portion 24 of the needle hub 18. A connection hole 42 is formed in the conduit connection portion 40, opening to the base end face. The connection hole 42 has a roughly circular cross-section. The connection hole 42 has a bottom portion 44 on the tip side, which is opposite the opening. The inner hole of the conduit connection portion 40 penetrates the bottom portion 44 in the axial direction and communicates with the inner hole of the connection port 46, which will be described later. The base end side of the connection hole 42, which is the opening side, is wider than the tip end side, which is the bottom portion 44 side. The connection hole 42 gradually widens from the bottom portion 44 side toward the opening end, which is the base end side, and the inner surface of the peripheral wall of the connection hole 42 is tapered on the bottom portion 44 side.

[0039] A connection port 46 is provided at the bottom 44 of the connection hole 42. The connection port 46 is cylindrical and protrudes from the bottom 44 toward the base end toward the opening of the connection hole 42. The inner circumferential surface of the connection port 46 is a cylindrical surface with a substantially constant diameter in the axial direction. The outer circumferential surface of the connection port 46 has a tapered outer circumferential surface, with the diameter gradually decreasing toward the base end in the axial direction. The connection port 46 may be a separate component from the pipe connection part 40, but in this embodiment it is integrally formed with the pipe connection part 40.

[0040] A pair of engaging arms 48, 48 are provided at the base end portion 36 of the needle hub 18. The engaging arms 48 extend laterally (up and down in Figure 2) from the base end of the conduit connection portion 40 on both sides, and are curved and extend toward the tip, and are provided on both sides laterally with a predetermined gap between them and the base end portion 36. The engagement arms 48, 48 have a curved shape and are narrow at the connection portion with the conduit connection portion 40, and are allowed to undergo elastic deformation in a direction that brings them closer together when external forces are applied. In addition, hooks 50 are formed at the tip portions of each of the engaging arms 48, 48.

[0041] The base portion 36 is attached to the connection port 46 in an external state by inserting the tip of the external conduit 52 into the connection hole 42 of the conduit connection portion 40. The external conduit 52 is, for example, a tube made of synthetic resin. The external conduit 52 is bonded or welded to the inner circumferential surface of the connection hole 42 and the connection port 46 as needed.

[0042] The external conduit 52 is connected to the conduit connection part 40, so that the tip portion 24 and the external conduit 52 are connected on both sides of the base portion 36, and the lumen of the puncture needle 16 and the lumen of the needle hub 18 are in communication with the external conduit 52. As a result, a fluid passage 54 is provided in the puncture needle body 12, extending from the tip opening of the puncture needle 16 to the external conduit 52.

[0043] Between the tip portion 24 and the conduit connection portion 40 of the needle hub 18, an intermediate portion 56 is provided as a contact portion that constitutes the tip side of the base portion 36. The intermediate portion 56 is located on the base side of the tips of the engaging arms 48, 48, which are formed by the hooks 50, 50, and is provided between opposing engaging arms 48, 48. In the axial longitudinal section of the intermediate portion 56, which passes through the engaging arms 48, 48 as shown in Figure 2 and is parallel to the opposing direction of the engaging arms 48, 48, the outer dimensions perpendicular to the axis are larger than those of the tip portion 32. The tapered portion 58 may be a flat surface partially provided on both the left and right sides of the intermediate portion 56, but in this embodiment it is provided over substantially the entire circumference. In the axial longitudinal section of the intermediate portion 56, which passes through the opposing direction of the engaging arms 48, 48 as shown in Figure 2, the tapered portion 58 is provided on the outer surface, and its outer dimensions gradually increase toward the base end. In the axial longitudinal section of the intermediate portion 56, the internal dimension is substantially constant in the direction of the needle axis, and the thickness gradually increases toward the base end. In this embodiment, the tapered portion 58 is inclined at a substantially constant angle in the direction of the needle axis, but for example, the angle of inclination may gradually increase or decrease toward the base end.

[0044] Because the intermediate portion 56 is provided on the tip side of the conduit connection portion 40 which has the connection hole 42, the outer peripheral corner on the bottom 44 side of the connection hole 42 in the conduit connection portion 40 is relatively thick in the axial longitudinal cross-section parallel to the opposing direction of the engaging arms 48, 48 shown in Figure 3. As a result, the outer peripheral corner on the bottom 44 side of the connection hole 42 is not the thinnest part of the needle hub 18. That is, the thinnest part of the needle hub 18 is located away from the outer peripheral corner on the bottom 44 side of the connection hole 42, and in this embodiment, it is located in the axial intermediate portion of the peripheral wall of the connection hole 42 in the conduit connection portion 40. Note that the thinnest part of the needle hub 18 does not necessarily have to be located at the base end portion 36 of the needle hub 18, and for example, it may be located at the tip portion 32 of the tip portion 24 of the needle hub 18.

[0045] In the axial longitudinal section parallel to the opposing directions of the engaging arms 48, 48 shown in Figure 2, the minimum thickness dimension of the intermediate portion 56 is greater than or equal to the thickness dimension of the tip portion 32 at the tip portion 24.

[0046] As shown in Figures 1-4, the needle tip protector 14 has a roughly cylindrical shape that extends in the direction of the needle axis. The needle tip protector 14 is integrally molded from a hard synthetic resin such as polypropylene, polycarbonate, glycol-modified polyethylene terephthalate, ABS resin, or MBS resin. Preferably, the needle tip protector 14 is transparent or semi-transparent, allowing the transmission of visible light. The needle tip protector 14 has a cylindrical peripheral wall 60, and an inner hole 62 is formed in the inner circumference of the peripheral wall 60, penetrating in the direction of the needle axis.

[0047] The peripheral wall 60 has a cylindrical portion 64 at the tip end that has a roughly circular cross-section, and an enlarged portion 66 at the base end that is wider than the cylindrical portion 64 and extends outward, so that the shape differs in the direction of the needle axis.

[0048] The enlarged portion 66 has a roughly elliptical cylindrical shape, and the width of the outer surface in the left-right direction (lateral direction) in Figure 4 is larger than the width of the outer surface in the up-down direction (vertical direction) in Figure 4, which is the narrow direction. Of the wall portions constituting the enlarged portion 66, the parts constituting the vertical wall portions are narrow portions 68, 68, while the parts constituting the horizontal wall portions are wide portions 70, 70. The opposing directions of the narrow portions 68, 68 and the opposing directions of the wide portions 70, 70 are roughly perpendicular to each other. On the inner circumference of the enlarged portion 66, an internal space 72 having a flattened cross-section where the horizontal dimension is larger than the vertical dimension is formed at the base end portion of the inner hole 62 that penetrates the needle tip protector 14. The internal dimension of the internal space 72 in the lateral direction gradually increases towards the base end. In this embodiment, the enlarged portion 66 has a narrow portion 68 and a wide portion 70, but for example, it may have a substantially constant width dimension around its entire circumference.

[0049] The wide sections 70,70 have through-windows 74,74 formed therein, which serve as engaging parts that penetrate in the thickness direction of the plate. The circumferential dimensions of the through-windows 74,74 are larger than the circumferential dimensions of the hooks 50,50.

[0050] The peripheral wall 60 of the needle tip protector 14 is provided with a pair of flexible pieces 76, 76 as projections that extend from the cylindrical portion 64 toward the base end. The flexible pieces 76, 76 are positioned corresponding to the wide portions 70, 70, are positioned opposite each other in the lateral direction, and are spaced apart from each other in the circumferential direction. The tip portions of the flexible pieces 76, 76 that connect to the cylindrical portion 64 extend approximately parallel to the needle axis direction. The base portions of the flexible pieces 76, 76 have a tapered shape that slopes inward in the lateral direction toward the base end, and their outer surfaces 77 are inclined surfaces. The flexible pieces 76, 76 are each curved in the circumferential direction. The radial distance between opposing surfaces at the protruding tips of the flexible pieces 76, 76 is slightly larger than the outer diameter of the tip portion 24.

[0051] Furthermore, the protruding tips (base ends in the direction of the needle axis) of the flexible pieces 76, 76 are located closer to the tip in the direction of the needle axis than the base end of the expanding portion 66. Therefore, the entirety of the flexible pieces 76, 76 is housed within the internal space 72 of the expanding portion 66; in other words, the expanding portion 66 is located outside the flexible pieces 76, 76.

[0052] The enlarged portion 66 is composed of side wall portions 78, and a pair of side wall portions 78, 78 are provided on the inner circumference of the enlarged portion 66. As shown in Figures 3 and 4, the side wall portions 78, 78 are flat plates that extend in a direction substantially perpendicular to the vertical direction, and are arranged opposite each other at a predetermined distance in the vertical direction. Therefore, the opposing direction of the side wall portions 78, 78 is substantially perpendicular to the opposing direction of the flexible pieces 76, 76.

[0053] The side wall portions 78, 78 are provided at a distance on the inner circumference side from the enlarged portion 66 of the circumferential wall 60. As a result, a gap 80, 80 is formed between the side wall portions 78, 78 and the narrowed portions 68, 68 of the enlarged portion 66, at least in the central circumferential portion of the narrowed portions 68, 68. The side wall portions 78, 78 are provided on the tip side of the flexible pieces 76, 76 beyond the base end. In this embodiment, the distance between the side wall portions 78, 78 is approximately equal to the outer diameter dimension of the tip portion 24 of the needle hub 18.

[0054] Each side wall portion 78 is composed of a pair of leaf springs 82, 82 and is elastically deformable in the thickness direction. The leaf springs 82, 82 are integrally formed with the wide portions 70, 70 of the enlarged portion 66 and protrude laterally inward from the wide portions 70, 70. The protruding tips of the leaf springs 82, 82 are separated from each other laterally, and a slit 84 is formed between the protruding tips, extending axially. When the puncture needle body 12, which will be described later, is inserted into the needle tip protector 14, the guide projection 34 of the needle hub 18 is inserted into the slit 84, and as the guide projection 34 moves within the slit 84, the puncture needle body 12 is guided axially relative to the needle tip protector 14.

[0055] As shown in Figure 1, a wing-shaped portion 86 is provided at the tip of the needle tip protector 14. The wing-shaped portion 86 is made of, for example, a soft synthetic resin. The wing-shaped portion 86 is integrally formed with a cylindrical fitting cylinder portion 88, with plate-shaped connecting portions 90, 90 protruding tangentially from the fitting cylinder portion 88, and wing bodies 92 are integrally formed on the protruding tip sides of the connecting portions 90, 90 from the fitting cylinder portion 88. The wing-shaped portion 86 is attached to the peripheral wall 60 of the needle tip protector 14 by fitting the fitting cylinder portion 88 onto the tip of the cylindrical portion 64.

[0056] The needle assembly 10 is constructed by inserting the puncture needle body 12 through the opening on the proximal end of the needle tip protector 14 into the inner hole 62 of the needle tip protector 14, thereby externally attaching the needle tip protector 14 to the puncture needle body 12. In the initial state before use of the needle assembly 10, as shown in Figure 1, the needle tip protector 14 is positioned at a puncture position relative to the puncture needle body 12, where the needle tip 20 of the puncture needle 16 is exposed beyond the tip of the needle tip protector 14. In the initial state when the needle tip protector 14 is positioned at the puncture position relative to the puncture needle body 12, the tip portion 32 of the needle hub 18 is housed in the needle tip protector 14, and the tip portion 32 is inserted between the flexible pieces 76, 76 of the needle tip protector 14. Therefore, in the initial state, at least a part of the tip portion 32 is located beyond the proximal end faces of the flexible pieces 76, 76. The flexible pieces 76, 76 are positioned with their proximal ends inserted between the tip 32 of the needle hub 18 and the engaging arms 48, 48. The conduit connection portion 40 is positioned to protrude further than the needle tip protector 14 and is exposed from the needle tip protector 14.

[0057] In this initial state, as shown in Figure 2, the hooks 50, 50 provided on the engaging arms 48, 48 of the needle hub 18 are inserted into and engaged with the through windows 74, 74 provided in the enlarged portion 66 of the needle tip protector 14. This connects the needle tip protector 14 and the needle hub 18, maintaining the protruding state of the needle tip 20, and restricting the movement of the puncture needle 16 toward the base end in the needle axis direction due to resistance during puncture, for example, when puncturing by holding the wing-shaped portion 86.

[0058] In the initial state of the needle assembly 10, the protruding tips of the flexible pieces 76, 76 of the needle tip protector 14 are slightly separated from the outer surface of the tip portion 24. The flexible pieces 76, 76 may also be in contact with the outer surface of the tip portion 24, and may be slightly pushed outwards by this contact.

[0059] In the initial state of the needle assembly 10, the intermediate portion 56 of the needle hub 18 of the puncture needle body 12 is located on the proximal end side of the flexible pieces 76, 76 of the needle tip protector 14 located at the puncture position. Therefore, the intermediate portion 56 is provided in the part of the needle hub 18 that is not protected by the needle tip protector 14.

[0060] The needle assembly 10 is used for infusion, blood sampling, and hemodialysis by inserting the puncture needle 16 into the patient's blood vessel and leaving the puncture needle body 12 in place, through the fluid channel 54. In this embodiment, the needle assembly 10 is provided with a wing-shaped portion 86, which allows the puncture needle 16 of the puncture needle body 12 to be inserted while, for example, pinching the wing-shaped portion 86. When leaving the puncture needle body 12 in the inserted state, it can be fixed with tape at the position of the wing-shaped portion 86, providing a large contact area with the skin.

[0061] When removing the puncture needle body 12, the needle tip protector 14 remains tape-fixed to the wing-shaped portion 86, and the engaging arms 48, 48 on the needle hub 18 are pressed inward by the fingers. As shown in Figures 7 and 8, this releases the engagement between the hooks 50, 50 and the through-windows 74, 74, allowing the puncture needle body 12 to be moved towards the proximal end relative to the needle tip protector 14. By moving the puncture needle body 12 towards the proximal end relative to the needle tip protector 14 and removing the puncture needle 16 from the skin, the needle tip protector 14 moves toward the needle tip 20 relative to the puncture needle body 12. In this way, the connection between the puncture needle body 12 and the needle tip protector 14 by the engaging arms 48, 48 at the puncture position can be released by operating the engaging arms 48, 48, and the release of the connection allows the puncture needle body 12 and the needle tip protector 14 to move relative to each other in the axial direction.

[0062] When the engaging arms 48, 48 are pushed inward, as shown in Figure 7, the engaging arms 48, 48 first come into contact with the outer surface 77 of the flexible pieces 76, 76 of the needle tip protector 14 at the hooks 50, 50 that constitute the tip portion. Since the outer surface 77 of the flexible pieces 76, 76 is an inclined surface that slopes outward in the left-right direction toward the tip, when the engaging arms 48, 48 are pressed against the flexible pieces 76, 76, the component force due to the contact acts on the needle tip protector 14 toward the tip. When the engaging arms 48, 48 are engaged with the through windows 74, 74, the flexible pieces 76, 76 are elastically deformed inward toward the central axis when the engaging arms 48, 48 are pressed against them. In this way, the flexible pieces 76, 76 of the needle tip protector 14 are contact portions that the engaging arms 48, 48 come into contact with as they move inward.

[0063] Then, when the engagement arms 48, 48 and the through windows 74, 74 are released, the elastically deformed flexible pieces 76, 76 return to their original shape. Consequently, a force acts on the needle tip protector 14 toward the tip side of the needle hub 18, either due to the elasticity of the flexible pieces 76, 76 or because the outer surfaces of the flexible pieces 76, 76 that the engaging arms 48, 48 contact are inclined. In other words, the contact of the engaging arms 48, 48 with the flexible pieces 76, 76 exerts a contact reaction force toward the base end as a mechanical action on the needle hub 18.

[0064] Due to the mechanical action of the engaging arms 48, 48 contacting the flexible pieces 76, 76, the needle tip protector 14 moves slightly toward the tip relative to the needle hub 18. As a result, even if the operating force applied to the engaging arms 48, 48 is released and the engaging arms 48, 48 move outward due to elasticity, the hooks 50, 50 will not re-engage with the through windows 74, 74, and the needle tip protector 14 will remain in a state where it can move in the needle axis direction relative to the needle hub 18. In other words, in this embodiment, as the engagement of the engaging arms 48, 48 with the through windows 74, 74 is released, the needle tip protector 14 moves toward the tip, axially forward, to such an extent that it becomes impossible for the engaging arms 48, 48 to re-engage with the through windows 74, 74, based on the contact action of the engaging arms 48, 48 with the flexible pieces 76, 76.

[0065] When the engagement arms 48, 48 are released from the engagement with the through windows 74, 74, and the engagement arms 48, 48 are pushed further inward, as shown in Figure 8, the engagement arms 48, 48 come into contact with the tapered portion 58 of the intermediate portion 56, which is a contact portion provided on the needle hub 18. Then, due to the mechanical action caused by the contact between the engagement arms 48, 48 and the tapered portion 58, the inward movement of the engagement arms 48, 48 is restricted by the needle hub 18. As a result, damage due to excessive deformation of the engagement arms 48, 48 is prevented. In Figure 8, the engagement arms 48, 48 are in contact with the base end of the tapered portion 58, but by adjusting the inclination angle of the tapered portion 58, for example, the engagement arms 48, 48 may come into contact with the tapered portion 58 over a predetermined range in the direction of the needle axis, or the engagement arms 48, 48 may come into contact with the tip of the tapered portion 58.

[0066] Because the intermediate portion 56 of the needle hub 18 is relatively thick, even if the operating force applied to the engaging arms 48, 48 is transmitted to the intermediate portion 56 by contact between the engaging arms 48, 48 and the intermediate portion 56, sufficient durability of the intermediate portion 56 is ensured. The intermediate portion 56 has a tapered portion 58 that becomes larger in diameter towards the base end and is thicker towards the base end, so a large load-bearing strength can be obtained at the base end of the intermediate portion 56 where the engaging arms 48, 48 contact. Because the contact portion of the engaging arms 48, 48 in the intermediate portion 56 is thick, stress distribution toward the tip end of the intermediate portion 56 can also be expected, thereby further improving the load-bearing performance of the intermediate portion 56. The stress caused by the contact of the engaging arms 48, 48 with the intermediate portion 56 may be distributed to the tip portion 24 or the pipe connection portion 40 as needed.

[0067] As shown in Figure 9, by moving the puncture needle body 12 backward to a predetermined protective position relative to the needle tip protector 14 (moving the needle tip protector 14 forward toward the needle tip 20 side of the puncture needle body 12), the needle tip 20 of the puncture needle 16 is housed and covered within the inner circumference of the needle tip protector 14.

[0068] As the needle tip protector 14 moves to a protective position relative to the puncture needle body 12, the free ends of the flexible pieces 76, 76 move over the locking projections 30, 30 and towards the tip, causing the elastically restored flexible pieces 76, 76 to be positioned towards the tip relative to the locking projections 30, 30. Then, when the puncture needle body 12 attempts to move relative to the needle tip protector 14 toward the tip, the base end surfaces of the flexible pieces 76, 76 abut against the tip surfaces of the locking projections 30, 30 and lock in place. As a result, the movement of the puncture needle body 12 toward the tip relative to the needle tip protector 14 is restricted by the locking of the flexible pieces 76, 76 and the locking projections 30, 30, preventing the re-exposure of the needle tip 20 of the puncture needle body 12.

[0069] If the puncture needle body 12 attempts to move further towards the proximal end relative to the needle tip protector 14, which is in a protected position, the tip locking portion 28 provided on the needle hub 18 of the puncture needle body 12 abuts against the side walls 78, 78 of the needle tip protector 14 in the axial direction and locks into place. This restricts the movement of the puncture needle body 12 toward the proximal end and prevents the puncture needle body 12 from being pulled out toward the proximal end relative to the needle tip protector 14. In this way, with the needle tip 20 of the puncture needle 16 protected by the needle tip protector 14, the movement of the puncture needle body 12 relative to the needle tip protector 14 is restricted on both the tip and proximal end sides, and the protective state of the needle tip 20 by the needle tip protector 14 is maintained.

[0070] In this embodiment, a pair of flexible pieces 76, 76 are provided, and coupled with the fact that the flexible pieces 76, 76 are integrally molded with the peripheral wall 60 of the needle tip protector 14, when the flexible pieces 76, 76 and the locking projections 30, 30 are locked together, rattling of the needle tip protector 14 relative to the puncture needle body 12 is prevented. By providing two or more flexible pieces 76 in this way, the retraction of the needle tip protector 14 toward the proximal end relative to the puncture needle body 12 can be more reliably prevented, and the effect of preventing the re-exposure of the needle tip 20 can be exhibited more stably. In this case, it is preferable that the multiple flexible pieces 76 are arranged substantially symmetrically with respect to the central axis of the needle tip protector 14.

[0071] With the needle tip 20 of the puncture needle body 12 protected by the needle tip protector 14, the tape fixing of the wing-shaped portion 86 is released and the needle assembly 10 is removed from the patient. However, the procedure for protecting the needle tip 20 is not limited to the procedure described above. Specifically, for example, the tape fixing of the wing-shaped portion 86 may be released, the entire needle assembly 10 may be moved backward to remove the puncture needle 16 from the blood vessel, and then the puncture needle body 12 may be moved backward relative to the needle tip protector 14 so that the needle tip 20 of the puncture needle 16 is protected.

[0072] Figure 10 shows the main parts of a needle assembly 100 as a second embodiment of the present invention. The needle assembly 100 includes a needle hub 102. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the figures, and their descriptions are omitted.

[0073] The needle hub 102 has an intermediate portion 104 that acts as a contact portion between the tip portion 32 and the conduit connection portion 40 which serves as the base portion. The intermediate portion 104 has a tapered portion 58 on the tip side of its outer circumference and a convex portion 106 on the base end side of its outer circumference.

[0074] The protrusion 106 projects outward in the left-right direction from the outer circumferential surface of the intermediate portion 104. The protrusion 106 has a substantially constant semicircular cross-section and extends linearly in the vertical direction. The protrusion 106 is located between the opposing engaging arms 48, 48. The specific shape of the protrusion 106 is merely illustrative and not particularly limited. Specifically, for example, the protrusion 106 may have a polygonal cross-sectional shape, or it may be a spot-shaped projection rather than a continuous ridge of a predetermined length.

[0075] In this type of needle hub 102, when an inward operating force (inward in the direction opposite to the engaging arms 48,48) is applied to the engaging arms 48,48, and the engaging arms 48,48 move inward, they come into contact with the convex portion 106 of the intermediate portion 104. As a result, the amount of inward movement of the engaging arms 48,48 is limited by the mechanical action caused by the contact between the engaging arms 48,48 and the intermediate portion 104. Consequently, damage due to excessive deformation of the engaging arms 48,48 is prevented, and the durability of the engaging arms 48,48 is improved.

[0076] Since a protrusion 106 is provided on the intermediate portion 104, and the engaging arms 48, 48 abut against the intermediate portion 104 at the protrusion 106, the amount of inward movement that the engaging arms 48, 48 are allowed to move can be adjusted by the size, shape, position of the protrusion 106, etc.

[0077] In the intermediate section 104, the portion where a load is applied due to contact by the engaging arms 48, 48 is thickened by the protrusion 106, thereby preventing damage to the intermediate section 104 due to contact by the engaging arms 48, 48.

[0078] Figure 11 shows the base end of a needle assembly 110 as a third embodiment of the present invention. The needle assembly 110 includes a needle hub 112. The needle hub 112 has an intermediate portion 114 as a contact portion between the tip portion 32 and the conduit connection portion 40 which serves as the base portion. The intermediate portion 114 has a tapered portion 58 on the tip side of its outer circumferential surface and a recess 116 on the base end side of its outer circumferential surface.

[0079] The recess 116 is provided opening to the left-right outer surface of the intermediate portion 114 and has a groove-like shape with a substantially constant semicircular cross-section that extends linearly in the vertical direction. The recess 116 is located between the opposing engaging arms 48, 48. The specific shape of the recess 116 is merely illustrative and not particularly limited. Specifically, for example, the recess 116 may have a polygonal cross-sectional shape, or it may be a spot-shaped recess rather than a groove.

[0080] In such a needle hub 112, when an inward operating force (inward in the direction opposite to the engaging arms 48,48) is applied to the engaging arms 48,48, and the engaging arms 48,48 move inward, the engaging arms 48,48 come into contact with at least one of the tip and base ends of the recess 116. As a result, the amount of inward movement of the engaging arms 48,48 is limited by the mechanical action caused by the contact between the engaging arms 48,48 and the intermediate portion 114. Consequently, damage due to excessive deformation of the engaging arms 48,48 is prevented, and the durability of the engaging arms 48,48 is improved.

[0081] A recess 116 is provided in the intermediate portion 114, and the engaging arms 48, 48 abut against the intermediate portion 114 in the recess 116. As a result, the amount of inward movement allowed for the engaging arms 48, 48 can be adjusted by the position, shape, and size of the recess 116. For example, even if the needle hub 112 and the engaging arms 48, 48 are made thick to ensure strength, and the gap between the needle hub 112 and the engaging arms 48, 48 is small, the recess 116 in the intermediate portion 114 of the needle hub 112 makes it possible to ensure a sufficient amount of inward movement for the engaging arms 48, 48.

[0082] Figure 12 shows the base end of a needle assembly 120 as a fourth embodiment of the present invention. The needle assembly 120 includes a needle hub 122. The needle hub 122 is composed of two parts, with a tip portion 24 and a base portion 124 being separate components. The tip portion 24 has substantially the same structure as the tip portion 24 of the above embodiment, except that the base end side is not integrally formed with the base portion 124.

[0083] The base portion 124 comprises a connecting cylindrical portion 126 on the tip side and a pipe connection portion 40 on the base side. The outer surface of the pipe connection portion 40 has a tapered shape that narrows in width towards the base side, but the outer surface of the pipe connection portion 40 may also be straight, for example. The connecting cylindrical portion 126, which serves as the contact portion, is substantially cylindrical in shape, and in the longitudinal cross-section shown in Figure 12, the inner and outer surfaces have a straight shape that extends linearly in the direction of the needle axis. As a result, the connecting cylindrical portion 126 has a straight portion 128 on its outer surface that extends linearly in the direction of the needle axis. The inner diameter of the connecting cylindrical portion 126 is substantially the same as that of the base side of the tip portion 24. The connecting cylindrical portion 126 may also have a tapered shape that widens in width towards the base side, for example.

[0084] Furthermore, a pair of engaging arms 130, 130 are integrally formed at the left and right outer ends of the tip side of the pipe connection portion 40, as arms that protrude toward the tip. The engaging arms 130, 130 are provided spaced apart to the left and right outward relative to the connecting cylinder portion 126, and their tips, which are composed of hooks 50, 50, are located toward the tip side of the connecting cylinder portion 126. In other words, the connecting cylinder portion 126 is located between the opposing engaging arms 130, 130. The base ends of the engaging arms 130, 130 are thinned in the left and right direction, and the tips are allowed to move inward to the left and right due to the elastic deformation of the base ends.

[0085] The tip portion 24 is then inserted from the tip side into the connecting cylindrical portion 126 of the base portion 124, and fixed by adhesive or welding as necessary, thereby forming the needle hub 122. Note that the tip portion 24 and the base portion 124 may be fixed by fitting together, and do not necessarily need to be glued or otherwise bonded.

[0086] The needle hub 122 is inserted into the needle tip protector 14, and the needle hub 122 and the needle tip protector 14 are positioned in the needle axis direction by the engagement arms 130, 130 of the needle hub 122 engaging with the through windows 74, 74 of the needle tip protector 14. In this state where the needle hub 122 and the needle tip protector 14 are connected and positioned by the engagement arms 130, 130, the flexible pieces 76, 76 of the needle tip protector 14 are located on the tip side of the engagement arms 130, 130 and are not inserted between the opposing engagement arms 130, 130.

[0087] When an inward operating force is applied to the engaging arms 130, 130 in the opposing direction, the engaging arms 130, 130 move inward and come into contact with the straight portion 128 of the connecting cylindrical portion 126 of the needle hub 122. As a result, the inward movement of the engaging arms 130, 130 is restricted by the mechanical action caused by contact with the connecting cylindrical portion 126, preventing excessive deformation of the engaging arms 130, 130. Consequently, by moving the engaging arms 130, 130 inward until they come into contact with the connecting cylindrical portion 126, it is possible to release the engagement between the hooks 50, 50 and the through windows 74, 74 while preventing excessive deformation of the engaging arms 130, 130, allowing the engaging arms 130, 130 to be operated appropriately.

[0088] Thus, the contact portion into which the engaging arms 130, 130 abut is not necessarily limited to a portion whose shape changes in the axial direction, but may also be composed of a straight portion 128 that extends in a substantially constant shape in the axial direction.

[0089] In this embodiment, a structure in which the tip portion 24 and base portion 124 of the needle hub 122 are separate components has been described. However, for example, in the needle assembly 140 shown in Figure 13, the tip portion 24 and base portion 36 are integrally formed in the needle hub 142, and an intermediate portion 144 including the straight portion 128 can be used as a contact portion.

[0090] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the contact portion does not have to be provided on both the needle tip protector 14 and the needle hub 18, but may be provided on only one of them.

[0091] When the flexible pieces 76, 76 of the needle tip protector 14 are used as contact points, the outer surfaces of the flexible pieces 76, 76 can also be provided with protrusions, recesses, straight sections, flat sections, etc.

[0092] In the tapered portion 58 of the first embodiment described above, the contact surfaces of the engaging arms 48, 48 are curved in the circumferential direction. However, the contact portion that the arm contacts may be composed of a flat surface with a flat contact surface. This makes it possible to make surface contact or linear contact extending in a straight line without curving in the circumferential direction between the arm and the flat surface when the contact surface of the arm is flat. Furthermore, when the tapered portion 58 of the needle hub 18 or the outer surface 77 of the needle tip protector 14 is curved in the circumferential direction, the inner surface of the engaging arm 48 that contacts it may be curved in accordance with the circumferential direction, resulting in linear contact that curves in the circumferential direction.

[0093] In the above embodiment, the contact portion of the needle hub 18 was composed of an intermediate portion 56 provided between the tip portion 24 and the conduit connection portion 40. However, for example, the engaging arms 48, 48 may be made to contact the conduit connection portion 40, so that the contact portion is composed of the conduit connection portion 40. Similarly, the contact portion of the needle tip protector 14 may be provided in a portion different from the flexible pieces 76, 76.

[0094] The engaging arms 48, 48 may contact the contact portion on the hooks 50, 50, or they may contact the contact portion on the base end side of the hooks 50, 50. Furthermore, the present invention originally includes all of the inventions described in (i) to (x) below, and its structure and effects are noted below. The present invention (i) A needle assembly comprising a puncture needle, a needle hub supporting the puncture needle, a needle tip protector that covers the tip of the puncture needle by moving in the axial direction relative to the puncture needle, and an arm provided on the base end side of the needle hub and releasably engaged with the needle tip protector, wherein the needle assembly is provided with a contact portion that the arm abuts when the arm is moved inward toward the needle hub, (ii) The needle assembly according to (i), wherein the contact portion is located between the needle hub and the arm portion. (iii) The needle assembly according to (ii), wherein the contact portion is provided on the needle tip protector. (iv) The needle assembly according to (iii), wherein the needle tip protector has a projection that engages with the needle hub, and the contact portion is provided on the projection, (v) The needle assembly according to (i) or (ii), wherein the contact portion is provided on the needle hub, (vi) The contact portion is configured to include a protrusion provided on the outer surface of the needle hub, the needle assembly as described in (v), (vii) The contact portion is configured to include a recess provided on the outer surface of the needle hub, the needle assembly according to (v) or (vi), (viii) The contact portion is configured to include a tapered portion provided on the outer surface of the needle hub, the needle assembly according to any one of (v) to (vii), (ix) The contact portion is configured to include a straight portion provided on the outer surface of the needle hub, the needle assembly according to any one of (v) to (viii), (x) The needle assembly according to any one of (i) to (ix), wherein the mechanical action exerted on the needle hub by the contact of the arm with the contact portion is a contact reaction force acting toward the base end of the needle hub, This includes inventions relating to the present invention. In the invention described in (i) above, for example, when the arm is moved inward to release the engagement with the needle tip protector, the arm comes into contact with the contact part, allowing the user to grasp, by feel or other means, that the amount of inward movement of the arm is sufficient, and also limiting the amount of inward movement of the arm. In the invention described in (ii) above, the contact portion is located between the needle hub and the arm, so that the arm comes into contact with the contact portion as it moves inward. Moreover, because the needle hub is located inside the contact portion, force can be effectively transmitted and sufficient feedback can be obtained when the arm and the contact portion come into contact. In the invention described in (iii) above, by having the arm contact the contact portion of the needle tip protector, it becomes possible to cause relative movement between the needle tip protector and the needle hub in the needle axis direction based on an external force applied to the arm, for example. In the invention described in (iv) above, in a needle tip protector that is externally fitted onto the needle hub and covers the tip of the puncture needle, the projection is provided on an inner circumference portion that can engage with the needle hub, making it easier to insert between the arm portion and the needle hub on the inner circumference side than the arm portion, and making it easier to provide a contact portion between the arm portion and the needle hub. In the invention described in (v) above, the contact between the arm and the contact portion of the needle hub limits the amount of inward movement of the arm, thereby preventing excessive deformation of the arm and improving the durability of the arm. In the invention described in (vi) above, the contact portion includes a protrusion that projects from the outer surface of the needle hub, making it possible to easily set the distance between the contact portion and the arm portion by the shape and size of the protrusion. In the invention described in (vii) above, the contact portion includes a recess that opens to the outer surface of the needle hub, making it easier to secure the distance between the arm portion and the contact portion even when the distance between the arm portion and the needle hub is short. In the invention described in (viii) above, the contact portion includes a tapered portion provided on the outer surface of the needle hub, making it possible to easily set the distance between the contact portion and the arm portion by the inclination direction and angle of the tapered portion. As described in (ix) above, the contact portion may include a straight portion provided on the outer surface of the needle hub. In the invention described in (x) above, for example, during the disengagement operation to release the engagement between the arm and the needle tip protector, the release force applied to the arm acts toward the base end of the needle hub due to the contact between the arm and the contact part. As a result, by simply manipulating the arm, the needle hub slightly detaches from the needle tip protector toward the base end. Therefore, once the engagement between the arm and the needle tip protector is released, even if the release force pushing the arm inward is released and the arm moves to return to its original position outward, the arm will not re-engage with the needle tip protector. Consequently, the time during which the release force is applied to the arm can be shortened, reducing the effort required to pull the needle hub away from the needle tip protector. [Explanation of symbols]

[0095] 10,100,110,120,140 Needle assembly 12 Puncture needle 14 Needle tip protector 16 Puncture needle 18,102,112,122,142 Needle Hub 20 needle tip 24 Tip part 26 Needle fixing part 28. Tip locking section 30 Locking protrusion 32 Tip 34 Guide protrusions 36,124 proximal part 38 recesses 40 Pipeline connection 42 connection holes 44 Bottom 46 connection ports 48,130 Engaging arm (arm portion) 50 hooks 52 External conduit 54 Fluid flow channels 56,104,114,144 Intermediate part (contact part) 58 Tapered section 60 Peripheral wall 62 Internal bore 64 Cylindrical part 66 Enlarged section 68 Narrow part 70 Wide section 72 Interior space 74 Through-window 76 Flexible piece (projecting piece, contact part) 77 Exterior 78 Side wall section 80 gap 82 Leaf spring 84 slits 86 Wings 88 Fitting cylinder 90 Connection part 92 Wing body 106 Convex part 116 recess 126 Connecting cylinder part (contact part) 128 Straight section

Claims

1. A puncture needle and The needle hub that supports the puncture needle, A needle tip protector that covers the tip of the puncture needle by moving in the axial direction relative to the puncture needle, An arm provided on the base end side of the needle hub and releasably engaged with the needle tip protector, A needle assembly comprising, A contact portion is provided on the needle hub that the arm portion contacts when the arm portion is moved inward toward the needle hub, The needle hub is provided with a conduit connection section having a connection hole that opens towards the base end, and a connection port to which an external conduit is connected is formed protruding from the bottom of the connection hole. The arm portion protrudes radially outward from the pipe connection portion and extends toward the tip. The aforementioned contact portion is formed such that the portion forming the fluid flow path increases in thickness toward the base end, A needle assembly in which the contact portion is located on the tip side of the connection hole in the needle hub, rather than on the bottom side.

2. The needle assembly according to claim 1, wherein the contact portion includes a protrusion provided on the outer surface of the needle hub.

3. The needle assembly according to claim 1 or 2, wherein the contact portion includes a recess provided on the outer surface of the needle hub.

4. The needle assembly according to any one of claims 1 to 3, wherein the contact portion includes a tapered portion provided on the outer surface of the needle hub.

5. The needle assembly according to any one of claims 1 to 4, wherein the contact portion includes a straight portion provided on the outer surface of the needle hub.

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