WO2013027355A1

WO2013027355A1 - Indwelling needle assembly

Info

Publication number: WO2013027355A1
Application number: PCT/JP2012/005053
Authority: WO
Inventors: 健志山口
Original assignee: 二プロ株式会社
Priority date: 2011-08-23
Filing date: 2012-08-08
Publication date: 2013-02-28
Also published as: JP5880983B2; JPWO2013027355A1

Abstract

Provided is an indwelling needle assembly that has a novel structure, is able to stably achieve protection of a needle tip by means of a needle tip protector, and reliably performs adhesion to the magnet of an occlusion member without an accompanying enlargement of the magnet, an outer needle unit, or an inner needle unit, even if the inner needle has a large gauge. The indwelling needle assembly (10) results from being provided with an outer needle unit (14) and an inner needle unit (12) having a needle tip protector (22), and in the needle tip protector (22), sandwiching a distal aperture (52), a first magnet (54) of which the magnetic poles are aligned in a perpendicular-axis direction perpendicular to the direction of the needle shaft is disposed in an affixed manner at one side in the perpendicular-axis direction, while an occlusion member (56) that can occlude the distal aperture (52) by being able to be drawn towards the first magnet (54) is disposed at the other side in the perpendicular-axis direction and in a manner so as to be able to move to the side of the first magnet (54). Furthermore, a second magnet (90) is disposed in the outer needle cap (28) of the outer needle unit (14), the magnetic poles of the second magnet (90) are aligned similarly to the first magnet (54) in the perpendicular-axis direction, and the second magnet (90) is provided to the outside of the first magnet (54) in the perpendicular-axis direction.

Description

Indwelling needle assembly

The present invention relates to an indwelling needle assembly that is punctured and placed in a blood vessel when performing infusion, blood collection, hemodialysis, and the like, and in particular, includes a needle tip protector that protects the needle tip of an inner needle after use. The present invention relates to an indwelling needle assembly.

Conventionally, an indwelling needle assembly in which an outer needle of an outer needle unit is passed through and an inner needle of an inner needle unit is assembled is known. When performing infusion, blood collection, hemodialysis, etc., the indwelling needle assembly punctures a patient's blood vessel, and then removes the inner needle unit including the inner needle from the outer needle unit including the outer needle, thereby removing the outer needle from the patient. It is used for treatment by placing it in the blood vessel.

By the way, the inner needle of the inner needle unit removed from the outer needle unit after puncturing the patient's blood vessel has a sharp needle tip at its distal end, and this needle tip is a doctor, nurse, or waste disposal company. There is a risk that an accidental puncture accident may occur. Such an erroneous puncture accident may cause infection such as AIDS or virus from blood or the like adhering to the needle tip, and it is important to prevent it beforehand.

Therefore, an indwelling needle assembly including a protector has been proposed in which when the inner needle is pulled out from the outer needle, a slide-type cover provided in the inner needle unit is extended to accommodate the entire inner needle. For example, the one described in Japanese Patent No. 3400550 (Patent Document 1) and Japanese Patent Laid-Open No. 7-148270 (Patent Document 2). In Japanese Patent Laid-Open No. 2002-102345 (Patent Document 3), a spring-type needle tip protector is disposed in the outer needle unit, and the needle tip protector is detached from the outer needle unit by pulling out the inner needle. It has been proposed to cover the needle tip.

However, in the indwelling needle assembly provided with the protector having such a conventional structure, since the protector is structured to cover the entire inner needle, there is a problem that the indwelling needle assembly itself cannot be increased in size. . Further, in the case of a spring-type needle tip protector, there is a problem that a biasing force of the spring is applied when the inner needle is pulled out, and a large force is required when the inner needle is pulled out. In addition, the tip of the inner needle may re-project from the protector.

On the other hand, the applicant of the present application, in Japanese Patent No. 4661240 (Patent Document 4), includes a needle tip protector that can accommodate only a needle tip that is slidably attached to the inner needle, and is proximal to the needle tip protector. While the end is not removable from the inner needle, the distal end opening of the needle tip protector is positioned against the magnet when the needle tip of the inner needle is housed in the needle tip protector from the opening. A structure has been proposed in which a cover member made of a magnetic material or magnet is adsorbed to close the distal opening of the needle tip protector. According to such a structure, since the needle tip is protected by the small needle tip protector that accommodates only the needle tip, an increase in the size of the indwelling needle assembly can be avoided. Further, since the biasing force of the spring is not exerted when the inner needle is pulled out, it is possible to avoid an increase in the pulling force of the inner needle. Furthermore, since the distal side opening of the needle tip protector is closed by the closing member attracted by the magnetic force, the closing member can be stably held in the closed position, and the opening is surely opened again. It was a breakthrough that could be prevented. Further, the applicant of the present application can realize highly reliable protection of the needle tip without causing an increase in the size of the magnet or the like even when the inner needle has a large diameter in the indwelling needle assembly having the previously proposed structure. We have been studying further improved structures.

Japanese Patent No. 3400550 JP 7-148270 A JP 2002-102345 A Japanese Patent No. 4661240

The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that, even when the inner needle has a large diameter, without enlarging the magnet, the outer needle unit, and the inner needle unit, It is an object of the present invention to provide an indwelling needle assembly having a novel structure capable of reliably adsorbing a closing member to a magnet and stably realizing protection of the needle tip by a needle tip protector.

That is, the first aspect of the present invention includes an inner needle having a needle tip at a distal end, an inner needle hub attached to the proximal end of the inner needle, and movement in the needle axis direction with respect to the inner needle. An inner needle unit having a needle tip protector attached thereto, an outer needle through which the inner needle can be inserted, an outer needle hub attached to the proximal end of the outer needle and through which the inner needle can be inserted; An outer needle unit that is detachably attached to the proximal end of the outer needle hub and through which the inner needle can be inserted and has an outer needle cap that covers the proximal end of the outer needle hub. A needle is inserted into the outer needle cap and the outer needle hub and accommodated in the outer needle, and the inner needle unit is brought into contact with the outer needle cap by contacting the inner needle unit with the outer needle cap. In the indwelling needle assembly in which the needle units are assembled to each other, the inner needle unit The needle tip protector includes a cylindrical portion through which the inner needle is inserted, and a distal side opening through which the inner needle is inserted is formed on the distal side of the cylindrical portion. A first magnet having magnetic poles arranged in a direction perpendicular to the axis is fixedly disposed on one side of the direction perpendicular to the axis of the needle across the distal opening. A closing member that can be attracted to the first magnet and can close the distal opening is disposed on the other side in the straight direction so as to be movable toward the first magnet, and the cylindrical portion. A proximal opening through which the inner needle is inserted is formed on the proximal side of the inner needle, and the needle tip of the inner needle is assembled so as not to come out of the proximal opening. A second magnet is disposed on the outer needle cap of the outer needle unit, and in an assembled state of the outer needle unit and the inner needle unit, The magnetic poles of the second magnet are arranged in the axial direction in the same manner as the first magnet, and the second magnet is arranged on the outer side of the first magnet in the axial direction. The indwelling needle assembly is characterized in that the needle tip protector is detachably attracted to the outer needle cap by the attractive force of the first magnet and the second magnet.

According to this aspect, when the inner needle unit is pulled out from the outer needle unit, the needle tip protector adsorbed to the outer needle cap as the inner needle moves in the pulling direction is moved distally in the needle axis direction. The inner needle is detached from the distal opening of the cylindrical portion, and the closing member is attracted by the first and second magnets to close the distal opening. The Further, the inner needle unit is in a state where the needle tip is housed inside the cylindrical portion of the needle tip protector by preventing the needle tip of the inner needle from coming out of the proximal opening. It is designed to be removed from the outer needle unit.

As a result, the state in which the needle tip of the inner needle of the inner needle unit detached from the outer needle unit is held in the needle tip protector is maintained, so that the used needle tip can be used by doctors, nurses, disposal companies, etc. It is possible to prevent erroneous puncture.

In particular, since the magnetic pole of the first magnet provided in the needle tip protector is directed so as to directly face the closing member in the axial direction across the inner needle (distal opening), the first magnet The magnetic force can be efficiently applied to the closing member, and the closing member can be reliably sucked when the inner needle is detached from the distal opening. For example, in the case of an indwelling needle assembly used for artificial dialysis treatment, etc., the diameter of the inner needle (distal opening) is increased, the occlusion member is enlarged and the separation distance from the first magnet is increased. There is a concern that it may be difficult to stably suck the blocking member. However, according to this aspect, the magnetic pole of the first magnet is directed so as to directly face the closing member in the direction perpendicular to the axis across the inner needle (distal opening). It is possible to stably perform attraction by the first magnet of the closing member even when the is large.

Further, the second magnet provided on the outer needle cap is arranged so that the magnetic poles are arranged in the direction perpendicular to the axis in the same direction as the first magnet and located outside the first magnet. It is possible to stably attract the needle tip protector to the outer needle cap by effectively applying the attractive force of the two magnets to each other.

In particular, the magnetic poles of the first magnet and the second magnet are similarly arranged in the direction perpendicular to the axis, and the two magnets are arranged so as to overlap each other in the direction perpendicular to the axis. Thus, it is possible to suck the closing member with a larger force while avoiding an increase in the number of parts and an increase in the size of the member.

According to a second aspect of the present invention, in the indwelling needle assembly according to the first aspect, the outer needle cap is provided with a fitting recess having a non-circular cross section that opens to the proximal end side. While the second magnet is disposed on the peripheral wall portion of the fitting recess, the distal end of the cylindrical portion of the needle tip protector projects with the same non-circular cross section as the fitting recess. A fitting convex portion having an outer shape slightly smaller than the fitting concave portion is provided, and the outer needle cap and the needle tip protector are connected to the inner needle by fitting the fitting concave portion and the fitting convex portion. And the first magnet and the second magnet are arranged to face each other in the direction perpendicular to the axis.

According to this aspect, by providing the fitting concave portion and the fitting convex portion with the noncircular cross section, the needle tip protector can be easily and reliably positioned with respect to the outer needle cap, and the fitting concave portion with the noncircular cross section is fitted. By simply disposing the first and second magnets on the peripheral wall portion of the joint convex portion, the magnets can be positioned easily and reliably.

A third aspect of the present invention is the indwelling needle assembly according to the first or second aspect, wherein the closing member is made of a magnetic material.

According to this aspect, unlike the case where the closing member is a magnet, the closing member does not need to be arranged with the same polarity, so that the closing member can be easily and reliably assembled.

According to a fourth aspect of the present invention, in the indwelling needle assembly according to any one of the first to third aspects, the blocking member has a disk shape, and covers the distal opening. It has an outer diameter to obtain.

According to this aspect, since there is no corner portion over the entire circumference of the closing member and the movement resistance at the closing time can be further reduced, the closing member can be reliably and stably closed. Further, since the movement resistance is small, the closing member can be adsorbed with a weaker magnetic force. Therefore, even when the inner needle has a large diameter, that is, when the closing member that closes the distal side opening has a large diameter, it is possible to realize reliable protection of the needle tip without increasing the size of the magnet or the like. is there. In addition, since it is difficult to accurately control the polarity on the circumference of the closing member, it is desirable that the disk-shaped closing member is not a magnet but a magnetic body.

In the indwelling needle assembly of the present invention, the magnetic pole of the first magnet provided on the needle tip protector is directed so as to directly face the closing member across the inner needle, and the first magnet provided on the outer needle cap. Since the two magnets are arranged so that the magnetic poles are arranged in the direction perpendicular to the axis in the same manner as the first magnet and are superimposed on the outside of the first magnet, Thus, it is possible to suck the closing member with a larger force while avoiding an increase in the number of parts and an increase in the size of the member.

The longitudinal cross-sectional view which shows the state before use of the indwelling needle assembly as a 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the state after extraction of the inner needle unit of the indwelling needle assembly shown in FIG. Explanatory drawing which shows the process at the time of use of the indwelling needle assembly shown to FIG. 1 and FIG. FIG. 2 is an enlarged longitudinal sectional view of a needle tip protector portion of the indwelling needle assembly shown in FIG. 1. FIG. 5 is an enlarged cross-sectional view of the closing member portion of the indwelling needle assembly shown in FIG. 1, corresponding to the VV cross section of FIG.

Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the medical staff side at the time of operation of the indwelling needle assembly is expressed as the proximal side, and the patient side is expressed as the distal side.

First, FIGS. 1 and 2 are longitudinal sectional views of an indwelling needle assembly 10 having a structure according to the present invention. As shown in FIGS. 1 and 2, the indwelling needle assembly 10 includes an inner needle unit 12 and an outer needle unit 14. The inner needle unit 12 has an inner needle 18 having a sharp needle tip 16 at a distal end, an inner needle hub 20 attached to the proximal end of the inner needle 18, and moves in the needle axial direction with respect to the inner needle 18. A needle tip protector 22 is provided that can be mounted. On the other hand, the outer needle unit 14 includes an outer needle 24 through which the inner needle 18 can be inserted, an outer needle hub 26 that is attached to the proximal end of the outer needle 24 and through which the inner needle 18 can be inserted, and a proximity of the outer needle hub 26. An outer needle cap 28 that covers the proximal end of the outer needle hub 26 and covers the inner needle 18 is detachably attached to the distal end. The inner needle 18 is inserted into the outer needle cap 28 and the outer needle hub 26 and accommodated in the outer needle 24, and the inner needle unit 12 is brought into contact with the outer needle cap 28, whereby the inner needle unit 12 is contacted. 12 and the outer needle unit 14 are assembled together to form the indwelling needle assembly 10.

In the inner needle unit 12, the inner needle 18 is a hollow needle and is formed of a known material such as stainless steel, aluminum, titanium, or an alloy thereof. The needle tip 16 provided at the distal end of the inner needle 18 has a tapered shape whose outer diameter gradually decreases toward the tip, and can puncture a living body easily and with low stimulation. On the other hand, the inner needle hub 20 attached to the proximal end of the inner needle 18 includes a substantially cylindrical pedestal portion 30 in which the proximal end of the inner needle 18 is fixed in an embedded state, and a distal end of the pedestal portion 30. The substantially cylindrical protector accommodating portion 32 that protrudes and the substantially cylindrical cap coupling portion 34 that protrudes from the proximal end of the pedestal portion 30 are integrally formed of synthetic resin. The proximal end of the inner needle 18 is exposed at the proximal end surface of the pedestal portion 30, and the lumen 96 of the inner needle 18 communicates with the internal space of the cap connecting portion 34.

Furthermore, an inner needle cap 36 is removably assembled to the opening of the cap connecting portion 34. The inner needle cap 36 is a stepped cylindrical synthetic resin member provided with a step portion at an axially intermediate portion. The opening on the small diameter side of the inner needle cap 36 is covered with a gas tight filter 38 in a liquid-tight manner. That is, the ventilation filter 38 has a property of allowing gas to pass through but blocking liquid. A syringe or the like can be connected to the large-diameter side opening of the inner needle cap 36. And the opening part of the cap connection part 34 is liquid-tightly covered by assembling | attaching the small diameter side edge part of the inner needle cap 36 with respect to the opening part of the cap connection part 34 in close contact.

The needle tip protector 22 of the inner needle unit 12 is composed of a stepped cylindrical synthetic resin member provided with a step portion at an axially intermediate portion, and includes a cylindrical portion 40 through which the inner needle 18 is inserted. ing. The large-diameter side end which is the distal side of the tubular part 40 is provided with a fitting convex part 42 which protrudes in a substantially rounded non-circular cross section as shown in FIG. A recess 44 is formed in the fitting convex portion 42, and the opening of the concave portion 44 is covered with a lid member 46, whereby a magnet housing space 48 is formed in the fitting convex portion 42. Yes.

Distal openings

52a and 52b through which the inner needle 18 is inserted are respectively penetrated through the bottom plate 50 and the lid member 46 of the recess 44. In the magnet housing space 48, a first magnet 54 in which magnetic poles are arranged in the axial direction on one side of the axial direction orthogonal to the needle axis direction across the

distal openings

52a and 52b. A thin, substantially disk-shaped closing member 56 that is fixedly disposed and can be attracted to the first magnet 54 on the other side in the axial direction and can close the distal opening 52 is first. It is movably disposed on the magnet 54 side. In the present embodiment, the N pole is set on the inner surface of the first magnet 54 in the direction perpendicular to the axis, and the S pole is set on the outer surface. Furthermore, a wall 58 that extends in the needle axis direction is provided at the small-diameter opening that is the proximal side of the tubular portion 40, and the proximal opening through which the inner needle 18 is inserted into the wall 58. The part 60 is penetrated.

With respect to such a needle tip protector 22, the inner needle 18 is inserted through the proximal opening 60, the tubular portion 40, and the

distal openings

52 a and 52 b in this order, so that the needle with respect to the inner needle 18 is inserted. The tip protector 22 is mounted so as to be movable in the needle axis direction. In the assembled state of the inner needle unit 12 and the outer needle unit 14 shown in FIG. 1, the needle tip protector 22 is accommodated and disposed in the protector accommodating portion 32 provided in the inner needle hub 20. In the state where the inner needle unit 12 shown in FIG. 2 is pulled out from the outer needle unit 14, the needle tip protector 22 is moved to a position where the needle tip 16 of the inner needle 18 is accommodated in the cylindrical portion 40. . As will be described later, the needle tip 16 of the inner needle 18 cannot be removed from the proximal opening 60 of the needle tip protector 22.

Next, in the outer needle unit 14, the outer needle 24 has a hollow needle shape, and preferably has an appropriate flexibility. For example, it can be composed of various soft resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane, polyether nylon resin, and polypropylene. For the same reason as the needle tip 16 of the inner needle 18, the distal end 62 of the outer needle 24 is also tapered so that the outer diameter gradually decreases toward the tip. It should be noted that the distal end 62 of the outer needle 24 may be provided with one or more through holes as required so that fluid can be efficiently distributed to the outer needle 24.

An outer needle hub 26 having a substantially cylindrical shape is fixed to the proximal end of the outer needle 24 in a liquid-tight manner, and the lumen 98 of the outer needle 24 and the inside of the outer needle hub 26 are communicated with each other. In the outer needle hub 26, a synthetic resin outer needle connector 68 having a substantially cylindrical shape is liquid-tightly fixed to a synthetic resin cylindrical body 64 provided on the distal side via an elastic tube 66. It is set as the structure. A female luer taper 70 that allows connection to other medical devices is formed on the inner peripheral surface of the outer needle connector 68. On the outer periphery near the proximal end of the outer needle connector 68, a male screw 72 is provided to ensure connection with other medical devices. The outer needle connector 68 is not provided, and it is possible to connect to other medical devices using the flexibility of the elastic tube 66.

The outer needle cap 28 is attached to the proximal end of the outer needle connector 68 of the outer needle hub 26. The outer needle cap 28 has a structure in which elastic packings 76a and 76b are disposed inside a cylindrical member 74 made of synthetic resin. On the distal side of the cylindrical member 74, a tubular protrusion 78 is provided that is fluid-tightly connected to the female luer taper 70 of the outer needle connector 68. Further, a guide wall portion 80 is provided so as to surround the tubular protrusion 78, and a female screw 82 into which the male screw 72 of the outer needle connector 68 is screwed is formed inside the guide wall portion 80. The opening on the proximal end side of the tubular projection 78 is covered with an elastic packing 76 in a liquid-tight manner.

The elastic packings 76a and 76b are respectively provided with

slits

84a and 84b at the center portions, and the inner needle 18 can be passed through the

slits

84a and 84b. In addition, after the inner needle 18 is pulled out from the outer needle cap 28, the opening of the tubular protrusion 78 is closed by the elastic packing 76, and the liquid can be prevented from flowing out from the proximal end of the outer needle unit 14. In this way, the male thread 72 of the outer needle connector 68 is screwed to the female thread 82 of the guide wall 80 of the outer needle cap 28 while the tubular protrusion 78 of the outer needle cap 28 is connected to the female luer taper 70 of the outer needle connector 68. Thus, the proximal end side opening of the outer needle connector 68 is covered with the outer needle cap 28 in a liquid-tight manner.

Furthermore, a fitting recess 86 is formed in the proximal end side of the cylindrical member 74 of the outer needle cap 28. As shown in FIGS. 5A and 5B, which will be described later, the fitting recess 86 has a substantially non-circular cross-sectional shape that is the same as the fitting protrusion 42 of the needle tip protector 22. A second magnet 90 is fixedly disposed on the peripheral wall 88 that defines the planar inner peripheral surface of the fitting recess 86. Here, in the assembled state of the outer needle unit 14 and the inner needle unit 12 shown in FIG. 1, the second magnet 90 has the magnetic poles of the second magnet 90 arranged in the straight axis direction in the same manner as the first magnet 54. The second magnet 90 is disposed on the outer side of the first magnet 54 in the axial direction. As a result, the fitting convex portion 42 of the needle tip protector 22 is fitted to the fitting concave portion 86 of the outer needle cap 28, and the needle tip protector 22 is removed by the attractive force of the first magnet 54 and the second magnet 90. The needle cap 28 is detachably adsorbed.

Next, the steps when using the indwelling needle assembly in the present embodiment will be described with reference to FIGS. FIGS. 3 (a), 4 (a), and 5 (a) show the situation before using the indwelling needle assembly, which is equivalent to FIG. Then, after puncturing the needle tip 16 and the outer needle 24 of the inner needle 18 into the body, the inner needle unit 12 is relatively pulled out from the outer needle unit 14 as shown in FIG. When pulling out the inner needle unit 12 from the outer needle unit 14, the needle tip protector 22 is attracted to the outer needle cap 28 by the attractive force of the first magnet 54 and the second magnet 90, so that the inner needle 18 is pulled out. As the needle moves, the needle tip protector 22 adsorbed to the outer needle cap 28 moves to the distal side moving end in the needle axis direction. When the inner needle 18 is detached from the distal opening 52 of the tubular portion 40, the closing member 56 is attracted by the first and

second magnets

54 and 90 to close the distal opening 52 (see FIG. 3 (c) FIG. 4 (b) and FIG. 5 (b)). Further, the needle tip 16 of the inner needle 18 is prevented from coming out of the proximal opening 60, so that the needle tip 16 of the inner needle 18 is accommodated inside the needle tip protector 22, and the inner needle unit 12 is disengaged from the outer needle unit 14 (states shown in FIGS. 3D, 4C, and 5C). As a result, the inner needle unit 12 and the outer needle unit 14 are separated, and the inner needle unit 12 can be safely discarded in a state where the needle tip 16 of the inner needle 18 is accommodated in the needle tip protector 22. .

Here, a mechanism for preventing the inner needle 18 from coming out of the proximal end opening 60 of the needle tip 16 will be described in detail. As shown in FIG. 4, the inner needle 18 has a protruding portion 92 at a location moved proximally from the needle tip 16 by a predetermined distance. The protrusion 92 has an outer diameter dimension in the needle axis direction that is larger than an inner diameter dimension of the proximal opening 60 of the needle tip protector 22 and smaller than an inner diameter dimension of the

distal openings

52a and 52b. . As a result, the needle tip 16 of the inner needle 18 can be accommodated inside the tubular portion 40 of the needle tip protector 22 through the

distal openings

52b and 52a of the needle tip protector 22, while the needle tip protector. 22 cannot pass through the proximal opening 60 of the needle 22 so that the needle tip 16 is prevented from coming out of the needle tip protector 22. As shown in FIG. 4C, the formation portion of the protrusion 92 in the inner needle 18 is formed when the protrusion 92 contacts the peripheral edge of the proximal opening 60 of the needle tip protector 22. Is set to be completely accommodated inside the cylindrical portion 40. Further, it is desirable to dispose a metal ring 94 having an inner diameter that is slightly larger than the outer diameter of the inner needle 18 and through which the protrusion 92 cannot be inserted, on the proximal side of the protrusion 92 of the inner needle 18. Thereby, the inner needle 18 can be further prevented from coming out of the proximal opening 60 of the needle tip protector 22. In FIG. 3, the protrusion 92 and the metal ring 94 are not shown for the purpose of clarifying the drawing.

Such a protrusion 92 is, for example, with respect to a predetermined position of the inner needle 18 inserted through the proximal opening 60, the tubular portion 40, and the

distal openings

52a and 52b of the needle tip protector 22 in this order. It can be provided by crushing or the like. Alternatively, the protrusion 92 can be provided by pressing a separate elastic ring at a predetermined position of the inner needle 18.
Furthermore, a liquid absorber (not shown) that absorbs blood, body fluid, and the like may be provided in the internal space of the tubular portion 40 of the needle tip protector 22. Examples of the material of the liquid absorber include sponge, polyurethane, rubber-like elastic member, and the like.

In the indwelling needle assembly 10 of this embodiment having such a structure, as shown in an enlarged view in FIG. 4, the magnetic pole of the first magnet 54 provided on the cylindrical portion 40 of the needle tip protector 22 is In the direction perpendicular to the needle axis direction across the inner needle 18, it is directed so as to directly face the closing member 56. Therefore, since the magnetic force of the first magnet 54 can be efficiently applied to the closing member 56, the diameter of the inner needle 18 is increased as in the indwelling needle assembly 10 used for, for example, artificial dialysis treatment, and the closing member 56 is Even when the distance between the first magnet 54 and the closing member 56 increases as the size increases, the closing member 56 is reliably sucked when the inner needle 18 is detached from the distal opening 52, and the inner needle 18 is Re-protrusion from the distal opening 52 of the needle tip protector 22 can be reliably prevented. Further, the second magnet 90 provided on the outer needle cap 28 is arranged so that the magnetic poles are arranged in the direction perpendicular to the axis in the same direction as the first magnet 54 and located outside the first magnet 54. The suction force of the one magnet 54 and the second magnet 90 can be effectively applied to each other, and the needle tip protector 22 can be reliably attracted to the outer needle cap 28. Furthermore, since the magnetic poles of the first magnet 54 and the second magnet 90 are similarly arranged in the direction perpendicular to the axis and the

magnets

54 and 90 are arranged so as to overlap each other in the direction perpendicular to the axis, the necessary arrangement of the magnets can be changed. By devising well, the closing member 56 can be attracted with a larger magnetic force while avoiding an increase in the number of parts and an increase in the size of the magnet of the member.

For example, the material of the magnet used for the closing member 56, the first magnet 54, and the second magnet 90 is not particularly limited, and examples include a Samakova magnet, an Alnico magnet, a neodymium magnet, and a ferrite magnet. The closing member 56 is preferably made of a magnetic material because of the ease of positioning with respect to the first magnet 54 and the second magnet 90. The material of the magnetic material used for the closing member 56 is not particularly limited as long as the magnet can adsorb, but a magnetic material such as stainless steel having good rust resistance is preferable. Further, the shape of the closing member 56 is not particularly limited as long as it is a shape that can close the distal side opening 52 of the tubular portion 40 of the needle tip protector 22 after the inner needle 18 is removed. Thus, a thin disk shape is preferable. Since the circular closure member 56 has no corners on the outer peripheral surface, it can be smoothly moved by being prevented from being caught on the inner surface of the magnet housing space 48 when attracted to the first magnet 54. It is.

Further, as shown in FIG. 5, the fitting concave portion 86 of the outer needle cap 28 has a substantially semicircular non-circular cross section, while the fitting convex portion 42 of the needle tip protector 22 is the same as the fitting concave portion 86. And has an outer shape slightly smaller than the fitting recess 86. Thereby, the outer needle cap 28 and the needle tip protector 22 are highly positioned around the needle axis of the inner needle 18 only by fitting the fitting concave portion 86 and the fitting convex portion 42. Therefore, the first magnet 54 and the second magnet 90 can be reliably arranged to face each other in the axial direction, and a desired attraction force by the first magnet 54 and the second magnet 90 can be obtained with certainty.

In particular, in the fitting recess 86 of the outer needle cap 28, a space for accommodating the second magnet 90 is ensured by skillfully utilizing the thick peripheral wall portion 88 to define the planar inner peripheral surface. Yes. Accordingly, the first magnet 54 and the second magnet 90 can be arranged opposite to each other in the axial direction without increasing the overall size of the indwelling needle assembly, and a large magnetic force can be exerted on the closing member 56. is there.

As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the first magnet and the second magnet need only be arranged opposite to each other so that the magnetic poles are similarly arranged in the direction perpendicular to the needle axis, and the arrangement of the N pole and the S pole is opposite to that of the embodiment. Needless to say, the same effects can be obtained even if they are arranged.

The fitting concave portion 86 of the outer needle cap 28 and the fitting convex portion 42 of the needle tip protector 22 are not limited to specific shapes as long as they are configured with a non-circular cross section that can be easily positioned in the circumferential direction. For example, in addition to the substantially semi-cylindrical cross-sectional shape of the embodiment, a rectangular cross-section, a polygonal cross-section, or the like may be used.

Further, an uneven engagement portion may be provided between the overlapping surfaces of the fitting concave portion 86 of the outer needle cap 28 and the fitting convex portion 42 of the needle tip protector 22 so as to further improve the positioning accuracy.

Further, on the proximal end side of the closing member 56, the distal opening 52 of the cylindrical portion 40 of the needle tip protector 22 is closed to fill the inner space of the cylindrical portion 40 of the needle tip protector 22 with the needle of the inner needle 18. When the tip 16 is stored, a conical recess may be formed in a portion where the needle tip 16 can come into contact. When the inner needle 18 is displaced in the needle tip protector 22 due to the recess, the needle tip 16 pushes the blocking member 56 that closes the distal opening 52 of the tubular portion 40 of the needle tip protector 22 and moves distally. Protruding from the side opening 52 or protruding from a place other than the distal opening 52 can be prevented.

10: Indwelling needle assembly, 12: Inner needle unit, 14: Outer needle unit, 16: Needle tip, 18: Inner needle, 20: Inner needle hub, 22: Needle tip protector, 24: Outer needle, 26: Outer needle Hub: 28: outer needle cap, 40: cylindrical portion, 42: fitting convex portion, 52: distal opening, 54: first magnet, 56: occlusion member, 60: proximal opening, 86: Fitting recess, 88: peripheral wall, 90: second magnet

Claims

An inner needle having a needle tip at a distal end, an inner needle hub attached to the proximal end of the inner needle, and a needle tip protector attached to the inner needle so as to be movable in the needle axis direction An inner needle unit,
An outer needle through which the inner needle can be inserted, an outer needle hub attached to the proximal end of the outer needle and through which the inner needle can be inserted, and a detachably attached to the proximal end of the outer needle hub An outer needle unit having an outer needle cap through which an inner needle can be inserted and covering a proximal end of the outer needle hub,
The inner needle is inserted into the outer needle cap and the outer needle hub and accommodated in the outer needle, and the inner needle unit is brought into contact with the outer needle cap, thereby In the indwelling needle assembly in which the outer needle units are assembled to each other,
The needle tip protector of the inner needle unit includes a cylindrical portion through which the inner needle is inserted, and a distal side opening through which the inner needle is inserted is formed on the distal side of the cylindrical portion. And a first magnet having magnetic poles arranged in a direction perpendicular to the axis is fixedly disposed on one side of the axis perpendicular to the needle axis direction across the distal opening. On the other hand, a closing member that can be attracted to the first magnet on the other side in the axial direction and can close the distal opening is movably disposed on the first magnet side, A proximal opening through which the inner needle is inserted is formed on the proximal side of the cylindrical portion, and the needle tip of the inner needle is assembled so that it cannot be pulled out from the proximal opening. While
A second magnet is disposed on the outer needle cap of the outer needle unit. When the outer needle unit and the inner needle unit are assembled, the magnetic pole of the second magnet is in the direction perpendicular to the first axis. The magnets are arranged in the same manner as the magnets, and the second magnets are arranged on the outer sides of the first magnets in the direction perpendicular to the axis. The attraction of the first magnets and the second magnets The indwelling needle assembly, wherein the needle tip protector is detachably attracted to the outer needle cap by force.
While the outer needle cap is provided with a fitting recess having a non-circular cross section that opens to the proximal end side, the second magnet is disposed on the peripheral wall portion of the fitting recess,
The distal end of the cylindrical portion of the needle tip protector is provided with a fitting convex portion protruding in the same non-circular cross section as the fitting concave portion and having a slightly smaller outer shape than the fitting concave portion. And
The outer needle cap and the needle tip protector are positioned around the needle axis of the inner needle by the fitting of the fitting recess and the fitting protrusion, and the first magnet and the second magnet are positioned on the shaft. The indwelling needle assembly according to claim 1, wherein the indwelling needle assembly is arranged to face each other in a straight direction.
The indwelling needle assembly according to claim 1 or 2, wherein the closing member is made of a magnetic material.
The indwelling needle assembly according to any one of claims 1 to 3, wherein the closing member has a disk shape and has an outer diameter capable of covering the distal opening.