Catheter assembly

Abstract

To provide a catheter assembly which has a warp suppressing mechanism for suppressing warp of an inner needle and is used in infusion, blood transfusion, or the like.SOLUTION: A catheter assembly 10 includes an inner needle 12, a catheter 30 having a lumen into which the inner needle is detachably inserted, and a warp suppressing mechanism 90 for suppressing warp of the inner needle by supporting the inner needle through the catheter. The catheter has one or more catheter side part openings and a step part which is provided so as to increase an inner diameter and an outer diameter of the catheter. The warp suppressing mechanism has a contact support part that is contactable with the catheter when the catheter advances relative to the inner needle. The contact support part can support a proximal end side of a distal end part of the catheter side part opening located closest to a distal end side among the one or more catheter side part openings, or a proximal end side of the step part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a catheter assembly used, for example, when performing infusion, blood transfusion, or the like.

Background Art

[0002] When constructing an introduction part for infusion or blood transfusion in a patient, for example, as disclosed in Patent Document 1, a catheter assembly having a multi-structured needle in which an inner needle is inserted into a catheter (outer needle) is used. In using this catheter assembly, the user punctures the multi-structured needle into the patient, advances the catheter relative to the inner needle and inserts it into the blood vessel, and further detaches the inner needle from the catheter to留置 the catheter.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] One aspect of the present invention is a catheter assembly including an inner needle, a catheter having a lumen into which the inner needle is removably inserted, and a bending suppression mechanism that suppresses bending of the inner needle by supporting the inner needle via the catheter, wherein the catheter is formed with one or more catheter side openings and a stepped portion provided so that the inner diameter and outer diameter of the catheter increase, the bending suppression mechanism has a contact support portion that can contact the catheter when the catheter advances relative to the inner needle, and the contact support portion can support a position closer to the proximal end than the tip of the catheter side opening at the most distal end among the one or more catheter side openings or closer to the proximal end than the stepped portion.

Brief Description of the Drawings

[0005] [Figure 1]This is a perspective view showing the overall configuration of a catheter assembly according to the first embodiment of the present invention. [Figure 2] Figure 1 is a side cross-sectional view showing the catheter, catheter hub, and inner needle. [Figure 3] This is a side cross-sectional view showing the catheter, catheter hub, and inner needle of a catheter assembly according to the second embodiment. [Figure 4] This is a side cross-sectional view showing the catheter, catheter hub, and inner needle of a catheter assembly according to the third embodiment. [Figure 5] This is a plan cross-sectional view showing the catheter, catheter hub, and inner needle of a catheter assembly according to the fourth embodiment. [Figure 6] Figures 6A to 6F are cross-sectional views of the catheter and inner needle according to the first to sixth configuration examples. [Figure 7] Figure 7A is a cross-sectional view of the catheter and inner needle according to the seventh configuration example, and Figure 7B is a cross-sectional view of the catheter and inner needle according to the eighth configuration example. [Figure 8] This is a perspective view showing the overall configuration of the catheter assembly according to the fifth embodiment. [Figure 9] Figure 8 is a side cross-sectional view showing the catheter, inner needle, and bending suppression mechanism. [Figure 10] Figure 8 is a perspective view showing the operation of the catheter assembly. [Figure 11] This is a perspective view showing the overall configuration of the catheter assembly according to the sixth embodiment. [Figure 12] Figure 12A is a cross-sectional view of the multi-tube structure shown in Figure 11. Figure 12B is a cross-sectional view showing the operation of the catheter during fluid flow. [Figure 13] This is a perspective view showing the overall configuration of the catheter assembly according to the seventh embodiment. [Figure 14] This is a perspective view showing the overall configuration of the catheter assembly according to the eighth embodiment. [Figure 15] Figure 14 is a partial cross-sectional view showing the deflection suppression mechanism. [Figure 16] This is a schematic side view showing the overall configuration of the catheter assembly according to the ninth embodiment. [Figure 17] This is a perspective view showing the overall configuration of the catheter assembly according to the 10th embodiment. [Figure 18] Figure 17 is a magnified perspective view showing the deflection suppression mechanism. [Modes for carrying out the invention]

[0006] Hereinafter, preferred embodiments of the catheter assembly according to the present invention will be given and described in detail with reference to the attached drawings.

[0007] [First Embodiment] The catheter assembly 10 according to the first embodiment is a medical device used when administering intravenous fluids or blood transfusions to a patient (living body), and involves puncturing, inserting, and leaving the catheter 30 in the patient's body to create an inlet / outlet port for fluids (medicinal solutions or blood). This catheter assembly 10 is configured to insert a catheter that is longer than a peripheral venous catheter (for example, a central venous catheter, PICC, midline catheter, etc.). However, the catheter assembly 10 may also be used to insert a peripheral venous catheter that is shorter than a central venous catheter. Furthermore, the catheter assembly 10 is not limited to venous catheters, but may also be used to insert arterial catheters such as peripheral arterial catheters.

[0008] As shown in Figure 1, the catheter assembly 10 comprises an inner needle 12, a housing 20 (inner needle hub) that fixes and holds the inner needle 12, a catheter 30 positioned outside the inner needle 12, and a catheter hub 50 that fixes and holds the catheter 30. Furthermore, the catheter assembly 10 comprises a catheter operating member 60 that controls the forward and backward movement of the catheter 30 and the catheter hub 50, and a guide wire 70 and a guide wire operating member 80 that guide the advancement of the catheter 30.

[0009] In addition, the catheter 30 according to the present embodiment is configured as a multi-lumen type having a plurality (two in the present embodiment) of lumens 31 inside (see also FIG. 2). And, in the assembled state before use (pre-puncture state) of the catheter assembly 10, the inner needle 12 is inserted and disposed in one main lumen 34 among the plurality of lumens 31, and the guide wire 70 is accommodated inside the inner needle 12 to form the multi-structure needle 11.

[0010] In this multi-structure needle 11, in the pre-puncture state, while the tip 13 of the inner needle 12 protrudes from the tip of the catheter 30, the guide wire 70 is disposed inside the inner needle 12. And, the housing 20 accommodates the proximal end side of the multi-structure needle 11 inside, and also accommodates the catheter hub 50, the catheter operation member 60, and the guide wire operation member 80 together.

[0011] In using this catheter assembly 10, a user such as a doctor or a nurse grips and operates the housing 20 to puncture the multi-structure needle 11 into the patient's body. Further, while maintaining the puncture state, the guide wire 70 is sent out from the inner needle 12 into the blood vessel, and the catheter 30 is inserted into the blood vessel along this guide wire 70. Then, by retracting and removing the inner needle 12 with respect to the catheter 30, the catheter 30 is left in the blood vessel. In the indwelling state, the catheter 30 allows a plurality of types of drugs to be administered separately or procedures such as blood sampling while administering drugs by communicating the two lumens 31 in the blood vessel. Hereinafter, each component of this catheter assembly 10 will be described in detail.

[0012] As shown in FIGS. 1 and 2, the inner needle 12 is configured as a hollow tube having a rigidity capable of puncturing the skin of a living body, and a sharp tip 13 is provided at its tip. Inside the inner needle 12, a hollow portion 12a is provided along the axial direction. Note that the inner needle 12 may have a solid structure without the hollow portion 12a.

[0013] The needle tip 13 has a blade surface 15 inclined at a predetermined angle with respect to the axis of the inner needle 12 by obliquely cutting a cylindrical tube. The blade surface 15 has an elliptical shape surrounding a tip opening 15a communicating with the hollow portion 12a. When the catheter assembly 10 is used, the blade surface 15 is directed in the direction facing the user (upward when the patient's body surface is on the lower side). Thereby, at the time of puncture, the edge of the blade surface 15 cuts the skin and penetrates into the body.

[0014] Hereinafter, unless otherwise instructed, the directions and positions of the respective components of the catheter assembly 10 will be described based on the orientation of the blade surface 15 (also refer to the arrow directions in FIG. 1). In particular, the arrangement of the plurality of lumens 31 of the catheter 30 will be described in relation to the blade surface 15.

[0015] In FIGS. 1 and 2, the blade surface 15 simply cut obliquely with respect to the axis of the inner needle 12 is illustrated, but the shape of the blade surface 15 is not particularly limited. For example, the needle tip 13 may be configured in a lancet type in which two inclined blade surfaces 15 form a cutting edge (peak) at the center in the width direction, or may be configured in a back cut type in which the opposite side of the blade surface 15 is cut.

[0016] Further, the inner needle 12 is provided with a hole 14 penetrating the hollow portion 12a and the outer surface. That is, the inner needle 12 constitutes an introduction path for confirming blood flashback during puncture of the multi-structured needle 11 by the tip opening 15a, the hollow portion 12a, and the hole 14.

[0017] Examples of the constituent material of the inner needle 12 include metal materials such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy, or hard resins, ceramics, etc. The inner needle 12 is firmly fixed to the housing 20 by appropriate fixing means such as fusion bonding, adhesion, insert molding, etc.

[0018] The housing 20 of the catheter assembly 10 is an inner needle hub 19 that fixes and holds the inner needle 12 and moves integrally with the inner needle 12, and constitutes the grip portion that is grasped by the user. The housing 20 has an overall elongated bowl shape and is designed to be of an appropriate size (thickness and length) to make it easy for the user to grasp.

[0019] The housing 20 is provided with a housing space 20a for accommodating the catheter hub 50, catheter operating member 60, and guide wire operating member 80. A pair of side walls 21 flanking the housing space 20a extend parallel to the longitudinal direction and have groove-shaped rail portions 21a on the inner surface of the tip end, which is formed higher than the proximal end. The pair of rail portions 21a slidably accommodate the side edges 61a of the catheter operating member 60. One of the pair of side walls 21 (the left side wall 21 in Figure 1) has a bulge portion 22 that bulges outward in the width direction at the tip end. A support member 91, which is a deflection suppression mechanism 90, is attached to the recess 22a for positioning this bulge portion 22.

[0020] The support member 91 is pivotally supported on the side wall 21 so as to be rotatable and has a sliding contact support portion 92 that protrudes to the right from the housing space 20a of the housing 20. This sliding contact support portion 92 rubs against the catheter 30 (multi-layered needle 11) held by the catheter operating member 60 as the catheter 30 moves forward. This sliding contact support portion 92 does not need to be in contact with the catheter 30 before use or when the catheter 30 moves relative to the housing 20. Furthermore, the support member 91 has a groove (not shown) at its upper end that accommodates the side edge 61a of the catheter operating member 60 when the catheter operating member 60 is housed in the housing 20. The presence of the side edge 61a in this groove restricts rotation and keeps the support member 91 ready to support the catheter 30. On the other hand, when the catheter operating member 60 moves forward, the support member 91 becomes rotatable as the side edge 61a disengages from the groove, and then rotates toward the outside of the side wall 21 as the catheter operating member 60 makes contact. As a result, the support member 91 (sliding contact support portion 92) remains in the housing 20, while the catheter hub 50 and catheter operating member 60 are smoothly ejected from the housing 20.

[0021] Furthermore, the housing 20 includes a block-shaped needle holding portion 24 that holds the inner needle 12 at the axial intermediate position of the housing space 20a. A guide mechanism (not shown) is provided on the base end side of the housing 20 from the needle holding portion 24, which guides the sliding of the guide wire operating member 80 and restricts the detachment of the guide wire operating member 80. In addition, a rear wall 25 that closes the housing space 20a is provided at the very base end of the housing 20.

[0022] The constituent material of the housing 20 is not particularly limited, but thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer may be used. In the illustrated example, the housing 20 is configured with the upper surface of the containment space 20a exposed, but the housing 20 may also be formed in a rectangular tube shape, such as by covering the containment space 20a with an upper wall.

[0023] On the other hand, the catheter 30 of the catheter assembly 10 is formed in a perfectly circular shape when viewed in a cross-sectional view perpendicular to the axial direction, and extends along the axial direction for an appropriate length. The length of the catheter 30 is not particularly limited and can be appropriately designed according to the application and various conditions, for example, it can be set to about 14 to 500 mm.

[0024] As shown in Figure 2, the catheter 30 is composed of a main body 32 that constitutes most of its axial length, and a soft tip 33 (flexible part) provided at the tip of the main body 32 that is softer than the main body 32. The main body 32 and the soft tip 33 are firmly fixed together by appropriate fixing methods such as heat fusion or adhesive, and their outer surfaces are formed in a continuous series. In addition, the connecting boundary between the main body 32 and the soft tip 33 overlaps each other in a tapered manner, gradually changing the physical properties of the catheter 30.

[0025] The catheter 30 has multiple lumens 31, including a main lumen 34 (first lumen) through which the inner needle 12 is inserted in the pre-puncture state, and a sub-lumen 41 (second lumen) extending parallel to the main lumen 34. The main lumen 34 and the sub-lumen 41 are each formed in a circular shape in a cross-sectional view perpendicular to the axis of the catheter 30.

[0026] The main lumen 34 extends along the entire axial length of the catheter 30 and communicates with a first tip opening 34a (main opening) formed at the tip of the catheter 30 and a first proximal opening 34b formed at the proximal end of the catheter 30. The first tip opening 34a exposes the needle tip 13 of the inner needle 12.

[0027] The inner circumferential surface of the catheter 30, which constitutes the main lumen 34, is divided into a tip inner circumferential surface 36, where the gap between it and the outer circumferential surface 16 of the inner needle 12 is zero (narrow), and a basic inner circumferential surface 38, which forms a gap 39 between it and the outer circumferential surface 16 of the inner needle 12, with a predetermined position P in the axial direction as the starting point. Furthermore, a tapered inner circumferential surface 37 is formed at the tip of the basic inner circumferential surface 38, connecting the tip inner circumferential surface 36 and the basic inner circumferential surface 38.

[0028] The inner circumferential surface 36 of the tip has a diameter that matches or is slightly smaller than the outer diameter of the outer circumferential surface 16 of the inner needle 12, thereby forming a contact portion 35 that adheres closely to the outer circumferential surface 16 of the inner needle 12 and closing the gap 39 of the basic inner circumferential surface 38. Therefore, the diameter of the inner circumferential surface 36 of the tip is preferably designed according to the outer diameter of the inner needle 12, for example, in the range of 0.3 mm to 1.8 mm. In addition, the length of the inner circumferential surface 36 in the longitudinal direction (axial direction) is preferably in the range of 0.1 mm to 4.0 mm in order to insert the tip of the catheter 30 well.

[0029] The soft tip 33 described above, together with the main body 32, constitutes the tip of the catheter 30, and its inner surface forms the inner circumferential surface 36 (adhesion portion 35). The very tip of the inner circumferential surface 36 of the soft tip 33 forms the first tip opening 34a. The very tip of the outer circumferential surface of the soft tip 33 is formed as a tapered tip portion 40 with an inclination that matches (or is less inclined than) the inclination of the cutting surface 15 of the needle tip 13.

[0030] The tapered inner surface 37 of the main lumen 34 gradually decreases in diameter toward the tip (tip inner surface 36) over a short axial range. On the other hand, the basic outer surface 44 constitutes the inner surface of the main lumen 34 over most of the axial range.

[0031] The diameter of the basic inner surface 38 is larger than the outer diameter of the outer surface 16 of the inner needle 12, that is, larger than the gap of the inner surface 36 at the tip. This allows the inner needle 12 and the catheter 30 to slide smoothly. In addition, the hole 14 of the inner needle 12 is opposite the basic inner surface 38 and communicates with the gap 39 of the basic inner surface 38 in the pre-puncture state. Therefore, it is possible to flush blood back into the gap between the inner needle 12 and the catheter 30 effectively. The diameter of the basic inner surface 38 should be designed to be, for example, about 1.02 to 1.33 times the diameter of the inner surface 36 at the tip.

[0032] The sub-lumen 41 is located along the axial direction of the catheter 30, separated from the main lumen 34. In other words, the main lumen 34 and the sub-lumen 41 extend within the catheter 30 along axes parallel to each other. At an intermediate position near the tip of the catheter 30, the sub-lumen 41 bends radially outward and communicates with a second lateral opening 41a (sub-opening) formed on the outer surface (lateral side) of the catheter 30.

[0033] The second lateral opening 41a is located closer to the base end than the first tip opening 34a. Preferably, the distance between the first tip opening 34a and the second lateral opening 41a is 17 mm or more.

[0034] The catheter assembly 10 has a distance of 17 mm or more between the first tip opening 34a and the second lateral opening 41a, so that the drug flowing out from either the first tip opening 34a or the second lateral opening 41a is mixed with blood in the blood vessel before being mixed with the drug flowing out from the other. In other words, drugs that are incompatible with each other can be successfully administered using a single catheter 30. The proximal end of the sub-flumen 41 communicates with the second proximal opening 41b, which is adjacent to the first proximal opening 34b.

[0035] Furthermore, in this embodiment, the diameter of the inner surface of the sub-lumen 41 is set to be smaller than the diameter of the inner surface (tip inner surface 36) of the main lumen 34. That is, the multiple lumens 31 consist of a large-diameter main lumen 34 in which the inner needle 12 is placed, and a small-diameter sub-lumen 41 in which nothing is placed. Moreover, while the diameter of the main lumen 34 changes along the axial direction, the inscribed circle diameter of the sub-lumen 41 remains constant along the axial direction of the catheter 30. The diameter of the sub-lumen 41 is not particularly limited as long as it is possible to flow the drug in from the second proximal opening 41b and guide the drug to the second lateral opening 41a, and may be in the range of 0.3 to 1.2 mm, for example.

[0036] On the other hand, the outer surface of the catheter 30 is formed as a tip outer surface 42 with a small outer diameter in the range from the tip to a predetermined position P. For example, the tip outer surface 42 has an outer diameter that is slightly larger than that of the inner needle 12. The outer surface of the catheter 30 also has a tapered outer surface 43 that widens from the predetermined position P toward the proximal end, and a basic outer surface 44 that is connected to the proximal end of the tapered outer surface 43 and is wider than the tip outer surface 42. The basic outer surface 44 is provided at the position where the sub-flumen 41 is formed.

[0037] In the catheter 30 described above, the inner circumferential surface 36 of the tip and the outer circumferential surface 42 of the tip overlap in the axial direction, the tapered inner circumferential surface 37 and the tapered outer circumferential surface 43 overlap, and the basic inner circumferential surface 38 and the basic outer circumferential surface 44 overlap. Therefore, near a predetermined position P, the wall thickness of the main body 32 itself does not change; in other words, even if the shape of the main body 32 becomes thinner, its wall thickness remains constant and continuous. Furthermore, at the position where the outer diameter becomes thicker due to the formation of the sub-flumen 41, a continuous inclined surface 45 is provided that is inclined continuously with the tapered outer circumferential surface 43 and connects to the basic outer circumferential surface 44.

[0038] The constituent material of the main body 32 is not particularly limited, but a soft resin material is preferred. Examples include fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxy fluororesin (PFA), olefin resins such as polyethylene and polypropylene or mixtures thereof, polyurethane, polyester, polyamide, polyether nylon resin, and mixtures of olefin resins and ethylene-vinyl acetate copolymer. The constituent material of the soft tip 33 is also not particularly limited, but a resin material such as polyurethane is preferred.

[0039] Furthermore, the catheter 30 is preferably made of a transparent material, which allows the user to clearly see the flashback of blood flowing into the main lumen 34 and sub-lumen 41. Alternatively, the catheter 30 may have a transparent core for the main lumen 34 and an opaque core for the sub-lumen 41. This is because the blood can be seen by the user as it flows into the gap 39. Conversely, the sub-lumen 41 may have a transparent core and the main lumen 34 may have an opaque core. Also, even if the catheter assembly 10 does not have a hole 14 (notch) in the inner needle 12, as the catheter 30 advances relative to the inner needle 12, blood flows into the main lumen 34 when contact between the tip of the inner needle 12 and the inner surface of the main lumen 34 of the catheter 30 ceases, allowing the flashback to be confirmed.

[0040] The proximal end of the catheter 30 is fixed to the tip inside the catheter hub 50 by appropriate fastening means such as crimping, fusion, or adhesive. The catheter hub 50 is exposed on the patient's skin when the catheter 30 is inserted into the patient's blood vessel and is attached with tape or the like to be placed together with the catheter 30. The material constituting the catheter hub 50 is not particularly limited, and for example, the materials listed for the housing 20 may be used as appropriate.

[0041] As shown in Figures 1 and 2, the catheter hub 50 has a main hub 51 (first catheter hub) which is formed in a cylindrical shape that tapers towards the tip, and a sub-hub 52 (second catheter hub) which is connected to the side of the main hub 51. The main hub 51 constitutes the main port through which one of two types of drugs flows in during infusion, etc., and the sub-hub 52 constitutes the sub-port through which the other of the two types of drugs flows in.

[0042] The main hub 51 securely holds the catheter 30 at its tip and has a main space 51a (first space) on the proximal end side of the securing portion. The main space 51a communicates with the main lumen 34, and the inner needle 12 is inserted through it in the pre-puncture state. Inside the main hub 51, there is a flow path 53 that communicates with the sub-lumen 41 of the catheter 30 and with the sub-space 52a in the sub-hub 52. The sub-space 52a and the flow path 53 constitute a communication passage 55 that communicates with the sub-lumen 41.

[0043] The sub-hub 52 is formed in a cylindrical shape with a sub-space 52a inside, and is positioned above the main space 51a, corresponding to the arrangement of the main lumen 34 and sub-lumen 41 of the catheter 30. This makes it easy to manufacture the main hub 51 in a shape that separates the flow path 53 and the main space 51a. In addition, it becomes possible to make the housing 20 narrow in the width direction, allowing the user to easily grasp the housing 20 during puncture.

[0044] The main hub 51 and the sub-hub 52 are connection parts to which connectors for infusion tubing can be connected (for example, they are provided with a flange portion 54 that protrudes radially outward at the base end, or the inner circumferential surface of the main space portion 51a or the sub-space portion 52a is formed as a Luer taper). The main space portion 51a of the main hub 51 and the sub-space portion 52a of the sub-hub 52 may house a hemostatic valve (not shown) to prevent backflow of blood, and a plug (not shown) that allows infusion by passing through the hemostatic valve when the connector for the infusion tubing is inserted.

[0045] As shown in Figure 1, the catheter 30 and catheter hub 50 are operated by a catheter operating member 60 to move relative to the inner needle 12 and the housing 20. The catheter operating member 60 directly holds the catheter 30 and also houses and holds the catheter hub 50. The catheter operating member 60 has an operating plate portion 61 that extends in the longitudinal direction of the housing 20 and a hub housing portion 62 that is connected to the base end of the operating plate portion 61 and houses the catheter hub 50.

[0046] The operating plate portion 61 is the part that the user's fingers are placed on to perform forward and backward movements. In the pre-puncture state, the pair of side edges 61a of the operating plate portion 61 are positioned on the pair of rail portions 21a of the housing 20 and on the upper surfaces of the pair of side walls 21. In addition, one or more catheter holding portions, each consisting of a pair of projections (not shown), are provided along the longitudinal direction on the lower surface of the operating plate portion 61, and the catheter 30 is held in place at each location.

[0047] In other words, as shown in Figures 1 and 2, the multi-layered needle 11 (catheter 30) is supported at an intermediate axial position by a deflection suppression mechanism 90 composed of the support member 91 and the operating plate portion 61 described above. The support points by the support member 91 (deflection suppression mechanism 90) are located on the proximal end side of the tapered outer peripheral surface 43 and the continuous inclined surface 45, and also on the proximal end side of the second lateral opening 41a. The support member 91 can support the catheter 30 near the second lateral opening 41a, which is on the tip side of the support member 91 and closest to it.

[0048] More specifically, the support member 91 can support the catheter 30 at a position of 5 mm or less from the second lateral opening 41a, which is closer to the tip of the support member 91. Here, it is preferable that the deflection suppression mechanism 90 be provided as far to the tip as possible from the viewpoint of suppressing deflection of the inner needle 12 and the tip of the catheter 30. On the other hand, the catheter 30 having a main lumen 34 and a sub-lumen 41 needs to have openings spaced a certain distance apart so that the drug solution discharged from each opening mixes in the blood. However, if the deflection suppression mechanism 90 is located further to the tip than the second lateral opening 41a, the deflection suppression mechanism 90 may come into contact with the catheter 30 near the second lateral opening 41a and cause damage. Therefore, by providing the deflection suppression mechanism 90 at the shortest possible distance for the drug solution discharged from each opening to mix in the blood, and near the second lateral opening 41a, it is possible to achieve both mixing in the blood and deflection suppression.

[0049] The hub housing section 62 comprises an upper plate 63 connected to the operating plate section 61 and a pair of side plates (not shown) forming a storage chamber for housing the catheter hub 50. The upper plate 63 is provided with a roughly isosceles triangular cutout in accordance with the shape of the catheter hub 50, and a mounting hole 63a for the sub-hub 52 to protrude. The hub housing section 62 holds the flange portion 54 of the catheter hub 50 detachably with appropriate frictional force by the pair of side plates and an arch portion 64 that bridges in an arc shape at the base end.

[0050] As shown in Figures 1 and 2, the guide wire 70 of the catheter assembly 10 is positioned in the hollow portion 12a of the inner needle 12 and extends along the axial direction of the inner needle 12. This guide wire 70 extends from the proximal end opening (not shown) of the inner needle 12 and is fixed to the guide wire operating member 80. The guide wire 70 is formed to be longer in the axial direction than the inner needle 12 and has appropriate rigidity and flexibility.

[0051] In the pre-puncture state, the tip of the guidewire 70 is positioned proximal to the hole 14 of the inner needle 12. This allows blood that flows from the blood vessel into the hollow portion 12a during puncture to flow out to the outside of the inner needle 12 through the hole 14, enabling the user to visually observe a flashback. Then, in the puncture state of the inner needle 12, the guidewire 70 is advanced into the blood vessel by being fed out from the tip opening 15a of the inner needle 12 under the user's operation of the guidewire operating member 80.

[0052] Returning to Figure 1, the guidewire operating member 80 of the catheter assembly 10 has a holding block 81 that fixes and holds the guidewire 70 at the proximal end of the housing 20, and an operating arm 82 that extends from the holding block 81 toward the tip. The tip of the operating arm 82 is equipped with an operating projection 83 that the user can directly contact and operate, and is slidably mounted on the flat upper surface of the guidewire operating member 80. In other words, as the operating arm 82 is extended, the holding block 81 extends, pushing the guidewire 70 toward the tip. Then, depending on the amount the guidewire operating member 80 is extended, the guidewire 70 is fed out from the tip opening 15a of the inner needle 12.

[0053] The catheter assembly 10 according to the first embodiment is basically configured as described above, and its effects will be explained below.

[0054] As described above, the catheter assembly 10 is used to construct the introduction point for intravenous fluids to the patient. During use, the user grasps the housing 20 and inserts the multi-layered needle 11 into the patient. At this time, the support member 91 of the housing 20 supports the basic outer surface 44 of the catheter 30 (where the multiple lumens 31 extend), ensuring good linearity of the catheter 30. During insertion, the inner needle 12 is inserted first by cutting the skin or blood vessel with the cutting edge 15, followed by the insertion of the catheter 30 into the body.

[0055] As shown in Figure 2, when the catheter 30 is inserted, the sufficiently narrow outer surface 42 of the tip is inserted first, resulting in sufficiently low puncture resistance. In addition, the inner surface 36 of the tip, including the soft tip 33, is in close contact with the inner needle 12 and does not bend radially inward. This also suppresses axial contraction of the tip of the catheter 30, allowing the catheter 30 to be inserted easily. In particular, since a thicker inner needle 12 can be used, the bending of the catheter 30 is further reduced.

[0056] Furthermore, when a blood vessel is punctured, the tip of the guidewire 70 is located on the proximal end side of the hole 14, so that the blood that flows into the hollow portion 12a of the inner needle 12 flows through the hole 14 into the main lumen 34 of the catheter 30 (the gap 39 in the basic inner surface 38). This allows the user to visually confirm that the main lumen 34 has secured the blood vessel by observing a blood flashback.

[0057] As the catheter 30 is further inserted, it moves from the predetermined position P to the tapered outer surface 43. At this time, the biological tissue expands, but it is possible to smoothly insert the catheter 30 along the tapered outer surface 43, and even when it reaches the continuous inclined surface 45, the inclination allows for continued smooth insertion of the catheter 30. In particular, since the sub-flumen 41 has a small diameter and the rate of change of the outer diameter of the basic outer surface 44 relative to the tip outer surface 42 is small, the puncture resistance of the catheter 30 is greatly suppressed. Therefore, the catheter 30 can be smoothly inserted up to the basic outer surface 44.

[0058] Once the multi-layered needle 11 has been inserted into the blood vessel to a certain extent, the user extends the guidewire operating member 80 to feed out the guidewire 70 from the tip opening 15a of the inner needle 12. Subsequently, the user extends the catheter operating member 60 to advance the catheter 30 and catheter hub 50 along the guidewire 70. At this time, the basic inner surface 38 of the main lumen 34 forms a gap 39 between it and the inner needle 12, which reduces the sliding resistance between the inner needle 12 and the catheter 30, allowing the catheter 30 to move smoothly relative to the inner needle 12.

[0059] Furthermore, once the multi-layered needle 11 has been inserted into the blood vessel to a certain extent, blood will begin to flow into the sub-flumen 41 through the second lateral opening 41a. This allows the user to clearly recognize that the sub-flumen 41 has secured a blood vessel.

[0060] In particular, when the tip 13 of the inner needle 12 moves proximal to the catheter 30 beyond the basic inner surface 38, the inner needle 12 can be easily retracted relative to the catheter 30. Once the catheter 30 and catheter hub 50 are delivered from the inner needle 12 and housing 20, they are placed in the patient. During placement, infusion tubes are connected to the main hub 51 and sub-hub 52, respectively. As a result, the first drug is administered to the patient via the main space 51a and main lumen 34, and the second drug is administered to the patient via the sub-space 52a, flow path 53, and sub-lumen 41.

[0061] As described above, in the catheter assembly 10 according to the first embodiment, the tip inner circumferential surface 36 of the main lumen 34 is in close contact with the outer circumferential surface 16 of the inner needle 12, while a gap 39 is formed between the basic inner circumferential surface 38 on the proximal end side of the tip inner circumferential surface 36 and the outer circumferential surface 16 of the inner needle 12. Therefore, at the position where the tip inner circumferential surface 36 is formed, the catheter 30 is reliably supported by the inner needle 12 even when subjected to pressure from biological tissue during puncture, and bending and contraction of the catheter 30 are suppressed. Thus, the tip of the catheter 30 is smoothly inserted into the body. In addition, the gap 39 of the basic inner circumferential surface 38 suppresses sliding resistance between the catheter 30 and the inner needle 12, facilitating relative movement between the inner needle 12 and the catheter 30, and improving operability during insertion and placement of the catheter 30. Furthermore, the arrangement of the hole 14 allows the user to easily recognize the location of the blood vessel. In other words, the catheter assembly 10 allows for easy insertion of a catheter 30 having multiple lumens 31, enabling smooth administration of multiple types of drugs or various procedures such as blood sampling.

[0062] Furthermore, the inner circumferential surface 36 of the tip forms a contact portion 35 with the inner needle 12, allowing the tip of the catheter 30 to have a thinner outer shape and to be supported more securely by the inner needle 12. Thus, the insertion performance of the catheter 30 is greatly improved. Moreover, because the outer circumferential surface 42 of the tip of the catheter 30 is thinner than the basic outer circumferential surface 44, it can be easily inserted into the blood vessel from the tip. In addition, since the tapered outer circumferential surface 43 is inserted after the outer circumferential surface 42, and then the basic outer circumferential surface 44 is inserted, it becomes possible to easily insert the thicker basic outer circumferential surface 44.

[0063] Furthermore, when the catheter 30 has a soft tip 33, the soft tip 33 easily bends and curves along the blood vessel wall when it comes into contact with the blood vessel wall during insertion into the blood vessel, significantly reducing the occurrence of inflammation and damage to the blood vessel wall. In particular, since the inner circumferential surface 36 of the tip of the catheter 30 is supported by the inner needle 12, bending and contraction of the soft tip 33 can be effectively suppressed during insertion before reaching the blood vessel.

[0064] Furthermore, the catheter assembly 10 has a second lateral opening 41a of the sub-lumen 41 located proximal to the hole 14, which allows the tip of the catheter 30 to be made narrower and improves insertability. It also allows for quick confirmation of the blood flowing into the main lumen 34. The second lateral opening 41a of the sub-lumen 41 can suppress the immediate mixing of drugs when multiple types of drugs are administered into a blood vessel.

[0065] Furthermore, the catheter assembly 10 has a deflection suppression mechanism 90 (support member 91, holding part of catheter operating member 60) on the proximal side of the second lateral opening 41a. This reduces the sliding resistance of the catheter 30 against the deflection suppression mechanism 90 when the catheter 30 is advanced. In addition, the deflection suppression mechanism 90 supports the catheter 30 on the proximal side of the tapered outer surface 43 and continuous inclined surface 45 of the catheter 30. This further reduces the sliding resistance of the catheter 30 against the deflection suppression mechanism 90 when the catheter 30 is advanced. Moreover, by preventing the deflection suppression mechanism 90 from hitting and damaging the second lateral opening 41a and the tapered outer surface 43, and by eliminating steps caused by the second lateral opening 41a and the tapered outer surface 43 at the contact point and planned contact point of the deflection suppression mechanism 90, the deflection of the inner needle 12 can be prevented with a constant force.

[0066] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible in accordance with the spirit of the invention.

[0067] For example, in the above-described embodiment, an example was given in which a guidewire 70 is used as an insertion assist mechanism to assist in the insertion of the catheter 30. The insertion assist mechanism is not limited to this, and various configurations may be adopted. For example, the insertion assist mechanism may be configured such that the proximal end opening of the inner needle 12 is exposed from the inner needle hub 19, allowing the guidewire 70 to be used as an add-on. Furthermore, the insertion assist mechanism may be configured to automatically retract the guidewire 70 exposed from the needle tip 13 into the hollow portion 12a. Alternatively, the catheter assembly 10 may be configured without a guidewire 70 and a guidewire operating member 80.

[0068] The insertion assist mechanism may be configured to extend the guide wire 70 by more than twice the amount of movement of the guide wire operating member 80. For example, in this type of structure, the guide wire 70 is folded back inside the housing 20, and the guide wire operating member 80 moves this folded portion forward and backward.

[0069] Furthermore, the catheter assembly 10 may be equipped with a safety mechanism (not shown) to prevent accidental needle sticking of the inner needle 12 when the inner needle 12 is removed. For example, the safety mechanism may be a full-cover type in which a cylindrical member (such as a telescopic type) protrudes from the inner needle hub 19 when the inner needle 12 is removed, and the inner needle 12 is housed inside. Alternatively, the safety mechanism may be a covering member that partially covers the needle tip 13 of the inner needle 12 and its surrounding area. Furthermore, the safety mechanism may be of a type that automatically or manually retracts the inner needle 12 into the housing 20 (inner needle hub 19) when the inner needle 12 is removed.

[0070] Alternatively, the safety mechanism may be configured to extend a blunt needle with a tip that is less likely to puncture the skin from the needle tip 13 when the inner needle 12 is removed. If this blunt needle is configured to extend from the needle tip 13 when the catheter 30 is advanced relative to the inner needle 12, it is possible to prevent the inner needle 12 from puncturing the catheter 30.

[0071] The catheter assembly 10 may be equipped with a hemostatic mechanism (not shown) to prevent leakage of blood backed up from the patient. For example, the hemostatic mechanism may be a hemostatic valve housed within the catheter hub 50. Alternatively, the hemostatic valve may be a cap type that is detachably attached to the proximal end of the catheter hub 50. Or, the hemostatic mechanism may be an air vent member attached to a predetermined position (such as the proximal end) of the inner needle 12, which is permeable to gas but impermeable to liquid.

[0072] The catheter assembly 10 may include a catheter hub rotation mechanism (not shown) that allows the catheter hub 50 to rotate relative to the inner needle 12 in order to prevent the catheter 30 from sticking to the inner needle 12 before puncture with the multi-layered needle 11. For example, the catheter hub rotation mechanism can be configured by forming a notch in at least one of the left-right directions on the axial direction of the housing 20 and the catheter operating member 60 at a position corresponding to the sub-hub 52 in the pre-puncture state.

[0073] Furthermore, the catheter 30 may employ various mechanisms in addition to the flexibility mechanism provided by the soft tip 33. For example, a rigidity mechanism can be applied to prevent the catheter 30 from collapsing by embedding a ring-shaped, mesh-shaped, or coil-shaped reinforcing material, or a blade, inside the catheter 30.

[0074] Furthermore, the catheter assembly 10 may be fitted with a kink prevention mechanism (not shown) to prevent kinking of the catheter 30. For example, one kink prevention mechanism is to make the tip portion of the catheter hub 50 deformable.

[0075] In this embodiment, the catheter assembly 10 is configured with a separation mechanism (separate component) that separates the catheter hub 50 from the catheter operating member 60 when the catheter hub 50 detaches from the inner needle 12. However, the catheter assembly 10 may also be configured such that the catheter hub 50 and the catheter operating member 60 are inseparable and can be placed as a single unit (non-separation mechanism).

[0076] Furthermore, the inner circumferential surface 36 at the tip of the main lumen 34 only needs to have a smaller diameter than the basic inner circumferential surface 38, and the gap between it and the outer circumferential surface 16 of the inner needle 12 is not zero (i.e., a contact portion 35 is not formed). This configuration is still possible because, even with this configuration, the inner needle 12 can adequately support the catheter 30, which is compressed inward, during puncture.

[0077] Furthermore, other embodiments and configuration examples of the present invention will be described with reference to Figures 3 to 18. In the following description, the same components or components having the same function will be denoted by the same reference numerals, and their detailed descriptions will be omitted. It goes without saying that the catheter assembly mechanisms described above (insertion assistance mechanism, safety mechanism, hemostasis mechanism, catheter hub rotation mechanism, flexibility mechanism, rigidity mechanism, kink prevention mechanism, separation mechanism, non-separation mechanism) can be appropriately adopted in the following embodiments and configuration examples as well.

[0078] [Second Embodiment] As shown in Figure 3, the catheter assembly 110 according to the second embodiment differs from the catheter assembly 10 according to the first embodiment in the structure of the multi-layered needle 111 (inner needle 112 and catheter 130). Specifically, in the catheter 130, the diameter of the sub-lumen 141 is larger than the diameter of the main lumen 134 through which the inner needle 112 is inserted and positioned, and the inner needle 112 is formed to be thinner in accordance with this main lumen 134.

[0079] Furthermore, the inner needle 112 has a groove 113 cut out for a predetermined length from the blade surface 15 toward the base end, which serves as an introduction path to realize a blood flashback. The base end of the groove 113 communicates with a gap 139 formed by the outer circumferential surface 116 of the inner needle 112 and the inner circumferential surface (basic inner circumferential surface 138) of the main lumen 134.

[0080] On the other hand, the catheter 130, like the first embodiment, is composed of a main body 132 and a soft tip 133 (flexible part) provided at the tip of the main body 132. However, the soft tip 133 is provided in a range from the tip of the main lumen 134 to slightly towards the proximal end of the tip of the sub-lumen 141 (second tip opening 141a). A stylet 170 is positioned on the sub-lumen 141.

[0081] The main lumen 134 of the catheter 130 is provided with a tip inner circumferential surface 136 with a diameter approximately the same as the outer diameter of the inner needle 112, and a basic inner circumferential surface 138 that includes a tapered inner circumferential surface 137 and has a diameter slightly larger than the outer diameter of the inner needle 112 (the diameter of the tip inner circumferential surface 136). The tip inner circumferential surface 136 forms a contact portion 135 with the outer circumferential surface 116 of the inner needle 112, excluding the groove portion 113 (the gap is set to zero). The basic inner circumferential surface 138 forms a gap 139 with the outer circumferential surface 116 of the inner needle 112.

[0082] On the other hand, the sub-lumen 141 is located in the direction (upward) facing the cutting edge 15. This sub-lumen 141 extends along the axial direction of the catheter 130 (parallel to the main lumen 134) and communicates with a second tip opening 141a located proximal to the first tip opening 134a of the main lumen 134.

[0083] The outer circumferential surface of the catheter 130 has a tip outer circumferential surface 142 at a position overlapping with the tip inner circumferential surface 136, and a basic outer circumferential surface 144 with an outer diameter corresponding to the sub-flumen 141 at a position overlapping with the basic inner circumferential surface 138. The tip of the basic outer circumferential surface 144 is connected to an inclined end surface 145 that is inclined with respect to the axis of the catheter 130. A second tip opening 141a is formed on the inclined end surface 145, and the tip of the inclined end surface 145 is connected to the base end of the tapered outer circumferential surface 143.

[0084] The stylet 170, positioned in the sub-flumen 141, is a solid, rod-shaped member with a larger diameter than the inner needle 112, providing rigidity to the entire catheter 130 and improving its ability to be inserted into the body. The tip of the stylet 170 is inclined to the same extent as the inclined end face 145 of the catheter 130, and is positioned slightly proximal to the second tip opening 141a in the pre-puncture state. This prevents tissue fragments from getting stuck in the sub-flumen 141.

[0085] Furthermore, the stylet 170 extends within the sub-blumen 141 and is inserted from the sub-blumen 141 into the sub-space 152a of the sub-hub 152, which is connected to the main hub 151 (catheter hub 150), via a connecting passage 153. The proximal end of the stylet 170 is fixedly held by a stylet holding member 171 attached to the protruding end of the sub-hub 152. Therefore, once the catheter 130 has been inserted into the blood vessel to a certain extent, the user can remove the stylet 170 from the catheter 130 by grasping the stylet holding member 171.

[0086] A suitable gap is provided between the outer surface of the stylet 170 and the inner surface of the sub-blumen 141, allowing the stylet 170 to slide against the catheter 130. Furthermore, the inflow of blood into the gap between the stylet 170 and the sub-blumen 141 indicates that the tip of the sub-blumen 141 has been inserted into the blood vessel. The cross-section of the stylet 170 may be a smaller, similar shape to the sub-blumen 141, but the inclusion of a groove allows for better confirmation of flashback. The stylet 170 may also be made of a hollow, transparent material, which also allows for good confirmation of flashback.

[0087] As described above, the catheter assembly 110 according to the second embodiment can obtain the same effects as the catheter assembly 10 according to the first embodiment. That is, since the tip of the catheter 130 is supported by the outer surface 116 of the inner needle 112, bending and contraction are suppressed, and it can be smoothly inserted into the body. In particular, when the inner needle 112 is made thin, the wound on the patient can be made smaller when the inner needle 112 is inserted, and hemostasis in the event of accidental puncture is made easier.

[0088] Furthermore, the second tip opening 141a of the sub-blumen 141, which faces the tip of the catheter 130, is prevented from being occluded by the blood vessel wall when the catheter is placed inside a blood vessel. Therefore, blood can be effectively aspirated from the second tip opening 141a of the sub-blumen 141. In addition, the catheter assembly 110 has a stylet 170 detachably positioned on the sub-blumen 141, which allows the stylet 170 to improve the rigidity and straightness of the catheter 130.

[0089] [Third Embodiment] As shown in Figure 4, the catheter assembly 210 according to the third embodiment differs from the catheter assemblies 10 and 110 according to the first and second embodiments in the structure of the multi-layered needle 211 (catheter 230) and the catheter hub 250. Specifically, in a side cross-sectional view of the catheter 230, the main lumen 234 through which the inner needle 12 is inserted and positioned is located on the upper side of the sub-lumen 241. In the third embodiment, the diameter of the main lumen 234 (basic inner surface 238) is larger than the diameter of the sub-lumen 241. The main body and soft tip (flexible part) constituting the catheter 230 have the same configuration as in the second embodiment, with the soft tip provided in the range from the tip of the catheter 230 to the basic outer surface 244.

[0090] The main lumen 234 of the catheter 230 has a basic inner surface 238 including a tip inner surface 236 and a tapered inner surface 237, similar to the main lumen 34 of the first embodiment. The outer surface of the catheter 230 has a tip outer surface 242, a tapered outer surface 243 and a basic outer surface 244, but a sub-lumen 241 extends from the basic outer surface 244 to the area where the tapered outer surface 243 and the tip outer surface 242 are formed. The sub-lumen 241 is provided in the downward direction opposite to the direction facing the cutting surface 15 of the inner needle 12. The second tip opening 241a of the sub-lumen 241 is positioned approximately in the same axial position as the first tip opening 234a of the main lumen 234.

[0091] Therefore, the overall shape of the catheter 230 is thicker, but the lower side of the first tip opening 234a (the side where the sub-flumen 241 is formed) is formed as an inclined end surface 245 that connects to the tapered tip 40. The inclined end surface 245 is inclined at an appropriate angle below the cutting surface 15 of the inner needle 12, which facilitates the insertion of the tip of the catheter 230 (the outer peripheral surface 242 of the tip). The second tip opening 241a is provided on this inclined end surface 245. In addition, although not shown, reducing the inner diameter of the tip of the sub-flumen 241 can further improve the smooth insertion of the tip of the catheter 230.

[0092] On the other hand, the main hub 251 of the catheter hub 250 forms a first space 251a that communicates with the main lumen 234 at the top of the catheter 230. The main hub 251 also has a bypass passage 253 that connects the sub-lumen 241 provided on the lower side of the catheter 230 with the second space 252a of the sub-hub 252 which is connected to the upper side of the main hub 251. The bypass passage 253 is provided so as to wrap around within the peripheral wall surrounding the first space 251a of the main hub 251 and communicates with the second space 252a.

[0093] As described above, the catheter assembly 210 according to the third embodiment can also obtain the same effects as the catheter assembly 10. In particular, with the catheter assembly 210, the second tip opening 241a of the sub-flumen 241 is located on the tip side of the hole 14 of the inner needle 12, making it possible to quickly confirm that blood has flowed into the sub-flumen 241.

[0094] [Fourth Embodiment] As shown in Figure 5, the catheter assembly 310 according to the fourth embodiment differs from the catheter assemblies 10, 110, and 210 according to the first to third embodiments in the structure of the multi-layered needle 311 (catheter 330) and the catheter hub 350. Specifically, in a plan view of the catheter 330, the sub-lumen 341 extends parallel to each other, adjacent to the main lumen 334 in the lateral direction (to the right in Figure 5). While the inner needle 12 is inserted and positioned in the main lumen 334, the guide wire 70 is slidably positioned in the sub-lumen 341.

[0095] In the fourth embodiment, the diameter of the main lumen 334 is set to be larger than the diameter of the sub-lumen 341. The main body and soft tip (flexible part) constituting the catheter 330 have the same configuration as in the second embodiment, with the soft tip provided in the range from the tip of the catheter 330 to the basic outer surface 344.

[0096] The main lumen 334 of the catheter 330, similar to the main lumen 34 of the first embodiment, communicates with the tip opening 334a and has a basic inner surface 338 including the tip inner surface 336 and the tapered inner surface 337. The outer surface of the catheter 330 also has a tip outer surface 342, a tapered outer surface 343, and a basic outer surface 344.

[0097] The sub-blume 341 is provided at the location where the basic outer surface 344 is formed. The diameter of the sub-blume 341 is set to an appropriate dimension according to the outer diameter of the guide wire 70. An inclined end surface 345 is formed at the tip of this basic outer surface 344, which is connected to the tapered outer surface 343, and a second tip opening 341a is formed on this inclined end surface 345.

[0098] On the other hand, the catheter hub 350 has a main hub 351 and a sub-hub 352, with the sub-hub 352 connected to the side of the main hub 351. The main hub 351 has a first space 350a that communicates with the main lumen 334, and a communication passage 353 that communicates with the second space 352a of the sub-hub 352. That is, the guidewire 70 is slidably inserted into the sub-lumen 341 via the second space 352a and the communication passage 353.

[0099] As described above, the catheter assembly 310 according to the fourth embodiment can also obtain the same effects as the catheter assembly 10. In particular, by slidably positioning the guide wire 70 on the sub-flumen 341, the catheter assembly 310 can reinforce the catheter 330 when the multi-layered needle 311 is inserted, thereby improving the insertion performance of the catheter 330. Furthermore, the guide wire 70 can be inserted into the blood vessel from the sub-flumen 341, thereby effectively guiding the insertion of the catheter 330.

[0100] The catheter assemblies 10, 110, 210, 310 described above, and the catheter assemblies 510, 610, 710, 810, 910, 1010 described later, are not particularly limited in terms of the arrangement of the main lumen and sub-lumen. In other words, all of the arrangements of the main lumen α and sub-lumen β in catheters 430A to 430F related to the first to sixth configuration examples shown in Figures 6A to 6F can be adopted.

[0101] Specifically, the catheter 430A shown in Figure 6A has the same arrangement of the main lumen 34 and sub-lumen 41 as described in the first embodiment. That is, the diameter of the main lumen α is larger than the diameter of the sub-lumen β, and the sub-lumen β is positioned above the main lumen α. Note that the cross-sectional shape of the catheter 430A perpendicular to the axial direction may be a shape other than the elliptical shape shown in Figure 6A, and may be formed in a circular shape, for example. The same applies to the other catheters 430B to 430F.

[0102] The positions of the main lumen α and sub-lumen β will be explained using the cutting edge 15 of the inner needle 12, which is located in the main lumen α, as an indicator. That is, as described above, the cutting edge 15 of the inner needle 12 is positioned so that it faces upward when the patient's body surface is facing downwards during puncture. Therefore, sub-lumen β being located above the main lumen α means that sub-lumen β is located in the circumferential direction of the catheter 430A, in the direction that the cutting edge 15 faces upwards.

[0103] The catheter 430A shown in Figure 6A allows for the confirmation of flashback using Sublumen β. Furthermore, when inserting the catheter 430A, the tip (angled end face) of Sublumen β is prevented from catching on the blood vessel wall on the opposite side of the insertion site, thus preventing obstruction of movement. Consequently, inflammation and damage to the blood vessel wall can be suppressed. In addition, the second tip opening of Sublumen β can be prevented from being closed by the blood vessel wall, thus preventing a decrease in flow rate.

[0104] The catheter 430B shown in Figure 6B has the same arrangement of the main lumen 334 and sub-lumen 341 as described in the fourth embodiment. That is, the diameter of the main lumen α is larger than the diameter of the sub-lumen β, and the sub-lumen β is positioned in the lateral direction of the main lumen α (the direction perpendicular to the direction facing the cutting edge 15) within the circumferential direction of the catheter 430B. With this configuration, the same effect as the arrangement shown in Figure 6A can be obtained, and flashback of the main lumen α can also be clearly observed.

[0105] The catheter 430C shown in Figure 6C has the same arrangement of the main lumen 234 and sub-lumen 241 as described in the third embodiment. Specifically, the diameter of the main lumen α is larger than the diameter of the sub-lumen β, and the sub-lumen β is positioned on the lower side of the main lumen α in the circumferential direction of the catheter 430C (opposite the direction facing the cutting edge 15). This configuration makes it possible to better confirm the flashback of the main lumen α.

[0106] The catheter 430D shown in Figure 6D has the same arrangement of the main lumen 134 and sub-lumen 141 as described in the second embodiment. That is, the diameter of the main lumen α is smaller than the diameter of the sub-lumen β, and the sub-lumen β is positioned above the main lumen α in the circumferential direction of the catheter 430D. Furthermore, the catheter 430E shown in Figure 6E has the same arrangement of the main lumen α and sub-lumen β positioned laterally to the main lumen α. In addition, the catheter 430F shown in Figure 6F has the same arrangement of the main lumen α and sub-lumen β positioned below the main lumen α. These catheters 430D to 430F shown in Figures 6D to 6F can also provide sufficient effects, similar to the catheters 430A to 430C described above.

[0107] Furthermore, while the cross-sectional shapes of the main lumen α and sub-lumen β are shown as perfectly circular in Figures 6A to 6F, the cross-sectional shapes of these lumens are not particularly limited. For example, the lumen with the smaller flow path cross-sectional area (e.g., the sub-lumen) may be formed in a shape (C-shape, U-shape, ellipse, polygonal shape, etc.) that surrounds a portion of the circumferential outer side of the main lumen α. This makes it possible to further reduce the overall outer diameter of the catheters 430A to 430F.

[0108] Furthermore, the catheter assembly may have a configuration having three or more lumens 431, as shown in the seventh and eighth configuration examples catheters 430G and 430H in Figures 7A and 7B. Specifically, in the catheter 430G shown in Figure 7A, the first and second sub-lumens β1 and β2 are arranged side by side in the width direction (a direction perpendicular to the direction facing the cutting surface 15) above the main lumen α. In the catheter 430H shown in Figure 7B, the main lumen α is positioned at the axial center of the catheter 430H, with the first sub-lumen β1 positioned above it (in the direction facing the cutting surface 15) and the second sub-lumen β2 positioned below it (in the opposite direction from the direction facing the cutting surface 15).

[0109] Furthermore, the catheter assembly may be configured to allow flashbacks to be confirmed in the order of main lumen α followed by sub-lumen β, by appropriately setting the diameter and length of each flashback channel. This allows the flashback of the lumen with an opening at the tip to be confirmed first, thus reducing discomfort for the user. Alternatively, the catheter assembly may be configured to allow flashbacks to be confirmed in the order of sub-lumen β followed by main lumen α, by appropriately setting the diameter and length of each flashback channel. This makes it easier for users to use, as they would naturally assume that if sub-lumen β is in a blood vessel, then main lumen α is also in a blood vessel.

[0110] [Fifth Embodiment] As shown in Figures 8 to 10, the catheter assembly 510 according to the fifth embodiment includes a catheter 530 having three lumens 531, similar to the seventh and eighth configuration examples, and is configured to support a multi-layered needle 511 by a deflection suppression mechanism 590 of the inner needle hub 519. In detail, in a side cross-sectional view along the axial direction, the catheter 530 has the main lumen 534 on the lower side, the first sub-lumen 540 in the middle, and the second sub-lumen 545 on the upper side.

[0111] The inner needle hub 519 of the catheter assembly 510 has a pair of bifurcated extensions 520 that branch off from a base 521 at the center in the width direction. This inner needle hub 519 holds the catheter hub 550 in an exposed state at the top and bottom. The inner needle hub 519 may also be made into a housing by attaching covers to the lower or upper sides of the pair of extensions 520. If a cover is attached to the upper side, it is preferable to provide a slit in the upper cover to expose the tab from the housing and allow for operation.

[0112] The deflection suppression mechanism 590 includes a pair of openable and closable support arms 591 and a restraining part 592 that can restrain the pair of support arms 591 in a closed state and release the restraint. The pair of support arms 591 are pivotally supported by a pair of support pins 593 and are openable and closable in the left-right direction relative to a pair of extensions 520 of the inner needle hub 519.

[0113] Each support arm 591 is provided with a support groove 591a for holding the inner needle 12 in a closed state. A pair of support grooves 591a constitute a support hole 594 that supports the multi-layered needle 511. In the initial state of the catheter assembly 510, the wall surface constituting the support hole 594 functions as a sliding contact support portion 595 that rubs against the catheter 530 as the catheter 530 advances toward the inner needle 12. In the pre-puncture state, a small gap is formed between the outer surface of the catheter 530 and the inner surface of the sliding contact support portion 595. The sliding contact support portion 595 also surrounds the entire circumference of the catheter 530 in a contactable manner.

[0114] Each support arm 591 is provided with a curved engagement groove 591b when viewed from the front in the closed state. The restraint part 592 has a head 592a that corresponds to the shape of the pair of engagement grooves 591b connected together, and engages with each other in the pre-puncture state to close each support arm 591. As the catheter hub 550 advances, the restraint on the pair of support arms 591 is released by being pushed by the catheter hub 550.

[0115] On the other hand, the main lumen 534, the first sub-lumen 540, and the second sub-lumen 545 extend parallel to each other within the catheter 530. Furthermore, at the tip of the catheter 530, the main lumen 534, the first sub-lumen 540, and the second sub-lumen 545 overlap in a stepped manner.

[0116] Specifically, the main lumen 534 is longer than the first and second sub-lumens 540 and 545, and communicates with the first tip opening 534a (main opening) at the very front of the catheter 530 and the first proximal opening (not shown) at the very proximal end of the catheter 530. The catheter 530 also has a first tapered outer surface 535 whose outer diameter gradually decreases toward the first tip opening 534a. A first lateral opening 534b (main opening) is provided at an intermediate position in the catheter 530 (between the first tapered outer surface 535 and the second tip opening 540a, which will be described later), and communicates with the main lumen 534.

[0117] The first sub-lumen 540 is shorter than the main lumen 534 and longer than the second sub-lumen 545. Here, the tip of the catheter 530 has increased thickness (outer diameter) because the first sub-lumen 540 overlaps with the main lumen 534, and the very tip of the first sub-lumen 540 has a second tapered outer surface 541 (tapered portion) that forms a step. The first sub-lumen 540 communicates with a second tip opening 540a (sub-opening) formed on this second tapered outer surface 541. The first sub-lumen 540 also communicates with a second proximal opening (not shown) at the very base of the catheter 530 (located coaxially with the first proximal opening). Between the second tapered outer surface 541 of the catheter 530 and the third tip opening 545a, which will be described later, there is a second lateral opening 540b (sub-opening) that communicates with the first sub-lumen 540.

[0118] The second sub-lumen 545 is formed to be the shortest. The tip of the catheter 530 has a further increase in thickness (outer diameter) due to the overlap of the second sub-lumen 545 with respect to the main lumen 534 and the first sub-lumen 540, and the very tip of the second sub-lumen 545 has a third tapered outer surface 546 (tapered portion) that forms a stepped portion. The second sub-lumen 545 communicates with a third tip opening 545a (sub-opening) formed on this third tapered outer surface 546. The second sub-lumen 545 also communicates with a third proximal opening (not shown) at the very base of the catheter 530 (located coaxially with the first proximal opening). A third lateral opening 545b (sub-opening) that communicates with the second sub-lumen 545 is provided on the proximal side of the third tapered outer surface 546 of the catheter 530.

[0119] Furthermore, the first lateral opening 534b and the second tip opening 540a are set to be separated by 17 mm or more. Similarly, the second lateral opening 540b and the third tip opening 545a are also set to be separated by 17 mm or more.

[0120] In this embodiment, the sliding contact support portion 595 of the deflection suppression mechanism 590 is located proximal to the third lateral opening 545b of the catheter 530 in the pre-puncture state. More specifically, the sliding contact support portion 595 is provided to support a position near the third lateral opening 545b, which is the most proximal sub-opening of the two sub-blumes 540 and 545 (for example, 5 mm or less proximal to the catheter).

[0121] In the initial state of the catheter assembly 510, the sliding contact support portion 595 may be located on the tip side of the third tip opening 545a of the second sub-blumen 545 (see the dashed line in Figure 9). Specifically, the sliding contact support portion 595 is capable of supporting the proximal end side of the second tip opening 540a (the most tip-side sub-opening of the two sub-blumens 540 and 545). Even with this configuration in which the deflection suppression mechanism 590 supports the tip side of the third tip opening 545a, damage to the second tip opening 540a and the second tapered outer surface 541 of the first sub-blumen 540 can be suppressed, and the deflection suppression effect of the inner needle 12 is improved.

[0122] The catheter hub 550 of the catheter assembly 510 has a main hub 551 that functions as a port for the main lumen 534. Furthermore, the catheter hub 550 has a first subport 552 that functions as a port for the first sub-lumen 540, and a second subport 553 that functions as a port for the second sub-lumen 545. The tip of the main hub 551 is provided with a hub operating section 551a for the user to place their finger on, and this hub operating section 551a has a surface that pushes out the aforementioned restraining section 592. The hub operating section 551a may be configured to be detachable from the main hub 551.

[0123] Each of the first and second subports 552 and 553 has a connecting portion of the main hub 551, a flexible tube 554 (flexible part) fixed to this connecting portion, and a subhub 555 connected to the base end of the flexible tube 554. The subhub 555 is configured as a connector to which a medical device is connected. Inside the first subport 552 (main hub 551, flexible tube 554, subhub 555), a first communication passage 552a is formed that communicates with the first sub-flumen 540. Similarly, inside the second subport 553, a second communication passage 553a is formed that communicates with the second sub-flumen 545.

[0124] The catheter assembly 510 according to the fifth embodiment is basically configured as described above. When the multi-layered needle 511 is inserted, the bending suppression mechanism 590 supports the position near the proximal end of the third lateral opening 545b. Therefore, bending of the inner needle 12 can be effectively suppressed, and the multi-layered needle 511 can be inserted.

[0125] After puncture with the multi-layered needle 511, as shown in Figure 10, the user advances the catheter hub 550 to advance the catheter 530 relative to the inner needle 12. At this time, the deflection suppression mechanism 590 supports the proximal end of the third lateral opening 545b of the second sub-blumen 545, allowing the catheter 530 to advance smoothly without getting caught. In addition, when the catheter hub 550 advances, it pushes out the restraint portion 592, which releases the pair of support arms 591 in the left and right directions. This easily releases the support of the multi-layered needle 511 by the deflection suppression mechanism 590, allowing the catheter 530 and catheter hub 550 to be separated from the inner needle 12.

[0126] Thus, the same effects as the catheter assembly 10 can be obtained with the catheter assembly 510. For example, when the catheter 530 is placed, the catheter assembly 510 allows for easy supply of drug solutions or blood to the main lumen 534 and the first and second sub-hubs 540 and 545 by connecting medical devices to the main hub 551 and sub-hub 555. Furthermore, after the catheter 530 is placed, different types of drug solutions can be efficiently administered intravascularly through the main lumen 534 and the first and second sub-hubs 540 and 545, which extend parallel to each other.

[0127] Furthermore, even though the catheter assembly 510 has a configuration with multiple lumens, namely the main lumen 534 and the first and second sub-lumens 540 and 545, the deflection suppression mechanism 590 supports the proximal end of the second tip opening 540a (the tipmost sub-opening). This suppresses the deflection of the inner needle 12 and reduces damage to the catheter 530.

[0128] In other words, in order to suppress the bending of the inner needle 12, it is preferable that the bending suppression mechanism 590 supports the inner needle 12 at a point close to the needle tip 13. However, if the bending suppression mechanism 590 is configured to support the tip side of the multiple sub-openings, the possibility of contact with the sub-openings and damage to the catheter 530 increases when the catheter 530 moves. In contrast, the catheter assembly 510 according to this embodiment can achieve both prevention of bending of the inner needle 12 and mobility of the catheter by appropriately arranging the formation positions of the sub-openings and the support positions of the bending suppression mechanism 590.

[0129] Furthermore, the catheter assembly 510 is more reliably protected from damage by the bending suppression mechanism 590 supporting the proximal side of the third lateral opening 545b (the sub-opening located furthest proximal). In addition, because the bending suppression mechanism 590 supports the proximal side of the third tapered outer surface 546, it is possible to prevent the bending suppression mechanism 590 from getting caught on the third tapered outer surface 546. Therefore, the mobility of the catheter 530 can be further improved.

[0130] Furthermore, the catheter assembly 510, with its sub-openings including second and third lateral openings 540b and 545b, can effectively discharge the drug solution or blood flowing through the first and second sub-blumes 540 and 545 into the blood vessel. Moreover, since the bending suppression mechanism 590 is located more proximal to the third lateral opening 545b, damage near the third lateral opening 545b is also suppressed.

[0131] Here, the catheter assembly 510 has a distance of 17 mm or more between the first tip opening 534a and the second tip opening 540a, which allows the drug solution flowing out from the first tip opening 534a and the drug solution flowing out from the second tip opening 540a to be mixed in the blood vessel. In other words, drugs that are contraindicated for combination can be administered successfully using a single catheter 530.

[0132] Furthermore, the catheter assembly 510 is supported by the deflection suppression mechanism 590 at a position of 5 mm or less on the proximal side of the third transverse opening 545b, thereby shortening the distance from the needle tip 13 of the inner needle 12 to the deflection suppression mechanism 590. As a result, the deflection of the inner needle 12 can be suppressed more firmly.

[0133] Furthermore, the catheter assembly 510, with its deflection suppression mechanism 590 surrounding the entire circumference of the catheter 530, can reliably suppress vertical and horizontal movement of the inner needle 12 (such as deviation from the deflection suppression mechanism 590 or deflection of the inner needle 12).

[0134] Furthermore, the catheter assembly 510 includes first and second subports 552 and 553, which include a subhub 555 and a flexible tube 554, allowing the subhub 555 to be positioned in any position or orientation. Therefore, the user can easily perform puncture with the multi-layered needle 511 and insertion of the catheter 530.

[0135] Furthermore, the main opening through which the main lumen 534 communicates, and the sub-openings through which the first and second sub-lumens 540 and 545 communicate, are not limited to the above configuration (first tip opening 534a, first lateral opening 534b, second tip opening 540a, second lateral opening 540b, third tip opening 545a, third lateral opening 545b), and various configurations can be adopted. For example, the main opening may consist only of the first tip opening 534a.

[0136] The sub-opening of the first sub-blumen 540 may be either the second tip opening 540a or the second lateral opening 540b. Similarly, the sub-opening of the second sub-blumen 545 may be either the third tip opening 545a or the third lateral opening 545b.

[0137] For example, if the sub-openings of the first and second sub-flumens 540 and 545 are composed only of the second lateral opening 540b and the third lateral opening 545b, respectively, then the second tapered outer circumferential surface 541 and the third tapered outer circumferential surface 546 constitute the stepped portion of the occluded catheter 530. In this configuration, the deflection suppression mechanism 590 may be configured to support the position near the proximal end of the second tapered outer circumferential surface 541 and the third tapered outer circumferential surface 546. This configuration also effectively avoids the deflection suppression mechanism 590 catching on the second tapered outer circumferential surface 541 and the third tapered outer circumferential surface 546.

[0138] Furthermore, the deflection suppression mechanism 590 may employ various configurations. For example, the inner surface of the support hole 594 constituting the sliding contact support portion 595 may be formed in a tapered shape that narrows towards the tip. This reduces the snagging of the third tapered outer surface 546 against the sliding contact support portion 595, even in a configuration such as the catheter 530 which has a tapered portion (for example, a third tapered outer surface 546) and a sliding contact support portion 595 on its tip side.

[0139] It should be noted that the configuration of the sub-blumen in the catheter 530 (including the tapered portion) and the configuration of the bending suppression mechanism 590 described above are also applicable to the embodiments described later.

[0140] [Sixth Embodiment] As shown in Figures 11, 12A, and 12B, the catheter 630 of the catheter assembly 610 according to the sixth embodiment has a main lumen 634 and a sub-lumen 641 arranged vertically, with the two lumens separated by a partition wall 640. This partition wall 640 is configured to be deformable in response to the pressure of the main lumen 634 and the sub-lumen 641.

[0141] Specifically, the main lumen 634 of the catheter 630 communicates with a tip opening 634a formed at the tip of the catheter 630, as well as with a proximal opening (not shown) formed at the proximal end of the catheter 630. The inner needle 12 is positioned in this main lumen 634 so as to be detachable in the pre-puncture state.

[0142] The sub-lumen 641 of catheter 630 is located below the main lumen 634 and extends parallel to the main lumen 634. The sub-lumen 641 communicates with a lateral opening 641a formed midway along the lower side of catheter 630.

[0143] The septum 640 extends along the axial direction of the catheter 630 and separates the main lumen 634 from the sub-lumen 641. In a cross-sectional view perpendicular to the axial direction of the catheter 630, the septum 640 is connected at a position approximately 180° out of phase with respect to the tubular wall portion 639 of the catheter 630, but is formed to be longer than the diameter of the tubular wall portion 639 (with a margin of error). Moreover, the septum 640 is more flexible than the tubular wall portion 639 and can deform when subjected to a positive pressure above a certain level from the drug solution.

[0144] For example, as shown in Figure 12A, the partition wall 640 expands downwards when the inner needle 12 is inserted into the main lumen 634, allowing the inner needle 12 to be positioned well. Also, for example, as shown in Figure 12B, the partition wall 640 increases the flow path cross-sectional area of ​​the main lumen 634 when a large amount of liquid chemical is flowed through the main lumen 634. On the other hand, when a large amount of liquid chemical is flowed through the sub-lumen 641, the flow path cross-sectional area of ​​the sub-lumen 641 is increased as shown by the dashed line in the illustrated example.

[0145] Returning to Figure 11, the catheter assembly 610 securely holds the proximal end of the catheter 630 by the catheter hub 650. This catheter hub 650 has a sub-hub 652 that protrudes upward from the main hub 651, similar to the first embodiment.

[0146] The catheter operating member 660 is formed as a long plate to accommodate the elongated inner needle 12 and catheter 630 (multi-layered needle 611), and is rotatably fixed to the catheter hub 650. The catheter operating member 660 has a pressing portion 661 that can press against the portion of the catheter 630 between the proximal end and the tip. The pressing portion 661 constitutes part of the deflection suppression mechanism 690. The catheter operating member 660 also has a plurality of anti-slip ribs 662 provided at intervals on its upper surface.

[0147] The housing 620 of the catheter assembly 610 is formed in an elongated bowl shape and accommodates the proximal end of the multi-layered needle 611 and also movably houses the catheter hub 650. The housing 620 has a bottom plate 621 and left and right side walls 622 extending upward from both sides of the bottom plate, and is open at the top and tip. The tip of the bottom plate 621 is a sliding contact support portion 691 that rubs against the catheter 630 as the catheter 630 advances relative to the inner needle 12.

[0148] The sliding contact support portion 691, together with the pressing portion 661, constitutes the deflection suppression mechanism 690. The deflection suppression mechanism 690 is capable of supporting the inner needle 12 and the catheter 630 (multi-layered needle 611) between the sliding contact support portion 691 and the pressing portion 661 when the catheter 630 advances relative to the inner needle 12. Furthermore, in the pre-puncture state, the sliding contact support portion 691 is positioned to support the catheter 630 beyond the lateral opening 641a.

[0149] The catheter assembly 610 according to the sixth embodiment is basically configured as described above. When using the catheter assembly 610, the user presses the tip of the catheter operating member 660 with the index finger of one hand, and punctures the patient by pressing the tip of the catheter assembly 610 (the tip of the catheter 630 through which the inner needle 12 is inserted) against the patient. With the catheter operating member 660 (pressing part 661) pressing against the middle part of the catheter 630, the catheter 630 is supported by being sandwiched between the pressing part 661 and the tip of the housing 620 (sliding contact support part 691). As a result, the bending of the multi-layered needle 611 is suppressed.

[0150] Then, by advancing the catheter operating member 660 relative to the inner needle 12 and housing 620, the tip of the catheter 630 is inserted to the target position in the blood vessel. As the catheter 630 moves toward the tip relative to the inner needle 12, the catheter 630 slides against the sliding contact support portion 691. After that, while holding the catheter operating member 660 with the other hand, the housing 620 is pulled toward the proximal end. This causes the inner needle 12 to detach from the catheter hub 650, and by removing the catheter operating member 660, the catheter 630 and catheter hub 650 can be left in the patient.

[0151] The catheter assembly 610 described above can achieve the same effects as the other embodiments described above. Specifically, the deflection suppression mechanism 690 supports the position near the proximal end (for example, a proximal position of 5 mm or less) of the lateral opening 641a (the leading edge sub-opening) of the sub-flumen 641. This reduces damage to the catheter 630 while suppressing the deflection of the inner needle 12.

[0152] In particular, this catheter assembly 610 divides the main lumen 634 and the sub-lumen 641 with a pressure-deformable partition wall 640. This allows the main lumen 634 to be enlarged in the pre-puncture state, simplifying the relative movement of the inner needle 12 and the catheter 630. The partition wall 640 then deforms appropriately according to the fluid pressure when drugs or blood are administered. For example, even when a relatively large amount of drug solution flows through the sub-lumen 641 compared to the drug solution in the main lumen 634, it is possible to easily secure the flow path cross-sectional area.

[0153] [Seventh Embodiment] As shown in Figure 13, the catheter 730 of the catheter assembly 710 according to the seventh embodiment is configured similarly to the catheter 30 of the first embodiment and has a main lumen 734 and a sub-lumen 741 inside. A deflection suppression mechanism 790 is provided at the tip of the catheter assembly 710 to suppress the bending of the inner needle 12 and the catheter 730 (multi-structured needle 711).

[0154] Specifically, the internal needle hub 719 has an upper housing 720 and a lower housing 721, and in the pre-puncture state, the upper housing 720 and the lower housing 721 are stacked vertically. The respective tip portions 720a and 721a of the upper housing 720 and the lower housing 721 are held by a guide wire operating member 780, which will be described later, thereby restricting vertical expansion. On the left and right sides of the internal needle hub 719, a slit 722 extending in the longitudinal direction is formed between the upper housing 720 and the lower housing 721. The upper housing 720 has a pair of lateral gripping portions 720b that are inclined diagonally with respect to the slit 722, and when puncturing with the multi-layered needle 711, the user is allowed to grip this pair of lateral gripping portions 720b.

[0155] The deflection suppression mechanism 790 is composed of the tip portion 720a of the upper housing 720 and the tip portion 721a of the lower housing 721. A retaining groove 723 with a semicircular cross-section is formed on the opposing surfaces of the tip portions 720a and 721a of the upper housing 720 and the lower housing 721. The walls constituting the retaining groove 723 form a hole-shaped sliding contact support portion 791 that rubs against the catheter 730 as the catheter 730 advances toward the inner needle 12. In the initial state of the catheter assembly 710, a small gap is formed between the outer surface of the catheter 730 and the sliding contact support portion 791.

[0156] The catheter 730 has a tip opening 734a at its tip that communicates with the main lumen 734, and a lateral opening 741a of the sub-lumen 741 located at a predetermined distance (for example, 17 mm or more) from the tip opening 734a. The catheter 730 is fixedly held in place by the catheter hub 750.

[0157] The catheter hub 750 includes a main hub 751 communicating with the main lumen 734, and a subport 752 provided on the side of the main hub 751. In this case, the subport 752 has a subhub 753 to which a medical device can be connected, a rigid tube 754 connected to the main hub 751 and protruding to the outside of the inner needle hub 719, and a flexible tube 755 (flexible tube) extending between the rigid tube 754 and the subhub 753 and being more flexible than the rigid tube 754. The subport 752 is exposed to the outside through the slit 722 of the inner needle hub 719, with the rigid tube 754 of the main hub 751 protruding laterally.

[0158] A catheter operating member 760 is attached to the catheter hub 750 on the proximal side of the subport 752. The catheter operating member 760 has a central base 761 that is detachably connected to the proximal end of the catheter hub 750, and a pair of finger rests 762 that extend from the central base 761 to both the left and right sides. In the pre-puncture state, the central base 761 is housed within the inner needle hub 719, and the finger rests 762 protrude outward in the left and right directions through the slit 722.

[0159] Furthermore, in the pre-puncture state, the catheter assembly 710 has a deflection suppression mechanism 790 (sliding contact support portion 791) located proximal to the lateral opening 741a of the sub-flumen 741. The sliding contact support portion 791 is provided proximal to the lateral opening 741a, which is located at the furthest tip.

[0160] The guide wire 770 extends axially within the inner needle 12, protruding from the base end opening (not shown) of the inner needle 12, and is connected to the base end of the guide wire operating member 780 via a connecting portion (not shown) located within the inner needle hub 719. The guide wire operating member 780 is provided so as to be displaceable in the front-rear direction relative to the inner needle hub 719. The guide wire operating member 780 also has a pair of regulating arms 781 that embrace the tip of the inner needle hub 719 in the pre-puncture state. The guide wire operating member 780 also has a tab 782 for finger gripping and a plurality of ribs 783 for anti-slip.

[0161] In use, the catheter assembly 710, configured as described above, is used by the user to insert the multi-layered needle 711 (inner needle 12, catheter 730) into the patient. At this time, the bending suppression mechanism 790 supports the multi-layered needle 711 and suppresses bending. Next, the user operates the guidewire operating member 780 toward the tip to make the guidewire 770 protrude from the tip of the inner needle 12 and insert it into the blood vessel. As the guidewire operating member 780 moves toward the tip, the pair of regulating arms 781 move toward the tip of the inner needle hub 719, and the vertical expansion restriction of the tip of the upper housing 720 and the tip of the lower housing 721 is released.

[0162] Next, the user operates the catheter manipulating member 760 toward the tip to advance the catheter 730 and catheter hub 750. During this movement, the upper housing 720 opens relative to the lower housing 721 as a pair of lateral gripping portions 720b contact the rigid tube 754 of the catheter hub 750 and are pushed upward. This allows the catheter manipulating member 760 to move toward the tip, enabling the catheter 730 to be successfully inserted into the blood vessel.

[0163] The user then removes the inner needle 12 from the catheter 730 by pulling the inner needle hub 719 towards the proximal end relative to the catheter 730 and catheter hub 750. As a result, the catheter 730 and catheter hub 750 are left in place on the patient side.

[0164] As described above, the catheter assembly 710 according to the seventh embodiment can also obtain the same effects as the embodiments described above. In other words, the deflection suppression mechanism 790 supports the proximal end of the lateral opening 741a (the leading edge sub-opening) of the sub-blumen 741. This makes it possible to suppress the deflection of the inner needle 12 and reduce damage to the catheter 730.

[0165] Furthermore, in the catheter assembly 710, since the inner needle hub 719 has a slit 722, even when a subport 752 is provided on the catheter hub 750, the subport 752 can easily move along the slit 722. In other words, the movement of the catheter 730 relative to the inner needle 12 can be made smooth. In particular, in the catheter assembly 710, since the subport 752 protrudes laterally from the inner needle hub 719, the subport 752 is prevented from getting in the way when puncturing the multi-layered needle 711, etc., making the user's work easier. Moreover, by positioning a rigid tube 754 at the point where the subport 752 of the catheter assembly 710 contacts the inner needle hub 719, the movement of the catheter hub 750 can be made smoother.

[0166] [Eighth Embodiment] As shown in Figures 14 and 15, the catheter assembly 810 according to the eighth embodiment has a catheter hub 850 extending from the proximal end of the catheter operating member 860, and a subport 852 is provided on the extended portion of the catheter hub 850. The catheter 830, like the first embodiment, has a main lumen 834 and a sub-lumen 841, and in the pre-puncture state, it houses the inner needle 12 to form a multi-layered needle 811. The catheter 830 has a tip opening 834a at its tip that communicates with the main lumen 834, and a lateral opening 841a that communicates with the sub-lumen 841 at a predetermined distance (for example, 17 mm or more) from the tip opening 834a.

[0167] Furthermore, the subport 852 of the catheter hub 850 includes a subhub 853 and a flexible tube 855 that connects the main hub 851 and the subhub 853.

[0168] Furthermore, the inner needle hub 819 of the catheter assembly 810 has an upper housing 820 and a lower housing 821 that overlap vertically, similar to the seventh embodiment, with their respective tips 820a and 821a closed in the pre-puncture state. A slit 822 extending in the longitudinal direction of the inner needle hub 819 is formed between the upper housing 820 and the lower housing 821. In addition, the tip 821a of the lower housing 821 has a right tip 823R and a left tip 823L, and is configured to expand in the left-right direction.

[0169] The tip portion 820a of the upper housing 820 has a restricting portion 824 that restricts the right tip portion 823R and the left tip portion 823L of the lower housing 821 from opening in the left-right direction in the pre-puncture state. The restricting portion 824 holds both the left and right sides of the right tip portion 823R and the left tip portion 823L with a pair of plate portions (not shown), and connects the upper sides of the pair of plate portions (not shown) with a bridging portion.

[0170] The catheter assembly 810 has a bending suppression mechanism 890 formed by its right tip 823R and left tip 823L. Retaining grooves 825 are formed in both the right tip 823R and the left tip 823L. The walls forming the two retaining grooves 825 form a perforated sliding contact support portion 891 that rubs against the catheter 830 as it advances toward the inner needle 12. In the initial state of the catheter assembly 810, a small gap is formed between the outer surface of the catheter 830 and the inner surface of the sliding contact support portion 891. In addition, the sliding contact support portion 891 (bending suppression mechanism 890) supports the proximal end of the sub-blumen 841 more than the lateral opening 841a (the sub-opening located at the furthest tip).

[0171] Furthermore, the upper housing 820 is provided with a guide passage 826 that extends in the longitudinal direction. The subport 852 (flexible tube 855) of the catheter hub 850 is exposed from the inside to the outside of the upper housing 820 through this guide passage 826.

[0172] The catheter operating member 860 has a central base 861 detachably connected to the proximal end of the catheter hub 850, and a pair of finger rests 862 extending from the central base 861 to both sides in the left-right direction. The pair of finger rests 862 are inclined upward toward the left-right outward direction. Multiple anti-slip protrusions 862a are provided on the lower surface of the finger rests 862.

[0173] The catheter assembly 810 also includes a guide wire 870 and a guide wire operating member 880. The upper surface of the guide wire operating member 880 is provided with a number of ribs 881 for finger rests. The guide wire operating member 880 is connected to the proximal end of the guide wire 870 via an intermediate connecting portion (not shown) located within the inner needle hub 819. The guide wire operating member 880 is provided so as to be displaceable in the front-rear direction relative to the upper housing 820.

[0174] In use, the catheter assembly 810, configured as described above, is used by the user to insert the multi-layered needle 811 (inner needle 12, catheter 830) into the patient. At this time, the bending suppression mechanism 890 supports the multi-layered needle 811 and suppresses bending. Next, the user operates the guidewire operating member 880 toward the tip to make the guidewire 870 protrude from the tip of the inner needle 12 and insert it into the blood vessel.

[0175] The user then operates the catheter manipulator 860 toward the tip to advance the catheter 830 and catheter hub 850. During this movement, the upper housing 820 is pushed upward by the catheter manipulator 860, opening relative to the lower housing 821. The detachment of the upper housing 820 allows the right tip 823R and the left tip 823L of the lower housing 821 to move further apart from each other in the left-right direction. This allows the catheter manipulator 860 to move toward the tip, enabling the catheter 830 to be inserted smoothly into the blood vessel.

[0176] The user then removes the inner needle 12 from the catheter 830 by pulling the inner needle hub 819 towards the proximal end relative to the catheter 830 and catheter hub 850. As a result, the catheter 830 and catheter hub 850 are left in place on the patient side.

[0177] As described above, the catheter assembly 810 according to the eighth embodiment can also obtain the same effects as the embodiments described above. That is, the deflection suppression mechanism 890 supports the proximal end of the lateral opening 841a (the leading edge sub-opening) of the sub-blumen 841. This makes it possible to suppress the deflection of the inner needle 12 and reduce damage to the catheter 830.

[0178] Furthermore, the catheter assembly 810 has a subport 852 that protrudes upward from the upper housing 820. This simplifies the gripping of the internal needle hub 819 and improves user operability.

[0179] [Ninth Embodiment] As shown in Figure 16, the catheter assembly 910 according to the ninth embodiment is basically configured in the same way as the catheter assembly 810 according to the eighth embodiment, and includes an inner needle 12, an inner needle hub 919, a catheter 930, a catheter hub 950, a catheter operating member 960, a guide wire 970, a guide wire operating member 980, and a deflection suppression mechanism 990.

[0180] The catheter 930 has a main lumen 934 and a sub-lumen 941, and in the pre-puncture state, it houses the inner needle 12 to form a multi-layered needle 911. The catheter 930 has a tip opening 934a that communicates with the main lumen 934 at its tip, and a lateral opening 941a that communicates with the sub-lumen 941 at a predetermined distance (for example, 17 mm or more) from the tip opening 934a.

[0181] The catheter hub 950 is positioned proximal to the catheter operating member 960 and has a main hub 951 and a subport 952 provided on the extension portion of the main hub 951. The subport 952 has a subhub 953 and a flexible tube 955 connecting the main hub 951 and the subhub 953.

[0182] The inner needle hub 919 of the catheter assembly 910 has an upper housing 920 and a lower housing 921 that overlap vertically, with their respective tips 920a and 921a closed in the pre-puncture state. A slit 922 extending in the longitudinal direction of the inner needle hub 919 is formed between the upper housing 920 and the lower housing 921. In this embodiment, the slit 922 extends towards the proximal end of the initial position of the catheter operating member 960 in the pre-puncture state.

[0183] The lower housing 921 has right and left distal ends that can be separated from each other to the left and right when separated from the upper housing 920, and the bending suppression mechanism 990 is constituted by these right and left distal ends. Similar to the eighth embodiment, the bending suppression mechanism 990 constitutes a sliding contact support portion 991 by holding grooves (not shown) at the right and left distal ends. Further, the bending suppression mechanism 990 is located on the proximal side of the lateral opening 941a located at the most distal end side.

[0184] The catheter operation member 960 is supported by the upper housing 920 of the inner needle hub 919 so as to be slidable in the front-rear direction. On the upper surface of the catheter operation member 960, a protrusion 961 for finger hanging is provided. The guide wire operation member 980 is displaceable with respect to the upper housing 920 and is connected to the proximal end portion of the guide wire 970 via an intermediate connecting portion (not shown) disposed within the inner needle hub 919. On the upper surface of the guide wire operation member 980, a plurality of ribs 981 for finger hanging are provided.

[0185] Here, in the catheter assembly 910, the distance Xa from the tip of the inner needle hub 919 to the protrusion 961 of the catheter operation member 960, the distance Xb from the protrusion 961 to the rib 981, and the distance Xc from the rib 981 to the proximal end of the inner needle hub 919 are set such that Xa < Xb < Xc. Thereby, when the user operates with one hand, the catheter assembly 910 can arrange the positions of the fingers well with respect to each operation member.

[0186] In use, the catheter assembly 910 configured as described above punctures the patient with the multi-structured needle 911 (inner needle 12, catheter 930) by the user. At this time, the bending suppression mechanism 990 supports the multi-structured needle 911 and suppresses bending. Next, the user operates the guide wire operation member 980 in the distal direction to project the guide wire 970 from the tip of the inner needle 12 and insert it into the blood vessel.

[0187] The user then operates the catheter manipulator 960 toward the tip to advance the catheter 930 and catheter hub 950. During this movement, the upper housing 920 is pushed upward by the catheter manipulator 960, opening relative to the lower housing 921. The detachment of the upper housing 920 allows the right and left tip ends of the lower housing 921 to move further apart from each other in the left-right direction. This allows the catheter manipulator 960 to move toward the tip, enabling the catheter 930 to be inserted smoothly into the blood vessel.

[0188] The user then removes the inner needle 12 from the catheter 930 by pulling the inner needle hub 919 towards the proximal end relative to the catheter 930 and catheter hub 950. As a result, the catheter 930 and catheter hub 950 are left in place on the patient side.

[0189] As described above, the catheter assembly 910 according to the eighth embodiment can also obtain the same effects as the embodiments described above. That is, the deflection suppression mechanism 990 supports the proximal end of the lateral opening 941a (the leading sub-opening) of the sub-blumen 941. This makes it possible to suppress the deflection of the inner needle 12 and reduce damage to the catheter 930.

[0190] [Tenth Embodiment] As shown in Figure 17, the catheter assembly 1010 according to the 10th embodiment includes an inner needle 12, a catheter 1030, a catheter hub 1050 connected to the catheter 1030, a catheter operating member 1060 for moving the catheter hub 1050 toward the tip, an inner needle hub 1019 connected to the inner needle 12, a guide wire (not shown) inserted through the inner needle 12, a guide wire operating member 1080 connected to the guide wire, and a deflection suppression mechanism 1090 for suppressing the deflection of the inner needle 12 during puncture. The inner needle 12 and the catheter 1030 form a multi-layered needle 1011 in the pre-puncture state.

[0191] The catheter 1030 is configured in the same manner as in the fifth embodiment. That is, it has a main lumen 1034, a first sub-lumen 1040, and a second sub-lumen 1045. The main lumen 1034 communicates with a first tip opening 1034a and a first transverse opening 1034b at the tip of the catheter 1030, and with a proximal opening (not shown) at the proximal end of the catheter 1030. The first sub-lumen 1040 communicates with a second tip opening 1040a and a second transverse opening 1040b at the tip of the catheter 1030, and with a proximal opening (not shown) at the proximal end of the catheter 1030. The second sub-lumen 1045 communicates with a third tip opening 1045a and a third transverse opening 1045b at the tip of the catheter 1030, and with a proximal opening (not shown) at the proximal end of the catheter 1030.

[0192] The catheter hub 1050 is fixed to the proximal end of the catheter 1030. The catheter hub 1050 is housed within the inner needle hub 1019 in the pre-puncture state of the catheter assembly 1010. The catheter hub 1050 has a main hub 1051 connected to the catheter 1030, and a first side port 1052 and a second side port 1053 protruding laterally (horizontally perpendicular to the axis of the main hub 1051) from the main hub 1051. The first and second side ports 1052 and 1053 have a flexible tube 1054 connected to the main hub 1051 via a rigid tube 1051a, and a sub-hub 1055 connected to the other end of the flexible tube 1054. A clamp 1056 is attached to the flexible tube 1054, which can open and close the communication passage inside the flexible tube 1054.

[0193] Furthermore, the catheter assembly 1010 has a sliding member 1057 that slides integrally with the catheter hub 1050 along the housing 1020 (lower extension 1022). The sliding member 1057 has a pair of retaining projections 1057a that are grasped by the user when the catheter hub 1050 is detached from the housing 1020.

[0194] Furthermore, the slide member 1057 has a housing groove 1057b for accommodating the tip end of the catheter hub 1050. In particular, the catheter hub 1050 according to this embodiment has a pair of wings 1058 extending outward in the width direction from the outer peripheral surface of the tip end, and the housing groove 1057b is formed in a shape that can accommodate the pair of wings 1058. Small holes (not shown) are provided in the wings 1058, and protrusions (not shown) provided in the housing groove 1057b are inserted into these small holes. In addition, the housing groove 1057b is open upward, making it possible to detach the catheter hub 1050 upward.

[0195] The catheter operating member 1060 is an annular member supported so as to be slidable in the front-rear direction at the tip of the housing 1020 of the inner needle hub 1019, which will be described later. The catheter operating member 1060 is provided with a flange-shaped finger rest 1061. The side wall 1062 of the catheter operating member 1060 is provided with a recess 1063 that opens toward the tip. The second side port 1053 of the catheter hub 1050 protrudes laterally through the recess 1063.

[0196] The internal needle hub 1019 has a housing 1020 that functions as a gripping portion for the user to grasp, and an upper extension 1021 and a lower extension 1022 that extend parallel to each other in the direction toward the tip from the tip of the housing 1020. In the pre-puncture state of the catheter assembly 1010, the catheter 1030 and the catheter hub 1050 are positioned between the upper extension 1021 and the lower extension 1022.

[0197] The deflection suppression mechanism 1090 is provided at the tip of the inner needle hub 1019. Specifically, the deflection suppression mechanism 1090 includes a support member 1091 that is rotatably supported on the upper extension 1021 around a left-right axis. The support member 1091 has a sliding contact support portion 1092 that rubs against the catheter 1030 when the catheter 1030 advances relative to the inner needle 12. A shaft portion 1093 is provided on the upper part 1091u of the support member 1091. The shaft portion 1093 is pivotally supported on the upper extension 1021. Furthermore, the tip of the guide wire operating member 1080 is located on the tip side of the upper part 1091u of the support member 1091. For this reason, the upward rotation of the support member 1091 is restricted by the guide wire operating member 1080.

[0198] As shown in Figure 18, the sliding support portion 1092 has an upper support portion 1094 that can support the catheter 1030 from above, and left and right lateral support portions 1095 that can support the catheter 1030 from the side. The lateral support portions 1095 protrude downward from both the left and right ends of the upper support portion 1094. Therefore, the sliding support portion 1092 is formed in an inverted U shape when viewed from the longitudinal direction of the catheter assembly 1010. In the pre-puncture state, a small gap is formed between the outer surface of the catheter 1030 and the sliding support portion 1092.

[0199] As shown in Figure 17, in the initial state of the catheter assembly 1010, the sliding contact support portion 1092 supports the proximal end of the third transverse opening 1045b, which is located at the furthest distal end.

[0200] The guidewire operating member 1080 is an operating part for inserting the guidewire into the blood vessel prior to inserting the catheter 1030 into the patient's blood vessel. The tip of the guidewire operating member 1080 is provided with a finger-grip projection 1081 and multiple anti-slip ribs 1082. The guidewire operating member 1080 is supported on the upper surface of the upper extension 1021 so as to be slidable in the front-rear direction. One end of the guidewire is positioned near the tip of the inner needle 12, the other end is connected to the guidewire operating member 1080, and the middle part is folded back within the housing 1020.

[0201] In using the catheter assembly 1010, a puncture procedure is performed in which the catheter assembly 1010 is inserted into the patient's skin. The user grasps the housing 1020 in the pre-puncture state shown in Figure 17 and presses the tip of the catheter assembly 1010 against the patient, inserting it into the skin toward the target blood vessel. This causes the tips of the inner needle 12 and the catheter 1030 to penetrate the skin.

[0202] Next, when the user moves the guidewire operating member 1080 in the proximal direction, the guidewire, which has been folded in the middle section within the housing 1020, moves in the distal direction within the inner needle 12. As a result, the guidewire protrudes from the tip of the inner needle 12 and is inserted into the blood vessel. As the guidewire operating member 1080 moves in the proximal direction, the tip of the guidewire operating member 1080 moves proximal beyond the upper part of the support member 1091. This releases the restriction on the upward rotation of the support member 1091 by the guidewire operating member 1080.

[0203] Once the tip of the guidewire is inserted to the target position within the blood vessel, the user then operates the catheter manipulating member 1060 toward the tip while fixing the position of the inner needle hub 1019 to advance the catheter 1030, catheter hub 1050, and slide member 1057. This inserts the catheter 1030 to the target position within the blood vessel. At this time, the support member 1091 rotates upward as it is pushed by the slide member 1057 moving toward the tip. This allows the catheter 1030 to detach toward the tip from the inner needle hub 1019.

[0204] Next, the user holds down the pair of retaining protrusions 1057a of the slide member 1057, maintaining the positions of the catheter 1030, catheter hub 1050, and slide member 1057, while pulling the housing 1020 towards the proximal end. This causes the catheter 1030, catheter hub 1050, and slide member 1057 to completely exit the inner needle hub 1019, and the inner needle 12 to be withdrawn from the catheter 1030 towards the proximal end. After that, the catheter hub 1050 is removed from the slide member 1057. Then, by attaching tape or the like (not shown) to the pair of wings 1058 of the catheter hub 1050, the catheter 1030 and catheter hub 1050 are placed in the patient's blood vessel.

[0205] As described above, the catheter assembly 1010 according to the 10th embodiment can also obtain the same effects as the embodiments described above. Specifically, the deflection suppression mechanism 1090 supports the proximal side of the third lateral opening 1045b (the proximal sub-opening) of the second sub-blumen 1045. This makes it possible to suppress the deflection of the inner needle 12 and reduce damage to the catheter 1030.

[0206] In particular, the sliding support portion 1092 has an upper support portion 1094 that can support the catheter 1030 from above and a lateral support portion 1095 that can support the catheter 1030 from the side (Figure 18), and the third lateral opening 1045b is provided at either the upper or lateral part of the catheter 1030. This configuration effectively suppresses damage to the third lateral opening 1045b and an increase in sliding resistance when the catheter 1030 advances.

[0207] Furthermore, the present invention may be applied to other embodiments or other configuration examples by taking a portion of each configuration given in the first to tenth embodiments and the first to eighth configuration examples, without departing from the technical concept thereof.

[0208] The above embodiments can be summarized as follows:

[0209] The above embodiment discloses a catheter assembly comprising a catheter having a first lumen and a second lumen, and an inner needle inserted into the first lumen, wherein the inner needle is provided with an introduction channel for flashback confirmation that allows blood to flow between the catheter and the inner needle, and the distance between the inner surface of the tip of the first lumen connected to the tip of the catheter and the outer surface of the inner needle is narrower than the distance between the basic inner surface that constitutes most of the inner surface of the first lumen at the proximal end of the inner surface of the tip and the outer surface of the inner needle.

[0210] With this configuration, the catheter of the catheter assembly has the inner circumferential surface of the tip of the first lumen in close contact with or close to the outer circumferential surface of the inner needle, while the basic inner circumferential surface of the first lumen forms a gap between it and the outer circumferential surface of the inner needle. Therefore, at the position of the inner circumferential surface of the tip, even when subjected to pressure from biological tissue during puncture, the catheter is reliably supported by the inner needle, suppressing bending and contraction of the catheter. This allows the tip of the catheter to be smoothly inserted into the body. In addition, the gap in the first lumen reduces sliding resistance between the catheter and the inner needle, facilitating relative movement between the inner needle and the catheter, thus improving operability during catheter insertion and removal of the inner needle. Furthermore, the introduction route allows blood to flow when the inner needle reaches a blood vessel, enabling the user to clearly recognize the establishment of a blood vessel. In other words, the catheter assembly allows for easy insertion of a catheter with multiple lumens, enabling the administration of multiple types of drugs or various procedures such as blood sampling to be performed smoothly.

[0211] In the catheter assembly described above, the inner circumferential surface of the tip may close the gap formed between the basic inner circumferential surface and the outer circumferential surface of the inner needle by forming a contact portion that is in close contact with the outer circumferential surface of the inner needle.

[0212] With this configuration, the tip of the catheter can be made thinner by forming a tight seal between the inner circumferential surface of the tip and the inner needle, and is also more securely supported by the inner needle. Therefore, the catheter insertion performance is greatly improved.

[0213] In the catheter assembly described above, the outer surface of the catheter may include a basic outer surface located at the location where the basic inner surface is formed, a tip outer surface located at the location where the tip inner surface is formed and having a smaller outer diameter than the basic outer surface, and a tapered outer surface that narrows from the basic outer surface towards the tip outer surface.

[0214] With this configuration, the catheter can be easily inserted into the blood vessel from the tip because the outer surface of the tip is thinner than the outer surface of the base. In addition, since the tapered outer surface is inserted after the outer surface of the tip, and then the outer surface of the base is inserted, it becomes possible to easily insert the thicker outer surface of the base.

[0215] In the catheter assembly described above, the catheter may have a main body portion that constitutes the majority of the axial direction, and a flexible portion provided at the tip of the main body portion that is more flexible than the main body portion.

[0216] With this configuration, when a catheter with a flexible portion is inserted into a blood vessel, the flexible portion that comes into contact with the vessel wall easily bends and curves along the vessel, improving vascular insertability and significantly reducing inflammation and damage to the vessel wall. Furthermore, since the inner surface of the tip of the catheter is supported by the inner needle, bending and contraction of the flexible portion during insertion before reaching the blood vessel can be effectively suppressed.

[0217] In the catheter assembly described above, the tip-side opening of the second lumen may be located on the tip side of the proximal end of the introduction pathway in the axial direction of the catheter.

[0218] With this configuration, the catheter assembly can quickly confirm that blood has flowed into the second lumen because the opening at the tip of the second lumen is located further forward than the proximal end of the introduction pathway.

[0219] In the catheter assembly described above, the tip-side opening of the second lumen may be located more proximal to the proximal end of the introduction passage in the axial direction of the catheter.

[0220] With this configuration, the catheter assembly can be made narrower near the tip because the opening at the tip of the second lumen is located more proximal to the proximal end of the introduction pathway, thereby improving insertability. In addition, the blood flowing into the first lumen can be quickly confirmed.

[0221] In the catheter assembly described above, the opening at the tip of the second lumen can be configured to face the side of the catheter.

[0222] With this configuration, the opening at the tip of the second lumen faces the side of the catheter, thereby reducing insertion resistance.

[0223] In the catheter assembly described above, the opening at the tip of the second lumen may be provided so as to face the tip of the catheter.

[0224] With this configuration, the opening at the tip of the second lumen faces the tip of the catheter, which prevents the opening from being occluded by the blood vessel wall while the catheter is in place within a blood vessel. In particular, blood can be effectively aspirated from the opening of the second lumen.

[0225] In the catheter assembly described above, the diameter of the second lumen may be constant along the entire axial length of the catheter.

[0226] With this configuration, the catheter allows for stable drug flow due to the constant diameter of the second lumen, and also allows for the slidable positioning of the guidewire and stylet.

[0227] In the catheter assembly described above, a rod-shaped member that is elongated in the axial direction may be detachably arranged in the second lumen.

[0228] With this configuration, the catheter assembly has a rod-shaped member detachably positioned in the second lumen, which improves the rigidity and straightness of the catheter, allowing for better catheter insertion.

[0229] In the catheter assembly described above, the diameter of the basic inner surface of the first lumen may be larger than the diameter of the inner surface of the second lumen.

[0230] In the catheter assembly described above, the diameter of the basic inner surface of the first lumen may be smaller than the diameter of the inner surface of the second lumen.

[0231] In the catheter assembly described above, the second lumen may be formed in the circumferential direction of the catheter, in the direction facing the cutting edge of the inner needle that is exposed from the first lumen.

[0232] In the catheter assembly described above, the second lumen may be formed in a direction perpendicular to the direction in which the cutting edge of the inner needle, exposed from the first lumen, faces, within the circumferential direction of the catheter.

[0233] In the catheter assembly described above, the second lumen may be formed in the circumferential direction of the catheter, in the direction opposite to the direction in which the cutting edge of the inner needle exposed from the first lumen faces.

[0234] With this configuration, the catheter assembly can be appropriately designed in terms of the size and arrangement of the first and second lumens, taking into account factors such as catheter insertability, impact on blood vessels, and visibility of flashbacks.

[0235] The catheter assembly described above includes a first catheter hub that fixes and holds the catheter and has a first space that communicates with the first lumen, and a second catheter hub that is connected to the first catheter hub and has a second space that communicates with the second lumen, wherein a communication passage is provided within the first catheter hub that bypasses the first space and connects the second lumen and the second space.

[0236] With this configuration, the first and second catheter hubs can improve connectivity with connectors for infusion and blood transfusion tubes. In particular, the connecting passage connects the second space of the second catheter hub to the second lumen of the catheter, allowing for smooth flow of drugs and blood.

[0237] In the catheter assembly described above, the catheter assembly is equipped with a deflection suppression mechanism that supports the catheter, and the opening on the tip side of the second lumen may be located on the tip side of the deflection suppression mechanism in the assembled state.

[0238] With this configuration, the catheter assembly has its second lumen opening located more towards the tip than the flexure suppression mechanism. This reduces the sliding resistance against the flexure suppression mechanism when the catheter is advanced compared to when it is located more towards the proximal end. Furthermore, it prevents the flexure suppression mechanism from hitting the opening of the second lumen and damaging the catheter during its movement.

[0239] In the catheter assembly described above, the catheter assembly is provided with a deflection suppression mechanism that supports the catheter, and the catheter is provided with a tapered portion whose outer diameter increases towards the proximal end from a position a predetermined distance from the tip of the catheter, and the tapered portion may be located on the tip side of the deflection suppression mechanism in the assembled state.

[0240] With this configuration, the catheter assembly has a tapered section located towards the tip of the flexure suppression mechanism, which, as described above, reduces the sliding resistance of the catheter, prevents the flexure suppression mechanism from hitting the tapered section and damaging the catheter, and eliminates any steps, thus preventing the inner needle from bending. Furthermore, during catheter advancement, the flexure suppression mechanism holds the wider diameter section of the catheter rather than the narrower diameter section, effectively preventing the inner needle from bending.

[0241] The above embodiment discloses a catheter assembly comprising an inner needle, a catheter having a main lumen through which the inner needle is detachably inserted, and one or more sub-lumines provided separated from the main lumen, and a deflection suppression mechanism that suppresses the deflection of the inner needle by supporting the inner needle through the catheter, wherein the one or more sub-lumines communicate with each of the one or more sub-openings formed in the catheter, and the deflection suppression mechanism has a sliding support portion that rubs against the catheter when the catheter advances relative to the inner needle, and the sliding support portion is capable of supporting a portion on the proximal side of the furthest tip of the one or more sub-openings, or on the proximal side of a step portion that occurs in the catheter due to the formation of the sub-lumines.

[0242] With this configuration, even if the catheter assembly has multiple lumens, such as a main lumen and one or more sub-lumens, the bending suppression mechanism supports the proximal end of the leading sub-opening, thereby suppressing bending of the inner needle and reducing catheter damage. In other words, by appropriately positioning the formation location of the sub-opening and the support location of the bending suppression mechanism, the catheter assembly can achieve both prevention of inner needle bending and catheter mobility. Therefore, catheters with multiple lumens can be easily inserted, enabling smooth administration of multiple types of drugs or various procedures such as blood sampling.

[0243] In the catheter assembly described above, the bending suppression mechanism may be capable of supporting the area more proximal than the sub-opening that is the most proximal of the one or more sub-openings.

[0244] With this configuration, the catheter assembly supports the proximal end more than the most proximal sub-opening, thereby more reliably preventing catheter damage due to the bending suppression mechanism.

[0245] In the catheter assembly described above, the main lumen and the one or more sub-lumens may extend parallel to each other within the catheter.

[0246] With this configuration, the catheter assembly, through its main lumen and sub-lumen which extend parallel to each other, can effectively deliver different types of drug solutions into the bloodstream.

[0247] In the catheter assembly described above, the stepped portion is a tapered portion whose outer diameter gradually decreases toward the tip, the one or more sub-openings are provided in the tapered portion, and the deflection suppression mechanism may be capable of supporting the proximal end side of the tapered portion.

[0248] With this configuration, the catheter assembly can prevent the bending suppression mechanism from getting caught on the tapered portion by supporting the proximal end of the bending suppression mechanism more than the tapered portion. Therefore, the mobility of the catheter can be further improved.

[0249] In the catheter assembly described above, the one or more sub-openings include lateral openings provided on the outer circumferential surface of the catheter, and the bending suppression mechanism may be capable of supporting the proximal end side of the lateral openings.

[0250] With this configuration, the catheter assembly, with its sub-opening including a lateral opening, can effectively discharge the drug solution or blood flowing through the sub-flumen into the blood vessel. Furthermore, since the bending suppression mechanism is located proximal to the sub-opening, damage to the lateral opening is also suppressed.

[0251] In the catheter assembly described above, the main lumen communicates with the main opening formed in the catheter, and the distance between the main opening and the one or more sub-openings may be 17 mm or more.

[0252] With this configuration, the catheter assembly has a main opening and one or more sub-openings spaced 17 mm or more apart. This allows the drug flowing out of the sub-openings to mix with the blood in the blood vessels before mixing with the drug flowing out of the main opening. In other words, drugs that are normally incompatible can be successfully administered through a single catheter.

[0253] In the catheter assembly described above, the bending suppression mechanism may be capable of supporting the one or more sub-openings that are located closer to the tip than the bending suppression mechanism and at a position of 5 mm or less relative to the closest sub-opening.

[0254] With this configuration, the catheter assembly can be supported by the bending suppression mechanism at a position of 5 mm or less from the proximal end of the sub-opening. This shortens the distance from the tip of the inner needle to the bending suppression mechanism, allowing for more robust suppression of the inner needle's bending. In other words, from the viewpoint of suppressing bending of the inner needle and the tip of the catheter, it is preferable to provide the bending suppression mechanism as close to the tip as possible. On the other hand, catheters with multiple lumens require that the openings be spaced a certain distance apart so that the drug solutions discharged from each opening mix in the blood. However, if the bending suppression mechanism is located closer to the tip than the opening, it may come into contact with the catheter near the opening and cause damage. Therefore, as described above, by providing the bending suppression mechanism at the minimum distance necessary for the drug solutions discharged from each opening to mix in the blood, and near the opening, both mixing in the blood and bending suppression can be achieved.

[0255] In the catheter assembly described above, the main lumen and the one or more sub-lumens may be separated by a partition wall that can deform in response to pressure.

[0256] With this configuration, the catheter assembly is divided into a main lumen and one or more sub-lumens by a pressure-deformable partition wall. This allows the main lumen to be enlarged when the inner needle is inserted before catheter insertion, simplifying the relative movement of the inner needle and catheter. The partition wall then deforms appropriately according to the fluid pressure during drug or blood administration. For example, even when a relatively large amount of drug fluid flows through the sub-lumens compared to the drug fluid in the main lumen, it is possible to easily secure the flow path cross-sectional area.

[0257] In the catheter assembly described above, the bending suppression mechanism may surround the entire circumference of the catheter in a manner that allows contact with it.

[0258] With this configuration, the catheter assembly can reliably suppress vertical and lateral movement of the inner needle (such as deviation from the bending suppression mechanism or bending of the inner needle) by a bending suppression mechanism that surrounds the entire circumference of the catheter.

[0259] The catheter assembly described above includes a catheter hub for fixing and holding the catheter and an inner needle hub for fixing and holding the inner needle, wherein one or more sub-brumes communicate with one or more port passages provided in the catheter hub, and the ports may be configured as connectors that can be connected to medical devices.

[0260] With this configuration, by connecting medical devices to the ports, medications or blood can be easily supplied to one or more sub-brumens.

[0261] In the catheter assembly described above, the inner needle hub is configured as a housing that movably accommodates the catheter hub, and the housing may have a slit that exposes the port from the inside to the outside.

[0262] With this configuration, the catheter assembly, having a slit in the housing, allows the port to easily move along the slit, even in a configuration where the port is provided in the catheter hub. In other words, the catheter can move smoothly relative to the inner needle.

[0263] In the catheter assembly described above, the housing is separable into upper and lower halves, the slit constitutes part of the boundary of the housing that is separable into upper and lower halves, and the port may protrude laterally from the housing.

[0264] With this configuration, the catheter assembly has the port protruding laterally from the housing, which helps to prevent the port from getting in the way during puncture of the inner needle and catheter, thereby facilitating the user's work.

[0265] In the catheter assembly described above, the port may protrude upward from the inner needle hub.

[0266] With this configuration, the catheter assembly can be made easier to grasp and more user-friendly because the port protrudes upward from the housing.

[0267] In the catheter assembly described above, the port may have a connecting portion to which the medical device can be connected, and a flexible tube extending between the catheter hub and the connecting portion, which is more flexible than the connecting portion.

[0268] With this configuration, the catheter assembly includes a port with a connector and a flexible tube, allowing the connector to be positioned in any location and orientation, enabling the user to perform punctures and catheter insertions.

[0269] In the catheter assembly described above, the port may have a connecting portion to which the medical device can be connected, a rigid tube protruding to the outside of the inner needle hub connected to the catheter hub, and a flexible tube extending between the rigid tube and the connecting portion and being softer than the connecting portion.

[0270] With this configuration, the catheter assembly forms a port using a connecting part, a rigid tube, and a flexible tube, allowing the rigid tube to be positioned in contact with the inner needle hub, thus enabling smooth movement of the catheter hub. [Explanation of symbols]

[0271] 10, 110, 210, 310, 510, 610, 710, 810, 910, 1010… Catheter assemblies 12...Inner hand 30, 130, 230, 330, 430A~430H, 530, 630, 730, 830, 930, 1030… Catheter 34, 134, 234, 334, α, 534, 634, 734, 834, 934, 1034… Main lumens 41, 141, 241, 341, β, β1, β2, 540, 545, 641, 741, 841, 941… Sub-Blumen 90, 590, 690, 790, 890, 990, 1090… Bending suppression mechanism 92, 595, 691, 791, 891, 991, 1092... sliding contact support part (contact support part)

Claims

[Claim 1] The inner needle and, A catheter having a lumen through which the inner needle is detachably inserted, A catheter assembly comprising a deflection suppression mechanism that suppresses the deflection of the inner needle by supporting the inner needle via the catheter, The catheter includes, One or more catheter side openings, A stepped portion is provided on the outer circumferential surface of the catheter, on the proximal end side of the catheter, and is designed to increase the inner and outer diameters of the catheter. Formed, The deflection suppression mechanism has a contact support portion that can come into contact with the catheter when the catheter advances relative to the inner needle. The contact support portion is capable of supporting the catheter assembly at a point on the proximal end side of the tip of the catheter side opening that is the most distal of the one or more catheter side openings, or on the proximal end side of the stepped portion.

Images