WO2014196243A1

WO2014196243A1 - Catheter assembly

Info

Publication number: WO2014196243A1
Application number: PCT/JP2014/058489
Authority: WO
Inventors: 石田昌弘; 山下真之介
Original assignee: テルモ株式会社
Priority date: 2013-06-06
Filing date: 2014-03-26
Publication date: 2014-12-11

Abstract

This catheter assembly (10) is provided with an internal needle (12), a catheter (14), an internal needle hub (20), and a needle cover (40). The needle cover (40) includes an outer cylinder (80) having a protrusion (87), and a linked cylinder (90) connected to the outer cylinder (80), and having an engaging part (93) adapted to engage the protrusion (87) at a point at which the outer cylinder (80) has been relatively retracted by a prescribed amount, preventing the outer cylinder (80) from detaching, as well as regulating advance of the outer cylinder (80). The linked cylinder (90) is furnished with a first guide part (94) capable of guiding the protrusion (87) further back from the engaging part (93) while avoiding the engaging part (93), and a second guide part (95) capable of guiding the protrusion (87) into the engaging part (93).

Description

Catheter assembly

The present invention relates to a catheter assembly that is punctured and placed in a blood vessel when, for example, infusion is performed on a patient.

Conventionally, when an infusion is performed on a patient, a catheter assembly is used to form an introduction portion of the infusion into the body. For example, the catheter assembly has a puncture portion in which an inner needle and an outer needle (catheter) are stacked. After the user punctures the puncture portion into the body, the user pulls out the inner needle from the catheter and constructs an infusion line for administering the infusion agent into the body through the catheter.

On the other hand, the inner needle is housed in the housing member of the catheter assembly when the catheter is withdrawn, thereby ensuring safety during handling. For example, International Publication No. WO94 / 13341 discloses a catheter assembly including a plurality of cylinders (accommodating members) that accommodate inner needles. This catheter assembly includes an elastic piece that is elastically inclined toward the inside of the cylinder as a mechanism for preventing the advancement of the inner needle. The elastic piece engages with another cylindrical body, thereby maintaining the expanded state of the cylindrical body itself and preventing the inner needle from advancing.

By the way, in the catheter assembly disclosed in the pamphlet of International Publication No. WO94 / 13341, since the elastic piece provided on the cylindrical body is inclined inward, the elastic piece is not inserted when another cylindrical body is inserted into the cylindrical body. It gets in the way. That is, when assembling the catheter assembly, it takes time to assemble the cylinders, and in some cases, the structure of the cylinders may be damaged.

The present invention has been made in order to solve the above-described problems, and can easily assemble a plurality of cylinders that house the inner needles, and maintain a good stretched state between the cylinders. An object of the present invention is to provide a catheter assembly that can prevent the advancement of the inner needle.

In order to achieve the above object, the present invention provides a catheter set comprising an inner needle, a catheter through which the inner needle is inserted, and a housing member that houses the inner needle when the inner needle is removed from the catheter. The housing member is a first cylinder having a projection projecting in a radial direction, and is connected to the first cylinder, and is moved to the projection at a stage where it is retracted by a predetermined amount with respect to the first cylinder. Including a second cylinder having an engagement portion that engages to prevent the first cylinder from being detached and restricts the advancement of the first cylinder, and the wall portion constituting the second cylinder includes: A first guide part capable of guiding the protrusion to a position behind the engagement part while avoiding the engagement part; and a second guide part capable of guiding the protrusion from the back side position to the engagement part; Is provided.

According to the above, the catheter assembly includes the first guide body and the second cylinder body by including the first guide portion that can guide the protrusion at a position deeper than the engagement portion while avoiding the engagement portion. When assembling, it is possible to prevent inconvenience that the protrusion engages with the engaging portion. Therefore, damage to the first cylinder and the second cylinder can be suppressed, and both members can be assembled easily. Further, the catheter assembly includes the second guide portion that can guide the protrusion to the engaging portion from the back side position, so that the protrusion can be smoothly guided to the engaging portion when the second cylinder is retracted. . Therefore, the protrusion and the engaging portion can be reliably engaged, and the first cylinder and the second cylinder can be prevented from being detached and maintained in the extended state.

In this case, the first guide portion includes a first protrusion and a second protrusion that protrude from the wall portion toward the first cylinder, and the first protrusion includes the first cylinder. The projection is provided so as to be deflected to the side of the engagement portion between the end portion on the side where the first cylinder body is inserted and the engagement portion when assembled to the second cylinder body, The two protrusions preferably extend so as to be able to guide the protrusions to the back side position where the circumferential position coincides with the engagement part at a position shifted in the circumferential direction with respect to the first protrusion.

As described above, the first guide portion is configured by the first protrusion and the second protrusion, so that the protrusion is easily guided to the back side position when the first cylinder and the second cylinder are assembled. be able to. In other words, the first protrusion disengages the protrusion from the engaging portion to cut off the engagement with the engaging portion, and the second protrusion has the protrusion shifted in the circumferential direction with respect to the engaging portion on the back side. Can be guided to the position.

In addition, it is preferable that the first protrusion surround at least the near side of the engagement portion opposite to the back side position.

As described above, the first protrusion surrounds the front side of the engaging portion, so that the protrusion can be more reliably prevented from moving toward the engaging portion during assembly.

Further, the first protrusion extends laterally of the engaging part, contacts the second protrusion, and includes a contact portion with the second protrusion. May have an inclined portion whose protruding height gradually decreases along the circumferential direction and the separating direction from the engaging portion side.

As described above, since the inclined portion is formed on the base end side of the first protrusion, the protrusion passes through the inclined portion when being guided along the second protrusion. The part can be easily overcome. Further, the inclined portion can prevent the protrusion from being displaced in the circumferential direction when the protrusion moves to the engaging portion when the second cylinder is retracted.

Furthermore, the second guide part may be constituted by a third protrusion capable of guiding the protrusion obliquely from a position shifted in the circumferential direction with respect to the engaging part.

Thus, the catheter assembly has the third protrusion capable of guiding the protrusion obliquely, so that the second cylinder moves backward even when the second cylinder rotates in the circumferential direction with respect to the first cylinder. When moved, the protrusion can be guided to the engaging portion along the third protrusion.

Furthermore, the second protrusion and the third protrusion may be formed so as to protrude from each other.

As described above, the second protrusion and the third protrusion are configured to be connected to each other, so that the second protrusion and the third protrusion can be formed as a series of raised portions (land portions). Molding can be performed easily.

Here, the engaging portion protrudes in a direction in which the first cylindrical body relatively moves when the second cylindrical body is retracted and partially covers the opening portion when the protrusion enters and is caught. In addition, an elastic piece that is elastically displaceable in the radial direction of the second cylindrical body may be included.

Thus, the catheter assembly can firmly engage the protrusion and the engaging portion by configuring the engaging portion by the opening and the elastic piece. In particular, the elastic piece can be easily hooked to the protrusion entering the opening while allowing the protrusion to elastically deform when guiding the protrusion.

In this case, the elastic piece may have a recess into which the protrusion entering the opening can enter.

Thus, since the elastic piece has the recess, the protrusion entering the opening and the recess can be fitted together. Therefore, it is possible to suppress rotation in the mutual rotation direction when the first cylinder and the second cylinder are engaged.

Further, it is preferable that the elastic piece has a convex portion extending along a protruding direction of the elastic piece on a surface side facing the first cylindrical body.

Thus, since the elastic piece has the convex portion, it is possible to reliably prevent the protrusion from moving in the circumferential direction of the second cylindrical body.

According to the present invention, it is possible to easily assemble a plurality of cylinders that house the inner needle, and it is possible to prevent the advancement of the inner needle by maintaining the extended state between the cylinders satisfactorily.

It is a perspective view showing the whole catheter assembly composition concerning one embodiment of the present invention. FIG. 2 is an exploded perspective view of the catheter assembly of FIG. 1. 3A is a first cross-sectional view for explaining the operation of the catheter assembly of FIG. 1, and FIG. 3B is a second cross-sectional view for explaining the operation of the catheter assembly of FIG. FIG. 6 is a third cross-sectional view for explaining the operation of the catheter assembly of FIG. 1. It is a perspective view which expands and shows the engagement state of the outer cylinder and relay cylinder of the catheter assembly of FIG. 5A is a plan sectional view of the relay cylinder of FIG. 2, and FIG. 5B is a side sectional view of the relay cylinder of FIG. It is explanatory drawing which shows operation | movement of the protrusion at the time of assembling the outer cylinder and relay cylinder of a catheter assembly. It is explanatory drawing which shows operation | movement of the processus | protrusion at the time of the retraction of the relay cylinder of a catheter assembly. FIG. 8A is a perspective view showing a protrusion according to the first modified example, and FIG. 8B is a perspective view showing an elastic piece according to the second modified example. FIG. 9A is a plan sectional perspective view showing an elastic piece according to a third modified example, and FIG. 9B is a partial sectional perspective view showing an engagement avoiding protrusion according to the fourth modified example.

Hereinafter, preferred embodiments of the catheter assembly according to the present invention will be described and described in detail with reference to the accompanying drawings.

The catheter assembly according to the present invention is used at a connection portion with a patient in an infusion line for infusing the patient. Specifically, when the infusion line is constructed, the catheter assembly is punctured with respect to the patient and partly indwelled, and then the infusion agent is introduced into the body through the part indwelled (in the infusion). Configured.

As shown in FIG. 1, a catheter assembly 10 according to this embodiment includes a tubular inner needle 12 having a sharp needle tip 12a at the tip and an inner needle 12 inserted as a puncture portion to be punctured into a patient's body. And a tubular catheter 14 configured as an outer needle. Further, the catheter assembly 10 includes an inner needle hub 20 that holds the inner needle 12, a catheter hub 30 that holds the catheter 14, and a needle of the inner needle 12 when the inner needle 12 is withdrawn as an operation portion in the puncture of the puncture portion. A needle cover 40 covering the tip 12a.

In the following description, the direction of the catheter assembly 10 may be indicated based on the direction instruction shown in FIG. That is, the axial direction of the catheter assembly 10 is referred to as the X direction (the distal direction with the needle tip 12a is the X1 direction, and the proximal direction with the proximal end of the inner needle hub 20 is the X2 direction). Further, the width direction of the catheter assembly 10 is also referred to as a Y direction (a diagonally left direction in FIG. 1 is a Y1 direction and a diagonally right direction is a Y2 direction). Further, the vertical direction of the catheter assembly 10 is also referred to as the Z direction (the upward direction in FIG. 1 is the Z1 direction and the downward direction is the Z2 direction). Note that these directions are for convenience of explanation, and it is a matter of course that the catheter assembly 10 can be used in an arbitrary direction.

First, in order to facilitate understanding of the present invention, a method of using the catheter assembly 10 will be schematically described. In the catheter assembly 10, the inner needle hub 20 is gripped by a user (such as a doctor or nurse), and the puncture portion is punctured. In the initial state before use (before puncturing the patient), the puncture portion has a double tube structure in which the inner needle 12 is inserted into the catheter 14 and the inner needle 12 protrudes from the distal end of the catheter 14 by a predetermined length. . Hereinafter, the initial state of the catheter assembly 10 may be referred to as a “puncture enabled state”. In the initial state of the catheter assembly 10, the inner needle hub 20 and the catheter hub 30 are connected via a needle cover 40.

The catheter assembly 10 is in a puncturable state (see FIG. 3A), and the inner needle 12 and the catheter 14 are both inserted into the patient's blood vessel by the user's puncturing action. After puncturing the patient, the user fixes the positions of the catheter 14 and the catheter hub 30 and moves the inner needle hub 20 backward in the proximal direction, thereby performing an extraction operation of the inner needle 12. Thereby, the inner needle 12 and the needle cover 40 held by the inner needle hub 20 are moved backward, and the catheter hub 30 is detached from the needle cover 40 by moving backward by a predetermined amount (see FIGS. 3B and 3C).

As a result, in the catheter assembly 10, the inner needle 12, the inner needle hub 20, and the needle cover 40 are separated from the patient side, and only the catheter 14 and the catheter hub 30 are indwelled on the patient side. After the operation of removing the inner needle 12, the user constructs an infusion line by connecting a connector of an infusion tube (not shown) to the proximal end side of the indwelling catheter hub 30, and supplies the infusion agent (medical solution) to the patient. Do.

On the other hand, when the inner needle 12 is removed, the inner needle hub 20 and the needle cover 40 perform the accommodating operation of the inner needle 12. In this case, the needle cover 40 extends with respect to the inner needle hub 20, and the inner needle 12 is accommodated in the inner needle hub 20 and the needle cover 40, thereby preventing the inner needle 12 from being exposed to the outside. Hereinafter, the state of the inner needle hub 20 and the needle cover 40 after the operation of removing the inner needle 12 may be referred to as a “state after removal”.

Hereinafter, each configuration of the catheter assembly 10 will be specifically described with reference to FIGS. 1, 2, and 3A to 3C.

The inner needle 12 of the catheter assembly 10 is a tubular member having rigidity capable of puncturing the patient's skin. In the inner needle 12, the needle tip 12 a protrudes from the distal end opening of the catheter 14 in a state where puncture is possible, a midway portion in the longitudinal direction is inserted through the inside of the catheter hub 30, and a proximal end side is held inside the inner needle hub 20. It is formed in length. Examples of the constituent material of the inner needle 12 include a metal material such as stainless steel, aluminum or an aluminum alloy, titanium or a titanium alloy.

The catheter 14 that constitutes the puncture section together with the inner needle 12 is a flexible thin tubular member, and is formed to a length that can be reliably introduced and placed in the patient's body. A lumen 14 a is formed through the catheter 14 along the axial direction of the catheter 14. The lumen 14a has an inner diameter through which the inner needle 12 can be inserted.

As the constituent material of the catheter 14, a resin material, particularly a soft resin material is suitable. In this case, for example, a fluororesin such as polytetrafluoroetherene (PTFE), an ethylene / tetrafluoroetherene copolymer (ETFE), or a belfluoroalkoxy fluororesin (PFA), an olefin resin such as polyethylene or polypropylene, or A mixture thereof, polyurethane, polyester, polyamide, polyether nylon resin, a mixture of the olefin resin and an ethylene-vinyl acetate copolymer, and the like can be given. The catheter 14 may be made of a resin having transparency so that the whole or a part of the inside can be visually recognized.

The catheter hub 30 is connected and fixed to the proximal end of the catheter 14. The catheter hub 30 is formed in a tapered cylindrical shape, and has an internal space 32 corresponding to the cylindrical outer shape. In the internal space 32, the inner needle 12 is disposed along the axial direction of the catheter hub 30 in a puncturable state (see FIG. 3A). On the distal end side of the internal space 32, a connection mechanism (for example, a caulking pin) (not shown) that provides a liquid-tight connection between the proximal end portion of the catheter 14 and the distal end portion of the catheter hub 30 is provided. In addition, a flange 34 that protrudes outward and extends in the circumferential direction is provided on the outer peripheral surface of the proximal end of the catheter hub 30.

When the catheter assembly 10 is used, the catheter hub 30 is left on the patient's body surface with the catheter 14 punctured into a blood vessel, and is stuck to the skin with a tape or the like. The catheter hub 30 is preferably made of a material harder than the catheter 14. The constituent material of the catheter hub 30 is not particularly limited. For example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer can be suitably used. .

Further, when the catheter hub 30 is placed on the patient side, the connector of the infusion tube is connected as described above. For this reason, it is preferable that the internal space 32 accommodates a connection mechanism (for example, a valve portion, a seal member, a plug, etc.) (not shown) that can construct a route for an infusion line as the connector is inserted.

On the other hand, the inner needle hub 20 of the catheter assembly 10 partially covers the proximal end side of the catheter hub 30 in a puncturable state. Further, the inner needle hub 20 functions as a housing member 21 that houses the inner needle 12 together with the needle cover 40 in the state after being removed. That is, the housing member 21 is constituted by the inner needle hub 20 and the needle cover 40. The inner needle hub 20 includes a hub main body 50 that constitutes the proximal end side of the catheter assembly 10, and a hollow inner needle fixing member 60 that fits inside the proximal end side of the hub main body 50.

The hub body 50 is an elongated cylindrical body (outer shell), and is formed in an appropriate size (thickness, length) so that the user can easily perform a gripping operation when using the catheter assembly 10. An inner needle hub side hollow portion 52 that accommodates the needle cover 40 is provided inside the hub body 50. The inner peripheral surface 52 a constituting the inner needle hub side hollow portion 52 has a hub main body side protruding portion 54 protruding radially inward, and the inner peripheral surface 52 a on the proximal end side of the hub main body side protruding portion 54 is radially outward. And a hub main body side groove portion 55 that is notched.

The inner needle fixing member 60 is housed and fixed on the proximal end side of the inner needle hub side hollow portion 52. The inner needle fixing member 60 has a cylindrical shape that gradually decreases in diameter toward the distal end side in the inner needle hub side hollow portion 52. The narrowest distal end portion is configured as a holding portion 62 that holds (fixes and fixes) the proximal end side of the inner needle 12, and the largest diameter proximal end portion is fitted to the inner peripheral surface 52 a of the hub body 50. It is comprised as the fitting part 64 to be.

The needle cover 40 of the catheter assembly 10 is puncturable as shown in FIG. 3A, and most of the proximal end side is accommodated in the inner needle hub 20 and holds the catheter hub 30 on the distal end side. The needle cover 40 includes three cylinders, an inner cylinder 70, an outer cylinder 80 (first cylinder), and a relay cylinder 90 (second cylinder). The inner cylinder 70, the outer cylinder 80, and the relay cylinder 90 are designed so that the shapes of the respective cylinder portions are sequentially thickened, and are assembled so that the mutual axial centers of the cylinder portions are coaxial.

That is, the inner cylinder 70 has its proximal end inserted into the outer cylinder 80 and is movable in the axial direction relative to the outer cylinder 80. The outer cylinder 80 has a proximal end inserted into the relay cylinder 90 and is movable in the axial direction relative to the relay cylinder 90. Further, the entire relay cylinder 90 is inserted into the hub body 50 and is movable in the axial direction relative to the hub body 50. The needle cover 40 includes the inner needle 12 including the hub body 50 by moving the inner cylinder 70 relative to the outer cylinder 80, the outer cylinder 80 relative to the relay cylinder 90, and the relay cylinder 90 relative to the hub body 50. To a length that can be accommodated.

The inner cylinder 70 of the needle cover 40 functions as a needle tip protecting member that covers the needle tip 12a of the inner needle 12 when the inner needle 12 is accommodated. The distal end of the inner cylinder 70 is in a puncturable state and is located at a proximal end position relative to the distal end of the outer cylinder 80, and is displaced so as to protrude from the distal end of the outer cylinder 80 as the inner needle 12 is removed.

The inner cylinder 70 includes a hollow inner cylinder main body 72 having a predetermined length in the axial direction, and an arm 74 integrally formed with the inner cylinder main body 72. Further, an insertion hole 73 through which the inner needle 12 can be passed is formed through the inner cylinder main body 72 along the axial direction of the inner cylinder main body 72.

The inner cylinder main body 72 includes an intermediate cylinder part 75 to which an arm 74 is connected, a distal end cylinder part 76 protruding from the intermediate cylinder part 75 toward the distal end side, and a proximal end cylinder part 77 protruding from the intermediate cylinder part 75 toward the proximal end side. And have. The intermediate cylinder part 75 is formed in a size larger than the distal end cylinder part 76 and the proximal end cylinder part 77, and a pair of arms 74 are connected to both sides in the width direction (Y direction).

The pair of arms 74 includes a support portion 74a that is continuous with the intermediate cylinder portion 75, an arm base portion 74b that is continuous with the support portion 74a and extends in parallel with the distal end direction (X1 direction), and is continuous with the arm base portion 74b and protrudes outward in the width direction and in the distal direction. Arm protrusion 74c. The arm 74 is formed such that the arm protrusion 74 c extends outward in the width direction of the outer cylinder 80 in a natural state where no external force acts. Then, in a state where puncturing is possible (in a state where the inner cylinder 70 and the outer cylinder 80 overlap), the outer cylinder 80 is elastically pressed toward the inside by the side wall.

A protrusion 74d that protrudes inward in the width direction is provided at the tip of the pair of arm protrusions 74c. The pair of protrusions 74d are hooked to the flange portion 34 of the catheter hub 30 by the arm protruding portions 74c approaching inward in a puncture enabled state. As a result, the inner cylinder 70 sandwiches the catheter hub 30 between the distal end cylindrical portion 76 inserted into the proximal end side of the inner space 32 of the catheter hub 30 and the protrusion 74d, and the catheter hub 30 is firmly connected and held. To do. When the inner needle 12 is withdrawn, the inner cylinder 70 is displaced toward the distal end side of the outer cylinder 80 by the relative movement of the inner cylinder 70 and the outer cylinder 80, so that the pair of arm protrusions 74c are elastically expanded, The catch of the flange part 34 by 74d is cancelled | released. As a result, the catheter hub 30 is allowed to be detached from the inner cylinder 70 (needle cover 40).

The distal end cylinder portion 76 of the inner cylinder 70 is formed in a cylindrical shape having an outer diameter that substantially matches the inner diameter of the inner space 32 of the catheter hub 30. On the other hand, the proximal end cylinder part 77 of the inner cylinder 70 is formed in a cylindrical shape that is longer in the axial direction than the distal end cylinder part 76 and smaller than the inner diameter of the outer cylinder side hollow part 85 of the outer cylinder 80. At the distal end side of the base end cylinder part 77 (where the intermediate cylinder part 75 and the base end cylinder part 77 are connected), a stopper part 77b that prevents the inner cylinder 70 and the outer cylinder 80 from being detached in a punctureable state, and a stopper part A displacement-permissible space 77c that can displace 77b is provided.

Also, an inner cylinder side protrusion 77a is provided on the outer peripheral surface of the proximal end cylinder part 77 on the proximal end side with respect to the stopper part 77b. The inner cylinder side protrusion 77a is inserted into the elongated hole 86 of the outer cylinder 80 in a punctureable state, and when the inner cylinder 70 and the outer cylinder 80 are relatively moved, the inner cylinder 70 and the outer cylinder 80 are displaced relative to each other by a predetermined amount. regulate. Thereby, it is prevented that the inner cylinder 70 is completely removed from the outer cylinder 80.

The outer cylinder 80 of the needle cover 40 is a member disposed outside the inner cylinder 70 and functions as a needle tip protecting member that covers the tip of the inner needle 12 when the inner needle 12 is accommodated. The outer cylinder 80 has an arm accommodating portion 82 that can accommodate the arm 74 on the distal end side, and a cylindrical portion 84 that extends a predetermined length from the proximal end of the arm accommodating portion 82 in the proximal direction. Further, an outer cylinder side hollow portion 85 is formed through the cylindrical portion 84 along the axial direction.

The arm accommodating portion 82 is formed in a relatively large box shape with an upper portion and a tip portion opened. In a state where the catheter assembly 10 can be punctured, the proximal end of the catheter hub 30 and the distal end side of the inner cylinder 70 (such as the pair of arms 74 and the intermediate cylinder part 75) are arranged inside the arm housing part 82. On both side surfaces in the Y direction of the arm accommodating portion 82, there are provided concave grooves 82a that are formed in parallel to the axial direction of the outer cylinder 80 and open at the tip side. The arm 74 is slidably inserted into the concave groove 82a, and the arm 74 is guided by the concave groove 82a when the inner cylinder 70 and the outer cylinder 80 are relatively moved.

The cylindrical portion 84 of the outer cylinder 80 is formed to have a longer axial length than the proximal end cylinder portion 77 of the inner cylinder 70. A long hole 86 communicating with the outer cylinder side hollow portion 85 is formed at a distal end side of the cylindrical portion 84 with a predetermined length.

Further, a part of a separation preventing mechanism for preventing separation of the outer cylinder 80 and the relay cylinder 90 is provided on the proximal end side of the cylindrical portion 84. Specifically, a protrusion 87 having a predetermined shape is formed to protrude.

As shown in FIGS. 3A and 4, a pair of protrusions 87 are provided on the upper and lower sides of the outer peripheral surface 84 a of the cylindrical portion 84. The pair of protrusions 87 are located at opposite positions across the axis of the outer cylinder 80 and are formed in the same shape. One protrusion 87 protrudes from the outer peripheral surface 84a by a predetermined amount radially outward (height close to the inner peripheral surface 92b of the relay cylinder 90), and has a peripheral wall 87a perpendicular to the outer peripheral surface 84a. The projection 87 is formed in a substantially elliptical shape having a major axis in the axial direction of the outer cylinder 80 and a minor axis in the circumferential direction in plan view. Further, the protruding surface 87b of the protrusion 87 is flat.

The relay cylinder 90 of the needle cover 40 is a member arranged outside the outer cylinder 80 and functions as a needle tip protecting member that covers the body portion of the inner needle 12 when the inner needle 12 is accommodated. A relay cylinder-side hollow portion 92 is formed through the relay cylinder 90 along the axial direction. Further, the other part of the separation preventing mechanism corresponding to the protrusion 87 of the outer cylinder 80 is provided on the distal end side of the relay cylinder 90.

The separation preventing mechanism smoothly inserts the outer cylinder 80 into the relay cylinder 90 when the outer cylinder 80 and the relay cylinder 90 are assembled, and reliably prevents separation when the outer cylinder 80 and the relay cylinder 90 are moved relative to each other. It is configured as follows. Specifically, an engaging portion 93, a first guide portion 94, and a second guide portion 95 are provided on the wall portion 92 a constituting the relay cylinder side hollow portion 92.

The engaging portion 93 has a function of hooking (engaging) the protrusion 87 when the relay cylinder 90 is retracted from the outer cylinder 80 in order to prevent the outer cylinder 80 and the relay cylinder 90 from being detached. . The engaging portion 93 includes a pair of engaging ports 100 (opening portions) provided on the upper and lower sides of the wall portion 92 a and a pair of upper and lower elastic pieces 110 that partially cover the engaging port 100.

The engagement port 100 communicates with the relay cylinder side hollow portion 92 and is formed sufficiently larger than the protrusion 87. The lip 101 constituting the engagement port 100 is formed in an arc shape having a top portion 101a on the tip (X1 direction) side in a plan view, and both sides (Y direction) connected to the tip side are formed in a straight line. Yes. An elastic piece 110 is provided on the base end (X2 direction) side of the lip 101.

The elastic piece 110 is connected to the wall portion 92a so as to be elastically displaceable in the radial direction of the relay cylinder 90, and protrudes from the engagement port 100 toward the tip side. A gap 102 is formed on both sides of the elastic piece 110 so as not to contact the edge 101 of the engagement port 100. The distal end side of the elastic piece 110 is formed with a relatively wide space from the top portion 101a of the lip 101, and the engaging portion 93 is between the distal end side of the elastic piece 110 and the lip 101 (hereinafter referred to as an engagement space). 103), the protrusion 87 can be exposed. Further, a passage 150 of a second guide portion 95 described later is provided on the proximal end side of the elastic piece 110.

The elastic piece 110 is formed in a rectangular shape in plan view, and is continuous with the wall 92a. Therefore, the elastic piece 110 has a gentle arc shape in the width direction (Y direction) in front sectional view. Further, the elastic piece 110 is formed such that, in a side sectional view (see FIG. 5A), the thickness of the protruding portion 112 on the distal end side is thicker than the thickness of the proximal end coupling portion 111 that is continuous with the wall portion 92a. That is, the protruding portion 112 on the distal end side slightly bulges inward in the radial direction. Furthermore, the tip wall 113 of the protrusion 112 facing the arcuate mouth edge 101 is formed in a straight line.

On the other hand, the first guide portion 94 has a function of guiding the movement of the protrusion 87 when the outer cylinder 80 is inserted into the relay cylinder 90. The first guide portion 94 includes a pair of engagement avoidance protrusions 120 (first protrusions) provided on the upper and lower sides of the relay cylinder 90 and a standby direction guide protrusion 130 (first protrusion) provided on the left and right sides of the relay cylinder 90. 2 protrusions).

The engagement avoiding protrusion 120 restricts the protrusion 87 from moving toward the engagement port 100 by surrounding the front end side (front side) of the engagement port 100. The engagement avoiding protrusion 120 is formed to protrude radially inward from the inner peripheral surface 92b of the wall 92a. Further, the engagement avoiding protrusion 120 is also a step raised from the inner peripheral surface 92b, and the engagement portion 93 (engagement port 100) is provided at this step, whereby the width of the lip 101 is the thickness of the wall portion 92a. Is bigger than. One engagement avoiding protrusion 120 has an avoidance guide top 121 located on the distal end side in a plan sectional view (see FIG. 5B) and a pair of avoidance guide sides 122 that are separated from the avoidance guide top 121 in the circumferential direction.

The avoidance guide top 121 is provided at a position spaced from the engagement port 100 toward the front end side by a predetermined distance and in the same phase in the circumferential direction as the top portion 101a on the front end side of the engagement port 100. That is, the avoidance guide top 121 is located between the tip of the relay cylinder 90 and the engaging portion 93. In the avoidance guide top 121, a pair of avoidance guide sides 122 intersect at a predetermined angle. This angle is preferably set to 120 ° or less, for example, so that the protrusion 87 can be surely deflected from the engaging portion 93.

The pair of avoidance guide sides 122 guide the protrusion 87 moving in the proximal direction so as to go around in the circumferential direction when the outer cylinder 80 is inserted. The pair of avoidance guide sides 122 extend from one end (avoidance guide top 121) where they intersect each other so as to be spaced apart in the base end direction (X2 direction) and in the circumferential direction, and from the position 122a separated by a predetermined distance, the axis of the relay cylinder 90 And extend in the X2 direction. The width between the positions 122 a of the pair of avoidance guide sides 122 is wider than the width of the engagement port 100. Further, the other ends of the pair of avoidance guide sides 122 are connected to the standby direction guide protrusion 130.

The pair of standby direction guide protrusions 130 has a function of guiding the protrusion 87 whose phase is shifted in the circumferential direction to the proximal end side (back side position) of the engaging portion 93 when the outer cylinder 80 is inserted. . The pair of standby direction guide protrusions 130 are formed so as to spread in the proximal direction on the wall portions 92a on both sides in the Y direction. Further, the standby direction guide protrusion 130 is formed so as to protrude from the wall 92a inward in the radial direction with a protrusion height higher than that of the engagement avoidance protrusion 120. One standby direction guide protrusion 130 is a side cross sectional view (see FIG. 5A), a standby direction guide top 131 located on the front end side of the relay cylinder 90, and a pair of standbys separated from the standby direction guide top 131 in the circumferential direction. It has a direction guide side 132.

The standby direction guide top 131 is provided at a position that is 90 ° out of phase in the circumferential direction with the avoidance guide top 121 and at a position that substantially coincides (overlaps) in the axial direction. In the standby direction guide top 131, a pair of standby direction guide sides 132 intersect at an angle smaller than the intersection angle of the avoidance guide side 122 in the avoidance guide top 121.

The pair of standby direction guide sides 132 are formed so as to face the circumferential direction of the pair of avoidance guide sides 122, and the protrusion 87 that moves in the proximal direction when the outer cylinder 80 is inserted is opposite to the avoidance guide sides 122. Guide to the circumferential direction. The pair of standby direction guide sides 132 extend from one end (standby direction guide top 131) where they intersect with each other so as to be spaced apart in the proximal direction and the circumferential direction, and are curved so as to be slightly warped inward. The other end of the avoidance guide side 122 is connected at the position 132a on the base end side of the standby direction guide side 132. The standby direction guide side 132 further extends from the position 132a in the proximal direction and the circumferential direction to reach the passage 150.

On the other hand, the second guide part 95 has a function of guiding the protrusion 87 to the engaging part 93 when the relay cylinder 90 is moved backward with respect to the outer cylinder 80 during the extraction operation of the inner needle 12. The second guide part 95 is constructed by the engagement guide protrusions 140 (third protrusions) provided as a pair on the left and right sides of the relay cylinder 90 and the distal end sides of the engagement guide protrusions 140 approaching each other. And a pair of upper and lower passages 150.

The pair of engagement guide protrusions 140 function to guide the protrusion 87 toward the engagement portion 93 when the protrusion 87 is in a phase shifted in the circumferential direction of the engagement portion 93 when the relay cylinder 90 is retracted. have. The pair of engagement guide protrusions 140 are provided at positions opposite to the standby direction guide protrusion 130 in the axial direction so that the circumferential phase coincides with the standby direction guide protrusion 130. That is, one standby direction guide protrusion 130 and one engagement guide protrusion 140 are formed as a series of land portions 96 (protrusion portions) protruding radially inward from the wall portion 92a.

The pair of engagement guide protrusions 140 are formed so as to spread in the tip direction in the wall portions 92a on both sides in the Y direction. One engagement guide protrusion 140 has an engagement guide top portion 141 located on the base end side of the land portion 96 in a side sectional view, and a pair of engagement guide sides 142 separated from the engagement guide top portion 141 in the circumferential direction. And a passage side 143 that continues to the tip of the pair of engagement guide sides 142.

The engagement guide top 141 is provided at a position where the phase in the circumferential direction coincides with the standby direction guide top 131. In the engagement guide top 141, a pair of engagement guide sides 142 intersect at a predetermined angle.

The pair of engagement guide sides 142 guide the protrusion 87 toward the passage 150 when the relay cylinder 90 moves backward. The pair of engagement guide sides 142 extend from one end (engagement guide top 141) where they intersect with each other so as to be spaced apart in the distal direction and the circumferential direction. The length in the axial direction of the pair of engagement guide sides 142 is longer than the length in the axial direction of the standby direction guide side 132. And the channel | path side 143 is connected with the front end side.

The passage side 143 is a side that constitutes the passage 150, and is connected to the standby direction guide side 132 on the distal end side and is connected to the engagement guide side 142 on the proximal end side. The passage side 143 extends linearly between the standby direction guide side 132 and the engagement guide side 142, thereby forming the passage 150 along the axial direction of the relay cylinder 90.

The passage 150 is a groove formed between the passage sides 143 of the pair of engagement guide protrusions 140 and corresponds to the inner peripheral surface 92 b of the relay cylinder 90. The width of the passage 150 is set so as to substantially coincide with the width of the elastic piece 110 on the front end side (or become narrower than the width of the elastic piece 110). The passage 150 is also a path when the projection 87 moves in the proximal direction when the outer cylinder 80 is inserted, and thus the projection 87 is placed on the proximal side so that the phase coincides with the circumferential direction of the engaging portion 93. Can be guided to.

The relay cylinder 90 includes the engaging portion 93 and the first and

second guide portions

94 and 95 described above, so that when the outer tube 80 is inserted, the relay tube 90 is retracted from the outer tube 80 without hooking the protrusion 87 on the engaging portion 93. Sometimes the protrusion 87 can be guided to the engaging portion 93.

In addition, as shown in FIG. 2, a pair of upper and lower hook portions 97 are provided on the proximal end side of the relay cylinder 90. The hook portion 97 is formed by cutting a predetermined amount from the proximal end of the relay cylinder 90 to the distal end side, and has a claw portion 97a on the proximal end side. The claw portion 97a is elastically deformable in the radial direction of the relay cylinder 90. Yes. The claw portion 97a is configured to be caught by the hub body side protrusion 54 when the hub body 50 moves backward relative to the relay cylinder 90.

The catheter assembly 10 according to the present embodiment is basically configured as described above, and the effects thereof will be described below based on the operation of the catheter assembly 10 during assembly and use.

In assembling the catheter assembly 10, the inner needle fixing member 60 is inserted from the proximal end side of the hub body 50. Then, the relay cylinder 90 is inserted from the front end side of the hub body 50. At this time, the hook portion 97 of the relay cylinder 90 is elastically bent with respect to the hub main body side protrusion 54 of the hub main body 50, so that the relay cylinder 90 can be easily inserted into the inner needle hub side hollow portion 52. .

Next, the outer cylinder 80 is inserted from the front end side of the accommodated relay cylinder 90. In this case, the outer cylinder 80 can be easily inserted no matter how it faces the relay cylinder 90 in the circumferential direction. That is, the circumferential position of the protrusion 87 before insertion is not related to the arrangement of the engaging portion 93 and the first and

second guide portions

94 and 95 of the relay cylinder 90. Therefore, the outer cylinder 80 and the relay cylinder 90 can be efficiently connected.

For example, as shown in FIG. 6, when the protrusion 87 is inserted in the proximal direction from the position facing the avoidance guide top 121, the protrusion 87 is guided by the displacement of the outer cylinder 80 in the proximal direction. Contact the top 121. Thereby, the protrusion 87 is guided to one of the pair of avoidance guide sides 122 from the avoidance guide top 121.

The protrusion 87 moves in the circumferential direction (for example, the movement position A1) so as to deviate from the engagement port 100 along one avoidance guide side 122. Then, the protrusion 87 that has moved to the movement position A1 moves to the position 122a of the avoidance guide side 122, moves in the proximal direction while maintaining its circumferential position, and near the position 132a that intersects the standby direction guide side 132 (Moving position A2). Here, the standby direction guide protrusion 130 protrudes radially inward from the engagement avoidance protrusion 120. For this reason, the protrusion 87 moved to the position 132 a is next guided to the standby direction guide side 132 of the standby direction guide protrusion 130.

The projection 87 gets over the avoidance guide side 122 under the guide action of the standby direction guide side 132, and advances to the movement position A3 on the tip side of the passage 150. Here, the position of the position 132a in the axial direction is on the proximal end side of the elastic piece 110, and even if the protrusion 87 gets over the avoidance guide side 122, it is not caught by the elastic piece 110. Therefore, the protrusion 87 can surely enter the passage 150 without being engaged with the engaging portion 93. This moving position A3 corresponds to the base end position of the engaging portion 93, and the protrusion 87 further enters the back side position of the relay cylinder 90 as the outer cylinder 80 is inserted. Basically, the movement is finished at the standby position A4 where the phase in the circumferential direction coincides with the engaging portion 93, and the standby state is entered.

Note that the protrusion 87 is not necessarily arranged at the standby position A4 in which the phase in the circumferential direction coincides with that of the engaging portion 93, and may be arranged with the circumferential phase shifted from the engaging portion 93. That is, in this specification, the “back side position” of the relay cylinder 90 to which the protrusion 87 moves may be the base end side of the engaging section 93 in the relay cylinder 90 and may be taken at any position in the circumferential direction. obtain.

After the standby state is reached, in assembly, the proximal end cylinder portion 77 of the inner cylinder 70 is inserted into the outer cylinder 80, and the inner needle 12 with the catheter 14 and the catheter hub 30 disposed on the distal end side is inserted after a certain amount of insertion. Insert from the tip. At this stage, the distal end of the inner cylinder 70 is closer to the distal end side than the distal end of the outer cylinder 80, and the pair of arms 74 are expanded.

The inner needle 12 is inserted from the proximal end into the insertion hole 73 opened in the distal end cylindrical portion 76 of the inner cylinder 70, moves in the outer cylinder side hollow portion 85 in the axial direction, and moves to the inner needle fixing member 60. The holding part 62 is reached. The proximal end portion of the inner needle 12 is fixedly held by the holding portion 62 while being inserted into the inner needle fixing member 60 from the distal end of the holding portion 62 and passing through a packing (not shown) provided in the holding portion 62. The

After the inner needle 12 is fixed, the catheter hub 30 is attached to the distal end cylinder portion 76, and the inner cylinder 70 is pushed toward the proximal end of the outer cylinder 80. As the inner cylinder 70 moves in the proximal direction, the arm 74 of the inner cylinder 70 is closed by the outer cylinder 80, and the protrusion 74 d is caught by the flange portion 34 of the catheter hub 30. As a result, the catheter assembly 10 is in a puncturable state in which the inner needle 12 and the catheter 14 have a double tube structure, and the inner needle hub 20, the catheter hub 30 and the needle cover 40 are integrated. In this puncturable state, the catheter assembly 10 is provided with a user with external environmental protection means such as sterilization.

3A to 3C, the user integrally punctures the patient's blood vessel with the inner needle 12 and the catheter 14 in a puncturable state, and after the puncture, performs an operation of removing the inner needle 12. In the extraction operation, the catheter hub 30 is fixed with one hand, and the inner needle hub 20 (hub body 50) is grasped and retracted with the other hand. As a result, the hub body 50 moves backward with respect to the relay cylinder 90, and the relay cylinder 90 moves backward with respect to the outer cylinder 80.

At this time, since the relay cylinder 90 is rotatable in the circumferential direction with respect to the outer cylinder 80, the catheter assembly 10 can be removed from the outer cylinder 80 even if the hub body 50 is twisted in the circumferential direction during the extraction operation. Will not change the posture of the tip side part. Therefore, the inner needle 12 can be easily pulled out while maintaining the postures of the catheter 14 and the catheter hub 30.

Further, when the relay cylinder 90 rotates in the circumferential direction due to twisting of the hub body 50 or the like, the circumferential position of the engaging portion 93 with respect to the protrusion 87 of the outer cylinder 80 is shifted as shown in FIG. In FIG. 7, for convenience of explanation, a state in which the protrusion 87 has moved from the standby position A4 to the position B1 that is shifted in the circumferential direction is illustrated.

The catheter assembly 10 can guide the protrusion 87 to the engagement portion 93 by the engagement guide protrusion 140 even when the phases of the protrusion 87 and the engagement portion 93 are shifted as described above. That is, when the relay cylinder 90 moves backward with respect to the outer cylinder 80, the protrusion 87 comes into contact with the engagement guide top portion 141 and the engagement guide side 142, and is displaced in the distal direction along the engagement guide side 142. When the relay cylinder 90 moves backward by a predetermined amount, the protrusion 87 enters the passage 150 and moves linearly in the axial direction of the relay cylinder 90 under the guidance of the passage side 143.

Therefore, the protrusion 87 moves to the elastic piece 110 on the front end side of the passage 150, and the inner surface is further displaced in the front end direction along the arc-shaped elastic piece 110. When the protrusion 87 moves from the proximal end connecting portion 111 to the protruding portion 112, the elastic piece 110 is pushed by the protrusion 87 and elastically deforms radially outward. The protrusion 87 receives a pressing force from the elastic piece 110, so that the posture of the protrusion 87 is suppressed, and the protrusion 87 is guided into the engagement space 103 without being shaken in the circumferential direction. The peripheral wall 87 a of the protrusion 87 guided to the engagement space 103 is hooked on the edge 101 of the engagement port 100. Thereby, the outer cylinder 80 and the relay cylinder 90 are prevented from being separated from each other, and the relay cylinder 90 can pull out the outer cylinder 80 in the proximal direction.

At the stage where the relay cylinder 90 pulls out the outer cylinder 80, as shown in FIG. 3B, the stopper portion 77b can move into the displacement allowable space 77c of the inner cylinder 70, and the retraction of the outer cylinder 80 with respect to the inner cylinder 70 is allowed. . When the outer cylinder 80 is retracted by a predetermined amount, the hole edge of the elongated hole 86 is caught by the inner cylinder-side protrusion 77 a of the inner cylinder 70. Thereby, the inner cylinder 70 is pulled out by the outer cylinder 80 and moves in the proximal direction. Further, at this stage, the pair of arms 74 are released from the arm accommodating portion 82 and expand outward in the width direction. Therefore, the catheter hub 30 hooked on the protrusion 74d is smoothly detached from the inner cylinder 70, and the catheter 14 and the catheter hub 30 are left on the patient side. After indwelling, an infusion tube is connected to the catheter hub 30.

On the other hand, the separated inner needle 12, inner needle hub 20, and needle cover 40 are subjected to medical disposal. At this time, the inner needle hub 20 and the needle cover 40 act so as to maintain the extended state so that the inner needle 12 used for puncturing is not exposed to the outside. That is, the outer cylinder 80 and the relay cylinder 90 prevent the relay cylinder 90 from moving forward (reversely) by the engagement of the engaging portion 93 and the protrusion 87, and the relay cylinder 90 and the hub main body 50 are connected to the hook portion 97 and the hub main body side groove. The hub body 50 is prevented from moving forward (reversely) by the engagement of the portion 55.

Specifically, when the relay cylinder 90 is moved forward with respect to the outer cylinder 80, the peripheral wall 87a of the protrusion 87 inserted into the engagement port 100 and the tip wall 116 of the elastic piece 110 come into contact with each other. Since the tip wall 116 has a sufficient thickness due to the protrusion 112, the peripheral wall 87a can be firmly hooked. Therefore, in the connection portion between the outer cylinder 80 and the relay cylinder 90, the engagement state of the protrusion 87 and the engaging portion 93 is maintained firmly. Thereby, it is possible to satisfactorily prevent the inner needle 12 from jumping out due to the reverse return.

As described above, the catheter assembly 10 includes the first guide portion 94 that can guide the protrusion 87 while avoiding the engaging portion 93, so that the protrusion 87 is engaged when the outer tube 80 and the relay tube 90 are assembled. The inconvenience of engaging with the joint portion 93 can be prevented. Therefore, the outer cylinder 80 and the relay cylinder 90 can be prevented from being damaged and can be easily assembled. Further, the catheter assembly 10 includes the second guide portion 95 that can guide the protrusion 87, so that the protrusion 87 can be smoothly guided to the engaging portion 93 when the outer tube 80 is retracted with respect to the relay tube 90. . Therefore, the protrusion 87 and the engaging portion 93 can reliably establish the separation of the outer cylinder 80 and the relay cylinder 90 and the maintenance of the extended state.

In this case, the first guide portion 94 is configured by the engagement avoidance protrusion 120 and the standby direction guide protrusion 130, so that when the engagement avoidance protrusion 120 and the standby direction guide protrusion 130 are assembled, the protrusion 87. Can be easily guided to the rear side position. That is, the engagement avoiding protrusion 120 can block the engagement with the engaging portion 93 by causing the protrusion 87 to deviate from the engaging portion 93. Then, the standby direction guide protrusion 130 can guide the protrusion 87 shifted in the circumferential direction with respect to the engaging portion 93 to the standby position A4.

In addition, the catheter assembly 10 has the standby direction guide protrusion 130 protruding from the engagement avoidance protrusion 120 so that the protrusion 87 displaced in the circumferential direction by the engagement avoidance protrusion 120 is 130 can guide to the standby position A4. At this time, it is possible to guide the protrusion 87 so as to get over the engagement avoiding protrusion 120.

Further, by forming the engagement guide protrusion 140 on the opposite side of the standby direction guide protrusion 130, the standby direction guide protrusion 130 and the engagement guide protrusion 140 can be formed as a series of land portions 96. Thus, molding can be performed easily.

Furthermore, since the engaging portion 93 is configured by the engaging port 100 and the elastic piece 110, the catheter assembly 10 can firmly engage the protrusion 87 and the engaging portion 93. In particular, the elastic piece 110 can be easily hooked by the protrusion 87 that has entered the engagement port 100 while allowing the protrusion 87 to pass by elastic deformation when guiding the protrusion 87.

In addition, each structure (protrusion 87, engaging part 93, 1st and 2nd guide part 94, 95) of the catheter assembly 10 of this invention is not limited to said structure, Various modifications and applications Take an example. Hereinafter, some of these modifications will be described. In addition, in the following description, the same code | symbol is attached | subjected about the structure same as the catheter assembly 10 which concerns on this embodiment, or the structure which has the same function, and the detailed description is abbreviate | omitted.

The protrusion 88 according to the first modification shown in FIG. 8A is formed to be slightly wider than the protrusion 87 described above. The peripheral wall 88 a of the protrusion 88 has a front end surface 88 b that matches the arc shape on the front end side of the engagement port 100. The distal end surface 88b comes into close contact with a wide area of the distal end edge 101 when the projection 88 enters the engagement port 100, and thus the outer cylinder 80 and the relay cylinder 90 can be more reliably prevented from being detached. .

Also, a taper surface 88d that is inclined radially inward toward the base end side of the outer cylinder 80 is formed on the base end side protrusion surface 88c of the protrusion 88. The inclination of the tapered surface 88d is gentle and does not hinder the engagement of the peripheral wall 88a on the proximal end side and the distal end wall 113 of the elastic piece 110. When the outer cylinder 80 is inserted, the tapered surface 88d is guided by the engagement avoiding protrusion 120 and switched to the guide of the standby direction guiding protrusion 130. It works to get over easily. Thereby, the outer cylinder 80 and the relay cylinder 90 can be assembled more easily.

The elastic piece 115 according to the second modification shown in FIG. 8B is formed in a concave portion 116a in which the central portion in the width direction (Y direction) of the distal end wall 116 is recessed in the proximal direction. Since the engaging portion 93 has the concave portion 116a as described above, the base end portion of the protrusion 87 that has entered the engaging port 100 (engagement space 103) can be guided to the concave portion 116a.

Therefore, when the relay cylinder 90 is moved forward (reversely returned) with respect to the outer cylinder 80, the protrusion 87 and the recess 116a can be hooked, and the inner needle 12 can be prevented from popping out more reliably. Further, when the base end portion of the protrusion 87 is fitted in the recess 116a, the outer cylinder 80 and the relay cylinder 90 can be prevented from rotating in the rotation direction, and the engagement state can be maintained more firmly. Can do.

The elastic piece 117 according to the third modified example shown in FIG. 9A includes a pair of rails 118 (convex portions) on both sides in the width direction (Y direction) on the inner peripheral surface side. The pair of rails 118 slightly project inward in the radial direction of the relay cylinder 90 and are linearly formed on the elastic piece 117 along the X direction (the protruding direction of the elastic piece 117). The pair of rails 118 can reliably prevent the protrusion 87 from being displaced from the elastic piece 117 in the circumferential direction when the protrusion 87 moves to the elastic piece 117 through the passage 150 as the inner needle 12 is pulled out. The protrusion 87 can be smoothly guided to the engagement port 100.

In addition, the engagement avoidance protrusion 124 according to the third modification is formed to protrude to a predetermined position on the base end side, and does not come into contact with the standby direction guide protrusion 130. Therefore, a region 125 (that is, the inner peripheral surface 92b) through which the protrusion 87 can pass is present between the engagement avoidance protrusion 124 and the standby direction guide protrusion 130. Thereby, the protrusion 87 can be smoothly guided to the passage 150 through the region 125 when the outer cylinder 80 is inserted.

The engagement avoidance protrusion 126 according to the fourth modification shown in FIG. 9B extends to the side of the engagement portion 93 until it comes into contact with the standby direction guide protrusion 130, but the proximal end side including the contact portion is extended. The region 127 is formed in an inclined portion having a right triangle shape in sectional view. That is, the region 127 includes a wall surface 127a that is continuous with the lip 101 and protrudes in the radial direction, and an inclined surface 127b whose protrusion height gradually decreases from the top of the wall surface 127a toward the outer side in the circumferential direction (in the direction away from the engaging portion 93). Have

Thereby, when the protrusion 87 moves in the proximal direction when the outer cylinder 80 and the relay cylinder 90 are assembled, the protrusion 87 moves along the inclined surface 127b, so that the engagement avoiding protrusion 126 can be easily overcome. . Further, when the projection 87 moves in the distal direction when the relay cylinder 90 is retracted, the wall surface 127a regulates the circumferential displacement of the projection 87, so that the projection 87 can be smoothly guided to the engagement port 100.

In addition, as another modification other than the above, the base end portion of the protrusion 87 may be formed in a flat shape so as to be reliably hooked by the distal end wall 113 of the elastic piece 110. Further, the first and

second guide portions

94 and 95 may be formed on a barrier (rib) of the protrusion. For example, the protrusion 87 can be deflected along the barrier by forming a barrier so as to surround the periphery of the engagement port 100.

Further, in the catheter assembly 10, the formation relationship between the protrusion 87 of the outer cylinder 80, the engaging portion 93 of the relay cylinder 90, and the first and

second guide portions

94 and 95 may be reversed. In other words, the wall portion of the outer cylinder 80 includes the engaging portion, the first and second guide portions, and the relay cylinder 90 includes a protrusion on the inner peripheral surface. Furthermore, the catheter assembly 10 may be configured such that the relay cylinder 90 is inserted into the outer cylinder-side hollow portion 85 of the outer cylinder 80. In this case, a protrusion is provided on either the outer cylinder 80 or the relay cylinder 90, What is necessary is just to set it as the structure which provided the engaging part and the 1st and 2nd guide part in the other.

In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Yes.

Claims

An inner needle (12), a catheter (14) through which the inner needle (12) is inserted, and a housing member that houses the inner needle (12) when the inner needle (12) is removed from the catheter (14) (21) a catheter assembly (10) comprising:
The housing member (21) includes a first cylinder (80) having protrusions (87, 88) protruding in a radial direction,
The first cylinder (80) is connected to the first cylinder (80), and is engaged with the protrusions (87, 88) at a stage where the first cylinder (80) is retracted by a predetermined amount. And a second cylinder (90) having an engaging portion (93) for preventing detachment and restricting advance of the first cylinder (80),
The protrusions (87, 88) are formed on the wall (92a) constituting the second cylindrical body (90) at a position farther from the engaging portion (93), avoiding the engaging portion (93). A first guide part (94) capable of guiding and a second guide part (95) capable of guiding the projections (87, 88) from the back side position to the engaging part (93) are provided. A catheter assembly (10).
The catheter assembly (10) of claim 1,
The first guide part (94) is formed by a first protrusion (120, 124, 126) and a second protrusion (130) protruding from the wall part (92a) toward the first cylinder (80). Configured,
The first protrusions (120, 124, 126) are located on the side where the first cylinder (80) is inserted when the first cylinder (80) is assembled to the second cylinder (90). Between the end portion and the engaging portion (93), the protrusions (87, 88) are provided to deflect to the side of the engaging portion (93),
The second protrusion (130) is a position shifted in the circumferential direction with respect to the first protrusion (120, 124, 126), and the rear side position where the circumferential position coincides with the engagement part (93). A catheter assembly (10), wherein the protrusions (87, 88) extend in a guideable manner.
Catheter assembly (10) according to claim 2,
The catheter assembly (10), wherein the first protrusion (120, 124, 126) surrounds at least a front side opposite to the back side position of the engagement portion (93).
Catheter assembly (10) according to claim 3,
The first protrusion (126) extends laterally of the engagement part (93) and contacts the second protrusion (130).
The protrusion height of the proximal end side of the first protrusion (126) including the contact portion with the second protrusion (130) gradually decreases from the engagement part (93) side in the circumferential direction and the separation direction. A catheter assembly (10) having an inclined portion (127b).
The catheter assembly (10) according to any one of claims 2 to 4,
The second guide part (95) includes a third protrusion (140) capable of guiding the protrusions (87, 88) obliquely from a position shifted in the circumferential direction with respect to the engagement part (93). A catheter assembly (10) characterized in that.
The catheter assembly (10) according to claim 5,
The catheter assembly (10), wherein the second protrusion (130) and the third protrusion (140) are formed to protrude from each other.
A catheter assembly (10) according to any one of the preceding claims,
The engaging portion (93) includes an opening (100) into which the protrusion (87, 88) enters and is hooked,
When the second cylinder (90) is retracted, the first cylinder (80) protrudes in a relatively moving direction to partially cover the opening (100), and the second cylinder (90). A catheter assembly (10) comprising: an elastic piece (110, 115, 117) that is elastically displaceable in the radial direction.
The catheter assembly (10) according to claim 7,
The catheter assembly (10), wherein the elastic piece (115) has a recess (116a) into which the protrusions (87, 88) entering the opening (100) can enter.
A catheter assembly (10) according to claim 7 or 8,
The elastic piece (117) has a convex part (118) extending along the protruding direction of the elastic piece (117) on the surface facing the first cylinder (80). Assembly (10).