Indwelling needle assembly

Abstract

To provide an indwelling needle assembly which can improve operability of an operator and has a novel structure.SOLUTION: In an indwelling needle assembly 10, an inner needle unit 16 includes a storage housing 14 for storing a protector 52 and is provided with a connecting member 94 for connecting the storage housing 14 to an outer needle hub 20. The movements of the connecting member 94 are blocked by the protector 52, and the storage housing 14 and the outer needle hub 20 are kept in a connected state. By deformation or displacement of the protector 52 associated with pulling out of an inner needle 12, movements of the connecting member 94 are allowed to cancel the connected state of the storage housing 14 to the outer needle hub 20.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Conventionally, indwelling needle assemblies equipped with an inner needle unit and an outer needle unit have been known as medical devices used in treatments such as infusion, blood collection, and hemodialysis. In such indwelling needle assemblies, a protector that protects the pulled-out inner needle may be employed to prevent accidental punctures caused by the inner needle being pulled out after puncturing. An indwelling needle assembly equipped with a protector is disclosed, for example, in JP 2004-24622 A (Patent Document 1).

[0003] In such an indwelling needle assembly, after the outer needle has been inserted through the inner needle and punctured, the inner needle is pulled out while leaving the outer needle unit indwelling in the patient, thereby detaching the inner needle unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-24622 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the indwelling needle assembly of the conventional structure, there is room for improvement in the operability of the practitioner. For example, when the inner needle unit is detached after puncturing, the outer needle unit may be pulled by the inner needle unit and removed from the site to be punctured, and there is room for improvement. For example, in the indwelling needle assembly described in Patent Document 1, the tip of the second telescopic pipe 21 is tightly fitted into the engagement hole 11B of the hemostatic adapter 11, so the outer needle unit may be pulled by the inner needle unit and removed from the site to be punctured. The practitioner must hold the outer needle unit in place with one hand while pulling out the inner needle unit with the other hand, which requires special manipulation.

[0006] An object of the present invention is to provide an indwelling needle assembly of a novel structure which improves operability for the practitioner. [Means for solving the problem]

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely illustrative and may be combined with one another as appropriate, and the multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] In the first aspect, in an indwelling needle assembly in which an inner needle unit including an inner needle hub and an outer needle unit including an outer needle hub are detachably connected, an inner needle equipped with a protector is inserted removably into the outer needle, and the protector is deformed or displaced to protect the needle tip as the inner needle moves toward the needle tip upon withdrawal of the inner needle, the inner needle unit is provided with a storage housing that stores the protector, and a connecting member that connects the storage housing to the outer needle hub is provided, the protector prevents movement of the connecting member, maintaining the storage housing and the outer needle hub in a connected state, and deformation or displacement of the protector upon withdrawal of the inner needle allows movement of the connecting member, making it possible to release the connection state of the storage housing to the outer needle hub.

[0009] With an indwelling needle assembly constructed according to this aspect, the connection between the storage housing and the outer needle hub by the connecting member can be released by skillfully utilizing the protector that elastically deforms when the inner needle is pulled out. There is no longer a need to move the entire outer needle unit in the direction perpendicular to the axis relative to the inner needle unit, making it possible to simplify the operation.

[0010] In addition, as the protector in this embodiment, it is also possible to use, for example, an elastically deformable protector that is prevented from elastic deformation by the inserted inner needle, thereby maintaining the connecting member in a connected state between the storage housing and the outer needle hub, and that can allow movement of the connecting member by elastically deforming as the inner needle is pulled out.

[0011] In a second aspect, in the indwelling needle assembly of the first aspect, the connecting member has an engaging portion for engaging with the base end opening of the outer needle hub, and the tip portion of the storage housing is inserted through the base end opening of the outer needle hub, and the peripheral wall of the outer needle hub is sandwiched inside and outside by the engaging portion of the connecting member and the tip portion of the storage housing.

[0012] According to an indwelling needle assembly constructed according to this aspect, the connection between the outer needle unit and the inner needle unit before the inner needle is pulled out can be achieved more stably.

[0013] In a third aspect, in the indwelling needle assembly of the first or second aspect, the connecting member has a communication hole that communicates with the inner hole of the storage housing, and the protector, through which the inner needle is inserted and prevented from elastically deforming, abuts against the inner surfaces of both the inner hole and the communication hole, thereby preventing movement of the connecting member relative to the storage housing.

[0014] With an indwelling needle assembly constructed according to this aspect, the stability of positioning of the connecting member with respect to the storage housing by the protector before the inner needle is withdrawn can be improved, and it is also possible to minimize wobbling of the connecting member, for example.

[0015] In a fourth aspect, in the indwelling needle assembly according to any one of the first to third aspects, the abutment portion between the protector, through which the inner needle is inserted and prevented from elastically deforming, and the inner surface of the storage housing is in face-to-face contact.

[0016] In an indwelling needle assembly constructed according to this aspect, the abutment area of ​​the protector with respect to the storage housing is set in the circumferential direction, which can improve the positional stability of the protector with respect to the storage housing, and as a result, the positional stability of the connecting member, whose movement is restricted by the protector, with respect to the storage housing can also be improved.

[0017] In a fifth aspect, in the indwelling needle assembly according to any one of the first to fourth aspects, the storage housing is provided with a pair of gripping portions on its outer circumferential surface at a portion located on the tip side.

[0018] The indwelling needle assembly constructed according to this aspect allows the practitioner to grasp the area close to the needle tip, enabling the puncture operation to be carried out stably.

[0019] In a sixth aspect, in an indwelling needle assembly according to any one of the first to fifth aspects, an inclined surface is provided at the engagement portion between the connecting member and the outer needle hub, and by pulling out the inner needle, the connecting member moves along the inclined surface, thereby releasing the connection with the outer needle hub.

[0020] With an indwelling needle assembly constructed in accordance with this embodiment, there is no need to provide a special biasing means for displacing the connecting member, and it is also possible to release the connecting member from the outer needle hub by simply pulling out the inner needle.

[0021] Furthermore, in the indwelling needle assembly according to any one of the first to sixth aspects, an aspect may be adopted in which, by pulling out the inner needle, the connecting member is movable laterally relative to the storage housing in a direction along the patient's body surface.

[0022] With an indwelling needle assembly constructed according to this aspect, the movement of the connecting member when detaching the inner needle unit can be directed to the side, avoiding the downward direction where the patient's body surface is located or the upward direction where the operator operates. This prevents interference with the connecting member during operation by the practitioner, thereby preventing a decrease in operability.

[0023] A seventh aspect is an indwelling needle assembly in which an inner needle unit including an inner needle hub and an outer needle unit including an outer needle hub are detachably connected, the inner needle is inserted through the outer needle so as to be retractable, and the assembly is provided with a storage housing that stores the inner needle as the inner needle is withdrawn, and a connecting member is provided that connects the storage housing to the outer needle unit, and a blocking member is provided between the inner needle and the connecting member, the blocking member prevents movement of the connecting member, thereby maintaining the storage housing and the outer needle unit in a connected state by the connecting member, and the blocking member is displaced as the inner needle is withdrawn, allowing movement of the connecting member, thereby enabling the storage housing to be released from the connected state to the outer needle unit.

[0024] According to an indwelling needle assembly constructed in accordance with this aspect, a blocking member is provided that blocks movement of the connecting member that connects the storage housing and the outer needle unit, and the blocking member is displaced as the inner needle is pulled out, making it possible to release the connection between the storage housing and the outer needle unit by the connecting member. Therefore, it is possible to simultaneously improve, for example, the stability of the connection between the storage housing and the outer needle unit and the operability of releasing the connection.

[0025] Furthermore, in an indwelling needle assembly equipped with a protector, the following eighth aspect may also be employed.

[0026] The eighth embodiment comprises an inner needle that is retractable and a protective housing in which the inner needle is housed when pulled out, and a displacement member that is housed in the tip portion of the protective housing and that displaces as the inner needle is pulled out, the protective housing has a multi-tube structure consisting of a plurality of tubular bodies, and the plurality of tubular bodies are inserted inside and outside the protective housing at a position that is off to the base end side of the mounting position of the displacement member, and as the inner needle is pulled out, the plurality of tubular bodies are pulled out one by one and the inner needle is housed in the protective housing.

[0027] According to the indwelling needle assembly constructed according to this aspect, the protective housing has a structure in which multiple tubular bodies are inserted inside and outside, thereby making it possible to reduce the length of the protective housing and, in turn, the indwelling needle assembly. In particular, since the multiple tubular bodies are inserted inside and outside on the base end side of the protector mounting position, it is also possible to reduce the diameter of the indwelling needle assembly compared to, for example, the case in which the tubular bodies are inserted inside and outside on the outer periphery side of the protector.

[0028] Furthermore, in the indwelling needle assembly according to this embodiment, the presence of the displacement member allows the displacement member to have the function that the protective housing has in an indwelling needle assembly having a protective housing, improving operational stability. For example, by making the displacement member a protector that covers the needle tip, it is possible to more effectively prevent the exposure of the tip of the inner needle. For example, by making the displacement member inseparable from the protective housing, it is possible to prevent the protective housing from returning to its initial state from the state in which the inner needle is housed by the displacement member, and since it is not necessary to provide a locking mechanism in the tubular body itself that constitutes the protective housing, it is possible to prevent the inner needle unit from being separated from the outer needle unit due to the resistance when locking the tubular bodies together. For example, by making the displacement member a member that prevents the movement of the connecting member, it is possible to link the operation of pulling out the inner needle with the release of the connection of the connecting member. By dividing the functions in this way, it is possible to maintain a small size while improving operational stability, and it is also possible to improve the operability of the practitioner.

[0029] It is also possible to apply the indwelling needle assembly according to the present embodiment together with the indwelling needle assembly according to any one of the first to seventh embodiments, and in that case, the storage housing that stores the protector in the indwelling needle assembly according to any one of the first to seventh embodiments can also be constructed using the protective housing according to the present embodiment.

[0030] Furthermore, the indwelling needle assembly may also employ the following ninth aspect.

[0031] A ninth aspect is an indwelling needle assembly having an inner needle that is inserted removably through an outer needle, comprising a protective housing in which the inner needle is housed when pulled out, the protective housing having a multi-tube structure with a number of tubular bodies inserted inside and outside, the number of tubular bodies being pulled out sequentially as the inner needle is pulled out, and the base end of the most base-side tubular body of the number of tubular bodies pulled out sequentially is provided with a base end wall portion having a through hole penetrating from the inside to the outside.

[0032] According to the indwelling needle assembly constructed according to this aspect, the storage housing has a structure in which multiple tubular bodies are inserted inside and outside, thereby making the storage housing, and therefore the indwelling needle assembly, smaller in size in the longitudinal direction. In such a storage housing, by providing a through hole penetrating the housing from inside to outside, the negative pressure inside the housing can be reduced even during a rapid withdrawal operation, and the operation of withdrawing the tubular body can be performed more quickly. Note that the indwelling needle assembly according to this aspect can also be applied in combination with the indwelling needle assembly according to any one of the first to eighth aspects, and in that case, the storage housing that stores the protector in the indwelling needle assembly according to any one of the first to seventh aspects or the protective housing in the indwelling needle assembly according to the eighth aspect can also be constructed using the protective housing of this aspect. Effect of the Invention

[0033] According to the present invention, it is possible to provide an indwelling needle assembly of a new structure which can resolve at least one of the problems inherent in indwelling needle assemblies of conventional structures, such as by allowing the inner needle unit to be easily detached from the outer needle unit and improving operability for the practitioner. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a perspective view showing an indwelling needle assembly according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged front view of the indwelling needle assembly shown in FIG. [Diagram 3] FIG. 2 is an enlarged rear view of the indwelling needle assembly shown in FIG. [Figure 4] IV-IV cross section in FIG. [Diagram 5] VV cross section in Figure 2 [Figure 6] FIG. 6 is an enlarged cross-sectional view taken along line VI-VI in FIG. 4. [Figure 7] FIG. 7 is an enlarged cross-sectional view of the VII-VII section in FIG. [Figure 8] FIG. 2 is a perspective view showing a state in which the inner needle unit has been detached from the outer needle unit in the indwelling needle assembly shown in FIG. [Figure 9] FIG. 9 is a longitudinal sectional view showing the indwelling needle assembly shown in FIG. 8, and corresponds to FIG. 4. [Figure 10] FIG. 9 is a longitudinal sectional view showing the indwelling needle assembly shown in FIG. 8, and corresponds to FIG. 5. [Figure 11] FIG. 10 is an enlarged cross-sectional view taken along the line XI-XI in FIG. [Figure 12] FIG. 11 is a cross-sectional view showing a portion of an indwelling needle assembly according to a second embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view showing a part of the inner needle unit after the inner needle has been pulled out from the outer needle unit in the indwelling needle assembly shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] In order to clarify the present invention more specifically, embodiments of the present invention will be described in detail below with reference to the drawings.

[0036] First, in Figs. 1 to 7, an indwelling needle assembly 10 according to a first embodiment of the present invention is shown. This indwelling needle assembly 10 includes an inner needle unit 16 including an inner needle 12 and an inner needle hub 14, and an outer needle unit 22 including an outer needle 18 and an outer needle hub 20. In the pre-use state shown in Figs. 1 to 7, the inner needle 12 is inserted into the outer needle unit 22 so as to be retractable from the base end side, and the inner needle unit 16 and the outer needle unit 22 are connected to each other. In the following description, the axial direction refers to the left-right direction in Fig. 4, which is the needle axial direction of the inner needle 12 and the outer needle 18. The tip side refers to the left side in Fig. 4, which is the side of the needle tip 24 of the inner needle 12, and the base side refers to the right side in Fig. 4, which is the side that the user grasps and operates.

[0037] More specifically, the outer needle 18 is tubular and flexible, and has a length shorter than that of the inner needle 12. The outer peripheral surface at the tip of the outer needle 18 may be tapered, for example, so that the diameter gradually decreases toward the tip, thereby reducing the puncture resistance to the living body. In addition, the peripheral wall at the tip of the outer needle 18 may be provided with one or more through holes, thereby improving the efficiency of fluid flow through the outer needle 18.

[0038] The outer needle hub 20 has a generally tubular shape extending in the axial direction as a whole, and in this embodiment, is provided with a generally cylindrical peripheral wall 26. A generally cylindrical rivet pin 28 is fixed to the inner circumferential surface at the tip portion of the peripheral wall 26, and the base end portion of the outer needle 18 is sandwiched between the peripheral wall 26 and the rivet pin 28, and is bonded or welded as necessary, thereby fixing the outer needle hub 20 to the base end side of the outer needle 18.

[0039] A flange-shaped portion 32 that protrudes outwardly around the entire circumference in the circumferential direction is provided at the base-end opening 30 of the outer needle hub 20, and a screw thread is provided on the outer circumferential surface of the flange-shaped portion 32. This allows a luer lock type syringe, connector, or the like to be connected to the outer needle hub 20. In this embodiment, a positioning groove 34 extending in the axial direction is provided on a portion of the circumference of the flange-shaped portion 32 (upper part in FIG. 4).

[0040] In this embodiment, a hemostatic valve mechanism 36 is incorporated in a housed state inside the outer needle hub 20. The hemostatic valve mechanism 36 is composed of a disk valve 38, a plunger 40, and a plunger guide 42. When the inner needle 12 is pulled out, blood that has flowed back through the outer needle 18 is housed in the area of ​​the outer needle hub 20 distal side of the hemostatic valve mechanism 36, and therefore, by making at least the distal side of the arrangement position of the hemostatic valve mechanism 36 in the peripheral wall 26 of the outer needle hub 20 transparent, flashback can be confirmed from the outside.

[0041] The disk valve 38 is made of an elastic body such as rubber or elastomer, and has a central slit 44. A substantially cylindrical pusher 40 is located on the base end side of the disk valve 38, and a substantially cylindrical pusher guide 42 is positioned with respect to the peripheral wall 26 of the outer needle hub 20 by being fitted with a recess and projection on the outer periphery of the pusher 40.

[0042] By connecting a syringe or the like to the outer needle hub 20 provided with such a hemostatic valve mechanism 36, the plunger 40 pushed toward the tip side by the male luer of the syringe or the like can move toward the tip side by the guiding action of the plunger guide 42, pushing open the slit 44 of the disk valve 38. Furthermore, by removing the syringe or the like from the outer needle hub 20, the disk valve 38 can be elastically restored and deformed, causing the slit 44 of the disk valve 38 to close.

[0043] The inner needle 12 is made of a known material such as stainless steel, aluminum, titanium, or an alloy thereof, and is a hollow needle in this embodiment. The inner needle 12 may be a solid needle. The tip of the inner needle 12 is a sharp needle tip 24, and the base end of the inner needle 12 is inserted or pressed into a fixed cylindrical portion 46 provided on the inner needle hub 14, and is fixed to the base end side of the inner needle 12 by bonding or welding as necessary.

[0044] The inner needle hub 14 has a generally cylindrical shape extending in the axial direction as a whole, and in this embodiment, the aforementioned fixed tubular portion 46 is provided at the base end of the inner needle hub 14. In the inner needle hub 14, the fixed tubular portion 46 is formed at a position that has a double-tube structure, and a storage tubular portion 48 is provided on the outer periphery of the fixed tubular portion 46. It is preferable that at least the storage tubular portion 48 of the inner needle hub 14 is transparent, and blood that has flowed back through the inner needle 12 when the indwelling needle assembly 10 is punctured is stored in the storage tubular portion 48, so that flashback can be confirmed from the outside. An air vent filter 50 is provided at the base end opening of the storage tubular portion 48, and when blood is stored in the storage tubular portion 48, air in the storage tubular portion 48 is discharged through the air vent filter 50, and the air vent filter 50 prevents blood from leaking from the storage tubular portion 48.

[0045] The inner needle unit 16 also includes a protector 52 that protects the needle tip 24 of the inner needle 12 after use. The protector 52 is fitted onto the inner needle 12 so as to be movable in the axial direction. The structure of the protector is not limited, but the protector 52 in this embodiment is formed by pressing a metal plate or the like, and is made elastically deformable by using spring steel or the like.

[0046] That is, the protector 52 comprises a rear wall portion 54 and a pair of elastic arms 56, 56 protruding toward the tip side from both sides (both vertical sides in FIG. 4) of the rear wall portion 54. These elastic arms 56, 56 cross each other and extend toward the tip side, and their tip portions are elastically deformable in directions approaching or moving away from each other. The elastic arms 56, 56 have different axial dimensions, so that when the inner needle 12 is pulled out, the tip portions of the elastic arms 56, 56 are displaced in directions approaching each other and overlap each other in the axial direction.

[0047] When the inner needle 12 is inserted through such a protector 52, the tip portions of the elastic arms 56, 56 are pushed apart in a direction separating them from each other. In other words, a biasing force is applied to the tip portions of the elastic arms 56, 56 in a direction approaching each other based on elastic restoring deformation, and the tip portions of the elastic arms 56, 56 are prevented from deforming in a direction approaching each other by coming into contact with the inner needle 12.

[0048] In this embodiment, a region extending parallel to the axial direction is provided at the tip portions of the elastic arms 56, 56 which are pushed open by the insertion of the inner needle 12. In particular, in this embodiment, since the protector 52 is formed with a certain degree of width dimension (vertical dimension in FIG. 6), substantially rectangular flat plate-like portions 58, 58 are formed at the tip portions of the elastic arms 56, 56.

[0049] Here, the inner needle unit 16 includes a substantially cylindrical storage housing in which the protector 52 is stored, and in this embodiment, the storage housing is configured by the inner needle hub 14. In particular, in this embodiment, the inner needle hub 14 has a multi-tube structure in which a plurality (three) of axially extending tubular bodies are inserted inside and outside the hub substantially concentrically, and is configured to include a first tubular body 60 located on the outermost side, a second tubular body 62 located in the middle in the radial direction, and a third tubular body 64 located on the innermost side. These first to third tubular bodies 60, 62, and 64 are combined in a telescopic structure inserted inside and outside the tubular bodies so as to be expandable and contractible in the axial direction. As will be described below, in this embodiment, the inner needle hub in the narrow sense to which the base end side of the inner needle 12 is fixed is the first tubular body 60, but since they are combined in an integrally connected state, the inner needle hub in the broad sense is configured by the first to third tubular bodies 60, 62, and 64 working together. In a narrow sense, the large diameter cylindrical portion 84 (described later) on the tip side of the third cylindrical body 64 constitutes the storage housing 14 of the protector 52, and the first to third cylindrical bodies 60, 62, 64 constitute a protective housing that accommodates the pulled-out inner needle 12.

[0050] That is, the first cylindrical body 60 has a shape and diameter that vary in the axial direction, with the tip portion being a rectangular cylindrical portion 66 having a rectangular cross section, and the axial middle portion being a cylindrical portion 68 having a circular cross section. By providing the rectangular cylindrical portion 66 on the outermost first cylindrical body 60, the user can place the fingertips of the hand stably on the outer circumferential surface of the rectangular cylindrical portion 66 and grasp it (for example, hold it between the thumb and middle finger from both sides), making it easier to perform operations such as pulling out the inner needle 12 described below and dispensing the outer needle hub 20 towards the tip side with the fingertip of the first finger.

[0051] 1, 4 and the like, in an initial state in which the inner needle unit 16 and the outer needle unit 22 are connected and the needle tip 24 of the inner needle 12 is protruding from the outer needle 18 to be capable of puncturing, the portion located on the distal side of the inner needle unit 16 is arranged so that the distal portions of the first cylindrical body 60 and the third cylindrical body 64 are continuous with the proximal end side of the outer needle hub 20. The rectangular cylindrical portion 66 of the first cylindrical body 60 is fitted over a large-diameter cylindrical portion 84 (described below) that is provided at the distal end of the third cylindrical body 64 and houses the protector 52, to cover the outer peripheral surface.

[0052] In addition, it is desirable that the first cylindrical body 60 and the third cylindrical body 64 have a plurality of portions on their circumferences that directly contact or are indirectly adjacent to each other in the axis-perpendicular direction or via other members so as to suppress rattling in the axis-perpendicular direction. In addition, the outer peripheral surface of the rectangular cylindrical portion 66 of the first cylindrical body 60 has a substantially rectangular cross section, and for example, by pinching the gripping portion with fingertips from both sides and placing other fingertips from above, it is easy for the practitioner to stably grip the three surfaces excluding the surface located on the patient's body surface side by placing fingertips on each of them. In addition, the shape of the outer surface is not particularly limited, but in order to make it easier to pinch with the fingertips, it is preferable that a pair of gripping portions are formed on the outer peripheral surface, for example, on both side portions. The gripping portion may be, for example, a concave curved surface, or may be provided with a non-slip surface with fine unevenness or the like, or may be provided with a shape or mark to indicate that it is a portion to be gripped. Furthermore, taking into consideration the possibility of fingers getting caught on the connecting member 94 described later, the shape and position of the outer peripheral surface of the rectangular tubular portion 66 and the protruding tip surface of the connecting member 94 can be appropriately redesigned to prevent the connecting member 94 from protruding from the outer peripheral surface of the rectangular tubular portion 66, or walls can be provided around the connecting member 94 or the gripping portion, or the shape and position of the gripping portion can be appropriately redesigned to prevent fingers from getting caught on the connecting member 94.

[0053] Moreover, the aforementioned accommodating tube portion 48 and fixed tube portion 46 are integrally formed at the base end portion of the first cylindrical body 60. The outer diameter dimension of the accommodating tube portion 48 is smaller than the outer diameter dimension of the cylindrical portion 68; that is, a base end wall portion 70 is provided at the base end of the cylindrical portion 68, and the accommodating tube portion 48, which has a smaller diameter than the cylindrical portion 68, protrudes from the base end wall portion 70 toward the base end side. Then, the inner needle 12 fixed to the fixed tube portion 46 extends toward the tip side through an inner hole 72 of the third cylindrical body 64.

[0054] In addition, a substantially rectangular notch 74 is formed in a part of the circumferential direction (upper part in FIG. 4) at the tip of the rectangular tube portion 66, into which a connecting member 94 described later is fitted. Furthermore, a first engagement claw 76 protruding to the inner circumferential side is provided on the inner circumferential surface of the rectangular tube portion 66 or the cylindrical portion 68. In this embodiment, a pair of first engagement claws 76, 76 extend in the circumferential direction with a circumferential dimension of half a circumference or less, and are formed facing each other on both sides in the vertical direction in FIG. 4. In particular, in this embodiment, a pair of through holes 78, 78 penetrating the base end wall portion 70 from the inside to the outside are formed at positions corresponding to the pair of first engagement claws 76, 76 in the base end wall portion 70. As a result, when the first cylindrical body 60 is formed by injection molding, it is also possible to use the through holes 78 as holes for punching out the first engagement claws 76.

[0055] The second cylindrical body 62 has a substantially constant diameter dimension over substantially the entire axial length, and has an axial dimension shorter than that of the first cylindrical body 60, and in this embodiment, has an axial dimension substantially equal to that of the cylindrical portion 68 of the first cylindrical body 60. A second base end side engagement claw 80 protruding toward the outer periphery is provided at the base end of the second cylindrical body 62, and a second tip end side engagement claw 82 protruding toward the inner periphery is provided at the tip of the second cylindrical body 62. In this embodiment, these second base end side and tip end side engagement claws 80, 82 are formed in an annular shape over the entire circumference in the circumferential direction.

[0056] The third cylindrical body 64 is generally formed in a stepped cylindrical shape with a diameter dimension that varies in the axial direction as a whole. That is, the tip portion of the third cylindrical body 64 is a large diameter cylindrical portion 84 having a certain axial dimension and constituting a storage housing for the protector 52, and a small diameter cylindrical portion 88 is formed on the base end side of the large diameter cylindrical portion 84 via an annular wall portion 86 that expands in the axial direction. As a result, the inner diameter dimension of the inner hole 72 in the third cylindrical body 64 also varies in the axial direction, and the inner diameter dimension of the large diameter cylindrical portion 84 is larger than the inner diameter dimension of the small diameter cylindrical portion 88. In this embodiment, the inner peripheral shape of the large diameter cylindrical portion 84 is generally rectangular, and the inner peripheral shape of the small diameter cylindrical portion 88 is circular.

[0057] The outer diameter dimension of the large diameter cylindrical portion 84 is larger than the outer diameter dimension of the second cylindrical body 62, and smaller than the inner diameter dimension of the first cylindrical body 60. The outer diameter dimension of the small diameter cylindrical portion 88 is smaller than the inner diameter dimension of the second cylindrical body 62. As a result, the first, second, and third cylindrical bodies 60, 62, and 64 are mutually inserted in and outwardly at the position where the small diameter cylindrical portion 88 is formed, and the large diameter cylindrical portion 84 is housed on the inner peripheral side of the rectangular cylindrical portion 66 of the first cylindrical body 60 on the tip side of the second cylindrical body 62.

[0058] The axial dimension of the small diameter cylindrical portion 88 is approximately equal to the axial dimension of the second cylindrical body 62, and the axial dimension of the large diameter cylindrical portion 84 is greater than the rectangular cylindrical portion 66 of the first cylindrical body 60. As a result, when the first, second, and third cylindrical bodies 60, 62, and 64 are mutually inserted, the tip of the third cylindrical body 64 protrudes further toward the tip side than the tip of the first cylindrical body 60.

[0059] Further, a third engagement claw 90 that protrudes outwardly is provided at the base end of the small diameter cylindrical portion 88, and in this embodiment, the third engagement claw 90 is formed in an annular shape around the entire circumferential circumference.

[0060] The protector 52 is inserted from the tip side into the inner periphery of the large diameter cylindrical portion 84, the inner diameter of which is increased in the inner hole 72 of the third cylindrical body 64, and is housed therein. In this embodiment, the protector 52 is inserted to the innermost part of the large diameter cylindrical portion 84, i.e., the rear wall portion 54 of the protector 52 and the annular wall portion 86 of the third cylindrical body 64 abut against each other, and the protector 52 is fixed to the third cylindrical body 64 by a fixing means known in the art, such as a recess-projection fitting or a locking structure. However, the rear wall portion 54 and the annular wall portion 86 do not need to abut against each other, and the protector 52 may be fixed to the third cylindrical body 64 with both walls 54, 86 spaced apart from each other. In particular, in this embodiment, the protector 52 is housed in the large diameter cylindrical portion 84, so that the inner surface of the large diameter cylindrical portion 84 and the flat plate-shaped portions 58, 58 of the protector 52 come into contact with each other.

[0061] Here, an insertion hole 92 penetrating in the vertical direction in Fig. 4 is formed in the axial middle portion of the large diameter cylindrical portion 84 of the third cylindrical body 64. The insertion hole 92 is formed as a rectangular hole having a certain axial dimension and width dimension (vertical dimension in Fig. 6).

[0062] A connecting member 94 that connects the inner needle unit 16 and the outer needle unit 22 is fitted into and assembled in this insertion hole 92. This connecting member 94 is configured as a separate body from the protective housing, and is provided with an insertion portion 96 that is fitted into the insertion hole 92, and a connecting portion 98 that connects the inner needle unit 16 and the outer needle unit 22 outside the indwelling needle assembly 10, with the connecting portion 98 being provided continuous with one end portion of the insertion portion 96 (the upper end in FIG. 4 ). Note that, since the connecting member 94 is fitted into and assembled in the insertion hole 92, it is also possible to understand it as a part of the inner needle unit 16.

[0063] The insertion portion 96 is formed in a substantially rectangular plate shape, and has axial and widthwise dimensions substantially equal to those of the insertion hole 92. A substantially rectangular communication hole 100 is formed in the substantially central portion of the insertion portion 96, penetrating in the plate thickness direction (axial direction). The inner peripheral shape of the communication hole 100 is substantially rectangular corresponding to the inner peripheral shape of the large diameter cylindrical portion 84, and when the connecting member 94 is fitted into the insertion hole 92 (state before use), the inner hole of the large diameter cylindrical portion 84 and the communication hole 100 communicate with each other. Note that, at the end of the insertion portion 96 opposite to the side where the connecting portion 98 is provided, on both sides in the width direction, there are formed anti-detachment projections 102, 102 that project outward in the width direction beyond the opening periphery of the insertion hole 92.

[0064] The connecting portion 98 has a smaller width than the insertion portion 96, protrudes outward through the notch 74 in the first cylindrical body 60, and extends further toward the tip side than the rectangular cylindrical portion 66. A locking portion 104 protruding toward the inner periphery is provided at the tip of the connecting portion 98. The locking portion 104 is formed in a claw shape having a substantially triangular cross section, and a tip end face 106 and a base end face 108 of the locking portion 104 are inclined surfaces that are inclined toward each other toward the inner periphery. In this embodiment, a positioning protrusion 110 is provided on the inner periphery of the connecting portion 98 on the base end side than the locking portion 104, extending axially through the center in the width direction.

[0065] The connecting member 94 thus structured is fitted into the insertion hole 92, and the protector 52 is inserted from the tip side of the large diameter cylindrical portion 84, so that the protector 52 is also inserted into the communication hole 100. As a result, the flat plate-shaped portions 58, 58 of the protector 52 abut not only against the inner surface of the large diameter cylindrical portion 84, but also against the inner surface of the communication hole 100. This makes it possible to prevent the connecting member 94 from falling off from the insertion hole 92.

[0066] The inner needle unit 16 and the outer needle unit 22 constructed as described above are assembled and connected to each other. That is, the inner needle 12 extending from the inner needle hub 14 to the tip side passing through the protector 52 is inserted from the base end opening 30 of the outer needle hub 20, passed through the hemostatic valve mechanism 36 and the outer needle 18, and protrudes further to the tip side than the outer needle 18.

[0067] As a result, the locking portion 104 protruding further toward the tip side than the first cylindrical body 60 is locked from the outside to the flange-shaped portion 32 of the outer needle hub 20, and the tip portion of the large diameter cylindrical portion 84 of the third cylindrical body 64 protruding further toward the tip side than the rectangular cylindrical portion 66 is inserted into the inside of the outer needle hub 20 from the base-end opening 30 of the outer needle hub 20. The part of the tip portion of this large diameter cylindrical portion 84 that is inserted into the inside of the outer needle hub 20 is an insertion portion 112, and the peripheral wall 26 of the outer needle hub 20 is sandwiched between the locking portion 104 and the insertion portion 112 from the inside and outside.

[0068] In particular, in the present embodiment, the positioning groove 34 in the flange-shaped portion 32 and the positioning protrusion 110 in the connecting portion 98 are positioned in the circumferential direction, and the positioning protrusion 110 fits into the positioning groove 34. This prevents relative rotation between the inner needle unit 16 and the outer needle unit 22.

[0069] A method of using the indwelling needle assembly 10 as described above will be described with reference to Figures 8 to 11. First, with the inner needle 12 and the outer needle 18 overlapping, the indwelling needle assembly 10 is inserted into the patient's blood vessel. After flashback is confirmed at the distal end of the housing tubular portion 48 or the outer needle hub 20, the inner needle 12 is pulled out toward the base end, for example, by gripping both side surfaces (both left and right side surfaces in Figure 2) of the rectangular tubular portion 66 of the inner needle hub 14 with the fingers. This causes the first tubular body 60 located on the outermost side of the inner needle hub 14 to move toward the base end.

[0070] Then, when the first cylindrical body 60 moves to a certain extent toward the base end side, the first engagement claw 76 and the second base end side engagement claw 80 engage with each other, and after this engagement, the second cylindrical body 62 moves to the base end side together with the first cylindrical body 60. Furthermore, when the second cylindrical body 62 moves to a certain extent toward the base end side, the second tip side engagement claw 82 and the third engagement claw 90 engage with each other. That is, by pulling out the inner needle 12 toward the base end side, the first and second cylindrical bodies 60, 62 are successively pulled out toward the base end side. At this point, the locking portion 104 of the connecting member 94 attached to the third cylindrical body 64 is locked to the flange-shaped portion 32 of the outer needle hub 20, so that the third cylindrical body 64 does not move to the base end side. The first cylindrical body 60, the second cylindrical body 62 and the third cylindrical body 64 may be rotatable relative to one another, or may be made non-rotatable relative to one another by being engaged with one another in the circumferential direction while allowing relative movement in the withdrawal direction, for example, by means of projections and recesses extending in the longitudinal direction.

[0071] 9, when the first and second cylindrical bodies 60, 62 are pulled out to the most proximal end and the inner needle 12 is moved to the most proximal end, the needle tip 24 of the inner needle 12 is located inside the protector 52 and is located on the proximal side of the position of contact with the tip portions of the elastic arms 56, 56. That is, when the inner needle 12 is pulled out to the proximal end, the contact between the inner needle 12 and the tip portions of the elastic arms 56, 56 is released and the tip portions of the elastic arms 56, 56 deform in a direction approaching each other due to the biasing force. As a result, the tip side of the needle tip 24 of the inner needle 12 is covered by the tip portions of the elastic arms 56, 56, protecting the needle tip 24 of the inner needle 12, and even when an external force is applied to the inner needle 12 in a direction moving it toward the tip side, the needle tip 24 will come into contact with the tip portions of the elastic arms 56, 56, preventing re-exposure of the needle tip 24 of the inner needle 12. In this embodiment, the entire length of the pulled-out inner needle 12 is covered by the first, second and third cylindrical bodies 60, 62, 64 and the protector 52, so that a full-cover type protector is configured.

[0072] In short, in this embodiment, a full-cover type protector is used, and the entire length of the pulled-out inner needle 12, including the needle tip 24, is covered by the first, second and third cylindrical bodies 60, 62 and 64. Furthermore, since the protector 52 is positioned in the axial direction with respect to the third cylindrical body 64, even if an external force is applied in a direction that shrinks the first, second and third cylindrical bodies 60, 62 and 64 when the inner needle 12 is pulled out and the needle tip 24 is covered by the protector 52, the needle tip 24 of the inner needle 12 will come into contact with the protector 52, preventing the first, second and third cylindrical bodies 60, 62 and 64 from shrinking, and preventing the inner needle 12 from being re-exposed.

[0073] Furthermore, in this embodiment, as described above, by simply operating the first cylindrical body 60 fixed to the base end of the inner needle 12 in the withdrawal direction, the second and third cylindrical bodies 62, 64 are stretched in an interlocking manner, and the inner needle 12 withdrawn from the outer needle unit 22 is covered at the same time as it is withdrawn, and further, the protector 52 attached to the third cylindrical body 64 covers the needle tip 24 of the inner needle 12 at the same time as it is withdrawn. Therefore, it is not necessary to lock the first to third cylindrical bodies 60, 62, 64 and the protector 52 by the inner needle 12 to interlock them in the withdrawal direction, and it is not necessary to provide a partial protrusion or a large diameter portion on the outer circumferential surface of the inner needle 12. Therefore, in addition to preventing a situation in which the large diameter portion or the like interferes with the protector 52 and the protector 52 performs an unintended operation when the inner needle 12 is withdrawn, the number of interlocking members in the withdrawal direction can be reduced, and operational stability can also be improved.

[0074] Then, as the elastic arm portions 56, 56 elastically deform in the direction approaching each other, the abutment between the flat plate portions 58, 58 and the large diameter cylindrical portion 84 and the inner surface of the communicating hole 100 is released, and the connecting member 94, which was fitted into and positioned in the insertion hole 92, becomes displaceable in the direction of removing from the insertion hole 92.

[0075] Here, by further withdrawing the inner needle 12, the base end surface 108 of the locking portion 104 locked to the flange-shaped portion 32 comes into contact with the flange-shaped portion 32. As a result, since the connecting member 94 is displaceable in a direction in which it is removed from the insertion hole 92, by withdrawing the inner needle 12, the connecting member 94 moves outward (to the side of the indwelling needle assembly 10, or to the left in FIG. 2 ) along the base end surface of the locking portion 104, which is an inclined surface, and the locking of the locking portion 104 to the flange-shaped portion 32 is released.

[0076] Then, by further withdrawing the inner needle 12 towards the base end, the insertion portion 112 that was inserted into the outer needle hub 20 in the third cylindrical body 64 is also withdrawn from the outer needle hub 20, and the inner needle unit 16 can be detached from the outer needle unit 22. Thereafter, for example, the outer needle hub 20 is pushed into the patient's blood vessel (dispensing operation) and the tip of the outer needle 18 is sufficiently inserted into the patient's blood vessel to place the outer needle unit 22, and by connecting a syringe or the like to the outer needle hub 20, it becomes possible to inject a medicinal solution or the like in the syringe into the patient.

[0077] In particular, in this embodiment, the end of the insertion portion 96 of the connecting member 94 opposite to the displacement direction of the connecting member 94 is provided with anti-slip projections 102, 102 that protrude outward in the width direction beyond the opening periphery of the insertion hole 92. As a result, as shown in Fig. 11, the anti-slip projections 102, 102 come into contact with the opening periphery of the insertion hole 92, thereby preventing the connecting member 94, which is displaceable relative to the insertion hole 92, from falling off from the insertion hole 92. However, the protector 52 being inserted into the communication hole 100 in the insertion portion 96 can also prevent the connecting member 94 from falling off from the insertion hole 92.

[0078] In the indwelling needle assembly 10 of the present embodiment having the above-described structure, by pulling out the inner needle 12, the engagement between the locking portion 104 and the flange-shaped portion 32 of the outer needle hub 20 is released, and the inner needle unit 16 can be detached from the outer needle unit 22. In particular, by moving the connecting member 94 along the base-end end face 108 of the locking portion 104, which is an inclined surface, it is possible to avoid the troublesome operation of moving the inner needle unit and the outer needle unit in opposite directions after pulling out the inner needle, as is the case with indwelling needle assemblies of conventional structures.

[0079] Furthermore, in the initial state before the inner needle 12 is pulled out, the peripheral wall 26 of the outer needle hub 20 is clamped from the inside and outside by the engaging portion 104 and the insertion portion 112 at the tip of the third tubular body 64, and therefore the connection state between the inner needle unit 16 and the outer needle unit 22 can be stably maintained.

[0080] Furthermore, in the initial state before the inner needle 12 is pulled out, the flat portions 58, 58 of the protector 52 are in face-to-face contact with both the inner surface of the large diameter tubular portion 84 and the inner surface of the communicating hole 100, which more reliably prevents the connecting member 94 from coming out of the insertion hole 92 and also effectively prevents the protector 52 from shifting out of position within the third tubular body 64.

[0081] Furthermore, because the connecting member 94 is displaced so as to protrude laterally from the indwelling needle assembly 10, even if the user places their finger on the top surface (upper surface in FIG. 2) of the outer needle hub 20, this is unlikely to interfere with the movement of the connecting member 94, making it easy for the user to use their finger to push the outer needle hub 20 towards the tip side. In other words, the connecting member 94 is displaced stably without interfering with the dispensing operation of the outer needle hub 20 or being pressed against the patient's skin, and thus the connection between the inner needle unit 16 and the outer needle unit 22 can be more reliably released.

[0082] In the present embodiment, the inner needle hub 14 has a multi-tube structure, and the inner needle 12 is stored in the inner needle hub 14 by sequentially pulling out a plurality of tubular bodies (first and second tubular bodies 60, 62 in the embodiment). By employing such a structure, the axial length of the inner needle hub 14 can be reduced, and the indwelling needle assembly 10 can be made smaller. In particular, since the first, second and third tubular bodies 60, 62 and 64 are inserted inside and outside each other on the proximal side of the attachment position (large diameter tubular portion 84) of the protector 52 in the third tubular body 64, an increase in the diameter of the inner needle hub 14 can be avoided, as compared to, for example, a case in which a plurality of tubular bodies are inserted inside and outside on the outer periphery side of the attachment position of the protector.

[0083] Furthermore, since a through hole 78 penetrating from inside to outside is formed in the base end wall portion 70 of the first cylindrical body 60 located at the most base end side in the inner needle hub 14, the inside of the inner needle hub 14 does not become a large negative pressure when the first and second cylindrical bodies 60, 62 are pulled out, and the operation of pulling out the first and second cylindrical bodies 60, 62 can be performed smoothly. In particular, even in the case of a telescopic structure of multiple cylindrical bodies inserted inside and outside in multiple layers, since the base end wall portion 70 is connected to the outside, it is possible to quickly introduce outside air into the inside of the inner cylindrical body.

[0084] 12 shows a portion of an indwelling needle assembly 120 according to a second embodiment of the present invention. The indwelling needle assembly 120 has a structure in which a protector 122 serving as a blocking member is housed in the large diameter cylindrical portion 84 of the inner needle hub 14 that constitutes the storage housing.

[0085] The protector 122 is formed of, for example, a pressed product of spring steel, similar to the protector 52 of the first embodiment, and is allowed to be elastically deformed. The protector 122 includes a rear wall 54 and a pair of elastic arms 124, 124 protruding from both ends (both ends in the vertical direction in FIG. 12) of the rear wall 54 toward the tip side. The elastic arms 124, 124 are each formed into a substantially flat plate shape, and the tip portions can move relatively to each other in the direction approaching or separating by bending elastic deformation in the plate thickness direction. The elastic arms 124, 124 extend without intersecting each other, and the tips are separated from each other. The elastic arms 124, 124 have different axial dimensions, similar to the elastic arms 56, 56 of the first embodiment.

[0086] A convex portion (not shown) is formed on the outer surface of the rear wall portion 54, and a concave portion (not shown) is formed on the inner surface of the large diameter cylindrical portion 84, with the concave portion of the large diameter cylindrical portion 84 engaging with the convex portion of the rear wall portion 54. Therefore, the protector 122 is engaged with the large diameter cylindrical portion 84 regardless of whether the elastic arms 124, 124 are displaced, and the protector 122 is prevented from slipping out to the opening side of the large diameter cylindrical portion 84 (the left side in the figure). Furthermore, the inner peripheral shape of the large diameter cylindrical portion 84 and the outer peripheral shape of the rear wall portion 54 in a cross section perpendicular to the inner needle 12 are formed into a substantially corresponding rectangular shape, and the protector 122 is formed so as to be at a predetermined axial position relative to the large diameter cylindrical portion 84. Note that the inner needle 12 may be provided with a convex portion that cannot pass through the hole in the rear wall portion 54 to restrict movement of the protector 122 relative to the inner needle 12. In addition, engagement portions such as projections and recesses may be provided on the inner surface of the large diameter cylindrical portion 84 or the outer surface of the protector 122 to prevent the protector 122 from rotating around its axis relative to the large diameter cylindrical portion 84, and guide projections and guide recesses extending in the axial direction may be formed to restrict the rotation of the protector 122 relative to the large diameter cylindrical portion 84.

[0087] A needle tip protection portion 126 is provided at the tip of each elastic arm portion 124, expanding at an angle relative to the elastic arm portion 124. The needle tip protection portion 126 protrudes inward in the opposing direction of the elastic arms 124, 124 (the up and down direction in FIG. 12). The end of the needle tip protection portion 126 is a sliding contact portion 128 bent so as to face the elastic arm portion 124 approximately in parallel, thereby preventing the needle tip protection portion 126 from getting caught when it comes into contact with the outer circumferential surface of the inner needle 12.

[0088] The inner needle 12 is inserted between a pair of needle tip protection parts 126, 126, and the needle tip protection parts 126, 126 are pushed apart by the inner needle 12, causing the elastic arm parts 124, 124 to be in an elastically deformed state as shown in Fig. 12. The elastic arm parts 124, 124 in an elastically deformed state are pressed against the inner circumferential surfaces of the large diameter cylinder part 84 and the connecting member 94 of the inner needle hub 14, whereby the connecting member 94 and the large diameter cylinder part 84 are positioned relative to each other in the axis-perpendicular direction. In this embodiment, substantially the entire elastic arm parts 124, 124 abut against the inner circumferential surfaces of the large diameter cylinder part 84 and the connecting member 94, but, for example, only the tip part of the elastic arm part 124 may be made to abut against the inner circumferential surfaces of the large diameter cylinder part 84 and the connecting member 94.

[0089] The protector 122 includes a guide portion 130. The guide portion 130 protrudes toward the tip side from a portion at the outer peripheral end of the rear wall portion 54 that is separated from the elastic arm portions 124, 124. The guide portion 130 includes a support portion 132 extending in the axial direction, and a needle insertion portion 134 that protrudes from the tip of the support portion 132 in the direction in which the inner needle 12 is located. The needle insertion portion 134 is, for example, in the form of a plate extending in the direction perpendicular to the axis, and includes a guide hole 136 that penetrates in the axial direction. When the protector 122 is attached to the inner needle hub 14, the guide hole 136 is located on the needle axis of the inner needle 12 inserted into the protector 122, and allows the inner needle 12 to be inserted therethrough. The guide hole 136 may be a through hole as shown in this embodiment, or a notched hole with a part of the circumference open. When a notched hole is used as the guide hole 136, it is desirable that the guide hole 136 be open in the opposing direction of the elastic arms 124, 124, in order to position the inner needle 12 in a direction perpendicular to the opposing direction of the pair of elastic arms 124, 124. Also, two guide members 130 each having a notched hole may be provided facing each other, and the inner needle 12 may be inserted through each of the notched holes in the guide members 130.

[0090] In an indwelling needle assembly 120 equipped with such a protector 122, when the inner needle 12 is pulled out of the outer needle unit (not shown) after puncture and the inner needle 12 moves to the base end beyond between the needle tip protection parts 126 of the protector 122, the elastic arms 124 that were spread apart by the inner needle 12 restore their original shape. That is, as shown in Fig. 13, the elastic arms 124 incline so that their tip sides approach each other, and the needle tip protection parts 126 provided at the tips of the elastic arms 124 approach each other and move toward the tip side on the extension of the needle axis of the inner needle 12. As a result, the tip side of the needle tip 24 of the inner needle 12 is covered by the needle tip protection parts 126, and the protector 122 prevents the inner needle 12 from protruding again, preventing erroneous puncture by the inner needle 12, etc.

[0091] The protector 122 is provided with a guide portion 130, and the inner needle 12 is inserted into a guide hole 136 of the guide portion 130. This limits the relative tilting of the inner needle 12 with respect to the protector 122, and in particular prevents the needle tip 24 from moving laterally (perpendicular to the paper surface in FIG. 13) with respect to the protector 122. This prevents the needle tip 24 from being exposed laterally from the protector 122, and the needle tip 24 is effectively protected by the protector 122. The guide portion 130 is disposed at a position away from the rear wall portion 54 through which the inner needle 12 penetrates, toward the tip side, and therefore the inner needle 12 is positioned with respect to the protector 122 at two points separated in the needle axial direction by the guide portion 130 and the rear wall portion 54, and thus prevents the inner needle 12 from tilting with respect to the protector 122 more effectively.

[0092] However, in this embodiment, the needle insertion portion 134 does not have to be provided, and the guide portion 130 itself is not essential. When the needle insertion portion 134 is not provided, the support portion 132 is located on the side of the inner needle 12, thereby restricting lateral tilt of the inner needle 12. Also, by providing a plate-shaped portion extending inward from the side of the elastic arm portions 124, 124, the inner needle 12 is surrounded by the elastic arm portions 124, 124 and the plate-shaped portion when the inner needle 12 is pulled out or after the protector 122 is activated, making it easier for the inner needle 12 to be held in a position facing the elastic arm portions 124, 124. When such a plate-shaped portion is provided, the inner needle 12 can be held without providing the guide portion 130. Furthermore, a groove or a notch may be provided at the contact portion of the sliding contact portion 128 of the elastic arm portions 124 , 124 with which the inner needle 12 abuts, so that the inner needle 12 is less likely to slip relative to the sliding contact portion 128 .

[0093] In the first embodiment, the protector 52 is illustrated as having a structure in which the elastic arms 56, 56 extend and cross each other, but it is also possible to employ a protector 122 as shown in this embodiment in which the elastic arms 124, 124 do not cross each other. Note that the indwelling needle assembly 120 according to this embodiment also exerts the same effects as the indwelling needle assembly 10 according to the first embodiment.

[0094] Although the embodiments of the present invention have been described above, the present invention should not be interpreted as being limited to the specific descriptions in the embodiments, and can be implemented in various forms with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art.

[0095] For example, in the above embodiment, the storage housing in which the protector 52 is stored is configured by the inner needle hub 14, but the present invention is not limited to this embodiment. That is, the fixed tubular portion (and the storage tubular portion) that supports the inner needle is a separate structure from the first tubular body, the inner needle extends to the tip side through a central hole provided in the center of the base end wall portion of the first tubular body, and a large diameter portion is provided on the inner needle, and when the inner needle is withdrawn, the large diameter portion of the inner needle comes into contact with the opening periphery of the central hole, so that the first tubular body is withdrawn at the same time as the inner needle is withdrawn. As a result, the inner needle is protected by the first, second and third tubular bodies and the protector, as in the above embodiment. That is, the storage housing does not need to have the function of an inner needle hub.

[0096] In the above embodiment, the insertion part 112 that sandwiches the locking part 104 and the peripheral wall 26 of the outer needle hub 20 is constituted by the tip part of the large diameter cylindrical part 84, but the insertion part may be a half-split cylindrical body or a protruding piece partially provided in the circumferential direction. However, the insertion part is not essential. For example, a hole and a protrusion that are inserted inside and outside each other in the axial direction may be formed on the peripheral wall end surface where the base end surface of the outer needle hub 20 and the tip surface of the large diameter cylindrical part 84 of the third cylindrical body 64 are butted against each other, or an insertion part into the outer needle hub 20 may be provided at the tip part of the first cylindrical body 60, or the protector 52 may be protruded into the outer needle hub 20 and inserted therein.

[0097] Furthermore, the structure of the protector is not limited, and for example, the elastic arm portion may not cross, and may extend into the outer needle hub. However, the protector is not essential, and it is also possible to prevent the re-exposure of the needle tip of the inner needle by providing, for example, a locking mechanism that blocks movement in the direction opposite to the pulling direction in the multiple pulled-out tubular bodies. It is not essential that the needle tip of the inner needle be protected. In addition, the protector 52 in the above embodiment has a function of blocking movement in the contraction direction in the multiple pulled-out tubular bodies, a protector function that covers the needle tip 24, and a function of releasing the blocking of movement of the connecting member 94 as the inner needle 12 is pulled out, but if a locking mechanism that blocks movement in the contraction direction in the multiple pulled-out tubular bodies is adopted or a separate member that blocks the tip of the tubular body is provided on the base end side of the protector 52, it is also possible to provide only the function of releasing the blocking of movement of the connecting member 94 as the inner needle 12 is pulled out (no protector function).

[0098] Furthermore, in the above embodiment, the inner needle hub 14 is formed by inserting multiple tubular bodies (first, second, and third tubular bodies 60, 62, 64) inside and outside each other, but it may be formed by a single tubular body having a length approximately equal to the overall length of the inner needle, such as a tubular body with a bellows structure, and it is not limited to the full cover type as in the embodiment, but a partial cover type tubular body that covers only a part of the inner needle may also be adopted, and a protector may be stored in the tubular body and a connecting member may be attached to it.

[0099] In the above embodiment, when the inner needle 12 is inserted through the protector 52, the elastic arms 56, 56 directly contact the inner needle 12. However, a sleeve may be inserted around the inner needle so that the elastic arms come into contact with the sleeve, thereby preventing elastic deformation of the elastic arms. In this case, for example, the inner needle may be provided with a large-diameter portion that engages with the sleeve, and the sleeve may move toward the base end as the inner needle is withdrawn, thereby releasing the contact with the elastic arms. This can reduce the sliding resistance when the inner needle is withdrawn. However, the present invention is not limited to such a sleeve, and a mechanism may be adopted in which a member that moves in conjunction with the withdrawal of the inner needle and a mechanism that allows the blocking member to move or deform by the interlocking member may be adopted. Also, the member that moves in conjunction with the withdrawal of the inner needle and the member that allows the blocking member to move or deform by displacement may be separate members, and the latter may be displaced by the former. Furthermore, when a sleeve or the like is provided, the number of interlocking parts in the pulling-out direction increases, which can result in disadvantages such as making it difficult to achieve stable behavior, making the configuration more complicated, and requiring a larger protective housing, which can result in reduced operability for the practitioner.

[0100] In addition, in the above embodiment, a protector 52 was used that protects the needle tip by elastic deformation as the inner needle 12 is pulled out. However, it is also possible to use a protector that utilizes magnetic force to allow displacement as the inner needle is pulled out, as described in, for example, WO (International Publication) No. WO 2013 / 027355.

[0101] In addition, in the above embodiment, the blocking member that is provided between the inner needle 12 and the connecting member 94 and prevents the movement of the connecting member 94 to hold the storage housing 14 and the outer needle hub 20 in a connected state is constituted by the protector 52 that protects the needle tip 24 of the inner needle 12, but it is also possible to constitute such a blocking member by a member separate from the protector for needle tip protection. Specifically, for example, in the above embodiment, by disposing a needle tip protector that protects the needle tip by being displaced by a magnetic force as the inner needle is withdrawn as described in the above WO2013 / 027355 and the like on the base end side of the large diameter cylindrical portion 84 of the third cylindrical body 64 that constitutes the storage housing, it is also possible to provide a blocking member that exerts the function of holding and releasing the connected state by the connecting member 94 separately from the needle tip protector.

[0102] Furthermore, the blocking member is not limited to one that releases the connected state by the connecting member 94 by elastic deformation accompanying the withdrawal of the inner needle as illustrated. For example, similar to the above-mentioned needle tip protector, it is possible to employ one that releases the connected state by the connecting member by being displaced by magnetic force accompanying the withdrawal of the inner needle, one that releases the connected state by the connecting member by being displaced using a separately provided spring accompanying the withdrawal of the inner needle, or one that releases the connected state by the connecting member by being displaced using gravity due to its own weight accompanying the withdrawal of the inner needle.

[0103] In addition, in the above embodiment, a connecting member 94 that is directly engaged with the outer needle hub 20 is used, but any member that can connect the storage housing provided on the inner needle unit side to the outer needle unit may be used. For example, in the case where a separate member that can be attached and detached to the outer needle hub is attached, if the separate member is not detached from the outer needle hub until the inner needle hub is pulled out, it is considered that the outer needle unit includes the separate member, or that the separate member is connected to the outer needle hub via the separate member. For example, a member for covering the base end of the outer needle hub to prevent exposure before connection with the inner needle hub, a hemostatic member, or the like may be connected to the outer needle hub to form an outer needle hub unit. For example, the outer needle hub may be constructed by fixing a plurality of cylindrical members. Therefore, the connecting member in the present invention may be one that is engaged with a member separate from such an outer needle hub. In addition, in the above embodiment, the connecting member was a member that engages with the outer surface of the outer needle hub, but it may be a member that engages with the inner surface of the outer needle hub. For example, connection with the outer needle hub 20 may be achieved by forming notches in two circumferential locations that open at the tip of the insertion part 112 and extend in the axial direction, forming an arm as a connecting member that is movable in the direction perpendicular to the axis of the inner needle 12 by flexural deformation between the circumferential directions of the notches, and positioning the protector 122 inside the arm. Also, for example, an annular recess or protrusion may be formed on the inner surface of the pusher 40, and the protector 122 may be engaged with the inner surface of the pusher 40, thereby giving the protector 122 itself a function of connecting with the outer needle hub 20. In any of these cases, the deformation or displacement of the protector accompanying the withdrawal of the inner needle allows the movement of the arm or protector that constitutes the connecting member, and the connection state of the storage housing to the outer needle hub is released. Furthermore, the present invention originally includes each of the inventions described in (i) to (ii) below, and the configurations thereof will be described below. The present invention relates to (i) An indwelling needle assembly comprising a retractable inner needle and a protective housing in which the pulled-out inner needle is housed, and a displacement member which displaces as the inner needle is pulled out is housed in a tip portion of the protective housing, the protective housing has a multiple-tube structure consisting of a plurality of tubular bodies, the plurality of tubular bodies are inserted inside and outside the protective housing at a position offset toward the base end from the attachment position of the displacement member, the plurality of tubular bodies are pulled out one after another as the inner needle is pulled out and the inner needle is housed in the protective housing, a connecting member which is connected to an outer needle hub is attached to the tip portion of the protective housing in which the displacement member is housed, and the tubular body which is located furthest from the base end of the plurality of pulled-out tubular bodies and which is located furthest from the outer periphery in the initial state in which insertion is possible has a notch provided in a part of the circumferential direction into which the connecting member is inserted; (ii) An indwelling needle assembly having an inner needle that is inserted removably through an outer needle, the indwelling needle assembly further comprising a protective housing in which the pulled-out inner needle is housed, the protective housing having a multi-cylinder structure with a plurality of tubular bodies inserted therein and outwardly, the plurality of tubular bodies being successively pulled out as the inner needle is pulled out, and the tubular body that is located at the most proximal end of the pulled-out tubular bodies and that is located at the most outer periphery in the initial state in which it is capable of being punctured and is held to have a tubular part to which the proximal end of the inner needle is fixed and a through hole is provided at the proximal end of the tubular body; This includes inventions relating to. [Explanation of symbols]

[0104] 10,120: indwelling needle assembly, 12: inner needle, 14: inner needle hub (storage housing, protective housing), 16: inner needle unit, 18: outer needle, 20: outer needle hub, 22: outer needle unit, 24: needle tip, 26: peripheral wall, 28: rivet pin, 30: base end opening, 32: flange-shaped portion, 34: positioning groove, 36: hemostasis valve mechanism, 38: disk valve, 40: plunger, 42: plunger guide, 44: slit, 46: fixed tube portion, 48: storage tube portion, 50: ventilation filter, 52,122: protector (blocking member), 54: rear wall portion, 56,124: elastic arm portion, 58: flat plate portion, 60: first tube portion, 62: second tube portion, 6 4: third tubular body, 66: rectangular tubular portion, 68: cylindrical portion, 70: base end wall portion, 72: inner hole, 74: notch, 76: first engagement claw, 78: through hole, 80: second base end side engagement claw, 82: second tip end side engagement claw, 84: large diameter tubular portion, 86: annular wall portion, 88: small diameter tubular portion, 90: third engagement claw, 92: insertion hole, 94: connecting member, 96: insertion portion, 98: connecting portion, 100: communication hole, 102: removal prevention protrusion, 104: locking portion, 106: tip end surface, 108: base end surface, 110: positioning protrusion, 112: insertion portion, 126: needle tip protection portion, 128: sliding portion, 130: guide portion, 132: support portion, 134: needle insertion portion, 136: guide hole

Claims

[Claim 1] The needle is provided with a removable inner needle and a protective housing for accommodating the removable inner needle, a displacement member that is displaced as the inner needle is pulled out is accommodated in a tip portion of the protective housing, the protective housing has a multiple cylinder structure including a plurality of cylindrical bodies, and the plurality of cylindrical bodies are inserted inside and outside the protective housing at positions that are offset toward the base end side from a mounting position of the displacement member, When the inner needle is pulled out, the plurality of tubular bodies are successively pulled out and the inner needle is housed in the protective housing, a large-diameter cylindrical portion in which the displacement member is housed is provided at a tip end portion of a cylindrical body located at the tip end side among the plurality of pulled-out cylindrical bodies, The large diameter tubular portion is directly covered by the tubular body which is located at the most base end side among the multiple pulled out tubular bodies and which is located at the most outer periphery and is grasped in an initial state in which insertion is possible.

Images