Catheter assembly

Abstract

The present invention provides a catheter assembly that can effectively suppress accidental puncture by the inner needle after the needle member and catheter assembly have been inserted. [Solution] The catheter assembly 10 comprises a catheter member 12, a needle member 14 having an inner needle 141, a cylindrical body 16 that movably houses the needle member 14, and a feed member 20 for moving the catheter member 12 toward the tip. The catheter assembly 10 further includes a locking mechanism 34 that prevents the needle member 14 from moving due to the biasing force of a biasing member 18. When the feed member 20 moves toward the tip, the state in which the movement of the needle member 14 is prevented by the locking mechanism 34 is released by the release mechanism 36.

Description

Technical Field

[0001] The present disclosure relates to a catheter assembly for injecting a drug solution subcutaneously into a living body.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2013-22263 discloses a catheter assembly capable of accommodating an inner needle in a housing after puncturing a living body. The catheter assembly includes a housing, a catheter having an open tip, a catheter hub connected to the proximal end of the catheter, and an inner needle inserted into the lumen of the catheter and capable of puncturing the living body. After the inner needle and the catheter are punctured into the living body, by advancing an operation portion provided outside the housing by the user, the inner needle relatively retreats with respect to the catheter and is accommodated in the housing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the catheter assembly as described above is configured to advance the housing by the user operating the operation portion, for example, when removing the inner needle from the living body, if the user forgets to operate the operation portion, the tip of the inner needle may remain exposed and there is a possibility of accidental puncture.

[0005] An object of the present disclosure is to solve the above-described problems.

Means for Solving the Problems

[0006] (1) An aspect of the present disclosure is a catheter assembly comprising: a catheter member having a tubular catheter body and a catheter hub connected to the proximal end of the catheter body; a needle member having an inner needle inserted into the catheter lumen of the catheter body and protruding from the tip of the catheter body toward the tip, and an inner needle hub connected to the proximal end of the inner needle; a cylindrical body having a housing portion that is detachably connected in the axial direction to the proximal end of the catheter member and houses the needle member so as to be movable in the axial direction; a biasing member provided inside the cylindrical body that biases the needle member toward the proximal end; a feed member provided outside the cylindrical body for moving the catheter member toward the tip; a locking mechanism having a locking member that is movable in an intersecting direction intersecting the axis of the needle member and prevents the needle member from moving toward the proximal end due to the biasing force of the biasing member; and a release mechanism that moves the locking member in the intersecting direction by moving the feed member toward the tip relative to the cylindrical body, thereby releasing the state in which the movement of the needle member is prevented by the locking mechanism.

[0007] In this catheter assembly, the needle member is housed in the cylindrical body by the biasing force of the biasing member. The release mechanism can be activated in conjunction with the movement of the catheter member toward the tip, thereby releasing the locking mechanism. This allows the needle member to be automatically housed in the cylindrical body. Therefore, accidental puncture by the inner needle can be effectively suppressed after the needle member and catheter assembly have been inserted.

[0008] (2) In the catheter assembly described in (1) above, the feeding member has an inner wall portion that faces the axis and is in contact with at least a part of the locking member, the inner wall portion has a first inner wall portion that is spaced a first distance from the axis in the intersecting direction, and a second inner wall portion that is spaced a second distance from the axis in the intersecting direction, and the first distance and the second distance are different from each other, the release mechanism has a distance changing portion provided in the inner wall portion between the first inner wall portion and the second inner wall portion, the distance from the axis in the intersecting direction changes between the first distance and the second distance, the locking member is provided so as to be in contact with the inner wall portion, and when the feeding member moves relative to the cylindrical body toward the tip, the locking member moves toward the intersecting direction by the distance changing portion, thereby releasing the movement-restricting state of the needle member by the locking mechanism.

[0009] This configuration allows for the provision of a distance-changing section on the inner wall of the feed member, thereby activating the release mechanism by moving the feed member toward the tip, and effectively releasing the lock mechanism that prevents the needle member from moving.

[0010] (3) In the catheter assembly described in (1) above, the feeding member comprises a lumen and an inner wall portion facing the lumen and in contact with at least a part of the locking member, the inner wall portion comprises a pair of first inner wall portions facing each other in the intersecting direction and a pair of second inner wall portions facing each other in the intersecting direction, the pair of first inner wall portions having a first inter-wall distance which is the distance between them in the intersecting direction and the distance between them is different from the first inter-wall distance, and the release mechanism is The inner wall portion is provided between a pair of first inner wall portions and a pair of second inner wall portions, and each portion is provided between a pair of distance-changing portions, the distance between them in the intersecting direction is changed between the distance between the first walls and the distance between the second walls, and the locking members are provided in a pair so as to be in contact with the inner wall portions, and when the feed member moves relative to the cylindrical body toward the tip, the pair of locking members move in opposite directions along the intersecting direction due to the pair of distance-changing portions, thereby releasing the state in which the movement of the needle member is blocked by the pair of locking members.

[0011] This configuration allows the movement of the needle member to be more effectively prevented by the pair of locking members. The simple configuration also allows for the effective release of the restriction on the movement of the needle member by the pair of locking members.

[0012] (4) In the catheter assembly described in (2) or (3) above, the locking member may be provided between the needle member and the feeding member and may have an engagement structure that engages the inner needle hub of the needle member and the locking member with each other in the intersecting direction.

[0013] This configuration allows the needle member and the locking member to be effectively engaged by the engagement structure, thereby effectively preventing the needle member from moving through the locking mechanism.

[0014] (5) In the catheter assembly described in (4) above, the locking mechanism may include a locking maintenance part that biases the locking member toward the inner wall to maintain the engaged state of the engagement structure.

[0015] This configuration allows the lock retention mechanism to effectively maintain the engagement between the locking member and the inner needle hub.

[0016] (6) In the catheter assembly described in (4) or (5) above, the engagement structure may have a recess provided in either the inner needle hub or the locking member, and a protrusion provided in the other of the inner needle hub or the locking member that engages with the recess.

[0017] This configuration allows for the realization of an engagement structure with a simple design. By engaging the recessed portion with the convex portion, the needle member and the locking member can be engaged more effectively.

[0018] (7) In the catheter assembly described in any one of (1) to (6) above, the locking member comprises a hub contact portion that abuts against the inner needle hub and a contact portion that extends from the hub contact portion toward the inner wall portion and contacts the inner wall portion, wherein the contact portion may be formed in a tapered shape toward the inner wall portion.

[0019] This configuration effectively suppresses sliding resistance when the locking member and the feeding member move relative to each other by bringing the contact portion into contact with the inner wall. [Effects of the Invention]

[0020] According to this disclosure, by moving the feeding member relative to the cylindrical body in the direction of the tip, the lock mechanism can be released in conjunction with the catheter member, and the needle member can be automatically retracted into the cylindrical body. This effectively prevents accidental puncture by the inner needle after the needle member and catheter assembly have been inserted. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is an overall diagram of a catheter assembly according to the first embodiment of this disclosure. [Figure 2]FIG. 2 is an explanatory diagram showing a state in which the catheter assembly of FIG. 1 is punctured into a living body. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1. [Figure 5] FIG. 5 is a first explanatory diagram when the catheter assembly is ind留置ed in a living body. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. [Figure 7] FIG. 7 is a second explanatory diagram when the catheter assembly is ind留置ed in a living body. [Figure 8] FIG. 8 is a first cross-sectional explanatory diagram of the catheter assembly according to a modified example. [Figure 9] FIG. 9 is a second cross-sectional explanatory diagram of the catheter assembly according to a modified example. [Figure 10] FIG. 10 is an overall configuration diagram of the catheter assembly according to the second embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 10. [Figure 12] FIG. 12 is an explanatory diagram when the catheter assembly shown in FIG. 10 is ind留置ed in a living body. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII of FIG. 12.

MODE FOR CARRYING OUT THE INVENTION

[0022] As shown in FIG. 1, at least the tip of the catheter assembly 10 according to the first embodiment is inserted into the living body B (see FIG. 2), and a part thereof is ind留置ed in the living body B.

[0023] The catheter assembly 10 includes a catheter member 12, a needle member 14, a cylindrical body 16, a biasing member 18, and a feeding member 20. As shown in FIG. 2, the target site of the living body B is, for example, living tissue between the epidermis of the skin in the living body B and the blood vessel BV.

[0024] As shown in Figure 1, the catheter member 12 has a catheter body 121 and a catheter hub 122. The catheter body 121 is formed in a tubular shape with a catheter lumen 24 inside. The catheter body 121 is flexible. The tip 121a of the catheter body 121 opens toward the tip. The tip 121a of the catheter body 121 is the end that is inserted into the living body B (see Figure 2).

[0025] The catheter hub 122 is connected to the proximal end of the catheter body 121. The catheter hub 122 is cylindrical and has a hub lumen 261. The catheter hub 122 comprises a hub body 262, a hub tip 263, and a hub proximal end 264. The hub tip 263 is located at the tip of the hub body 262. The hub tip 263 is smaller in diameter than the hub body 262. The proximal end of the catheter body 121 is connected to the hub tip 263. The hub lumen 261 extends axially from the hub tip 263 to the hub proximal end 264. The tip of the hub lumen 261 communicates with the catheter lumen 24 of the catheter body 121.

[0026] As shown in Figure 3, the hub base end 264 is provided at the base end of the hub body 262. The hub base end 264 has a flange 28 that protrudes radially outward. The tip 161 of the cylindrical body 16 is inserted into the hub base end 264. As shown in Figure 1, the inner needle 141 of the needle member 14 is inserted through the catheter lumen 24 of the catheter member 12 and the hub lumen 261. At this time, the tip of the inner needle 141 protrudes from the tip 121a of the catheter body 121. When the needle member 14 is withdrawn from the catheter member 12 towards the base end, a supply device for supplying drug solution, such as a syringe or drug solution tube, can be connected to the hub base end 264 of the catheter hub 122.

[0027] The needle member 14 is inserted into the catheter lumen 24 and the cylindrical body 16 of the catheter body 121. The needle member 14 comprises an inner needle 141 and an inner needle hub 142.

[0028] The inner needle 141 is formed in a tubular shape with a lumen (not shown). The inner needle 141 protrudes from the tip 121a of the catheter body 121 toward the tip. The needle member 14 has an axis C that extends along the axial direction. The axis C of the needle member 14 is the central axis of the inner needle 141 and the central axis of the inner needle hub 142. As shown in Figure 2, the tip of the catheter assembly 10, including the catheter body 121, is inserted subcutaneously into the living body B. Note that the inner needle 141 is not limited to being formed in a tubular shape. For example, the inner needle 141 may have a solid shape without a lumen.

[0029] As shown in Figure 3, the inner needle hub 142 is connected to the base end of the inner needle 141. The inner needle hub 142 is housed inside the cylindrical body 16 and extends along the axial direction. The base end of the inner needle 141 protrudes in the base direction relative to the base end of the inner needle hub 142. However, the base end of the inner needle 141 does not necessarily have to protrude relative to the base end of the inner needle hub 142.

[0030] As shown in Figure 1, the inner needle hub 142 has a pair of retaining surfaces 151 and 152. The pair of retaining surfaces 151 and 152 face each other on the inner wall of the cylindrical body 16 (see Figure 4). The pair of retaining surfaces 151 and 152 are formed substantially parallel to the axis C of the needle member 14.

[0031] The cylindrical body 16 is formed from, for example, a transparent or translucent resin material. The cylindrical body 16 is detachably connected in the axial direction to the proximal end of the catheter member 12. The cylindrical body 16 is connected to the catheter hub 122. The cylindrical body 16 is hollow and extends along the axial direction. The cylindrical body 16 has a tip portion 161, a base portion 162, and a housing portion 32. The tip portion 161 is provided at the tip of the cylindrical body 16. The tip portion 161 is connected inside the hub base portion 264 of the catheter hub 122 (see Figure 3). The base portion 162 is provided at the proximal end of the cylindrical body 16.

[0032] The base end 162 of the cylinder is provided with a cap member 30. The cap member 30 closes the base end 162 of the cylinder. The cap member 30 is provided with a filter 31. The filter 31 is made of a breathable material. The filter 31 is provided in the cap hole 301 of the cap member 30. The outside of the cap member 30 and the housing portion 32 of the cylinder 16 are in communication through the filter 31. The filter 31 is, for example, a breathable filter that allows only gas to pass through but not liquid.

[0033] The cylindrical body 16 further comprises a pair of peripheral wall portions 163. The pair of peripheral wall portions 163 extend along the axial direction of the cylindrical body 16. Each of the pair of peripheral wall portions 163 has a through hole 164. That is, a pair of through holes 164 are provided. The pair of through holes 164 are provided between the tip portion 161 and the base portion 162 of the cylindrical body. Each of the pair of through holes 164 penetrates each of the pair of peripheral wall portions 163 and is provided at the same position in the axial direction of the cylindrical body 16. The pair of through holes 164 penetrate in a direction perpendicular to the axial direction of the cylindrical body 16 (the axis C of the needle member 14).

[0034] The housing section 32 is provided inside the cylindrical body 16. The housing section 32 houses the needle member 14 so that it can move in the axial direction of the cylindrical body 16. The housing section 32 extends along the axial direction of the cylindrical body 16. The housing section 32 comprises a first housing section 321, a second housing section 322, and an intermediate housing section 323.

[0035] The first housing section 321 is provided at the tip of the cylindrical body 16. The first housing section 321 opens at the tip of the cylindrical tip 161. When the cylindrical tip 161 of the cylindrical body 16 is connected to the catheter member 12, the hub lumen 261 of the catheter member 12 and the housing section 32 are in communication. In the catheter assembly 10 before use, the inner needle 141 is inserted through the first housing section 321.

[0036] The second housing portion 322 is provided in a direction toward the base end than the first housing portion 321. The second housing portion 322 is formed with a larger diameter than the first housing portion 321. However, it is not limited to the case where the second housing portion 322 is formed with a larger diameter than the first housing portion 321. For example, the first housing portion 321 and the second housing portion 322 may be formed with the same diameter. The base end of the second housing portion 322 is open. The base end of the second housing portion 322 is closed by the cap member 30.

[0037] The intermediate housing section 323 is provided between the first housing section 321 and the second housing section 322. The intermediate housing section 323 connects the first housing section 321 and the second housing section 322. The intermediate housing section 323 communicates with the first housing section 321 and the second housing section 322. In the catheter assembly 10 before use, the inner needle 141 and a portion of the inner needle hub 142 are inserted through the intermediate housing section 323.

[0038] The housing section 32 further includes a receiving section 324. The receiving section 324 is provided at the tip of the intermediate housing section 323. The receiving section 324 has a surface that intersects with the axial direction of the cylindrical body 16. The receiving section 324 is provided at the boundary between the intermediate housing section 323 and the first housing section 321.

[0039] The biasing member 18 is provided inside the cylindrical body 16. The biasing member 18 biases the needle member 14 toward the base end. The biasing member 18 is a spring member 181 having an axial biasing force. The spring member 181 is, for example, a coil spring. However, the spring member 181 is not limited to a coil spring. For example, the spring member 181 may be a leaf spring or an air spring, etc.

[0040] The biasing member 18 is housed in the intermediate housing 323. The biasing member 18 is provided between the receiving portion 324 of the intermediate housing 323 and the tip of the inner needle hub 142. The biasing force of the biasing member 18 causes the needle member 14, including the inner needle hub 142, to move relative to the cylindrical body 16 in the base end direction. In this embodiment, the biasing force of the biasing member 18 is the spring force of the spring member 181.

[0041] The feeding member 20 is located on the outside of the cylindrical body 16 and moves the catheter member 12 toward the tip. The tip of the feeding member 20 is connected to the hub base end 264 of the catheter hub 122. The feeding member 20 covers at least the tip portion of the cylindrical body 16. The feeding member 20 extends from the hub base end 264 toward the base.

[0042] The feed member 20 comprises a cylindrical portion 201 and a tip portion 202. The cylindrical portion 201 extends along the axial direction of the feed member 20. The cylindrical portion 201 has a lumen 201a. A portion of the cylindrical body 16 is inserted into the lumen 201a. The cylindrical portion 201 and a pair of circumferential wall portions 163 of the cylindrical body 16 are arranged substantially parallel to each other. The cylindrical portion 201 is supported so as to be movable in the axial direction relative to the circumferential wall portions 163 of the cylindrical body 16.

[0043] The tip portion 202 is provided at the tip of the cylindrical portion 201. The tip portion 202 intersects with the axial direction of the cylindrical portion 201. The tip portion 202 is inserted through the outer circumference of the tip portion 161 of the cylindrical body 16. The tip of the tip portion 202 abuts against the flange 28 of the hub base portion 264. When the user pushes the feeding member 20 toward the tip, the feeding member 20 moves relative to the cylindrical body 16 toward the tip. Together with the feeding member 20, the catheter member 12 moves relative to the cylindrical body 16 toward the tip.

[0044] The feeding member 20 further includes an inner wall portion 22. The inner wall portion 22 faces the lumen 201a of the cylindrical portion 201. The inner wall portion 22 is a surface formed on the inside of the cylindrical portion 201. The inner wall portion 22 faces the axis C of the needle member 14. The inner wall portion 22 includes a pair of first inner wall portions 221 and a pair of second inner wall portions 222.

[0045] As shown in Figure 4, the pair of first inner wall portions 221 (hereinafter also referred to as first inner wall portions 221A and 221B) face each other in a first orthogonal direction (arrow Z direction) perpendicular to the axis C of the needle member 14. One first inner wall portion 221A and the other first inner wall portion 221B are separated from each other by a first wall distance L1 in the first orthogonal direction. Each of the pair of first inner wall portions 221 extends from the tip end to the base end of the cylindrical portion 201. In the first orthogonal direction, the gap between each of the pair of first inner wall portions 221 and each of the pair of peripheral wall portions 163 of the cylindrical body 16 is approximately constant.

[0046] As shown in Figure 1, the pair of second inner wall portions 222 (hereinafter also referred to as second inner wall portions 222A and 222B) face each other in the first orthogonal direction. One second inner wall portion 222A and the other second inner wall portion 222B are separated from each other by a second wall distance L2 in the first orthogonal direction (see Figure 6). The first orthogonal direction is the vertical direction perpendicular to the axial direction of the catheter member 12.

[0047] Each of the pair of second inner wall portions 222 is positioned toward the base end of each of the pair of first inner wall portions 221. Each of the pair of second inner wall portions 222 extends to the base end of the cylindrical portion 201. The distance between the first wall L1 and the distance between the second wall L2 are different from each other. The distance between the first wall L1 is greater than the distance between the second wall L2 (L1 > L2).

[0048] The pair of first inner wall portions 221 are not limited to being configured to face each other in the first orthogonal direction (arrow Z direction). For example, the pair of first inner wall portions 221 may be configured to face each other in the direction of intersection with the axis C of the needle member 14. The pair of second inner wall portions 222 are not limited to being configured to face each other in the direction of intersection with the axis C of the needle member 14. For example, the pair of second inner wall portions 222 may be configured to face each other in the direction of intersection with the axis C.

[0049] The inner wall portion 22 of the feed member 20 is not limited to comprising a pair of first inner wall portions 221 and a pair of second inner wall portions 222. For example, the inner wall portion 22 may be configured to comprise one first inner wall portion 221 and one second inner wall portion 222. In this case, the first inner wall portion 221 is spaced at a first distance from the axis C of the needle member 14 in the direction of intersection with the axis C. The second inner wall portion 222 is spaced at a second distance from the axis C of the needle member 14 in the direction of intersection with the axis C. The first distance of the first inner wall portion 221 and the second distance of the second inner wall portion 222 are different from each other.

[0050] The catheter assembly 10 further includes a locking mechanism 34 and a release mechanism 36.

[0051] As shown in Figure 4, the locking mechanism 34 prevents the needle member 14 from moving toward the base end due to the biasing force of the biasing member 18. The locking mechanism 34 comprises a pair of locking members 341A and 341B, a pair of locking retention parts 342, and a pair of engagement structures 38.

[0052] Each of the locking members 341A and 341B is provided between the needle member 14 and the feeding member 20. The locking members 341A and 341B are positioned at the same location in the axial direction of the needle member 14 (see Figure 1). Each of the locking members 341A and 341B is provided to be movable in the first orthogonal direction (up and down direction of the catheter member 12, arrow Z direction). At least a portion of each of the locking members 341A and 341B is in contact with a pair of inner wall portions 22. Note that the direction of movement of each of the locking members 341A and 341B is not limited to the first orthogonal direction. For example, the direction of movement of each of the locking members 341A and 341B may be in a direction intersecting the axis C of the needle member 14 (a direction inclined with respect to axis C).

[0053] One locking member 341A faces one inner wall portion 22 (first inner wall portion 221A, second inner wall portion 222A), and the other locking member 341B faces the other inner wall portion 22 (first inner wall portion 221B, second inner wall portion 222B). When viewed from the axial direction of the needle member 14, one locking member 341A and the other locking member 341B are arranged symmetrically with respect to the needle member 14.

[0054] Each of the locking members 341A and 341B includes a hub contact portion 40, an arm portion 42, and a protruding portion 44. The hub contact portion 40 is provided inside the cylindrical body 16. The hub contact portion 40 is provided at one end of the catheter member 12 in the vertical direction (direction of arrow Z). The hub contact portion 40 of the locking member 341A is provided so as to be able to contact the retaining surface 152 of the inner needle hub 142. The hub contact portion 40 of the locking member 341B is provided so as to be able to contact the retaining surface 151 of the inner needle hub 142. The hub contact portion 40 extends in the direction of the axis C of the needle member 14 and in a second orthogonal direction (width direction of the locking members 341A and 341B) which is mutually orthogonal to the first orthogonal direction of axis C.

[0055] The arm portion 42 extends from the hub contact portion 40 toward the inner wall portion 22. The arm portion 42 comprises a first arm portion 421 and a second arm portion 422. The first arm portion 421 is formed from the end of the hub contact portion 40 along the vertical direction (arrow Z direction) of the catheter member 12. The first arm portion 421 is positioned on the outside in the width direction of the inner needle hub 142. The first arm portion 421 is positioned between the inner needle hub 142 and the cylindrical body 16 in the second orthogonal direction (width direction).

[0056] The second arm portion 422 is formed at the end of the first arm portion 421. The second arm portion 422 is formed substantially parallel to the hub contact portion 40. The second arm portion 422 is positioned closer to the peripheral wall portion 163 of the cylindrical body 16 than the hub contact portion 40. When viewed from the axial direction of the needle member 14, the hub contact portion 40 and arm portion 42 of the locking member 341A and the locking member 341B are each formed in a U-shape so as to wrap around the inner needle hub 142.

[0057] The protruding portion 44 extends from the end of the second arm portion 422 toward the inner wall portion 22. The direction in which the protruding portion 44 extends relative to the second arm portion 422 is in the vertical direction (arrow Z direction) of the catheter member 12. A portion of the protruding portion 44 is inserted into the through hole 164 of the cylindrical body 16. The tip of the protruding portion 44 protrudes outward from the peripheral wall portion 163 of the cylindrical body 16. The tip of the protruding portion 44 is exposed to the outside of the cylindrical body 16.

[0058] The tip of the protruding portion 44 is provided with a contact portion 46. The contact portion 46 contacts the inner wall portion 22 of the feeding member 20. The contact portion 46 is tapered toward the inner wall portion 22. The very tip of the contact portion 46 contacts the inner wall portion 22. At this time, the inner wall portion 22 and the contact portion 46 may be in point contact. In the vertical direction (arrow Z direction) of the catheter member 12, the hub contact portion 40 and the protruding portion 44 are arranged in opposite directions with the inner needle hub 142 in between. Note that the contact portion 46 is not limited to being tapered toward the inner wall portion 22. For example, the contact portion 46 may be formed with the same cross-section toward the inner wall portion 22.

[0059] In the catheter assembly 10 before use shown in Figure 1, the locking mechanism 34 is positioned facing a pair of first inner wall portions 221 (221A, 221B). As shown in Figure 4, the contact portion 46 of the locking member 341A contacts the first inner wall portion 221A, and the contact portion 46 of the locking member 341B contacts the first inner wall portion 221B.

[0060] A pair of locking retainers 342 bias the locking members 341A and 341B toward the inner wall portion 22, respectively. One locking retainer 342 is positioned between the contact portion 46 of the locking member 341A and the peripheral wall portion 163 of the cylindrical body 16. The other locking retainer 342 is positioned between the contact portion 46 of the locking member 341B and the peripheral wall portion 163 of the cylindrical body 16. Each locking retainer 342 is provided on the outside of the protruding portion 44 of each locking member 341A and locking member 341B. Each locking retainer 342 is a spring member 3421. The biasing force of each locking retainer 342 is the spring force of the spring member 3421.

[0061] Each lock-maintaining part 342 biases in the axial direction (arrow Z direction), thereby biasing each of the lock members 341A and 341B, including each contact portion 46, toward each inner wall portion 22 of the feed member 20. Specifically, the biasing force of the lock-maintaining part 342 biases the lock member 341A toward the first inner wall portion 221A of the feed member 20. The biasing force of the lock-maintaining part 342 biases the lock member 341B toward the first inner wall portion 221B of the feed member 20. The biasing direction of the pair of lock-maintaining parts 342 toward the lock members 341A and 341B is opposite for one lock member 341A and the other lock member 341B. In the embodiment shown in Figure 4, the biasing direction of the lock member 341A by the lock-maintaining part 342 is upward, and the biasing direction of the lock member 341B by the lock-maintaining part 342 is downward.

[0062] The engagement structure 38 engages each of the locking members 341A and 341B with the inner needle hub 142 of the needle member 14 in a first orthogonal direction. The engagement structure 38 comprises a pair of recesses 381 and a pair of protrusions 382. The pair of recesses 381 are provided on a pair of retaining surfaces 151 and 152 of the inner needle hub 142. Each recess 381 is recessed relative to each retaining surface 151 and 152. Each recess 381 extends in a second orthogonal direction of the inner needle hub 142 that intersects the axis C of the needle member 14 and the first orthogonal direction (see Figure 3).

[0063] A pair of protrusions 382 are provided on the hub contact portions 40 of the locking members 341A and 341B, respectively. Each of the pair of protrusions 382 is inserted into each of the pair of recesses 381. Specifically, the protrusion 382 of the locking member 341A is inserted into the recess 381 of the retaining surface 152 of the inner needle hub 142. The protrusion 382 of the locking member 341B is inserted into the recess 381 of the retaining surface 151 of the inner needle hub 142. By inserting each protrusion 382 into each recess 381, relative axial movement of the needle member 14 with respect to the locking members 341A and 341B is prevented. That is, the biasing force of the pair of locking retention portions 342 is applied to each of the locking members 341A and 341B, maintaining the engaged state in which the protrusions 382 of each hub contact portion 40 are inserted into the recesses 381.

[0064] The engagement structure 38 is not limited to the case where the inner needle hub 142 has a recess 381 and the locking members 341A and 341B have protrusions 382. For example, each of the locking members 341A and 341B may have a recess, and the inner needle hub 142 may have a protrusion, with each recess and each protrusion engaging with each other.

[0065] As shown in Figure 1, the release mechanism 36 releases the lock mechanism 34 from preventing the needle member 14 from moving toward the base end. The release mechanism 36 is provided on the inner wall portion 22 of the feed member 20. The release mechanism 36 is provided between a pair of first inner wall portions 221 and a pair of second inner wall portions 222. The release mechanism 36 includes a pair of distance changing portions 361. The distance changing portions 361 are provided between each of the pair of first inner wall portions 221 and each of the pair of second inner wall portions 222.

[0066] The pair of distance-changing sections 361 cause the distance between the pair of inner wall sections 22 to change relative to each other in the first orthogonal direction (arrow Z direction). The distance between the pair of distance-changing sections 361 changes relative to each other between the first wall distance L1 and the second wall distance L2. The pair of distance-changing sections 361 are formed such that the distance between them gradually changes in the axial direction of the feed member 20 from the base end of the first inner wall section 221 to the tip of the second inner wall section 222. In other words, each distance-changing section 361 continuously connects each first inner wall section 221 and each second inner wall section 222.

[0067] Furthermore, the pair of distance-changing sections 361 are not limited to a configuration in which the distance between them gradually changes between the first wall distance L1 and the second wall distance L2. For example, the pair of distance-changing sections 361 may be stepped in shape, where the distance between them changes at the boundary between each of the pair of first inner wall sections 221 and each of the pair of second inner wall sections 222.

[0068] Next, we will explain the procedure for implanting the catheter assembly 10 into biological tissue B.

[0069] As shown in Figure 1, prepare a catheter assembly 10 in an initial position where the catheter member 12 is located towards the tip relative to the cylindrical body 16. At this time, the locking member 341A (contact portion 46) of the locking mechanism 34 is in contact with the first inner wall portion 221A of the feeding member 20, and the locking member 341B (contact portion 46) is in contact with the first inner wall portion 221B of the feeding member 20 (see Figure 4).

[0070] Next, as shown in Figure 2, the inner needle 141 of the catheter assembly 10 and the tip of the catheter member 12 are inserted into the skin of the living body B. The tip of the inner needle 141 of the needle member 14 is inserted into the blood vessel BV, and the tip 121a of the catheter body 121 is inserted into the blood vessel BV. At this time, as the tip of the inner needle 141 is inserted into the blood vessel BV, blood that has flowed back from the blood vessel BV through the lumen of the inner needle 141 flows into the housing 32 of the cylindrical body 16. The user can visually confirm that the blood vessel BV has been punctured through the transparent or translucent cylindrical body 16. After that, the user withdraws the needle member 14 from the catheter member 12 towards the proximal end.

[0071] When the needle member 14 is removed from the catheter member 12, as shown in Figure 5, the user pushes the feed member 20 toward the tip, causing the catheter member 12 to move relative to the cylindrical body 16 toward the tip. The feed member 20 moves toward the tip along the tip portion 161 of the cylindrical body 16. As the feed member 20 moves toward the tip, the contact portions 46 of the locking member 341A and the locking member 341B change from contacting the first inner wall portion 221 to contacting the distance change portion 361.

[0072] The pair of distance-changing sections 361 push the locking members 341A and 341B toward the axis C of the needle member 14. That is, the pair of distance-changing sections 361 cause the pair of locking members 341A and 341B to move in opposite directions (away from each other) along the first orthogonal direction (arrow Z direction) while compressing the pair of locking maintenance sections 342. Specifically, in the vertical direction of the catheter member 12, one locking member 341A begins to move downward, and the other locking member 341B begins to move upward.

[0073] As the feed member 20 moves further toward the tip, the contact portions 46 of the locking members 341A and 341B come into contact with the respective second inner wall portions 222 beyond the distance change portion 361. Due to the difference between the first wall distance L1 and the second wall distance L2, the locking members 341A and 341B move toward the inner needle hub 142. As shown in Figure 6, as the locking members 341A and 341B move toward each other, the respective hub contact portions 40 move away from the holding surfaces 151 and 152 of the inner needle hub 142.

[0074] Specifically, when the hub contact portion 40 of the locking member 341A moves downward from the retaining surface 152, the protrusion 382 detaches from the recess 381 of the retaining surface 152. When the hub contact portion 40 of the locking member 341B moves upward from the retaining surface 151, the protrusion 382 detaches from the recess 381 of the retaining surface 151.

[0075] As a result, the engagement between the locking members 341A and 341B and the inner needle hub 142 of the needle member 14 is released, and the locking mechanism 34 releases the restriction on the needle member 14's movement toward the base end. The needle member 14, including the inner needle hub 142, becomes capable of axial movement relative to the cylindrical body 16.

[0076] Then, as shown in Figure 7, the biasing force of the biasing member 18 causes the needle member 14, including the inner needle hub 142, to move relative to the cylindrical body 16 in the proximal direction within the housing portion 32 of the cylindrical body 16. At this time, since the locking members 341A and 341B are detached from the needle member 14, only the needle member 14 moves in the proximal direction within the cylindrical body 16. Due to the movement of the needle member 14 in the proximal direction, the inner needle 141 moves through the inside of the catheter member 12 to the housing portion 32 of the cylindrical body 16.

[0077] As a result, the needle member 14 moves through the catheter lumen 24 and hub lumen 261 of the catheter member 12 toward the housing portion 32 of the cylindrical body 16. The inner needle 141 is housed in the housing portion 32 of the cylindrical body 16. The tip of the inner needle 141 is covered by the cylindrical body 16 and does not protrude toward the tip from the tip portion 161 of the cylindrical body. After the inner needle 141 is housed in the housing portion 32 of the cylindrical body 16, the needle member 14 is withdrawn from the catheter member 12 toward the proximal end. This completes the withdrawal of the needle member 14 from the catheter member 12.

[0078] Subsequently, a syringe or drug solution tube or other supply device (not shown) is connected to the hub proximal end 264 of the catheter hub 122 placed in the skin of living organism B, and the drug solution is administered into living organism B through the catheter lumen 24 of the catheter body 121.

[0079] The first embodiment provides the following effects.

[0080] As shown in Figure 1, the catheter assembly 10 includes a biasing member 18 that biases the needle member 14 toward the proximal end, a feeding member 20 for moving the catheter member 12 toward the tip, and a locking mechanism 34 that prevents the needle member 14 from moving due to the biasing force of the biasing member 18.

[0081] With this configuration, in the catheter assembly 10 in which the needle member 14 is housed in the cylindrical body 16 by the biasing force of the biasing member 18, the release mechanism 36 can be activated in conjunction with the movement of the catheter member 12 toward the tip, thereby releasing the locking mechanism 34. As a result, the needle member 14 can be automatically housed in the cylindrical body 16. This effectively prevents accidental puncture by the inner needle 141 after the needle member 14 and catheter assembly 10 have been inserted.

[0082] The inner wall portion 22 of the feed member 20 comprises a pair of first inner wall portions 221 (221A, 221B) and a pair of second inner wall portions 222 (222A, 222B). The pair of first inner wall portions 221 are spaced apart from each other by a first wall distance L1, and the pair of second inner wall portions 222 are spaced apart from each other by a second wall distance L2 which is different from the first wall distance L1. When the feed member 20 moves relative to the cylindrical body 16 in the direction of the tip, as shown in Figure 5, the distance changing portion 361 causes the locking members 341A and 341B to move in opposite directions (in the direction of separation), and the release mechanism 36 releases the movement-blocking state of the needle member 14.

[0083] This configuration allows the movement of the needle member 14 to be more effectively prevented by the locking members 341A and 341B. By providing a distance-changing section 361 on the inner wall 22 of the feed member 20, the release mechanism 36 is activated by the movement of the feed member 20 toward the tip, effectively releasing the state in which the movement of the needle member 14 is prevented by the locking members 341A and 341B.

[0084] As shown in Figure 4, the locking members 341A and 341B are provided between the needle member 14 and the feed member 20 and include an engagement structure 38 that engages the inner needle hub 142 of the needle member 14 with the locking members 341A and 341B.

[0085] With this configuration, the locking mechanism 34 can effectively prevent the needle member 14 from moving by engaging the needle member 14 with the locking members 341A and 341B using the engagement structure 38.

[0086] The locking mechanism 34 includes a locking maintenance part 342 that biases the locking members 341A and 341B toward the inner wall portion 22 to maintain the engaged state of the engagement structure 38.

[0087] With this configuration, the lock retention unit 342 can effectively maintain the engaged state between the lock members 341A and 341B and the inner needle hub 142.

[0088] The engagement structure 38 has a recess 381 provided in the inner needle hub 142 and a protrusion 382 provided on each of the locking member 341A and the locking member 341B that engages with the recess 381.

[0089] This configuration allows for the realization of the engagement structure 38 with a simple structure. By engaging the recess 381 and the protrusion 382 with each other, the locking member 341A and the locking member 341B can be engaged with the needle member 14 more effectively.

[0090] The locking members 341A and 341B are provided with a contact portion 46 that extends from the hub contact portion 40 toward the inner wall portion 22 and contacts the inner wall portion 22, and the contact portion 46 is formed in a tapered shape toward the inner wall portion 22.

[0091] This configuration allows the contact portions 46 of the locking members 341A and 341B to come into contact with the inner wall portion 22, thereby effectively suppressing the sliding resistance when the locking members 341A and 341B move relative to the feed member 20.

[0092] The catheter assembly 10 is not limited to having a pair of locking mechanisms 34 and a release mechanism 36. For example, the inner wall portion 22 of the feeding member 20 may have one first inner wall portion 221 and one second inner wall portion 222, and correspondingly, one locking mechanism 34 and one release mechanism 36 may be provided.

[0093] In this case, the first inner wall portion 221 of the inner wall portion 22 is spaced at a first distance from the axis C of the needle member 14, and the second inner wall portion 222 is spaced at a second distance from the axis C of the needle member 14, so that the first distance and the second distance are different from each other. Between the first inner wall portion 221 and the second inner wall portion 222, there is a distance changing portion 361 in which the distance of the needle member 14 with respect to the axis C changes between the first distance and the second distance. When the feed member 20 moves relative to the cylindrical body 16 in the tip direction, the locking member 341A and the locking member 341B are moved in a first orthogonal direction by the distance changing portion 361, thereby releasing the state in which the movement of the needle member 14 is blocked by the locking mechanism 34.

[0094] The engagement structure 38 is not limited to being composed of a protrusion 382 extending in the second orthogonal direction (width direction) of each of the locking members 341A and 341B, and a pair of recesses 381 extending in the second orthogonal direction of the inner needle hub 142. For example, the catheter assembly 10A according to the modified example shown in Figure 8 includes an engagement structure 38A. The engagement structure 38A includes a pair of recesses 381A provided on the inner needle hub 142 and protrusions 382A provided on each of the locking members 341A and 341B.

[0095] Each protrusion 382A is located at the second orthogonal center of the hub contact portion 40 of the locking member 341A and the locking member 341B. Each protrusion 382A projects toward the inner needle hub 142. Each recess 381A is located at the second orthogonal center of the inner needle hub 142. Each recess 381A is recessed toward the inner needle 141 so that the protrusion 382A can be inserted.

[0096] The protrusions 382A of locking members 341A and 341B engage with the recesses 381A of the inner needle hub 142, thereby engaging the inner needle hub 142 of the needle member 14 with the locking members 341A and 341B. The engagement structure 38A prevents relative axial movement between the locking members 341A and 341B and the needle member 14, creating a movement-restricted state. Alternatively, the inner needle hub 142 may be provided with a pair of protrusions, and each of the locking members 341A and 341B may be provided with recesses that engage with the protrusions.

[0097] In this configuration, in the catheter assembly 10A before use shown in Figure 8, when the feeding member 20 moves relative to the cylindrical body 16 toward the tip, the locking members 341A and 341B move from the first inner wall portion 221 (221A, 221B) through the distance change portion 361 to the second inner wall portion 222 (222A, 222B) (see Figure 9). As shown in Figure 9, when the contact portion 46 of each locking member 341A and locking member 341B comes into contact with each second inner wall portion 222 (222A, 222B), each convex portion 382 disengages from each concave portion 381. As a result, the engagement between the locking members 341A and 341B and the needle member 14 by the engagement structure 38A is released, and the movement-restricting state of the needle member 14 by the locking mechanism 34 is released.

[0098] As shown in Figure 10, the catheter assembly 10B according to the second embodiment includes a feeding member 20B and a locking mechanism 50.

[0099] The inner wall portion 22 of the feed member 20B comprises a pair of first inner wall portions 221 (221A, 221B) and a pair of second inner wall portions 222 (222A, 222B). One first inner wall portion 221A and the other first inner wall portion 221B are spaced apart from each other by a first inter-wall distance L1 in a first orthogonal direction (arrow Z direction). Each of the first inner wall portions 221A and 221B extends from the tip end of the cylindrical portion 201 toward the base end.

[0100] One second inner wall portion 222A and the other second inner wall portion 222B are spaced apart from each other by a second wall distance L2 in the first orthogonal direction (arrow Z direction). Each of the second inner wall portions 222A and 222B is positioned toward the base end of each of the first inner wall portions 221A and 221B. The first wall distance L1 and the second wall distance L2 are different from each other. The first wall distance L1 is smaller than the second wall distance L2 (L1 <L2)。

[0101] The locking mechanism 50 comprises a locking member 501A and a locking member 501B. One locking member 501A is positioned in one direction perpendicular to the axis C of the needle member 14 (arrow Z direction). The other locking member 501B is positioned in the other direction perpendicular to the axis C of the needle member 14 (arrow Z direction).

[0102] As shown in Figure 11, each locking member 501A and locking member 501B comprises a hub contact portion 40B and a projection portion 44B. The hub contact portion 40B is provided inside the cylindrical body 16. The hub contact portion 40B is provided at one end of the catheter member 12 in the vertical direction. The hub contact portion 40B extends in the second orthogonal direction. Each projection portion 44B extends from the hub contact portion 40B toward each inner wall portion 22. The tip of each projection portion 44B is provided with a contact portion 46. Each contact portion 46, each projection portion 44B, and each hub contact portion 40B are arranged linearly with respect to each other. When viewed from the axial direction of the needle member 14, one locking member 501A and the other locking member 501B are arranged in a straight line in the vertical direction (arrow Z direction) of the catheter member 12.

[0103] As shown in Figure 10, in the catheter assembly 10B before use, the locking members 501A and 501B are in contact with the first inner wall portions 221A and 221B, respectively. As shown in Figure 11, the first inner wall portions 221A and 221B push the locking members 501A and 501B toward the inner needle hub 142, respectively.

[0104] Specifically, the locking member 501A is pushed downward by the first inner wall portion 221A, and the protrusion 382 engages with the recess 381 of the retaining surface 151 of the inner needle hub 142. The locking member 501B is pushed upward by the first inner wall portion 221B, and the protrusion 382 engages with the recess 381 of the retaining surface 152 of the inner needle hub 142. As a result, the locking mechanism 50 prevents the biasing member 18 from moving the needle member 14 toward the base end.

[0105] As shown in Figure 12, as the feed member 20B moves relative to the cylindrical body 16 in the direction of the tip, the contact portions 46 of the locking member 501A and the locking member 501B move from a state in which they are in contact with the first inner wall portion 221 to a state in which they are in contact with the second inner wall portion 222 via the distance change portion 361.

[0106] When the locking members 501A and 501B come into contact with the distance-changing section 361, as shown in Figure 13, the biasing force of the locking maintenance section 342 causes the locking members 501A and 501B to move in directions away from the inner needle hub 142, due to the difference between the first wall distance L1 and the second wall distance L2. At this time, the directions of movement of the locking members 501A and 501B are opposite to each other with respect to the needle member 14. The locking members 501A and 501B move in directions away from each other from the axis C of the needle member 14.

[0107] The movement of the locking members 501A and 501B causes each protrusion 382 to detach from each recess 381. The locking mechanism 50 releases the restriction on movement between the locking members 501A and 501B and the needle member 14. As a result, the biasing force of the biasing member 18 causes the needle member 14 to move toward the base end, and the inner needle 141 is housed in the housing portion 32 of the cylindrical body 16.

[0108] The second embodiment provides the following effects.

[0109] As shown in Figure 11, the catheter assembly 10B includes a biasing member 18 that biases the needle member 14, a feed member 20B for moving the catheter member 12 toward the tip, and a locking mechanism 50 that prevents the needle member 14 from moving due to the biasing force of the biasing member 18.

[0110] With this configuration, in the catheter assembly 10B in which the needle member 14 is housed in the cylindrical body 16 by the biasing force of the biasing member 18, the release mechanism 36 can be activated in conjunction with the movement of the catheter member 12 toward the tip, thereby releasing the locking mechanism 50. As a result, the needle member 14 can be automatically housed in the cylindrical body 16. This effectively prevents accidental puncture by the inner needle 141 after the needle member 14 and catheter assembly 10B have been inserted.

[0111] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0112] 10, 10A, 10B... Catheter assemblies 12…Catheter component 14...needle member 16...Cylinder 18… Biasing member 20, 20B... Feed members 34, 50… Locking mechanism 36...Release mechanism 121...Catheter body 122...Catheter Hub 141...Inner hand 142...Inner needle hub 341A, 341B, 501A, 501B... Locking components

Claims

1. A catheter member having a tubular catheter body and a catheter hub connected to the proximal end of the catheter body, A needle member having an inner needle inserted into the catheter lumen of the catheter body and protruding from the tip of the catheter body toward the tip, and an inner needle hub connected to the proximal end of the inner needle, A cylindrical body having a housing portion that is detachably connected in the axial direction to the proximal end of the catheter member and that houses the needle member so as to be movable in the axial direction, A biasing member provided inside the cylindrical body, which biases the needle member toward the base end, A feed member provided on the outside of the cylindrical body for moving the catheter member toward the tip, A locking mechanism having a locking member that is movable in a direction intersecting the axis of the needle member, which prevents the needle member from moving toward the base end due to the biasing force of the biasing member, A release mechanism that moves the locking member in the intersecting direction as the feed member moves toward the tip relative to the cylindrical body, thereby releasing the state in which the movement of the needle member is blocked by the locking mechanism, A catheter assembly comprising the following components.

2. In the catheter assembly according to claim 1, The feed member has an inner wall portion that faces the axis and is in contact with at least a part of the locking member, The aforementioned inner wall portion is A first inner wall portion spaced at a first distance from the axis in the aforementioned intersecting direction, A second inner wall portion spaced at a second distance from the axis in the aforementioned intersecting direction, Equipped with, The first distance and the second distance are different from each other. The release mechanism is provided in the inner wall portion between the first inner wall portion and the second inner wall portion, and includes a distance changing portion in which the distance with respect to the axis in the intersecting direction changes between the first distance and the second distance. The locking member is provided so as to contact the inner wall portion, A catheter assembly wherein, when the feeding member moves relative to the cylindrical body in the direction of the tip, the locking member moves in the intersecting direction by the distance changing portion, thereby releasing the movement-restricted state of the needle member by the locking mechanism.

3. In the catheter assembly according to claim 1, The aforementioned feeding member is Lumen and, An inner wall portion facing the lumen and in contact with at least a part of the locking member, Equipped with, The aforementioned inner wall portion is A pair of first inner wall portions facing each other in the aforementioned intersecting direction, A pair of second inner wall portions facing each other in the aforementioned intersecting direction, Equipped with, The pair of first inner wall portions have a first inter-wall distance which is the distance between them in the intersecting direction. The pair of second inner wall portions have a distance between them that is different from the distance between the first walls, which is the distance between them in the intersecting direction. The release mechanism is provided in the inner wall portion between a pair of first inner wall portions and a pair of second inner wall portions, and comprises a pair of distance-changing portions in which the distance between them in the intersecting direction changes between the distance between the first walls and the distance between the second walls. The locking members are provided in pairs so as to contact the inner wall portion, A catheter assembly in which, when the feeding member moves relative to the cylindrical body in the direction of the tip, the pair of locking members move in opposite directions along the intersecting direction by the pair of distance changing parts, thereby releasing the movement-blocking state of the needle member by the pair of locking members.

4. In the catheter assembly according to claim 2 or 3, The locking member is provided between the needle member and the feed member, A catheter assembly comprising an engagement structure that engages the inner needle hub of the needle member and the locking member with each other in the aforementioned intersecting direction.

5. In the catheter assembly according to claim 4, The locking mechanism comprises a catheter assembly that includes a locking maintenance part that biases the locking member toward the inner wall to maintain the engaged state of the engagement structure.

6. In the catheter assembly according to claim 4, The aforementioned engagement structure is A recess provided in either the inner needle hub or the locking member, A protrusion is provided on the other side of the inner needle hub and the locking member, which engages with the recess, A catheter assembly having the following features.

7. In the catheter assembly according to claim 4, The locking member has a hub contact portion that contacts the inner needle hub, A contact portion that extends from the hub contact portion toward the inner wall portion and contacts the inner wall portion, Equipped with, The contact portion is formed in a tapered shape toward the inner wall portion, forming a catheter assembly.

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