Catheter assembly

Abstract

A catheter assembly (10) comprises a needle protection structure (18) that covers an inner needle (26) as a result of being actuated through the repulsion force of a biasing member (54). The catheter assembly (10) comprises a trigger structure (20) for causing the needle protection structure (18) to be actuated in conjunction with a needle hub (16) moving relatively toward the proximal end direction with respect to a catheter hub (24). The trigger structure (20) comprises an interlocking member (64) that is actuated in unison with the relative movement of the needle hub (16) in the proximal end direction with respect to the catheter hub (24). When the interlocking member (64) presses an operation button (58), the operation button (58) moves to an operation position, and the inner needle (26) is covered by an accommodation part (56).

Description

Catheter Assembly

[0001] The present invention relates to a catheter assembly for subcutaneously injecting a medicinal liquid into a living body.

[0002] The catheter assembly includes a catheter having an open tip, a catheter hub connected to the base end of the catheter, and an inner needle that is inserted into the lumen of the catheter and can be inserted into a living body.

[0003] JP 2001-502191 A discloses a needle protection device capable of protecting a needle tip, such as the tip of an inner needle in a catheter assembly. The needle protection device includes a needle guard slidably mounted on the inner needle, a spring that biases the needle guard toward the distal end of the inner needle, and a button that restricts movement of the needle guard toward the distal end. When a user presses the button, the engagement between the button and the needle guard is released, and the needle guard moves toward the distal end due to the resilient force of the spring. The needle guard covers the tip of the inner needle, preventing it from being exposed.

[0004] Special Publication No. 2001-502191

[0005] The needle protection device in JP 2001-502191 A is configured so that the user can press a button to activate the needle guard toward the tip. Therefore, if, for example, the user forgets to press the button when removing the inner needle from the living body, the needle guard will not move toward the tip, leaving the tip of the inner needle exposed, which could result in an accidental puncture.

[0006] The present invention aims to solve the above-mentioned problems.

[0007] (1) An aspect of the present invention comprises a tubular catheter body, a catheter hub connected to a proximal end of the catheter body, an inner needle inserted into a lumen of the catheter body and protruding from a tip of the catheter body in a distal direction, a needle hub provided at the proximal end of the inner needle and connected to the proximal end of the catheter hub, a needle protection structure that covers at least the tip of the inner needle by being actuated using the elastic force of an urging member, and a trigger structure that actuates the needle protection structure in accordance with relative movement of the needle hub in a proximal direction with respect to the catheter hub, wherein the needle protection structure comprises the urging member, a housing portion that is movable relative to the inner needle in the axial direction of the inner needle and that is capable of covering at least the tip of the inner needle, and the needle hub and an activation button movably provided on the outer periphery of the needle hub, wherein when the activation button is located in an initial position, relative movement between the inner needle and the accommodating section is restricted against the elastic force of the urging member, and when the activation button moves from the initial position to an activated position, relative movement between the inner needle and the accommodating section is enabled, so that the accommodating section covers at least the tip of the inner needle by utilizing the elastic force of the urging member, and the trigger structure comprises an interlocking member which is provided on the outside of the needle hub and presses the activation button in conjunction with relative movement of the needle hub in the proximal direction with respect to the catheter hub, and when the interlocking member presses the activation button, the activation button moves to the activated position.

[0008] With this catheter assembly, when the user withdraws the inner needle from the catheter, the interlocking member presses the activation button in conjunction with the needle hub pull-out action, thereby activating the needle protection structure. Therefore, the needle protection structure can be activated without the user having to intentionally operate the activation button, effectively preventing accidental punctures after the inner needle has been withdrawn from the catheter.

[0009] (2) In the catheter assembly described in (1) above, the interlocking member has an operating part facing the activation button and is swingably supported on a support part provided on the outer periphery of the needle hub, further distal than the operating part, and the interlocking member may swing so that the operating part presses the activation button toward the activation position as the needle hub moves relative to the catheter hub in the proximal direction.

[0010] With this configuration, by moving the needle hub relative to the catheter hub in the proximal direction, the interlocking member is swung, and the operating button can be pressed by the operating unit.

[0011] (3) In the catheter assembly described in (2) above, the interlocking member may have an inner protrusion that protrudes toward the outer peripheral surface of the catheter hub distally of the support portion, and the catheter hub may have an outer protrusion that protrudes outward from the outer peripheral surface of the catheter hub. When the needle hub is connected to the base end of the catheter hub, the inner protrusion may be positioned in the distal direction relative to the outer protrusion and closer to the outer peripheral surface of the catheter hub than the tip of the outer protrusion. When the needle hub is moved relative to the catheter hub in the proximal direction, the inner protrusion may ride up on the outer protrusion, causing the interlocking member to swing around the support portion as a fulcrum, and the operating portion may press the activation button.

[0012] With this configuration, the needle hub is moved relative to the catheter hub in the proximal direction, and the interlocking member is swung in conjunction with the movement of the outer protrusion over the inner protrusion, allowing the activation button to be pressed with the operating unit. This prevents forgetting to press the activation button and ensures that the activation button is pressed reliably.

[0013] (4) In the catheter assembly described in (3) above, when the needle hub is connected to the base end of the catheter hub, a resilient member having a resilient force that urges the interlocking member so that the inward protrusion of the interlocking member moves toward the outer peripheral surface of the catheter hub, with the support portion as a fulcrum.

[0014] With this configuration, when the catheter assembly, in which the catheter hub and needle hub are connected, is in a puncture state, the resilience of the resilient member allows the end of the inner protrusion to be positioned closer to the catheter hub than the outer protrusion, thereby preventing the operating part of the interlocking member from accidentally pressing the activation button.

[0015] (5) In the catheter assembly described in (3) or (4) above, one of the outer protrusion and the inner protrusion may have a guide groove formed in it, into which the other protrusion is inserted, extending in the axial direction of the needle hub.

[0016] With this configuration, when the needle hub is moved relative to the catheter hub in the base end direction and the inner protrusion overcomes the outer protrusion, the outer protrusion can be prevented from shifting position relative to the inner protrusion in a direction perpendicular to the base end direction and can be kept facing each other in the axial direction.

[0017] (6) In the catheter assembly described in any one of (3) to (5) above, the outward protrusion may be a lock fitting portion that can be fitted into a supply tool for supplying a medicinal solution to the catheter hub.

[0018] With this configuration, by utilizing the lock fitting portion of the catheter hub, there is no need to provide a new outward protrusion, making manufacturing easier and reducing manufacturing costs.

[0019] (7) In the catheter assembly described in any one of (1) to (6) above, the housing portion may be provided inside the needle hub and be capable of housing the inner needle. With this configuration, by housing the inner needle in the housing portion of the needle hub, the inner needle will not be exposed to the outside.

[0020] According to the present invention, when the user withdraws the inner needle from the catheter, the interlocking member of the trigger structure presses the activation button in conjunction with the needle hub pull-out action, thereby activating the needle protection structure. Therefore, the needle protection structure can be activated without the user having to intentionally operate the activation button, effectively preventing accidental punctures after the inner needle is withdrawn from the catheter.

[0021] FIG. 1 is an overall cross-sectional view of a catheter assembly according to an embodiment of the present invention. FIG. 2 is an explanatory view showing the puncture state of the catheter assembly. FIG. 3 is an enlarged cross-sectional view of the needle protection structure and trigger structure of the catheter assembly. FIG. 4 is a plan view of the needle protection structure shown in FIG. 3. FIG. 5A is a cross-sectional view taken along line VA-VA in FIG. 1. FIG. 5B is a cross-sectional view taken along line VB-VB in FIG. 7. FIG. 6 is a first explanatory view showing removal of the inner needle of the catheter assembly. FIG. 7 is a second explanatory view showing removal of the inner needle of the catheter assembly. FIG. 8 is a third explanatory view showing removal of the inner needle of the catheter assembly. FIG. 9 is an enlarged cross-sectional view showing a catheter assembly according to a modified example.

[0022] As shown in FIG. 1, at least the distal end of the catheter assembly 10 according to this embodiment is inserted into a living body B (see FIG. 2) and a portion of the catheter assembly 10 is retained within the living body B.

[0023] The catheter assembly 10 includes a catheter 12, a needle member 14 inserted inside the catheter 12, a needle protection structure 18 that covers at least the tip of the needle member 14 by moving a needle hub 16 of the needle member 14 in the proximal direction relative to a catheter hub 24, and a trigger structure 20 that activates the needle protection structure 18 in response to the relative movement of the needle hub 16 in the proximal direction relative to the catheter hub 24. As shown in Figure 2, the target site T of the living body B is, for example, biological tissue from the epidermis of the skin to a blood vessel BV in the living body B.

[0024] As shown in FIG. 1 , the catheter 12 includes a tubular catheter body 22 and a catheter hub 24 connected to the proximal end of the catheter body 22. The catheter body 22 is formed in a tubular shape with an internal lumen 221. The catheter body 22 is flexible. The distal end of the catheter body 22 may be tapered toward the distal end, for example. The distal end of the catheter body 22 opens toward the distal end. The distal end of the catheter body 22 is the end that is inserted into a living body B. An inner needle 26 of the needle member 14 is inserted into the lumen 221. The distal end of the inner needle 26 protrudes from the distal end of the catheter body 22.

[0025] 3 , the catheter hub 24 is cylindrical and has a hub lumen 28. The catheter hub 24 includes a first hub body 30, a hub distal end 32 provided at the distal end of the first hub body 30, and a hub proximal end 34 located at the proximal end of the first hub body 30. The hub lumen 28 extends axially from the hub distal end 32 to the hub proximal end 34. The distal end of the hub lumen 28 communicates with the lumen 221 of the catheter body 22.

[0026] The hub proximal end 34 has a lock fitting 36 that protrudes radially outward. The needle hub 16 of the needle member 14 is inserted into the proximal end of the first hub body 30. When the needle member 14 is removed proximally from the catheter 12, a supply tool for supplying a drug solution, such as a syringe or drug solution tube, can be connected to the proximal end of the first hub body 30. At this time, the supply tool, such as a syringe or drug solution tube, is fitted into and fixed in place in the lock fitting 36.

[0027] The catheter hub 24 has an outer protrusion 38 that protrudes radially outward from the outer peripheral surface of the catheter hub 24. The outer protrusion 38 is provided in the axial middle of the first hub body 30. The outer protrusion 38 protrudes in a direction perpendicular to the axial direction of the catheter hub 24. When viewed in the axial direction of the catheter hub 24, the outer protrusion 38 is formed in a rectangular shape that is elongated in the radial direction (see FIG. 5B). The outer protrusion 38 has a first protruding end portion 381 at its radially outer end. The first protruding end portion 381 has an end face that is approximately perpendicular to the extension direction of the outer protrusion 38.

[0028] The needle member 14 includes an inner needle 26, a needle holder 40 connected to the proximal end of the inner needle 26, and a needle hub 16 capable of accommodating the inner needle 26 and the needle holder 40. As shown in Figure 2, the distal end of the catheter assembly 10 including the catheter 12 is inserted subcutaneously into a living body B. The needle holder 40 and the inner needle 26 are arranged coaxially. The proximal end of the needle holder 40 has a holding portion 401 that expands radially outward.

[0029] 3, the needle hub 16 is cylindrical and has a hub lumen 161. The needle hub 16 includes a second hub body 42 and a hub tip portion 44 provided at the tip of the second hub body 42.

[0030] A portion of the second hub body 42 is housed inside a cylindrical housing 46. The tip of the second hub body 42 has an exposed portion 421 that protrudes distally from the housing 46. A portion of the second hub body 42 excluding the exposed portion 421 is housed inside the cylindrical housing 46. The second hub body 42 is held relative to the housing 46. The exposed portion 421 has a pair of insertion holes 481, 482. The pair of insertion holes 481, 482 are provided at the base end of the exposed portion 421 and penetrate the peripheral wall of the needle hub 16 in a direction perpendicular to the axial direction of the needle hub 16.

[0031] 1, a cap 50 is attached to the base end of the second hub body 42. The cap 50 closes the base end of the second hub body 42.

[0032] 3, the hub tip portion 44 is formed with a smaller diameter than the second hub body 42. The hub tip portion 44 is connected to the hub proximal end portion 34 of the catheter hub 24 by inserting it distally. At this time, the second hub body 42 of the needle hub 16 abuts against the lock fitting portion 36, thereby positioning the needle hub 16 and the catheter hub 24 in the axial direction of the catheter assembly 10.

[0033] The hub bore 161 has a step 52 at the boundary between the second hub body 42 and the hub tip portion 44. The step 52 is formed in an annular shape that extends radially outward from the hub tip portion 44.

[0034] The needle protection structure 18 comprises a biasing member 54 provided inside the needle hub 16 and biasing the inner needle 26 in the proximal direction, a housing portion 56 capable of covering at least the tip of the inner needle 26, and an actuation button 58 provided movably on the outer periphery of the needle hub 16. The housing portion 56 is a hub lumen 161 in the second hub body 42 of the needle hub 16.

[0035] The biasing member 54 is, for example, a spring member having a resilient force in the axial direction. The biasing member 54 is provided in the hub lumen 161 of the needle hub 16. The distal end of the biasing member 54 abuts against the stepped portion 52, and the proximal end abuts against the holding portion 401 of the needle holder 40. The biasing force of the biasing member 54 acts on the needle holder 40 and the inner needle 26 in the needle hub 16 toward the proximal end.

[0036] The activation button 58 is provided at the tip of the housing 46. The activation button 58 is provided to be movable in a direction perpendicular to the axial direction of the housing 46. The activation button 58 includes a pressing portion 581 disposed on the outer periphery of the housing 46 and a wall portion 582 disposed at the tip of the pressing portion 581. The pressing portion 581 is a plate piece disposed parallel to the axial direction of the housing 46. The pressing portion 581 extends from the tip of the housing 46 toward the base end. The activation button 58 is biased radially outward by a biasing means (not shown). As shown in FIG. 3 , in the initial position where no load is applied to the activation button 58, the pressing portion 581 is disposed radially outward relative to the outer circumferential surface of the housing 46. That is, the pressing portion 581 is raised radially outward from the outer circumferential surface of the housing 46. As shown in FIG. 7 , in the actuated position where the pressing portion 581 is biased toward the outer circumferential surface of the housing 46, the pressing portion 581 moves toward the housing 46. The pressing portion 581 is housed in a recess 461 formed on the outer circumferential surface of the housing 46 .

[0037] As shown in FIG. 3 , the wall portion 582 is provided at the tip of the pressing portion 581. The wall portion 582 extends in a direction perpendicular to the pressing portion 581. The wall portion 582 is inserted into a pair of insertion holes 481, 482 in the needle hub 16. The wall portion 582 has a passage hole 60 through which the needle member 14 can pass and a locking portion 62 that prevents the needle member 14 from moving. The passage hole 60 penetrates the wall portion 582. The passage hole 60 is disposed adjacent to the pressing portion 581. When the needle hub 16 is viewed in the axial direction, the diameter of the passage hole 60 is equal to or greater than the diameters of the biasing member 54 and the needle member 14. When the pressing portion 581 is pressed and moved toward the housing 46, the biasing member 54 and the needle member 14 become coaxial with the passage hole 60.

[0038] The locking portion 62 is provided at the end of the wall portion 582. The locking portion 62 is formed at the end opposite the pressing portion 581, with the passage hole 60 in between. In the initial position where no load is applied to the activation button 58, the locking portion 62 is disposed within the hub lumen 161 through the insertion holes 481, 482. The locking portion 62 protrudes radially inward beyond the inner circumferential surface of the needle hub 16. When the needle holder 40 abuts against the locking portion 62, movement of the needle holder 40 and the inner needle 26 toward the proximal end is prevented. That is, in the initial position, the needle member 14 and the biasing member 54 are housed in the exposed portion 421 and the hub distal end portion 44 of the needle hub 16. At this time, the distal end of the inner needle 26 protrudes distally beyond the distal end of the catheter 12.

[0039] The trigger structure 20 includes an interlocking member 64 provided on the outer periphery of the second hub body 42 of the needle hub 16. The interlocking member 64 is swingably supported by a support portion 66 provided on the outer periphery of the second hub body 42. The support portion 66 protrudes radially outward from the outer periphery of the second hub body 42. The support portion 66 extends in a direction perpendicular to the axial direction of the second hub body 42.

[0040] The interlocking member 64 is disposed radially outwardly and spaced apart from the outer peripheral surface of the needle hub 16. The interlocking member 64 is disposed substantially parallel to the axial direction of the needle hub 16. The interlocking member 64 extends along the axial direction of the needle hub 16.

[0041] The interlocking member 64 has an inward protrusion 68 provided at the tip end and an operating portion 70 provided at the base end. Between the tip and base ends of the interlocking member 64, the interlocking member 64 is pivotally supported on the end of the support portion 66 via a shaft 72.

[0042] The inner protrusion 68 faces the outer peripheral surface of the catheter hub 24 and protrudes in a direction perpendicular to the extension direction of the interlocking member 64. The second protruding end 681, which is the tip of the inner protrusion 68, may have a curved shape that is convex in the protruding direction. The inner protrusion 68 is not limited to being formed in a curved shape. For example, the inner protrusion 68 may have a rectangular shape or a triangular shape that tapers in the protruding direction. That is, the inner protrusion 68 may be formed in any shape that allows it to ride over the outer protrusion 38 without interfering with the movement (pulling operation) of the inner needle 26 when the inner needle 26 is pulled in the proximal direction. The inner protrusion 68 includes a guide groove 74. As shown in FIG. 5A , the guide groove 74 is located in the widthwise center of the inner protrusion 68 when viewed from the axial direction of the needle hub 16. The guide groove 74 is recessed from the second protruding end 681 of the inner protrusion 68. The guide groove 74 has a curved shape that corresponds to the second protruding end 681 of the inner protrusion 68. The guide groove 74 is not limited to being formed in a curved shape. The first protruding end 381 of the outer protrusion 38 can be inserted into the guide groove 74. The guide groove 74 may be formed in a shape that corresponds to the shape of the inner protrusion 68. The guide groove 74 may have a shape that allows the guide groove 74 to ride over the outer protrusion 38 without interfering with the movement (pulling operation) of the inner needle 26 when the inner needle 26 is pulled out in the proximal direction. The guide groove 74 is not limited to being provided in the inner protrusion 68. For example, the guide groove 74 may be provided in the first protruding end 381 of the outer protrusion 38, and the second protruding end 681 of the inner protrusion 68 may be inserted into the guide groove 74. Furthermore, the guide groove 74 may not be provided in either the outer protrusion 38 or the inner protrusion 68.

[0043] When the catheter hub 24 and the needle hub 16 are connected, the inner protrusion 68 is disposed distally relative to the outer protrusion 38. The second protruding end 681, which is the distal end of the inner protrusion 68, is disposed closer to the outer peripheral surface of the catheter hub 24 than the first protruding end 381 of the outer protrusion 38.

[0044] The operating portion 70 is disposed radially outward of the pressing portion 581 of the actuation button 58. The operating portion 70 and the pressing portion 581 are disposed substantially parallel to each other.

[0045] The trigger structure 20 further includes a resilient member 76. The resilient member 76 has a biasing force that biases the distal end of the interlocking member 64 toward the outer circumferential surface of the catheter hub 24. The resilient member 76 is a coil spring with a coil wound around a centerline parallel to the axis of the shaft 72. As shown in FIG. 4 , one end of the resilient member 76 is held by the support portion 66, and the other end of the interlocking member 64 is held on the underside of the interlocking member 64, proximal to the support portion 66. Note that the resilient member 76 is not limited to being disposed between the underside of the interlocking member 64 and the support portion 66. For example, the resilient member 76 may be disposed between the outer circumferential surface of the needle hub 16 and the underside of the interlocking member 64, biasing the interlocking member 64 in a direction away from the needle hub 16. Note that the resilient member 76 may not be disposed between the underside of the interlocking member 64 and the support portion 66, or between the outer circumferential surface of the needle hub 16 and the underside of the interlocking member 64.

[0046] Next, placement of the catheter 12 in the living body B will be described.

[0047] As shown in Figure 1, the catheter assembly 10 is prepared in an initial position where no load is applied to the actuation button 58. As shown in Figure 2, the tip of the inner needle 26 of the catheter assembly 10 is inserted into the skin of a living body B. The tip of the inner needle 26 of the needle member 14 is inserted into the blood vessel BV, and the tip of the catheter main body 22 is inserted into the blood vessel BV. The user then pulls the needle member 14 out of the catheter 12 in the proximal direction to remove it.

[0048] 6 , when the needle hub 16 is moved proximally relative to the catheter 12, the interlocking member 64 of the trigger structure 20 moves proximally together with the needle hub 16. The inner protrusion 68 of the interlocking member 64 comes into contact with the first protruding end 381 of the outer protrusion 38, and the first protruding end 381 begins to be inserted into the guide groove 74. At this time, because the guide groove 74 has a curved shape, the guide groove 74 is smoothly inserted into the first protruding end 381.

[0049] 7, as the needle hub 16 moves toward the proximal end, the inner protrusion 68 rides up onto the outer protrusion 38, causing the interlocking member 64 to begin to rotate around the shaft 72. That is, with the shaft 72 of the support portion 66 as the fulcrum, the distal end of the interlocking member 64 moves in a direction away from the catheter hub 24, and the proximal end moves in a direction approaching the housing 46, thereby swinging.

[0050] As the interlocking member 64 swings, the operating unit 70 presses the pressing portion 581 of the activation button 58 radially inward into the housing 46, placing it in an activated position. This moves the activation button 58 toward the housing 46, and the pressing portion 581 is inserted into the recess 461. The passage hole 60 moves and becomes coaxial with the hub lumen 161, and the locking portion 62 moves radially outward from the inside of the housing 46. This releases the locking portion 62 from preventing the needle 14 from moving proximally.

[0051] The needle member 14 is urged in the proximal direction by the urging force of the urging member 54, and the needle member 14 including the inner needle 26 and needle holder 40 moves from the hub lumen 161 through the passage hole 60 toward the inside of the second hub body 42 in the housing 46. The inner needle 26 is housed in the hub lumen 161 of the needle hub 16 in the housing 46. The tip of the inner needle 26 is covered by the needle hub 16 and does not protrude from the tip of the needle hub 16. As shown in Figure 8, the needle hub 16 with the inner needle 26 housed therein is removed from the catheter 12 in the proximal direction. Removal of the needle member 14 from the catheter 12 is then completed.

[0052] Thereafter, a syringe or a drug solution tube is connected to the hub base end 34 of the catheter hub 24 placed on the skin of the living body B, and the drug solution is administered into the living body B through the lumen of the catheter main body 22 .

[0053] The needle protection structure 18 is not limited to a configuration in which the needle member 14 (inner needle 26) is housed in the housing portion 56 by moving relative to the housing portion 56 in the proximal direction. For example, the housing portion 56 may move relative to the needle member 14 in the distal direction, thereby covering the needle member 14.

[0054] The interlocking member 64 of the trigger structure 20 is not limited to a configuration that allows it to swing via the support portion 66 and the shaft 72. For example, the interlocking member may be configured to slide in the proximal direction along the needle hub 16 as the needle hub 16 moves proximally relative to the catheter hub 24, and the actuation button 58 may be pressed as the interlocking member slides.

[0055] The interlocking member 64 is not limited to a configuration that allows it to swing via a shaft 72 that is arranged perpendicular to the axis of the needle hub 16. For example, the interlocking member may be configured to swing horizontally around a central axis that extends radially perpendicular to the axis of the needle hub 16, and the actuation button 58 may be pressed as the interlocking member swings horizontally.

[0056] This embodiment has the following advantages.

[0057] As shown in Figure 3, the catheter assembly 10 includes a needle protection structure 18 that is actuated by utilizing the elastic force of a biasing member 54 to cover the inner needle 26, and a trigger mechanism 20 that actuates the needle protection structure 18 in response to relative proximal movement of the needle hub 16 with respect to the catheter hub 24. The needle protection structure 18 has a housing 56 that is movable relative to the axial direction of the inner needle 26 and is capable of covering the inner needle 26, and an activation button 58 that is movably provided on the outer periphery of the needle hub 16. The trigger mechanism 20 includes an interlocking member 64 that presses the activation button 58 in response to relative proximal movement of the needle hub 16 with respect to the catheter hub 24. When the interlocking member 64 presses the activation button 58 in response to relative proximal movement of the needle hub 16 with respect to the catheter hub 24, the activation button 58 moves to the activated position and the inner needle 26 is covered by the housing 56.

[0058] As a result, when the user withdraws the inner needle 26 from the catheter 12, the interlocking member 64 presses the activation button 58 in conjunction with the pulling-out action of the needle hub 16, thereby activating the needle protection structure 18. Therefore, the needle protection structure 18 can be activated without the user intentionally operating the activation button 58, effectively preventing accidental puncture after the inner needle 26 is withdrawn from the catheter 12.

[0059] The interlocking member 64 has an operating part 70 facing the activation button 58, and is swingably supported by a support part 66 provided on the outer periphery of the needle hub 16, distal to the operating part 70. As the needle hub 16 moves relative to the catheter hub 24 in the proximal direction, the interlocking member 64 swings so that the operating part 70 presses the activation button 58 toward the activated position (see FIG. 6 ).

[0060] As a result, by moving the needle hub 16 relative to the catheter hub 24 in the proximal direction, the interlocking member 64 can be swung, and the operating button 58 can be pressed by the operating unit 70.

[0061] The interlocking member 64 has an inner protrusion 68 that protrudes toward the outer peripheral surface of the catheter hub 24 distally of the support portion 66. The catheter hub 24 has an outer protrusion 38 that protrudes outward from the outer peripheral surface of the catheter hub 24. When the needle hub 16 is connected to the proximal end of the catheter hub 24, the inner protrusion 68 is positioned distally relative to the outer protrusion 38 and is positioned closer to the outer peripheral surface of the catheter hub 24 than the first protruding end 381 (tip) of the outer protrusion 38.

[0062] 7, the needle hub 16 is moved relative to the catheter hub 24 in the proximal direction, and the interlocking member 64 is swung in conjunction with the movement of the inner protrusion 68 overcoming the outer protrusion 38, thereby allowing the activation button 58 to be pressed by the operating unit 70. This prevents the user from forgetting to press the activation button 58 and ensures that the activation button 58 is pressed reliably.

[0063] As shown in Figure 3, when the needle hub 16 is connected to the base end of the catheter hub 24, a resilient member 76 is provided that has a resilient force that urges the interlocking member 64 so that the inner protrusion 68 of the interlocking member 64 moves toward the outer peripheral surface of the catheter hub 24, with the support portion 66 as a fulcrum.

[0064] 2, when the catheter assembly 10 is in a puncture state in which the catheter hub 24 and the needle hub 16 are connected, the resilient force of the resilient member 76 can position the end of the inner protrusion 68 closer to the catheter hub 24 than the outer protrusion 38. This prevents the operating part 70 of the interlocking member 64 from accidentally pressing the activation button 58.

[0065] 5B, the inner protrusion 68 has a guide groove 74 formed therein, into which the outer protrusion 38 is inserted and which extends in the axial direction of the needle hub 16. As a result, when the needle hub 16 is moved relative to the catheter hub 24 in the proximal direction and the inner protrusion 68 passes over the outer protrusion 38, the outer protrusion 38 can be prevented from shifting position relative to the inner protrusion 68 in the direction perpendicular to the proximal direction, and can be kept facing each other in the axial direction.

[0066] 7 , the housing portion 56 is provided inside the needle hub 16 and is capable of housing the inner needle 26. As a result, when the needle member 14 is removed from the catheter 12, the needle member 14 is housed in the housing portion 56 of the needle hub 16, so that the needle member 14 is not exposed to the outside, and accidental puncture by the needle member 14 can be prevented.

[0067] As shown in Figure 9, a catheter assembly 10A according to a modified example has an outer protrusion 38A on the outer periphery of the catheter hub 24. The outer protrusion 38A is a lock fitting 36A provided on the hub proximal end 34. When the needle hub 16 is connected to the hub proximal end 34 of the catheter hub 24, the inner protrusion 68 of the interlocking member 64 is positioned further distally than the lock fitting 36A. The inner protrusion 68 engages with the lock fitting 36A.

[0068] By moving the needle hub 16 relative to the catheter hub 24 in the proximal direction, the inner protrusion 68 of the interlocking member 64 swings over the lock fitting portion 36A, and the pressing portion 581 of the activation button 58 is pressed by the operating portion 70.

[0069] This modification has the following advantages.

[0070] As shown in Figure 9, the outer protrusion 38A is a lock fitting portion 36A that can be fitted into a supply tool for supplying medicinal liquid to the catheter hub 24. Therefore, by utilizing the lock fitting portion 36A of the catheter hub 24, there is no need to provide a new outer protrusion 38, making manufacturing easier and reducing the manufacturing costs of the catheter assembly 10A.

[0071] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

Claims

a catheter hub connected to the proximal end of the catheter body; an inner needle inserted into the lumen of the catheter body and protruding in a distal direction from the tip of the catheter body; a needle hub provided at the proximal end of the inner needle and connected to the proximal end of the catheter hub; a needle protection structure that covers at least the tip of the inner needle by being activated using the elastic force of a biasing member; and a trigger structure that activates the needle protection structure in association with relative movement of the needle hub in the proximal direction relative to the catheter hub, wherein the needle protection structure has: the biasing member; a housing portion that is movable relative to the inner needle in the axial direction of the inner needle and is capable of covering at least the tip of the inner needle; and an actuation button provided movably on the outer periphery of the needle hub, wherein when the actuation button is in an initial position, the relative movement of the inner needle and the housing portion is restricted against the elastic force of the biasing member, When the activation button moves from the initial position to the activation position, relative movement between the inner needle and the accommodating portion becomes possible, so that the accommodating portion covers at least the tip of the inner needle by utilizing the elastic force of the biasing member, and the trigger structure comprises a linkage member that is provided on the outside of the needle hub and presses the activation button in linkage with the relative movement of the needle hub in the base end direction with respect to the catheter hub, and the linkage member presses the activation button, causing the activation button to move to the activation position.

2. A catheter assembly as claimed in claim 1, wherein the interlocking member has an operating part facing the actuation button and is supported so as to be able to swing on a support part provided on the outer periphery of the needle hub on the distal side of the operating part, and the interlocking member swings as the needle hub moves relative to the catheter hub in the proximal direction so that the operating part presses the actuation button towards the actuating position.

3. A catheter assembly as claimed in claim 2, wherein the interlocking member has an inner protrusion protruding towards the outer peripheral surface of the catheter hub further tip than the support part, and the catheter hub has an outer protrusion protruding outward from the outer peripheral surface of the catheter hub, and when the needle hub is connected to the base end of the catheter hub, the inner protrusion is positioned in the tip direction relative to the outer protrusion and is positioned closer to the outer peripheral surface of the catheter hub than the tip of the outer protrusion, and when the needle hub is moved relative to the catheter hub in the base end direction, the inner protrusion rides on the outer protrusion, causing the interlocking member to swing about the support part as a fulcrum and causing the operating part to press the operating button.

4. A catheter assembly as claimed in claim 3, comprising a resilient member having a resilient force which urges the interlocking member such that the inward protrusion of the interlocking member moves towards the outer circumferential surface of the catheter hub, with the support part as a fulcrum, when the needle hub is connected to the base end of the catheter hub.

5. A catheter assembly as claimed in claim 3, wherein one of said outer projection and said inner projection has a guide groove into which the other projection is inserted and which extends in the axial direction of said needle hub.

6. A catheter assembly according to claim 3, wherein the outer projection is a lock fitting portion that can be fitted with a supplying tool for supplying a medicinal liquid to the catheter hub.

7. A catheter assembly according to claim 1, wherein the housing portion is provided inside the needle hub and is capable of housing the inner needle.

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