JP6771406B2 - Catheter assembly - Google Patents

Description

The present invention relates to a catheter assembly having a multi-structured catheter.

Catheter assemblies are used to construct infusions and transfusion introductions in patients. For example, as disclosed in Patent Document 1, the catheter assembly forms a multi-structured needle in which an inner needle is inserted into a catheter (outer needle). In the use of the catheter assembly, the user punctures the patient with a multi-structured needle, inserts the catheter relative to the internal needle into the blood vessel, and then detaches the internal needle from the catheter. Detain.

Japanese Unexamined Patent Publication No. 2008-43445

By the way, in this type of catheter assembly, when the catheter is inserted into a blood vessel, the tip of the catheter rubs against the inner wall of the blood vessel, which may cause inflammation, damage, or the like. Therefore, it is conceivable to construct the catheter more flexibly to suppress inflammation and damage. However, if the catheter is made flexible in this way, the catheter easily receives the resistance of the living tissue when the multi-structured needle is punctured. Another inconvenience arises: it is difficult to enter the flexed blood vessel.

The present invention has been made in view of the above circumstances, and is a catheter set capable of reducing mechanical irritation to a blood vessel when inserting the catheter into a blood vessel while having appropriate rigidity at the time of puncture. The purpose is to provide a solid.

In order to achieve the above object, the catheter assembly according to the present invention includes an inner needle, an inner catheter arranged outside the inner needle, an outer catheter arranged outside the inner catheter, and the inner side. It comprises a catheter and a catheter hub that holds and holds the catheter and the outer catheter, the inner needle can be retracted relative to the outer catheter and removed from the inner and outer catheters, the inner catheter and the outer catheter. Since the outer catheter can move relative to each other in the longitudinal direction of the inner needle, the first state in which the tip of the inner catheter contacts the tip of the outer catheter and the tip of the inner catheter are the tip of the outer catheter. The catheter hub includes an inner catheter hub to which the inner catheter is fixed and an outer catheter hub to which the outer catheter is fixed, and is capable of transitioning to a second state, which is separated from the inner catheter hub. Provided an elastic portion that can be elastically deformed in the axial direction of the inner catheter hub at an axially intermediate position of the inner catheter hub, and the inner catheter hub at least on the distal end side of the elastic portion is relative to the outer catheter hub. It is configured to be relatively movable .

According to the above, the inner needle, the inner catheter and the outer catheter of the catheter assembly constitute a multi-structured needle that overlaps with each other. Therefore, the inner catheter supports the outer catheter from the inside to obtain appropriate rigidity of the catheter as a whole, and even if the outer catheter receives the resistance force of the living tissue at the time of puncture, the bending can be suppressed. Therefore, the catheter can be smoothly inserted into the blood vessel. In addition, since the medial catheter and the lateral catheter can move relative to each other in the longitudinal direction based on the retraction of the internal needle, the influence of the medial catheter can be suppressed before the lateral catheter is inserted into the blood vessel. Therefore, the catheter assembly can reduce mechanical irritation to the blood vessels and allow the catheter to be better placed. Further, since the catheter assembly can be transferred to the first state and the second state, it is possible to easily switch between supporting and releasing the support of the tip of the outer catheter by the tip of the inner catheter. Further, since the catheter hub is composed of the inner catheter hub and the outer catheter hub, the inner catheter and the outer catheter can be easily operated. Then, since the catheter assembly can apply an elastic force due to expansion and contraction of the elastic portion of the inner catheter hub to the inner catheter, the relative movement of the inner catheter with respect to the outer catheter can be easily performed.

In this case, it is preferable that the inner catheter can move relative to the outer catheter based on the retraction of the inner needle.

As described above, since the inner catheter can move relative to the outer catheter based on the retreat of the inner needle, the outer catheter can be satisfactorily supported by the inner catheter until the inner needle retracts.

In addition to the above configuration, the elastic portion may have a restoring force in the direction of separating the tip of the inner catheter and the tip of the outer catheter in the first state.

As described above, since the elastic portion has a restoring force in the direction of separating the tip of the outer catheter and the tip of the inner catheter in the first state, the second operation is performed without performing another operation in the retracting operation of the inner needle. It can be smoothly transitioned to the state.

Furthermore, the other of the inner and outer catheters and the inner needle or the inner needle hub that fixedly holds the inner needle have an engaging mechanism that continues the first state against the restoring force. It is good to be.

This engagement mechanism allows the catheter assembly to stably maintain the first state and to favorably support the inside of the lateral catheter with the medial catheter.

Further, in order to achieve the above object, the catheter assembly according to the present invention includes an inner needle, an inner catheter arranged outside the inner needle, and an outer catheter arranged outside the inner catheter. A catheter hub for fixing and holding the medial catheter and the lateral catheter is provided, and the internal needle is retractable relative to the lateral catheter and can be removed from the medial catheter and the lateral catheter. And the outer catheter can move relative to each other in the longitudinal direction of the inner needle, and the catheter hub is relative to the inner catheter hub to which the inner catheter is fixed and the inner catheter hub to which the outer catheter is fixed. The inner needle hub, which is composed of a movable outer catheter hub and fixedly holds the inner needle, locks the inner catheter hub when it is retracted relative to the outer catheter hub. The inner catheter hub and the outer catheter hub have a portion, and when the inner needle is retracted with respect to the catheter, the inner catheter hub and the outer catheter hub are characterized by having a releasing mechanism for releasing the locking of the retracting locking portion. To do .

As described above, since the catheter assembly has the retracting locking portion and the releasing mechanism, the inner catheter hub can be retracted based on the retracting of the inner needle hub, and the retracting of the inner catheter hub can be stopped by the releasing mechanism. .. As a result, the medial catheter can be placed at a position retracted to some extent, and the compression of the lateral catheter by the living tissue can be supported by the medial catheter.

Further, the release mechanism may be composed of a convex portion provided on either one of the inner catheter hub and the outer catheter hub, and a concave portion provided on the other.

As a result, the release mechanism can be made a simple structure, and the manufacturing cost of the inner catheter hub and the outer catheter hub can be reduced.

Furthermore, it is preferable that the inner needle hub has an advancing locking portion that locks the inner catheter hub and pushes out the inner catheter hub when advancing relative to the catheter hub.

The catheter assembly can smoothly push out the inner catheter and the inner catheter hub with respect to the outer catheter and the outer catheter hub by the locking portion at the time of advancement, and can be easily assembled to each other.

The inner catheter and the outer catheter are preferably made of materials having different hardness from each other.

As described above, since the inner catheter and the outer catheter are made of different materials, the outer catheter can obtain the desired flexibility, and the catheter combining the inner catheter and the outer catheter also has the desired rigidity. Can be.

In particular, the lateral catheter is preferably more flexible than the medial catheter.

As a result, a flexible outer catheter is inserted into the blood vessel, so that inflammation and damage to the blood vessel wall can be further reduced.

According to the present invention, the catheter assembly can have moderate rigidity at the time of puncture, while reducing mechanical irritation to the blood vessel when inserting the catheter into the blood vessel.

FIG. 1A is a partial side sectional view showing the overall configuration of the catheter assembly according to the first embodiment of the present invention in a pre-puncture state, and FIG. 1B shows an enlarged view of the tip of the multi-structure needle of FIG. 1A. It is a side sectional view. It is a partial side sectional view which shows the state after puncture that the inner needle retracted in the catheter assembly of FIG. FIG. 3A is an explanatory diagram showing a state when the multi-structured needle is punctured, and FIG. 3B is an explanatory view showing a state when the multi-structured needle is inserted into the catheter. FIG. 4A is a partial side sectional view showing the overall configuration of the catheter assembly according to the second embodiment in a pre-puncture state, and FIG. 4B is an enlarged side sectional view showing the tip of the multi-structured needle of FIG. 4A. Is. It is a partial side sectional view which shows the inner needle hub in the state before puncture of the catheter assembly which concerns on 3rd Embodiment.

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

[First Embodiment]
The catheter assembly 10 according to the first embodiment is used when infusion or blood transfusion is performed on a patient (living body), and a catheter is punctured, inserted and placed in the patient's body to construct an introduction part for a drug solution or the like. It is a device. The catheter assembly 10 is applied to the peripheral vein and inserts a catheter shorter than the central venous catheter. The catheter assembly 10 may be longer than a peripheral venous catheter, for example, a central venous catheter, a PICC, a midline catheter, or the like may be inserted. Further, the catheter assembly 10 is not limited to the intravenous catheter, and may be one into which an arterial catheter such as a peripheral arterial catheter is inserted.

As shown in FIG. 1A, the catheter assembly 10 fixes and holds the inner needle 12, the inner needle hub 14 that holds and holds the inner needle 12, the catheter 16 that is arranged outside the inner needle 12, and the catheter 16. It includes a catheter hub 18. In particular, the catheter 16 according to the present embodiment is configured as a double tube (multiple tube), and includes an inner catheter 20 and an outer catheter 30. Further, the catheter hub 18 is also composed of an inner catheter hub 40 that holds the inner catheter 20 fixedly and an outer catheter hub 50 that holds the outer catheter 30 fixedly (hereinafter, the inner catheter hub 40 is the inner hub 40 and the outer side). The catheter hub 50 is abbreviated as the outer hub 50).

The catheter assembly 10 forms a multi-structured needle 11 in which an inner needle 12 and a catheter 16 (inner and outer catheters 20, 30) are overlapped in this order from the inside in a state before use (pre-puncture state). In this pre-puncture state, the multi-structured needle 11 has the needle tip 12a of the inner needle 12 protruding from the tips of the inner catheter 20 and the outer catheter 30, and is integrally punctured in the patient's body. Then, the catheter 16 is placed in the blood vessel by inserting the catheter 16 into the blood vessel and retracting and removing the inner needle 12 from the catheter 16 while maintaining the puncture state. As will be described later, the catheter 16 may be configured such that only the outer catheter 30 is indwelled, or the outer and inner catheters 20 may be indwelled while overlapping. Hereinafter, each configuration of the catheter assembly 10 will be described in detail.

The inner needle 12 is formed of a hollow tube body having rigidity capable of puncturing the skin of a living body, and is provided with a sharp needle tip 12a at the tip thereof. A hollow portion 12b is provided inside the inner needle 12 along the axial direction. The inner needle 12 has a structure (a hole penetrating the hollow portion 12b and the outer surface, a groove formed on the outer peripheral surface of the inner needle 12, etc.) so that the flashback of blood can be visually recognized when the multi-structure needle 11 is punctured. It is good if it is provided. Further, the inner needle 12 may have a solid structure without the hollow portion 12b.

As shown in FIGS. 1A and 1B, the inner needle 12 has a stepped portion 13 at a position separated by a predetermined length from the needle tip 12a in the proximal direction. The step portion 13 is provided on the entire circumference of the inner needle 12 in the circumferential direction, and projects radially outward (outside in the orthogonal direction of the axial center of the inner needle 12) from the tip region α connected to the needle tip 12a. That is, in the inner needle 12, the tip region α is formed to be thin and the base end region β is formed to be thick with the step portion 13 as the base point. The stepped portion 13 constitutes one of the engaging mechanisms 60 for hooking the inner catheter 20. The step portion 13 may be provided only in a part of the inner needle 12 in the circumferential direction.

Examples of the constituent material of the inner needle 12 include a metal material such as stainless steel, aluminum or an aluminum alloy, titanium or a titanium alloy, a hard resin, and ceramics. The inner needle 12 is firmly fixed to the inner needle hub 14 by an appropriate fixing means such as fusion, adhesion, and insert molding.

The inner needle hub 14 of the catheter assembly 10 is a member that holds the inner needle 12 in a fixed manner and moves integrally with the inner needle 12. Further, the inner needle hub 14 is detachably attached to the base end of the catheter hub 18 to form a grip portion to be gripped by the user. The inner needle hub 14 has a substantially square tubular shape as a whole, has R-shaped corners so that the user can easily grasp it, and is designed to have an appropriate size (thickness and length). ing.

A connecting portion 15 is provided inside and at the tip of the inner needle hub 14 so as to be inserted and connected to the inside of the catheter hub 18 (inner hub 40). The connecting portion 15 is formed in a shape (for example, a columnar shape) corresponding to the inner peripheral surface of the catheter hub 18, and the outer peripheral surface thereof is fitted to the catheter hub 18 with an appropriate frictional force. As a result, the inner needle hub 14 can be easily detached from the catheter hub 18 in the punctured state of the multi-structure needle 11. The connection structure between the inner needle hub 14 and the catheter hub 18 is not particularly limited, and various configurations (screw structure and flange portion) in which the inner needle hub 14 and the catheter hub 18 can be separated by a simple operation are not particularly limited. Engagement structure with) can be adopted.

The inner catheter 20 constituting one of the catheters 16 having a double tube structure is a tubular member having flexibility and formed to a predetermined length, and is arranged outside the inner needle 12 to partially form the inner needle 12. Covers the target. Inside the inner catheter 20, a lumen 20a extending along the axial direction of the inner catheter 20 into which the inner needle 12 can be inserted and arranged is formed.

The outer peripheral surface of the inner catheter 20 on the distal end side is formed so as to taper toward the distal end. Further, the inner peripheral surface on the distal end side of the inner catheter 20 is formed in a predetermined shape so as to be in contact with the outer peripheral surface of the inner needle 12. Specifically, the diameter of the first inner peripheral surface 21 that contacts the outer peripheral surface of the tip region α of the inner needle 12 and the diameter of the base end side of the first inner peripheral surface 21 that is larger than the diameter of the first inner peripheral surface 21. It has a second inner peripheral surface 22 and a third inner peripheral surface 23 having a diameter larger than the diameter of the second inner peripheral surface 22 on the proximal end side of the second inner peripheral surface 22.

A stepped inner hook portion 24 perpendicular to the axial direction of the inner catheter 20 is provided between the first inner peripheral surface 21 and the second inner peripheral surface 22. The inner hooking portion 24 constitutes the other side of the engaging mechanism 60 that is hooked on the stepped portion 13 of the inner needle 12 in the state before puncture. That is, the engaging mechanism 60 is configured as the inner hook portion 24 and the stepped portion 13 of the inner needle 12 to prevent the inner catheter 20 from retracting relative to the inner needle 12.

Further, between the second inner peripheral surface 22 and the third inner peripheral surface 23, a tapered step 25 extending radially outward toward the proximal end direction is provided. The third inner peripheral surface 23 forms a gap 26 with respect to the outer peripheral surface of the inner needle 12 due to the tapered step 25. On the proximal end side of the inner catheter 20, the third inner peripheral surface 23 extends to form a spatial margin, and the sliding resistance of the inner needle 12 can be reduced.

The constituent material of the inner catheter 20 is not particularly limited as long as it has appropriate rigidity (stiffness) and flexibility, and an appropriate resin material may be applied. For example, the constituent materials of the inner catheter 20 include fluororesins such as polytetrafluoroethane (PTFE), ethylene / tetrafluoroethane copolymer (ETFE), and perfluoroalkoxy alkane resin (PFA), polyethylene, and polypropylene. Such as olefin resins or mixtures thereof, polyurethanes, polyesters, polyamides, polyether nylon resins, mixtures of the olefin resins with ethylene-vinyl acetate copolymers and the like.

The base end portion of the inner catheter 20 is fixed to the tip end portion of the inner hub 40 by an appropriate joining method such as caulking, fusion (heat fusion, high frequency fusion, etc.), adhesion with an adhesive, or the like. The inner hub 40 is inserted into the outer hub 50 and is detachably fixed to the outer hub 50 in the state before puncture.

The constituent material of the inner hub 40 is not particularly limited, but for example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer may be applied.

The inner hub 40 is a tubular body formed to have a diameter larger than that of the inner catheter 20, and has a tip tapered portion 41 that tapers at a steep angle toward the tip and a tip taper portion 41 that is connected to the tip taper portion 41 and is gentle toward the tip. It has a base end tapered portion 42 that tapers at an angle. Further, inside the inner hub 40, an internal space 40a is formed which communicates with the inner cavity 20a of the inner catheter 20 and into which the inner needle 12 is inserted.

The connecting portion 15 of the inner needle hub 14 is inserted into the proximal end of the proximal end tapered portion 42. The base end inner peripheral surface of the base end taper portion 42 is formed in an inner surface shape (for example, luer taper) into which the connecting portion 15 is fitted. An inner hub-side flange portion 43 that projects outward in the radial direction is provided on the outer peripheral surface of the proximal end of the proximal end tapered portion 42.

Further, when the inner catheter 20 and the inner hub 40 are indwelled together with the outer catheter 30 and the outer hub 50, the catheter assembly 10 allows the infusion solution to flow through the inner space 40a. For this reason, the internal space 40a includes a hemostatic valve (not shown) that prevents backflow of blood when the inner needle 12 is punctured, and a plug (not shown) that allows infusion through the hemostatic valve when the connector of the infusion tube is inserted. It may be contained.

A rubber member 44 (elastic portion) that can expand and contract in the axial direction of the inner hub 40 is provided at an axially intermediate position of the inner hub 40 according to the present embodiment. The rubber member 44 has an outer shape that is aligned (continuously connected) with the tubular portions of the front and rear inner hubs 40, and circulates in an annular shape along the circumferential direction of the inner hub 40.

The rubber member 44 elastically deforms (expands and contracts) in the axial direction of the inner hub 40, so that the inner hub 40 and the inner catheter 20 on the distal end side of the rubber member 44 and the inner hub 40 on the proximal end side of the rubber member 44 Change the relative distance to. Due to the expansion and contraction of the rubber member 44, the tip of the inner catheter 20 is in contact with the tip of the outer catheter 30 as shown in FIG. 1A (pre-puncture state) and as shown in FIG. It is possible to freely shift to the second state (post-puncture state) retracted in the proximal direction.

As shown in FIGS. 1A and 1B, the outer catheter 30 of the catheter assembly 10 is a flexible tubular member similar to the inner catheter 20, and the entire inner catheter 20 extending from the outer hub 50. Covering. Inside the outer catheter 30, a lumen 30a is formed which extends along the axial direction of the outer catheter 30 and on which the inner needle 12 and the inner catheter 20 can be placed.

The outer peripheral surface of the outer catheter 30 on the distal end side is formed so as to taper toward the distal end. The outer catheter 30 extends along the axial direction with a substantially constant wall thickness, and the inner peripheral surface forming the lumen 30a is in contact with the outer peripheral surface of the inner catheter 20.

The inner peripheral surface on the distal end side of the outer catheter 30 is formed so as to match (surface contact) the outer peripheral surface of the inner catheter 20 which is tapered, and the tip of the outer catheter 30 is more advanced than the inner catheter 20. It is in front and is in contact with the outer peripheral surface of the inner needle 12. Due to such a shape, the inner side of the outer catheter 30 is well supported when the multi-structure needle 11 is punctured, and the bending inward in the radial direction is suppressed. Further, the movement of the outer catheter 30 relative to the inner catheter 20 in the proximal direction is also restricted.

The outer catheter 30 is formed to be softer (that is, different in hardness) than the inner catheter 20. The flexibility of the outer catheter 30 may be realized by a material that is more flexible than the constituent material of the inner catheter 20, or may be realized by a shape such as thinning the outer catheter 30. The material constituting the outer catheter 30 is not particularly limited, and for example, a resin material such as polyurethane-based (ultra-soft polyurethane or the like), polyether-based, or polyolefin-based may be applied.

The base end portion of the outer catheter 30 is fixed to the tip end portion of the outer hub 50 by an appropriate joining method such as caulking, fusion (heat fusion, high frequency fusion, etc.), adhesion with an adhesive, or the like. For example, the outer peripheral surface of the outer catheter 30 on the proximal end side expands radially outward in the outer hub 50, and the outer peripheral surface is fixed to the inner peripheral surface of the outer hub 50 in a planar manner.

The outer hub 50 has a storage space 50a that communicates with the lumen 30a of the outer catheter 30, and is formed in a tubular shape that is slightly thicker than the inner hub 40. The outer hub 50 is attached to the head 51 to which the outer catheter 30 is fixed, the tapered connecting portion 52 which is connected to the proximal end of the head 51 and tapers at a steep angle toward the distal end, and the proximal end of the tapered connecting portion 52. It includes a body portion 53 that is continuous and tapers at a gentle angle toward the tip end direction.

The tapered connecting portion 52 of the outer hub 50 is set at the same inclination angle as the tip tapered portion 41 of the inner hub 40, and the outer peripheral surface of the tip tapered portion 41 can be surface-contacted. The contact between the tip tapered portion 41 and the tapered connecting portion 52 in the pre-puncture state prevents the inner hub 40 from moving to the tip more than necessary than the outer hub 50.

On the other hand, the body portion 53 is set at the same inclination angle as the proximal end tapered portion 42 of the inner hub 40, and the outer peripheral surface of the proximal end tapered portion 42 can be surface-contacted. The body 53 is made of the same material and is continuous in a series. Further, an outer hub side flange portion 54 projecting outward in the radial direction is formed on the outer peripheral surface on the base end side of the body portion 53.

The inner hub 40 and the outer hub 50 are fixed to each other so as to be detachable from each other in the pre-puncture state to form one catheter hub 18. For example, the outer diameter of the base end tapered portion 42 on the base end side is slightly larger than the inner diameter of the base end side (body portion 53) of the outer hub 50 than the rubber member 44 of the inner hub 40. When the inner hub 40 is deeply inserted into the outer hub 50, the inner hub 40 is fitted with an appropriate frictional force. The means for fixing the inner hub 40 and the outer hub 50 is not particularly limited, and for example, the screw structure of the base end tapered portion 42 and the body portion 53, and the inner hub side flange portion 43 and the outer hub side flange portion 54 are connected. It is advisable to adopt a structure that allows each other to work together.

The catheter assembly 10 having the above configuration constitutes a multi-structured needle 11 in which the needle tip 12a of the inner needle 12 is exposed from the tip of the catheter 16 (outer catheter 30) as described above in the pre-puncture state. In this state, the axes of the inner needle 12, the inner and outer catheters 20, and 30 are coaxially arranged.

Further, at the tip of the multi-structure needle 11, the first inner peripheral surface 21 of the inner catheter 20 is in surface contact with the tip region α of the inner needle 12, and the second inner peripheral surface 22 of the inner catheter 20 is the base of the inner needle 12. It is in surface contact with the edge region β. On the other hand, the third inner peripheral surface 23 of the inner catheter 20 faces the proximal region β of the inner needle 12 with a gap 26 in between. Further, the inner peripheral surface of the outer catheter 30 is in close contact with the outer peripheral surface of the inner catheter 20 to cover the inner catheter 20.

On the other hand, the catheter hub 18 is fixed by inserting the inner hub 40 into the outer hub 50, and the connecting portion 15 of the inner needle hub 14 is inserted and mounted from the base end of the catheter hub 18. Further, in the state where the inner hook portion 24 of the inner catheter 20 is engaged with the stepped portion 13 of the inner needle 12 as described above, the tip position of the inner catheter 20 is defined by the inner needle 12, and the inner catheter 20 is the inner hub 40. Acts to pull out toward the tip.

Here, since the inner hub 40 has the rubber member 44 described above, the rubber member 44 is extended by the pulling force of the inner catheter 20 and becomes elongated in the axial direction. The tip tapered portion 41 of the inner hub 40 comes into contact with the tapered connecting portion 52 of the outer hub 50, so that the rubber member 44 is restricted from stretching more than necessary. That is, in the pre-puncture state, the elastic restoring force of the rubber member 44 toward the proximal end direction is applied to the inner catheter 20 relative to the outer catheter 30. This elastic restoring force is smaller than the engaging force between the stepped portion 13 of the inner needle 12 and the inner hooking portion 24 of the inner catheter 20, and is based on the fitting force between the base end portion of the inner hub 40 and the connecting portion 15 of the inner needle hub 14. Is also small. Therefore, the catheter assembly 10 can stably maintain the state shown in FIG. 1A.

The catheter assembly 10 according to the first embodiment is basically configured as described above, and its action and effect will be described below.

When performing infusion or blood transfusion to a patient, a user (doctor, nurse, etc.) grasps and operates the internal needle hub 14, and as shown in FIG. 3A, the multi-structured needle 11 in the pre-puncture state is used in the patient's blood vessel 100. Puncture inside. At the time of puncture, the inner catheter 20 is contact-supported by the inner needle 12 near the base end of the needle tip 12a, and the outer catheter 30 is contact-supported by the inner needle 12 and the inner catheter 20. As a result, the flexibly configured outer catheter 30 is inserted into the blood vessel 100 without causing bending or wrinkles even if it receives resistance from living tissues such as skin and blood vessels.

Further, in the puncture, when the needle tip 12a of the inner needle 12 crosses the blood vessel wall 101 and enters the blood vessel 100, the user stops the insertion of the inner needle 12 and maintains this position while being relatively relative to the inner needle 12. The operation of advancing the catheter 16 is performed. At this time, the inner needle hub 14 fixed to the catheter hub 18 (inner hub 40) is retracted in the proximal direction, and the inner needle hub 14 is separated from the inner hub 40. The inner needle 12 also retracts integrally with the inner needle hub 14.

Then, the catheter assembly 10 also retracts the inner catheter 20 based on the retracting of the inner needle 12. That is, the inner catheter 20 and the inner hub 40 are arranged at positions where they engage with the engaging mechanism 60 of the inner needle 12 and come into contact with the tip of the outer catheter 30 in the pre-puncture state. In this state, the rubber member 44 extends to apply an elastic restoring force to the inner catheter 20 in the proximal direction. Therefore, when the stepped portion 13 (engagement mechanism 60) of the inner needle 12 retracts, the inner catheter 20 also It will also retreat.

As shown in FIG. 2, the retreat of the inner catheter 20 is continued until the elastic deformation of the rubber member 44 ends (becomes a natural state). After the rubber member 44 is elastically restored, the retraction of the inner catheter 20 is stopped, and the inner needle 12 and the inner needle hub 14 are retracted relative to the inner catheter 20 and the inner hub 40 and are removed from the inner hub 40. That is, the catheter assembly 10 shifts to the post-puncture state in which the tip of the inner catheter 20 is arranged at a position separated from the tip of the outer catheter 30 by the expansion and contraction of the rubber member 44.

In this post-puncture state, as shown in FIG. 3B, the inner catheter 20 is not completely removed from the patient's body, and the inner catheter 20 can guide the insertion of the outer catheter 30. Further, the catheter assembly 10 can obtain a distance that allows the outer catheter 30 to be sufficiently bent between the insertion point and the blood vessel wall 101 on the opposite side by retracting the inner catheter 20. This allows the user to easily insert the lateral catheter 30 in the extending direction of the blood vessel 100.

Further, as described above, since the outer catheter 30 is flexibly configured, the tip of the outer catheter 30 strongly contacts (rubs) the blood vessel wall 101, causing inflammation or damage to the blood vessel wall 101. Can be suppressed.

Then, after inserting the outer catheter 30 into the blood vessel 100, the outer catheter 30 and the outer hub 50 are placed in the patient. At this time, at least the inner needle 12 is also detached from the inner catheter 20. When the outer catheter 30 is indwelled, a connector (not shown) of the infusion tube is attached to the proximal end side of the outer hub 50. As a result, the infusion agent is supplied from the infusion tube via the outer hub 50 and the outer catheter 30.

In the indwelling, the inner catheter 20 and the inner hub 40 may be indwelled together, or the inner catheter 20 and the inner hub 40 may be pulled out (separated) from the outer catheter 30 and the outer hub 50 and indwelled. .. When the inner catheter 20 is indwelled together with the outer catheter 30, the kink of the outer catheter 30 is suppressed, and the collapse of the outer catheter 30 is satisfactorily suppressed by the inner catheter 20 even when pressure is applied from the living tissue. .. When only the outer catheter 30 is indwelled, inconveniences such as the outer catheter 30 applying strong stress to the insertion point to spread the wound can be suppressed.

As described above, in the catheter assembly 10 according to the first embodiment, the inner catheter 20 supports the outer catheter 30 from the inside in the state before puncture, and the catheter 16 as a whole can obtain appropriate rigidity. Therefore, even if the outer catheter 30 receives the resistance force of the living tissue at the time of puncture, the bending can be suppressed, and the catheter 16 can be smoothly inserted into the blood vessel 100. Further, since the inner catheter 20 and the outer catheter 30 can move relative to each other in the longitudinal direction, the influence of the inner catheter 20 can be suppressed before the outer catheter 30 is inserted into the blood vessel 100. Therefore, the catheter assembly 10 can reduce the mechanical irritation to the blood vessel 100 and better place the catheter 16.

In this case, since the inner catheter 20 can move relative to the outer catheter 30 based on the retreat of the inner needle 12, the outer catheter 30 can be satisfactorily supported by the inner catheter 20 until the inner needle 12 retreats. Further, the catheter assembly 10 can easily switch between supporting and releasing the tip of the outer catheter 30 by the tip of the inner catheter 20 by shifting between the pre-puncture state and the post-puncture state.

By fixing the inner catheter 20 via the rubber member 44, the elastic force of the rubber member 44 is applied, and the relative movement with respect to the outer catheter 30 can be easily performed. Since the rubber member 44 has a restoring force in the direction of separating the tip of the outer catheter 30 and the tip of the inner catheter 20 in the pre-puncture state, the rubber member 44 is brought into the post-puncture state by retracting the inner needle 12 without performing any other operation. The transition can be smooth. Further, since the catheter assembly 10 has the engaging mechanism 60, the pre-puncture state can be stably maintained, and the outer catheter 30 can be satisfactorily supported by the inner catheter 20.

Furthermore, the medial catheter 20 and the lateral catheter 30 are made of different materials so that the lateral catheter 30 can obtain the desired flexibility. Then, by inserting the flexible outer catheter 30 into the blood vessel 100, inflammation and damage to the blood vessel wall 101 can be further reduced. Further, the catheter 16 which is a combination of the inner catheter 20 and the outer catheter 30 can also have a desired rigidity, and can be satisfactorily inserted into the living body.

The catheter assembly 10 according to the present invention is not limited to the above-described embodiment, and various modifications can be made according to the gist of the invention. For example, in the catheter assembly 10 according to the first embodiment, the rubber member 44 is applied as an elastic portion that applies a retreating force to the inner catheter 20, but the structure is not limited to this. As another elastic portion, for example, a spring member can be applied.

Further, for example, the inner catheter 20 and the outer catheter 30 may have a configuration in which the tip of the inner catheter 20 protrudes from the tip of the outer catheter 30 in the state before puncture. For example, the multi-structured needle 11 in the pre-puncture state has a tapered shape in which the distal end surface of the inner catheter 20 and the distal surface of the outer catheter 30 are continuous from the outer peripheral surface of the inner needle 12 toward the radial outer side and the proximal end direction. If this is done, the patient can be punctured well.

[Second Embodiment]
As shown in FIG. 4A, the catheter assembly 10A according to the second embodiment has an engaging mechanism 61 in which the inner needle 12 and the inner needle hub 14 and the inner catheter 20 and the inner hub 40 are engaged with each other. It is different from the engaging mechanism 60 according to the above. In the following description, the same configurations as those of the catheter assembly 10 according to the first embodiment or the configurations having the same functions are designated by the same reference numerals, and detailed description thereof will be omitted.

Specifically, the engaging mechanism 61 is composed of a protruding portion 15a protruding from the tip end surface of the inner needle hub 14 (connecting portion 15) toward the tip end, and an inner hub 40 (tip tapered portion 41). That is, with the connecting portion 15 of the inner needle hub 14 inserted and fitted into the inner hub 40, the tip portion of the protruding portion 15a contacts and supports the inner peripheral surface of the tip tapered portion 41, whereby the rubber member 44 Maintain the stretched state of the (elastic part). In the illustrated example, the protruding portion 15a is formed in a tubular shape, but the present invention is not limited to this, and one or more rod-shaped protruding portions may be formed. Further, in the illustrated example, the protruding portion 15a is integrally molded with the connecting portion 15, but the present invention is not limited to this, and a separately formed portion may be joined to the connecting portion 15.

Therefore, as shown in FIG. 4B, the inner needle 12 of the catheter assembly 10A (multi-structure needle 11A) adopts a configuration in which the step portion 13 is not provided on the proximal end side of the needle tip 12a, that is, in the axial direction of the inner needle 12. It is possible to form a shape in which the outer diameter is uniformly extended along the above. This simplifies the manufacture of the inner needle 12. Further, the inner catheter 20 can also be configured not to have the inner hooking portion 24 on the inner peripheral surface, which simplifies the manufacture.

In short, various configurations may be adopted for the engaging mechanisms 60 and 61 that maintain the position of the inner catheter 20 in the pre-puncture state (the position where the tip of the outer catheter 30 and the tip of the inner catheter 20 come into contact with each other). For example, as shown by the alternate long and short dash line in FIG. 4A, the engaging mechanism 62 projects the protruding portion 15b radially outward from the outer peripheral surface of the inner needle 12, and causes the inner circumference of the inner hub 40 (tip tapered portion 41). It may be configured to engage with a surface.

[Third Embodiment]
In the catheter assembly 10B according to the third embodiment, as shown in FIG. 5, the inner needle hub 14, the inner hub 40, and the outer hub 50 are interlocked with each other to retract the inner catheter 20 and the inner hub 40. It is different from the catheter assemblies 10 and 10A according to the first and second embodiments. That is, the catheter assembly 10B can be configured so that the inner hub 40 does not have an elastic portion. The tip end side of the catheter assembly 10B can adopt the same configuration as the multilayer structure needle 11A of the second embodiment (see FIG. 4B).

Specifically, in the inner needle hub 70, the connecting portion 71 inserted into the catheter 16 extends long in the axial direction. The tip of the connecting portion 71 is provided with a first engaging convex portion 72 and a second engaging convex portion 73 that engage with the inner hub 40. The first engaging convex portion 72 is provided on the axially tip side of the connecting portion 71, and orbits the outer peripheral surface of the columnar connecting portion 71 in an annular shape in the circumferential direction. The second engaging convex portion 73 is provided at a position shortly spaced from the first engaging convex portion 72 toward the proximal end. The second engaging convex portion 73 projects more radially outward than the first engaging convex portion 72.

On the other hand, in the inner hub 40, the base end tapered portion 42 is formed to be short in the axial direction, and the diameter of the inner hooking convex portion 46 protruding inward in the radial direction at the most proximal end thereof and the diameter of the inner hooking convex portion 46 at the same axial position. It has an outer hooking convex portion 47 projecting outward in the direction. The inner hooking convex portion 46 and the outer hooking convex portion 47 orbit the inner peripheral surface and the outer peripheral surface of the inner hub 40 in an annular shape, and project in opposite directions with the same amount of protrusion.

The inner hook convex portion 46 engages with the first and second engaging convex portions 72 and 73 of the inner needle hub 14, and the catheter assembly 10 has the first engaging convex portion 72 and the inner hooking convex portion 72. The convex portion 46 constitutes the engaging mechanism 63. On the other hand, the outer hooking convex portion 47 is configured to be hooked on the inner peripheral surface of the outer hub 50.

The outer hub 50 has a first engaging recess 56 and a second engaging recess 57 on the inner peripheral surface of the body portion 53, and an outer hooking convex portion is provided between the first and second engaging recesses 56 and 57. The passage 58 is shallowly recessed so that the 47 can slide. The outer hooking protrusion 47 of the inner hub 40 is inserted and engaged with the first and second engaging recesses 56 and 57. The first engaging recess 56 is shallowly recessed from the inner peripheral surface. The second engaging recess 57 is provided at a position separated from the first engaging recess 56 to some extent in the direction of the proximal end, and is recessed deeper than the first engaging recess 56. In particular, the outer hub 50 projects the base end side (inner peripheral surface of the body portion 53) of the second engaging recess 57 radially inward from the tip end side (passage 58) of the second engaging recess 57. It is possible to securely lock the outer hook convex portion 47.

The catheter assembly 10B according to the third embodiment is basically configured as described above. In the assembly of the catheter assembly 10B, the inner needle 12 is inserted into the inner catheter 20, and the inner needle hub 14 is inserted together with the inner hub 40 into the accommodation space 50a of the outer hub 50. At this time, the inner hooking convex portion 46 of the inner hub 40 is arranged between the first engaging convex portion 72 and the second engaging convex portion 73 of the inner needle hub 14. When the inner needle hub 14 is inserted, the inner needle hub 14 advances toward the tip end, so that the second engaging convex portion 73 pushes out the inner hooking convex portion 46. As a result, the inner hub 40 is advanced relative to the outer hub 50. That is, the second engaging convex portion 73 functions as a locking portion when advancing.

The advancement of the inner hub 40 is continued until the outer hooking protrusion 47 of the inner hub 40 is engaged with the first engaging recess 56 of the outer hub 50. In this engaged state, the tip tapered portion 41 of the inner hub 40 contacts the tapered connecting portion 52 of the outer hub 50, and the inner hub 40 and the outer hub 50 form a catheter hub 18 in contact with each other. The multi-structure needle 11 also establishes a pre-puncture state in which the tip of the inner catheter 20 is in contact with the tip of the outer catheter 30.

When using the catheter assembly 10b, the user punctures the patient with the multi-structured needle 11 and retracts the inner needle hub 14 relative to the catheter hub 18 in the punctured state, thereby causing the inner needle 12 with respect to the outer catheter 30. To retreat. At this time, the first engaging convex portion 72 of the inner needle hub 14 hooks the inner hooking convex portion 46 of the inner hub 40, and the inner hub 40 is integrally retracted. The engaging force between the first engaging convex portion 72 and the inner hooking convex portion 46 is designed to be stronger than the engaging force between the outer hooking convex portion 47 and the first engaging concave portion 56, and the inner needle hub 14 is inside. The hub 40 can be reliably retracted.

The retreat of the inner needle hub 14 and the inner hub 40 is continued until the outer hooking protrusion 47 is engaged with the second engaging recess 57 of the outer hub 50. Here, the engaging force between the outer hooking convex portion 47 and the second engaging concave portion 57 is designed to be stronger than the engaging force between the first engaging convex portion 72 and the inner hooking convex portion 46. Therefore, when the inner needle hub 14 is further retracted after the outer hook convex portion 47 is engaged with the second engaging concave portion 57, the engagement between the first engaging convex portion 72 and the inner hook convex portion 46 is released. Will be done. That is, the outer hook convex portion 47 and the second engaging concave portion 57 function as a releasing mechanism 65 having a releasing mechanism for releasing the lock by the first engaging convex portion 72.

The release mechanism 65 causes the inner needle hub 14 to retract, leaving the inner hub 40. As a result, the catheter assembly 10B keeps the inner needle 12 and the inner needle hub 14 from the inner and outer catheters 20 and 30 while keeping the tip of the inner catheter 20 separated from the tip of the outer catheter 30 by a predetermined distance after puncture. It can be separated.

As described above, in the catheter assembly 10B according to the third embodiment, the engagement mechanism 63 by the first engaging convex portion 72 and the inner hooking convex portion 46, the outer hooking convex portion 47, and the second engaging concave portion 57 are released. It has a mechanism 65. Therefore, the inner hub 40 can be retracted based on the retracting of the inner needle hub 14, and the retreating of the inner hub 40 can be stopped by the release mechanism 65. As a result, the inner catheter 20 can be arranged at a position retracted to some extent, and the compression of the outer catheter 30 by the living tissue can be supported by the inner catheter 20.

Further, the release mechanism 65 can be easily configured by the outer hooking protrusion 47 of the inner hub 40 and the second engaging recess 57 of the outer hub 50, reducing the manufacturing cost of the inner hub 40 and the outer hub 50. can do. Further, the catheter assembly 10B can smoothly push out the inner catheter 20 and the inner hub 40 with respect to the outer catheter 30 and the outer hub 50 by the second engaging convex portion 73 of the inner needle hub 14, and can be assembled with each other. Can be easily performed.

The catheter assembly 10B according to the third embodiment can also take various application examples and modifications. For example, the protrusions or recesses provided on the inner needle hub 14, the inner hub 40, and the outer hub 50 may be freely designed as long as a desired engaging force can be obtained.

Further, when the inner hub 40 is removed at the same time as the inner needle hub 14 is removed from the outer hub 50, the outer hub 50 does not have to be provided with the second engaging recess 57.

Further, the first and second engaging protrusions 72 and 73, the inner and outer hooking protrusions 46 and 47, and the first and second engaging recesses 56 and 57 are partially or wholly formed as non-annular protrusions. You may. For example, when all the protrusions and recesses are formed on the protrusions, a mechanism (for example, spline engagement) for positioning the circumferential positions of the inner needle hub 14, the inner hub 40, and the outer hub 50 may be adopted.

10, 10A, 10B ... Catheter assembly 11 ... Multi-structure needle 12 ... Inner needle 13 ... Step portion 14, 70 ... Inner needle hub 15, 71 ... Connecting part 15a, 15b ... Protruding portion 16 ... Catheter 18 ... Catheter hub 20 ... Inner catheter 24 ... Inner hook 30 ... Outer catheter 40 ... Inner catheter hub 44 ... Rubber member 46 ... Inner hook convex 47 ... Outer hook convex 50 ... Outer catheter hub 52 ... Tapered connection 56 ... First engaging recess 57 ... Second engaging recess 60-63 ... Engagement mechanism 65 ... Disengaging mechanism 72 ... First engaging convex portion 73 ... Second engaging convex portion

Claims (9)

With the inner needle
An inner catheter located outside the inner needle and
An outer catheter located outside the inner catheter and
A catheter hub for fixing and holding the inner catheter and the outer catheter is provided.
The inner needle is retractable relative to the outer catheter and can be removed from the inner catheter and the outer catheter.
Since the inner catheter and the outer catheter can move relative to each other in the longitudinal direction of the inner needle, the first state in which the tip of the inner catheter contacts the tip of the outer catheter and the tip of the inner catheter are in contact with each other. It is possible to shift to a second state, which is separated from the tip of the outer catheter.
The catheter hub
With the inner catheter hub to which the inner catheter is fixed,
Includes an outer catheter hub to which the outer catheter is immobilized.
The inner catheter hub is provided with an elastic portion elastically deformable in the axial direction of the inner catheter hub at an axially intermediate position of the inner catheter hub, and the inner catheter hub at least on the distal end side of the elastic portion is the outer side. A catheter assembly characterized in that it is configured to be movable relative to a catheter hub . In the catheter assembly according to claim 1,
A catheter assembly characterized in that the inner catheter is movable relative to the outer catheter based on the retraction of the inner needle. In the catheter assembly according to claim 1 or 2 .
A catheter assembly characterized in that the elastic portion has a restoring force in a direction in which the tip of the inner catheter and the tip of the outer catheter are separated from each other in the first state. In the catheter assembly according to claim 3 ,
The other of the inner catheter and the outer catheter and the inner needle or the inner needle hub that fixedly holds the inner needle have an engaging mechanism that continues the first state against the restoring force. Catheter assembly. With the inner needle
An inner catheter located outside the inner needle and
An outer catheter located outside the inner catheter and
A catheter hub for fixing and holding the inner catheter and the outer catheter is provided.
The inner needle is retractable relative to the outer catheter and can be removed from the inner catheter and the outer catheter.
The inner catheter and the outer catheter can move relative to each other in the longitudinal direction of the inner needle.
The catheter hub
With the inner catheter hub to which the inner catheter is fixed,
The outer catheter is fixed and comprises an outer catheter hub that is movable relative to the inner catheter hub.
The inner needle hub that fixedly holds the inner needle has a retracting locking portion that locks the inner catheter hub when retracting relative to the outer catheter hub.
The catheter assembly is characterized in that the inner catheter hub and the outer catheter hub have a releasing mechanism for releasing the locking of the retracting locking portion when the inner needle is retracted with respect to the catheter. In the catheter assembly according to claim 5 ,
The release mechanism is a catheter assembly comprising a convex portion provided on one of the inner catheter hub and the outer catheter hub and a concave portion provided on the other. In the catheter assembly according to claim 5 or 6 .
The catheter assembly is characterized by having an advancing locking portion that locks the inner catheter hub and pushes out the inner catheter hub when advancing relative to the catheter hub. In the catheter assembly according to any one of claims 1 to 7 .
A catheter assembly characterized in that the inner catheter and the outer catheter are made of materials having different hardness from each other. In the catheter assembly according to claim 8 ,
The outer catheter is a catheter assembly characterized by being more flexible than the inner catheter.

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