Catheter assembly

Abstract

To provide a catheter assembly capable of preventing positional deviation between an inner needle and a catheter, at timing not intended by a user, and reducing a risk of drawing of the catheter with the inner needle from a blood vessel and detachment of the catheter from the blood vessel.SOLUTION: A catheter assembly 10 comprises a hub lock mechanism 20 for fixing a catheter hub 26 and an inner needle hub 34 so as to be freely released, the hub lock mechanism 20 has: an operation part 40 which is fitted to the inner needle hub 34, and is displaced by input of operation force of a user; a fixing part 44 fitted to the catheter hub 26; and a connecting member 42 for connecting the fixing part 44 and the operation part 40. The connection member 42 releases connection between the catheter hub 26 and the inner needle hub 34 by operation of the operation part 40.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a catheter assembly.

Background Art

[0002] Catheter assemblies are used for purposes such as infusion. A catheter assembly has a relatively flexible catheter that is indwelled in a blood vessel and an inner needle that is inserted through the inside of the catheter (for example, Patent Document 1). When inserting into a blood vessel, the catheter assembly is used with the tip of the inner needle protruding from the catheter. After the catheter is inserted into the blood vessel, the inner needle is removed from the catheter, and the catheter is indwelled in the patient's blood vessel. The catheter indwelled in the blood vessel is used for infusion and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional catheter assembly, the fixation between the inner needle and the catheter is achieved by frictional resistance due to the contact between the reduced-diameter portion at the tip of the catheter and the body portion of the inner needle. The magnitude of the frictional resistance is determined by the reduced-diameter dimension and the length of the tip of the catheter. Such a reduced-diameter portion at the tip of the catheter is formed by taper processing. However, the formation of the reduced-diameter portion by taper processing is difficult to control in manufacturing, and there is a large variation in the fixing force.

[0005] In order to insert the catheter assembly into the inside of a blood vessel, a procedure may be performed to move the catheter assembly back and forth with respect to the blood vessel. When performing such a procedure, if the fixing force between the inner needle and the catheter is insufficient, displacement between the two may occur, and there is a risk that the inner needle may pierce through the catheter. Also, if the fixing force between the inner needle and the catheter is too large, the catheter may be pulled out of the blood vessel together with the inner needle when the inner needle is removed.

[0006] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0007] One aspect of the following disclosure includes a catheter body having a lumen, a catheter hub fixed to a proximal end portion of the catheter body, an inner needle inserted through the lumen of the catheter body, an inner needle hub fixed to a proximal end of the inner needle, and a hub locking mechanism that releasably fixes the catheter hub and the inner needle hub. The hub locking mechanism has an operation portion attached to the inner needle hub and displaced by a user's operation, a fixing portion attached to the catheter hub, and a connecting member that connects the fixing portion and the operation portion. The connecting member connects the operation portion and the fixing portion when the operation portion is in a locked position, preventing axial relative displacement between the catheter hub and the inner needle hub, and releases the connection between the operation portion and the fixing portion when the operation portion is in a released position, allowing the relative displacement between the catheter hub and the inner needle hub. This is in a catheter assembly.

Effects of the Invention

[0008] The catheter assembly of the above aspect can prevent displacement between the inner needle and the catheter at a timing unintended by the user. Also, the above catheter assembly reduces the risk that the catheter is pulled out of the blood vessel together with the inner needle and becomes detached from the blood vessel.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0010] (First Embodiment) As shown in FIG. 1, the catheter assembly 10 according to the present embodiment has a puncture part 12 for puncturing a blood vessel and a hub 14 for a user to grip and operate. In the following description, the direction along the central axis of the catheter assembly 10 is called the axial direction, the direction in which the puncture part 12 is located is called the distal direction or the distal side, and the direction in which the hub 14 is located is called the proximal direction or the proximal side.

[0011] The catheter assembly 10 has a catheter 16, an inner needle assembly 18, and a hub locking mechanism 20. The inner needle assembly 18 is inserted inside the catheter 16 in an unused state. The inner needle assembly 18 has a sharp needle tip 22. The needle tip 22 forms a puncture portion 12 by protruding beyond the tip of the catheter 16. The hub locking mechanism 20 is formed on the hub 14 and connects the catheter 16 and the inner needle assembly 18.

[0012] The catheter 16 has a catheter body 24 and a catheter hub 26. The catheter body 24 is a tubular member that extends elongated in the axial direction. The catheter body 24 has a lumen 24a inside. The lumen 24a extends in the axial direction and penetrates between the tip portion 24b and the base portion 24c of the catheter body 24. The catheter body 24 preferably has flexibility and appropriate elasticity. The catheter body 24 is formed of a resin material. The material of the catheter body 24 is, for example, polyethylene, polytetrafluoroethylene, polyurethane, polyether nylon resin, or polypropylene, etc.

[0013] The catheter hub 26 is joined to the base portion 24c of the catheter body 24. The catheter hub 26 supports the catheter body 24. The catheter hub 26 is a tubular member having an outer diameter dimension larger than that of the catheter body 24. The catheter hub 26 has a through portion 26a on the tip side and a base portion 26b on the base side. The through portion 26a supports the base portion 24c of the catheter body 24. The base portion 26b has an outer diameter dimension larger than that of the through portion 26a. The base portion 26b has a flange 28 that protrudes in a flange shape at the base end. The flange 28 constitutes the fixing portion 44 of the present embodiment. The flange 28 is also used for connection with a connector (not shown) of an infusion line after the inner needle assembly 18 is removed.

[0014] The catheter hub 26 has a cavity 26c inside. The cavity 26c extends in the axial direction. The distal end side of the cavity 26c communicates with the lumen 24a of the catheter body 24. The proximal end side of the cavity 26c forms an opening 30 at the proximal end of the catheter hub 26. The catheter hub 26 is formed of a resin material such as polyethylene, polypropylene, polyurethane, polycarbonate, or ABS resin, for example.

[0015] The inner needle assembly 18 has an inner needle 32 and an inner needle hub 34. The inner needle 32 is substantially cylindrical. The inner needle 32 has a sharp needle tip 22 for puncturing the skin at the distal end. The inner needle 32 is a hollow needle having a through hole (not shown) penetrating in the axial direction. Note that the inner needle 32 may be a solid needle without a through hole. The inner needle 32 has an outer diameter dimension that can be inserted into the lumen 24a of the catheter body 24. The inner needle 32 has an axial length longer than the total length of the catheter body 24. In the initial state, the needle tip 22 of the inner needle 32 protrudes from the distal end portion 24b of the catheter body 24. The inner needle 32 is formed of metal or a hard resin. The inner needle 32 may be formed of a metal such as stainless steel, aluminum, an aluminum alloy, titanium, or a titanium alloy, for example.

[0016] The inner needle hub 34 supports the proximal end of the inner needle 32. The inner needle hub 34 is a cylindrical member having an outer diameter larger than that of the inner needle 32. The inner needle hub 34 has an insertion portion 36 and a gripping portion 38. The insertion portion 36 is located on the distal end side of the inner needle hub 34. The insertion portion 36 has an outer diameter dimension that can be inserted into the cavity 26c of the catheter hub 26. The insertion portion 36 has a tapered shape in which the outer diameter dimension gradually increases toward the proximal end. In the initial state, the insertion portion 36 closes the opening 30 of the catheter hub 26 in a liquid-tight and air-tight manner. The insertion portion 36 is joined to the proximal end of the inner needle 32. The insertion portion 36 and the gripping portion 38 are integrally formed.

[0017] The gripping portion 38 is located at the proximal end side of the insertion portion 36. The gripping portion 38 extends toward the proximal end. The gripping portion 38 has an outer diameter dimension and an axial length suitable for a gripping operation. A guide wire feeder may be connected to the proximal end of the gripping portion 38. By connecting the inner needle hub 34 configured as described above and the catheter hub 26 described above, the hub 14 of the catheter assembly 10 is configured.

[0018] The hub 14 has a hub locking mechanism 20. The hub locking mechanism 20 prevents the separation of the catheter hub 26 and the inner needle hub 34. As shown in FIG. 2, the hub locking mechanism 20 has an operation portion 40, a fixing portion 44, and a connecting member 42. The operation portion 40 is attached to the inner needle hub 34 and is displaced in the axial direction by the operation of the user. The operation portion 40 has a sliding portion 40a and an engaging portion 40b. The sliding portion 40a is a rod-shaped or plate-shaped member extending in the axial direction. The sliding portion 40a abuts against the outer peripheral surface of the gripping portion 38 of the inner needle hub 34. The sliding portion 40a is supported by a guide frame 46. The guide frame 46 maintains the sliding portion 40a in a state of abutting against the outer surface of the gripping portion 38. The guide frame 46 guides the moving direction of the sliding portion 40a in the axial direction. When the user inputs an operating force to the sliding portion 40a, the operation portion 40 is displaced in the axial direction while sliding on the outer peripheral surface of the gripping portion 38.

[0019] The engaging portion 40b protrudes outward from the sliding portion 40a. Although not particularly limited, the engaging portion 40b is located closer to the tip of the sliding portion 40a. The engaging portion 40b has a wedge-shaped recess 40c at the top. In the locked position, the operation portion 40 is arranged at a position where the recess 40c faces the second claw 54 of the connecting member 42 described later. In this positional relationship, the engaging portion 40b biases the second claw 54 radially outward. Also, the engaging portion 40b receives and holds a part of the second claw 54 in the recess 40c. The engaging portion 40b is displaced integrally with the operation portion 40. When the operation portion 40 is displaced, the second claw 54 disengages from the recess 40c.

[0020] The connecting member 42 is disposed between the operation portion 40 and the fixing portion 44. The connecting member 42 of the present embodiment has an arm 48 and a support 50. The arm 48 is a rod-shaped member extending in the axial direction. The support 50 projects outward from the inner needle hub 34 and supports the arm 48. The support 50 has a pivot 50a at its outer end. The support 50 is joined to the arm 48 at the pivot 50a. The pivot 50a is located approximately at the center between the tip and the base of the arm 48. The arm 48 is rotatable like a seesaw about the pivot 50a. The support 50 and the arm 48 may be either separate members or integral.

[0021] The tip of the arm 48 is located outside the catheter hub 26. The arm 48 has a first claw 52 at its tip. The first claw 52 has a wedge shape and projects inward from the arm 48. The base of the arm 48 is located outside the operation portion 40. The arm 48 has a second claw 54 at its base. The second claw 54 has a wedge shape and projects inward of the arm 48. In the initial state where the operation portion 40 is in the locked position, the second claw 54 engages with the recess 40c of the operation portion 40. In the initial state, the first claw 52 engages with the flange 28 (fixing portion 44) of the catheter hub 26.

[0022] The arm 48 and the support 50 are shaped into the initial shape shown in FIG. 3B. In the initial shape, the first claw 52 at the tip of the arm 48 is located outside the fixing portion 44. The connecting member 42 in the initial shape does not engage with the fixing portion 44.

[0023] The catheter assembly 10 of the present embodiment has the above configuration. Hereinafter, the operation of the catheter assembly 10 will be described.

[0024] As shown in FIG. 2, for the unused catheter assembly 10, the operation portion 40 is in the locked position. In the operation portion 40 in the locked position, the engaging portion 40b engages with the second claw 54. The engaging portion 40b positions the second claw 54 outward from the initial shape. Due to the outward displacement of the second claw 54, the arm 48 rotates about the pivot 50a, and the first claw 52 at the tip is displaced inward. As a result, the first claw 52 abuts against the tip side of the flange 28 (fixed portion 44) of the catheter hub 26 and engages with the flange 28. When an operating force directed toward the proximal end side is input to the inner needle hub 34, the first claw 52 catches on the flange 28 (fixed portion 44). The first claw 52 prevents the inner needle hub 34 from detaching from the catheter hub 26. Also, the displacement of the inner needle hub 34 in the distal end direction is prevented by the insertion portion 36 abutting against the catheter hub 26. Thus, the hub lock mechanism 20 prevents relative displacement in the axial direction between the catheter hub 26 and the inner needle hub 34.

[0025] After the catheter body 24 secures a blood vessel, the inner needle assembly 18 is removed from the catheter 16. When removing the inner needle assembly 18, the unlocking operation of the hub lock mechanism 20 shown in FIGS. 3A and 3B is performed. The unlocking operation is performed by sliding the operation portion 40 toward the proximal end side. Such an operation can be carried out by the user displacing the operation portion 40 toward the proximal end side with the thumb or the like while holding the inner needle hub 34. The user can perform the unlocking operation without changing the hand holding the inner needle hub 34. When the operation portion 40 is displaced from the locked position toward the proximal end side, as shown in FIG. 3A, the second claw 54 disengages from the recess 40c of the engaging portion 40b.

[0026] As shown in FIG. 3B, when the operation portion 40 moves to the release position, the engaging portion 40b completely disengages from the second claw 54. The arm 48 and the support 50 return to their initial shapes. As a result, the first claw 52 at the tip of the arm 48 is displaced outward, and the engagement between the first claw 52 and the flange 28 (fixed portion 44) is released. As a result, the inner needle hub 34 can be displaced toward the proximal end side with respect to the catheter hub 26. By the above operations, the inner needle hub 34 can be pulled out from the catheter hub 26.

[0027] In the catheter assembly 10 of the present embodiment, the fixing force between the inner needle assembly 18 and the catheter 16 is generated by the hub locking mechanism 20. Therefore, the catheter assembly 10 can prevent the displacement of the inner needle assembly 18 at an unintended timing. Further, after releasing the hub locking mechanism 20, the catheter assembly 10 can easily remove the inner needle assembly 18 from the catheter 16, and can prevent the event that the catheter 16 is pulled out from the blood vessel together with the inner needle assembly 18.

[0028] (Second Embodiment) As shown in FIG. 4, the catheter assembly 10A of the present embodiment includes a catheter 16, an inner needle assembly 18, and a hub locking mechanism 20A. The catheter assembly 10A is different from the catheter assembly 10 described with reference to FIGS. 1 to 3B in the hub locking mechanism 20A. In the configuration of the catheter assembly 10A, the same components as the corresponding components of the catheter assembly 10 in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0029] As shown in FIG. 5, the hub locking mechanism 20A includes an operation portion 40A, a connection member 42A, and a fixing portion 44 (flange 28). The operation portion 40A includes a sliding portion 40a that slides along the outer peripheral surface of the gripping portion 38. The moving direction of the sliding portion 40a is guided by a guide frame 46. The operation portion 40A has a biasing piece 56 at the tip of the sliding portion 40a.

[0030] The biasing piece 56 is a member that abuts against the outside of the connection member 42A and biases the connection member 42A inward. The biasing piece 56 has higher rigidity than the connection member 42A and has rigidity that does not deform outward yielding to the connection member 42A. Therefore, the biasing piece 56 has a wall thickness dimension larger than that of the connection member 42A. The biasing piece 56 may be formed of a material having higher rigidity than the material constituting the connection member 42A.

[0031] The biasing piece 56 has an upright portion 56a and an extending portion 56b, and has an L-shaped configuration in plan view. The upright portion 56a bends 90° from the sliding portion 40a and protrudes outward. The extending portion 56b bends 90° from the outer end of the upright portion 56a toward the tip and extends toward the tip. The extending portion 56b has a pressing protrusion 56c at the tip. The pressing protrusion 56c is a protrusion that protrudes short inward from the extending portion 56b. The pressing protrusion 56c has a hemispherical shape or a protrusion with a pointed tip. The pressing protrusion 56c abuts against the connecting member 42A from the outside and biases the connecting member 42A inward.

[0032] The connecting member 42A has an arm 48A, a support 50A, and a first claw 52. The arm 48A is a rod-shaped member extending in the axial direction. The tip of the arm 48A extends outside the flange 28 (fixing portion 44) of the catheter hub 26. The arm 48A has a first claw 52 at the tip. The base end of the arm 48A is located outside the insertion portion 36. The base end of the arm 48A is supported by the support 50A.

[0033] The support 50A has its inner end joined to the inner needle hub 34. The support 50A has a pivot 50b at its outer end. The support 50A is joined to the arm 48A at the pivot 50b. The pivot 50b is located at the base end of the arm 48A. The arm 48A is rotatable about the pivot 50b.

[0034] As shown in FIG. 6B, the connecting member 42A is shaped into an initial L-shaped configuration in which the arm 48A and the support 50A are bent 90°. In the initial configuration of the connecting member 42A, the first claw 52 is spaced apart from the flange 28 (fixing portion 44). In the initial configuration, the first claw 52 of the connecting member 42A does not engage with the flange 28 (fixing portion 44).

[0035] In the hub block mechanism 20A of the present embodiment, the configuration of the fixing portion 44 is the same as that of the fixing portion 44 of the first embodiment.

[0036] The catheter assembly 10A of this embodiment is configured as described above. Next, the operation of the catheter assembly 10A will be described.

[0037] As shown in FIG. 5, in the unused catheter assembly 10A, the operation unit 40A is located at the lock position. In the operation unit 40A at the lock position, the biasing piece 56 is located outside the connecting member 42A. The biasing piece 56 biases the arm 48A inward by the pressing projection 56c abutting against the arm 48A. The pressing projection 56c abuts against the arm 48A on the tip side of the support 50A. The arm 48A rotates and displaces about the pivot 50b by the biasing force of the biasing piece 56. The rotational displacement of the arm 48A displaces the first claw 52 at the tip inward from the initial shape. As a result, the first claw 52 abuts against the tip side of the flange 28 (fixed portion 44) of the catheter hub 26 and engages with the flange 28.

[0038] When an operating force for displacing the inner needle hub 34 toward the proximal end side is input, the first claw 52 is caught by the flange 28 (fixed portion 44) of the catheter hub 26. When the first claw 52 is caught, the pulling out of the inner needle hub 34 from the catheter hub 26 is prevented. Further, with respect to the displacement of the inner needle hub 34 in the distal end direction, the insertion portion 36 of the inner needle hub 34 abuts against the cavity 26c (see FIG. 1) of the catheter hub 26, thereby preventing the displacement of the inner needle hub 34 in the distal end direction with respect to the catheter hub 26. In this way, the hub lock mechanism 20A prevents the relative displacement between the catheter hub 26 and the inner needle hub 34.

[0039] The inner needle assembly 18 is removed from the catheter 16 after the catheter body 24 secures a blood vessel. When removing the inner needle assembly 18, the unlocking operation of the hub lock mechanism 20A shown in FIGS. 6A and 6B is performed. The unlocking operation is performed by an operation of sliding the operation unit 40A toward the proximal end side. This operation can be performed in the same manner as the operation unit 40 (first embodiment). As shown in FIG. 6A, with the unlocking operation, the biasing piece 56 is displaced toward the proximal end side integrally with the operation unit 40A.

[0040] As shown in FIG. 6B, when the operation unit 40A is displaced to the release position, the biasing piece 56 is completely disengaged from the connection member 42A. The arm 48A and the support 50A return to their initial shapes. As a result, the first claw 52 at the tip of the arm 48A is displaced outward, and the engagement between the first claw 52 and the flange 28 (fixed portion 44) is released. Thereby, the inner needle hub 34 becomes displaceable toward the proximal end side with respect to the catheter hub 26. By the above operations, the release operation of the hub lock mechanism 20A is completed.

[0041] As described above, the catheter assembly 10A of the present embodiment can also obtain the same effects as the catheter assembly 10 of the first embodiment.

[0042] (Third Embodiment) As shown in FIG. 7, the catheter assembly 10B of the present embodiment includes a catheter 16, an inner needle assembly 18, and a hub lock mechanism 20B. The catheter assembly 10B is different from the catheter assembly 10 described with reference to FIGS. 1 to 3B in the hub lock mechanism 20B. In the configuration of the catheter assembly 10B, the same components as the corresponding components of the catheter assembly 10 in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0043] As shown in FIG. 8A, the hub lock mechanism 20B includes an operation unit 40B, a connection member 42B, and a fixed portion 44B. The operation unit 40B includes a sliding portion 40a that slides along the outer peripheral surface of the gripping portion 38. The moving direction of the sliding portion 40a is guided by the guide frame 46. The operation unit 40B has a connecting piece 58 at the tip of the sliding portion 40a. The connecting piece 58 has an upright portion 58a and an extending portion 58b, and has an L-shaped shape in plan view. The upright portion 58a bends 90° from the sliding portion 40a and protrudes outward. The extending portion 58b bends 90° from the outer end of the upright portion 58a toward the tip and extends toward the tip.

[0044] The connecting member 42B is located at the tip of the extending portion 58b. The connecting member 42B is integrally formed with the extending portion 58b. The connecting member 42B has a weak portion 60 at the boundary with the extending portion 58b. As shown in FIG. 8B, the weak portion 60 has a pair of groove portions 60a, 60b and a thin portion 60c on both sides in the thickness direction. The groove portions 60a, 60b have a V-shaped cross section. The thin portion 60c is formed between the pair of groove portions 60a, 60b. The thin portion 60c is located at the boundary between the connecting member 42B and the extending portion 58b. The thin portion 60c can be broken by an axial tensile force.

[0045] As shown in FIG. 8A, the fixing portion 44B is located on the outer periphery of the catheter hub 26. The inner end of the fixing portion 44B is joined to the catheter hub 26. The outer end of the fixing portion 44B protrudes outside the catheter hub 26. The outer end of the fixing portion 44B is located radially outside the flange 28. The tip of the connecting member 42B is joined to the fixing portion 44B. Various fixing methods such as adhesion, welding, caulking, or screwing are used for the joining of the fixing portion 44B and the connecting member 42B. The joining strength between the fixing portion 44B and the connecting member 42B is greater than the strength (breaking load value) of the weak portion 60. Note that the fixing portion 44B and the connecting member 42B may be integrally formed.

[0046] The catheter assembly 10B of the present embodiment has the above configuration. Next, the operation of the catheter assembly 10B will be described.

[0047] As shown in FIG. 7, in the unused catheter assembly 10B, the catheter hub 26 and the inner needle hub 34 are joined via the hub lock mechanism 20B. In the hub lock mechanism 20B, the operation portion 40B, the connecting member 42B, and the fixing portion 44B are joined.

[0048] When an operating force for displacing the inner needle hub 34 toward the proximal end side is input, the joint portion of the operation portion 40B, the connecting member 42B, and the fixing portion 44B prevents the axial displacement of the inner needle hub 34.

[0049] When removing the inner needle assembly 18, the release operation of the hub lock mechanism 20B shown in FIGS. 9A and 9B is performed. The release operation is started by an operation of sliding the operation portion 40B toward the proximal end side. This operation is performed by displacing the operation portion 40B toward the proximal end side as shown in FIG. 9A. By the operation of displacing the operation portion 40B toward the proximal end side, a tensile force acts on the fragile portion 60.

[0050] When a sufficient tensile force acts, as shown in FIG. 9B, the fragile portion 60 breaks. The operation portion 40B separates from the connection member 42B. The connection member 42B is kept in a state of being joined to the fixing portion 44B. Thereby, the release operation of the hub lock mechanism 20B is completed. By displacing the operation portion 40B to the release position, the user can recognize the completion of the release of the hub lock mechanism 20B.

[0051] As described above, the catheter assembly 10B of the present embodiment can also obtain the same effects as the catheter assembly 10 of the first embodiment.

[0052] The technical idea obtained from the above embodiment is summarized below.

[0053] The above-described embodiment includes a catheter body 24 having a lumen 24a, a catheter hub 26 fixed to a proximal end portion 24c of the catheter body, an inner needle 32 inserted into the lumen of the catheter body, an inner needle hub 34 fixed to a proximal end of the inner needle, and a hub lock mechanism 20 that removably fixes the catheter hub and the inner needle hub. The hub lock mechanism includes an operation portion 40 attached to the inner needle hub and displaced by a user's operation, a fixing portion 44 attached to the catheter hub, and a connection member 42 that connects the fixing portion and the operation portion. When the operation portion is located at the lock position, the connection member connects the operation portion and the fixing portion to prevent an axial relative displacement between the catheter hub and the inner needle hub. When the operation portion is located at the release position, the connection member releases the connection between the operation portion and the fixing portion to allow the relative displacement between the catheter hub and the inner needle hub. The present invention relates to a catheter assembly.

[0054] The above catheter assembly obtains the fixing force between the catheter body and the inner needle hub by means of a hub locking mechanism. Thereby, the catheter assembly can obtain a reliable fixing force with little variation. Therefore, the catheter assembly can prevent displacement between the catheter body and the inner needle hub during use. Also, by releasing the hub locking mechanism, the inner needle hub can be easily pulled out, so that the catheter assembly can prevent the event that the catheter body is pulled out from the blood vessel. Furthermore, since the catheter assembly can perform the release operation by operating the operation part without replacing the inner needle hub, it has excellent operability.

[0055] In the above catheter assembly, the fixing part may be a flange 28 protruding outward from the catheter hub. This catheter assembly does not require a change in the catheter hub and can utilize existing products.

[0056] In the above catheter assembly, the connecting member has an arm 48 having a first claw 52 engaging with the fixing part at the tip and a second claw 54 engaging with the operation part at the base end, and is joined to the inner needle hub and supports the arm 50. The arm may be displaced from the lock position to the release position of the operation part, causing the second claw to disengage from the operation part, so that the first claw is displaced outward of the fixing part to release the engagement between the connecting member and the fixing part. This catheter assembly can generate a reliable fixing force with a simple structure.

[0057] In the above catheter assembly, the support body is joined to the arm at an intermediate position between the tip and the base end of the arm, and the support body supports the arm in an initial shape in which the first claw of the arm is separated from the fixing part. The operation part may bias the arm through the second claw at the lock position to engage the first claw with the fixing part against the initial shape of the arm. This catheter assembly can surely release the engagement between the arm and the fixing part only by removing the operation part from the second claw part.

[0058] In the above-described catheter assembly, the connecting member 42A includes an arm 48A having a first claw at its tip that engages with the fixing portion, and a support 50A that is joined to the inner needle hub and supports the base end of the arm. The operating portion 40A has a biasing piece 56 that abuts against the outer side of the arm at the locking position and biases the arm toward the fixing portion. When the operating portion is displaced to the release position, the biasing piece may disengage from the arm to release the engagement between the first claw of the arm and the fixing portion. In this catheter assembly, since the first claw is engaged with the fixing portion by an external biasing force applied to the arm, a fixing force can be generated more reliably.

[0059] In the above-described catheter assembly, the connecting member 42B is integrally joined to the operating portion via a fragile portion 60 that breaks when the operating portion 40B is displaced. The tip of the connecting member is joined to the fixing portion 44B, and the connecting member may be separated from the operating portion when the fragile portion breaks. In this catheter assembly, by integrating the connecting member with the operating portion, the number of parts can be reduced, and further simplification of the structure can be achieved.

[0060] In the above-described catheter assembly, the operating portion may be displaced in the axial direction. Such an operating portion is easy to input an operating force with the hand holding the inner needle hub and has excellent operability.

[0061] Note that the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

Explanation of Reference Numerals

[0062] 10, 10A, 10B... Catheter assemblies 20, 20A, 20B... Hub lock mechanisms 24... Catheter body 26... Catheter hub 28... Flange 32... Inner needle 34... Inner needle hub 40, 40A, 40B... Operating portions 42, 42A, 42B... Connecting members 44, 44B... Fixing portions 48, 48A... arms 50, 50A... supports 52... first claw 54... second claw 56... biasing piece 60... weak part

Claims

1. A catheter body having a lumen, A catheter hub fixed to the proximal end of the catheter body, An inner needle inserted through the lumen of the catheter body, An inner needle hub fixed to the proximal end of the inner needle, A hub locking mechanism for releasably fixing the catheter hub and the inner needle hub, and the hub locking mechanism includes An operation part attached to the inner needle hub and displaced by the operation of the user, A fixing part attached to the catheter hub, A connecting member connecting the fixing part and the operation part, and has When the operation part is in the locked position, the connecting member connects the operation part and the fixing part to prevent axial relative displacement between the catheter hub and the inner needle hub; when the operation part is in the released position, the connecting member disconnects the connection between the operation part and the fixing part to allow the relative displacement between the catheter hub and the inner needle hub, The connecting member An arm having a first claw engaging with the fixing part at the tip and a second claw engaging with the operation part at the base end, A support body joined to the inner needle hub and supporting the arm, and has When the second claw disengages from the operation part due to the displacement of the operation part from the locked position to the released position, the first claw is displaced outward of the fixing part to release the engagement between the connecting member and the fixing part, Catheter assembly.

2. The catheter assembly according to Claim 1, wherein The fixing part is a flange protruding outward from the catheter hub, Catheter assembly.

3. The catheter assembly according to Claim 1 or 2, wherein The support body is joined to the arm at the center between the tip and the base end of the arm, and the support body supports the arm in an initial shape in which the first claw of the arm is separated from the fixing part, The operation part biases the arm through the second claw at the locked position to engage the first claw with the fixing part against the initial shape of the arm, Catheter assembly.

4. A catheter body having a lumen, A catheter hub fixed to the proximal end of the catheter body, An inner needle inserted through the lumen of the catheter body, An inner needle hub fixed to the proximal end of the inner needle, A hub locking mechanism for releasably fixing the catheter hub and the inner needle hub, and the hub locking mechanism includes An operating part attached to the inner needle hub and displaced by a user's operation; A fixing part attached to the catheter hub; A connecting member connecting the fixing part and the operating part; and When the operating part is in the locked position, the connecting member connects the operating part and the fixing part to prevent axial relative displacement between the catheter hub and the inner needle hub. When the operating part is in the released position, the connecting member releases the connection between the operating part and the fixing part to allow the relative displacement between the catheter hub and the inner needle hub. The connecting member is integrally joined to the operating part via a weak part that breaks due to displacement of the operating part. The connecting member has a tip joined to the fixing part and separates from the operating part when the weak part breaks. Catheter assembly.

5. The catheter assembly according to any one of claims 1 to 4, wherein the operating part is displaced in the axial direction. Catheter assembly.

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