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 administering fluid or blood transfusion. [Background technology]

[0002] When constructing an introduction site for infusion or blood transfusion in a patient, a catheter assembly having a multi-layered needle with an inner needle inserted into a catheter (outer needle) is used, as disclosed in Patent Document 1, for example. When using this catheter assembly, the user inserts the multi-layered needle into the patient, advances the catheter relative to the inner needle to insert it into a blood vessel, and then detaches the inner needle from the catheter to leave the catheter in place. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-43445 Summary of the Invention

[0004] One aspect of the present invention is a catheter assembly comprising an inner needle, a catheter having a lumen through which the inner needle is removably inserted, and a deflection suppression mechanism that suppresses deflection 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 step portion provided so that the inner diameter and outer diameter of the catheter increase, and 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, and the contact support portion is capable of supporting a portion on the base end side of the distal end of the catheter side opening that is furthest to the distal end of the one or more catheter side openings, or on the base end side of the step portion. [Brief explanation of the drawings]

[0005]

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Embodiments 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 accompanying drawings.

[0007] 〔First Embodiment〕 The catheter assembly 10 according to the first embodiment is used when performing infusion, blood transfusion, etc. on a patient (living body), and is a medical device that punctures, inserts, and retains the catheter 30 into the patient's body to construct an inlet / outlet part for a liquid (medicine solution or blood). This catheter assembly 10 is configured to insert a catheter having a longer length than a peripheral venous catheter (for example, a central venous catheter, a PICC, a midline catheter, etc.). Note that the catheter assembly 10 may be configured to insert a peripheral venous catheter shorter than a central venous catheter. Further, the catheter assembly 10 is not limited to a venous catheter, and may be configured to insert an arterial catheter such as a peripheral arterial catheter.

[0008] As shown in FIG. 1, the catheter assembly 10 includes an inner needle 12, a housing 20 (inner needle hub) that fixedly holds the inner needle 12, a catheter 30 disposed outside the inner needle 12, and a catheter hub 50 that fixedly holds the catheter 30. Further, the catheter assembly 10 includes a catheter operation member 60 that operates the forward and backward movement of the catheter 30 and the catheter hub 50, and a guide wire 70 that guides the advancement of the catheter 30 and a guide wire operation member 80.

[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 therein (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-structured needle 11.

[0010] In this multi-structured needle 11, in the pre-puncture state, while the tip 13 of the inner needle 12 protrudes beyond 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-structured needle 11 therein and also accommodates the catheter hub 50, the catheter operating member 60, and the guide wire operating 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-structured 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 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). Thus, at the time of puncture, the edge of the blade surface 15 cuts through 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 (see also 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 portion 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 portion 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 fixedly holds the inner needle 12 and moves integrally with the inner needle 12, and constitutes a grip portion to be gripped by the user. The housing 20 has an overall elongated bowl shape and is designed to have an appropriate size (thickness and length) so that it is easy for the user to grip.

[0019] The housing 20 is provided with a housing space 20a for accommodating the catheter hub 50, the catheter operating member 60, and the guide wire operating member 80. A pair of side walls 21 sandwiching the housing space 20a extend parallel to the longitudinal direction and have groove-shaped rail portions 21a on the inner surfaces of the tip sides formed higher than the base end side. The pair of rail portions 21a slidably accommodate the side edges 61a of the catheter operating member 60. The tip side of one of the pair of side walls 21 (the left side wall 21 in FIG. 1) has a bulging portion 22 that bulges outward in the width direction. A support member 91, which is a deflection suppressing mechanism 90, is attached to the recess 22a for arranging the bulging portion 22.

[0020] The support member 91 is rotatably supported by the side wall 21 and has a sliding contact support portion 92 that protrudes rightward from the housing space 20a of the housing 20. This sliding contact support portion 92 rubs against the catheter 30 (multi-structured needle 11) when the catheter held by the catheter operating member 60 advances. This sliding contact support portion 92 does not have to contact the catheter 30 before use of the catheter or when the catheter moves relative to the housing 20. Further, the support member 91 has a groove portion (not shown) that accommodates the side edge 61a of the catheter operating member 60 at the upper end in a state where the catheter operating member 60 is accommodated in the housing 20. And when the side edge 61a exists in this groove portion, rotation is restricted and the catheter is supported in a standby state. On the other hand, when the catheter operating member 60 advances, the support member becomes rotatable as the side edge 61a comes out of the groove portion, and further rotates toward the outside of the side wall 21 by contacting the catheter operating member 60. As a result, the catheter hub 50 and the catheter operating member 60 are smoothly sent out from the housing 20 while the support member (sliding contact support portion 92) remains in the housing 20.

[0021] Further, the housing 20 includes a block-shaped needle holding portion 24 that holds the inner needle 12 at an axially intermediate position of the accommodation space 20a. A guide mechanism (not shown) is provided on the proximal side of the housing 20 relative to the needle holding portion 24 to guide the sliding of the guide wire operating member 80 and restrict the detachment of the guide wire operating member 80. Further, a rear wall 25 that closes the accommodation space 20a is provided on the most proximal side of the housing 20.

[0022] The constituent material of the housing 20 is not particularly limited, but for example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, or methacrylate-butylene-styrene copolymer may be applied. In the illustrated example, the housing 20 is configured to expose the upper surface of the accommodation space 20a, but the housing 20 may be formed in a rectangular tube shape that covers the accommodation space 20a with an upper wall or the like.

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

[0024] Also, as shown in FIG. 2, the catheter 30 is composed of a main body portion 32 that constitutes most of its axial direction and a soft tip 33 (flexible portion) provided at the tip of the main body portion 32 and softer than the main body portion 32. The main body portion 32 and the soft tip 33 are firmly fixed by an appropriate fixing method such as heat fusion or adhesion, and their outer peripheral surfaces are continuously formed in series. Further, the connection boundary portion between the main body portion 32 and the soft tip 33 overlaps each other in a tapered shape to gradually change the physical properties of the catheter 30.

[0025] The plurality of lumens 31 within the catheter 30 include a main lumen 34 (first lumen) through which the inner needle 12 is inserted and disposed 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 perfect circular shape in a cross-sectional view perpendicular to the axis of the catheter 30.

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

[0027] The inner peripheral surface of the catheter 30 constituting the main lumen 34 is divided into a distal inner peripheral surface 36 with a zero (narrow) interval from the outer peripheral surface 16 of the inner needle 12 and a basic inner peripheral surface 38 that forms a gap 39 with the outer peripheral surface 16 of the inner needle 12, with a predetermined position P in the axial direction as the base point. Further, a tapered inner peripheral surface 37 connecting the distal inner peripheral surface 36 and the basic inner peripheral surface 38 is formed at the distal end of the basic inner peripheral surface 38.

[0028] The distal inner peripheral surface 36 forms a contact portion 35 that contacts the outer peripheral surface 16 of the inner needle 12 because its diameter is equal to or slightly smaller than the outer diameter of the outer peripheral surface 16 of the inner needle 12, closing the gap 39 of the basic inner peripheral surface 38. Therefore, the diameter of the distal inner peripheral surface 36 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. Further, the longitudinal (axial) length of the distal inner peripheral surface 36 is preferably, for example, in the range of 0.1 mm to 4.0 mm in order to insert the distal end of the catheter 30 well.

[0029] The above-mentioned soft tip 33 forms the tip of the catheter 30 together with the main body 32, and its inner side forms the tip inner peripheral surface 36 (adhesive portion 35). And the foremost end of the tip inner peripheral surface 36 of the soft tip 33 forms the first tip opening 34a. Also, the foremost end on the outer peripheral surface side of the soft tip 33 is formed, for example, at the tip tapered portion 40 having an inclination that coincides with the inclination of the blade surface 15 of the needle tip 13 (or an inclination gentler than the blade surface 15).

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

[0031] The diameter of the basic inner peripheral surface 38 is larger than the outer diameter of the outer peripheral surface 16 of the inner needle 12, that is, it is formed larger than the interval of the tip inner peripheral surface 36. Thereby, the inner needle 12 and the catheter 30 can slide well. Also, the hole 14 of the inner needle 12 communicates with the gap 39 of the basic inner peripheral surface 38 facing the basic inner peripheral surface 38 in the state before puncture. Therefore, it is possible to satisfactorily flash back blood into the gap between the inner needle 12 and the catheter 30. The diameter of the basic inner peripheral surface 38 is preferably designed to be about 1.02 to 1.33 times the diameter of the tip inner peripheral surface 36, for example.

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

[0033] The second lateral opening 41a is provided at a position closer to the proximal end than the first tip opening 34a. The interval between the first tip opening 34a and the second lateral opening 41a is preferably separated by 17 mm or more.

[0034] In the catheter assembly 10, since the distance between the first tip opening 34a and the second lateral opening 41a is separated by 17 mm or more, after the drug flowing out from one of the first tip opening 34a or the second lateral opening 41a is mixed with blood in the blood vessel, it is mixed with the drug flowing out from the other. That is, incompatible drugs can be well administered with a single catheter 30. Note that the proximal end side of the sub-lumen 41 communicates with the second proximal opening 41b, and this second proximal opening 41b is adjacent to the first proximal opening 34b.

[0035] Also, the diameter of the inner peripheral surface of the sub-lumen 41 is set to be smaller than the diameter of the inner peripheral surface (tip inner peripheral surface 36) of the main lumen 34 in the present embodiment. That is, the plurality of lumens 31 are composed of the large-diameter main lumen 34 in which the inner needle 12 is disposed and the small-diameter sub-lumen 41 in which nothing is disposed. Further, while the diameter of the main lumen 34 changes along the axial direction, the inscribed circle diameter of the sub-lumen 41 is 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 allow the drug to flow in from the second proximal opening 41b and guide the drug to the second lateral opening 41a. For example, it may be in the range of 0.3 to 1.2 mm.

[0036] On the other hand, in the outer peripheral surface of the catheter 30, a range from the tip to a predetermined position P is formed as the tip outer peripheral surface 42 with a small outer diameter. For example, the tip outer peripheral surface 42 has an outer diameter that is slightly larger than that of the inner needle 12. Further, the outer peripheral surface of the catheter 30 has a tapered outer peripheral surface 43 that becomes thicker toward the proximal end direction from the predetermined position P, and a basic outer peripheral surface 44 that is continuous with the proximal end of the tapered outer peripheral surface 43 and is thicker than the tip outer peripheral surface 42. The basic outer peripheral surface 44 is provided at the formation position of the sub-lumen 41.

[0037] In the above catheter 30, on its axial direction, the tip inner peripheral surface 36 and the tip outer peripheral surface 42 overlap, the tapered inner peripheral surface 37 and the tapered outer peripheral surface 43 overlap, and the basic inner peripheral surface 38 and the basic outer peripheral surface 44 overlap. Therefore, in the vicinity of the predetermined position P, the wall thickness of the main body portion 32 itself does not change. In other words, even if the shape of the main body portion 32 becomes thinner, its wall thickness remains constant and continuous. Also, at the position where the outer diameter becomes thicker only by the formation of the sub lumen 41, a continuous inclined surface 45 that is continuous with the tapered outer peripheral surface 43 and is connected to the basic outer peripheral surface 44 is provided.

[0038] The constituent material of the main body portion 32 is not particularly limited, but a soft resin material is preferable. For example, 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 a mixture of an olefin resin and an ethylene-vinyl acetate copolymer can be mentioned. The constituent material of the soft tip 33 is also not particularly limited, but for example, a resin material such as polyurethane may be applied.

[0039] Also, the catheter 30 is preferably formed of a material having transparency, whereby the user can favorably visually recognize the flashback of the blood flowing into the main lumen 34 and the sub lumen 41. Note that the catheter 30 may have a configuration in which the meat portion constituting the main lumen 34 has transparency and the meat portion constituting the sub lumen 41 has opacity. This is because the user can visually recognize the blood flowing into the gap 39. Conversely, a configuration in which the meat portion constituting the sub lumen 41 has transparency and the meat portion constituting the main lumen 34 has opacity may also be used. Further, the catheter assembly 10 may be configured such that the inner needle 12 does not have the hole portion 14 (notch). As the catheter 30 relatively advances with respect to the inner needle 12, when the contact between the tip side of the inner needle 12 and the inner peripheral surface of the main lumen 34 of the catheter 30 disappears, blood flows into the main lumen 34, so that the flashback can be confirmed.

[0040] The proximal end portion of the catheter 30 is fixed to the distal end portion within the catheter hub 50 by an appropriate fixing means such as caulking, fusion bonding, adhesion, or the like. The catheter hub 50 is exposed on the patient's skin in a state where the catheter 30 is inserted into the patient's blood vessel, and is affixed with a tape or the like and left in place together with the catheter 30. The material constituting the catheter hub 50 is not particularly limited, and for example, the materials exemplified for the housing 20 may be appropriately adopted.

[0041] As shown in FIGS. 1 and 2, the catheter hub 50 has a main hub 51 (first catheter hub) formed in a tapered cylindrical shape in the distal end direction, and a sub-hub 52 (second catheter hub) connected to the side surface of the main hub 51. The main hub 51 constitutes a main port for allowing one of two types of drugs to flow in during infusion or the like, and the sub-hub 52 constitutes a sub-port for allowing the other of the two types of drugs to flow in.

[0042] The main hub 51 fixedly holds the catheter 30 at its distal end portion, and has a main space portion 51a (first space portion) on the proximal end side of the fixed portion. The main space portion 51a communicates with the main lumen 34, and the inner needle 12 is inserted therethrough in a state before puncture. Also, inside the main hub 51, a flow path 53 is provided that communicates with the sub-lumen 41 of the catheter 30 and also communicates with the sub-space portion 52a in the sub-hub 52. The sub-space portion 52a and the flow path 53 constitute a communication path 55 that communicates with the sub-lumen 41.

[0043] The sub-hub 52 is formed in a cylindrical shape having the sub-space portion 52a inside, and is provided above the main space portion 51a corresponding to the positional relationship between the main lumen 34 and the sub-lumen 41 of the catheter 30. Thereby, it can be easily manufactured into a shape in which the flow path 53 and the main space portion 51a are separated in the main hub 51. Also, it becomes possible to configure the housing 20 to be narrow in the width direction, and the user can easily grip and operate the housing 20 during puncture.

[0044] The main hub 51 and the sub-hub 52 serve as connection parts to which the connectors of the infusion tubes can be connected (for example, they are provided at the base with a flange part 54 protruding radially outward, or the inner peripheral surface of the main space part 51a or the sub-space part 52a is formed into a luer taper, etc.). In addition, in the main space part 51a of the main hub 51 and the sub-space part 52a of the sub-hub 52, a hemostatic valve (not shown) for preventing the backflow of blood and a plug (not shown) for enabling infusion by penetrating the hemostatic valve as the connector of the infusion tube is inserted may be accommodated.

[0045] As shown in FIG. 1, the above-mentioned catheter 30 and catheter hub 50 are operated for relative movement with the inner needle 12 and the housing 20 by a catheter operating member 60. The catheter operating member 60 directly holds the catheter 30 and also accommodates and holds the catheter hub 50. This catheter operating member 60 has an operation plate part 61 extending in the longitudinal direction of the housing 20 and a hub accommodating part 62 connected to the base end of the operation plate part 61 for accommodating the catheter hub 50.

[0046] The operation plate part 61 is a part where the user's finger is placed for forward and backward operations. A pair of side edges 61a of the operation plate part 61 are arranged on a pair of rail parts 21a of the housing 20 and the upper surfaces of a pair of side walls 21 in the state before puncture. In addition, on the lower surface of the operation plate part 61, one or more catheter holding parts each consisting of a pair of protruding pieces (not shown) are provided along the longitudinal direction, and the catheter 30 is clamped at each location.

[0047] That is, as shown in FIGS. 1 and 2, the multi-structured needle 11 (catheter 30) is supported at an intermediate position in the axial direction by a deflection suppression mechanism 90 composed of the above-mentioned support member 91 and operation plate part 61. The support location by the support member 91 (deflection suppression mechanism 90) is located on the proximal side of the tapered outer peripheral surface 43 and the continuous inclined surface 45 and on the proximal 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 distal side of the support member 91 and the closest.

[0048] More specifically, the support member 91 can support the catheter 30 at a position 5 mm or less from the second lateral opening 41a closer to the distal end side than the support member 91. Here, it is preferable that the bending suppression mechanism 90 is provided as close to the distal end side as possible from the viewpoint of suppressing the bending of the distal end side of the inner needle 12 and the catheter 30. On the other hand, for the catheter 30 having the main lumen 34 and the sub-lumen 41, it is necessary to provide the respective openings at a certain distance so that the chemical solutions discharged from the respective openings are mixed in the blood. However, if the bending suppression mechanism 90 exists on the distal end side of the second lateral opening 41a, there is a possibility that the bending suppression mechanism 90 contacts the catheter 30 near the second lateral opening 41a and causes damage or the like. Therefore, it is the minimum distance at which the chemical solutions discharged from the respective openings are mixed in the blood, and by providing the bending suppression mechanism 90 near the second lateral opening 41a, it is possible to achieve both mixing in the blood and bending suppression.

[0049] The hub storage portion 62 constitutes a storage chamber for storing the catheter hub 50 with an upper plate 63 connected to the operation plate portion 61 and a pair of side plates (not shown). The upper plate 63 is provided with an arrangement hole 63a that is cut out in a substantially isosceles triangle shape according to the shape of the catheter hub 50 and projects the sub-hub 52. And the hub storage portion 62 holds the flange portion 54 of the catheter hub 50 so as to be separable with an appropriate frictional force by a pair of side plates and an arch portion 64 that bridges in an arc shape on the proximal end side.

[0050] Also, as shown in FIGS. 1 and 2, the guide wire 70 of the catheter assembly 10 is disposed 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 operation member 80. The guide wire 70 is formed longer in the axial direction than the inner needle 12 and has appropriate rigidity and flexibility.

[0051] Before puncture, the tip of the guide wire 70 is disposed on the proximal side of the hole 14 of the inner needle 12. Thereby, when the inner needle 12 is punctured, the blood flowing into the hollow portion 12a from the blood vessel can flow out well to the outside of the inner needle 12 through the hole 14, and the user can visually recognize the flashback. Then, in the state where the inner needle 12 is punctured, the guide wire 70 advances into the blood vessel by being sent out from the tip opening 15a of the inner needle 12 under the operation of the guide wire operating member 80 by the user.

[0052] Returning to FIG. 1, the guide wire operating member 80 of the catheter assembly 10 includes a holding block 81 that fixedly holds the guide wire 70 on the proximal side of the housing 20, and an operating arm 82 that extends in the distal direction from the holding block 81. The distal end portion of the operating arm 82 is provided with an operating protrusion 83 that the user directly contacts and operates, and is slidably placed on the flat upper surface of the guide wire operating member 80. That is, as the operating arm 82 advances, the holding block 81 advances, thereby pushing out the guide wire 70 in the distal direction. Then, according to the advancement amount of the guide wire operating member 80, the guide wire 70 is sent 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 operation and effect will be described below.

[0054] As described above, the catheter assembly 10 is used when constructing an infusion introduction portion to a patient. In use, the user holds and operates the housing 20 to puncture the multiple structure needle 11 into the patient. At this time, the support member 91 of the housing 20 supports the basic outer peripheral surface 44 (the extending portion of the plurality of lumens 31) of the catheter 30, and ensures good linearity of the catheter 30. At the time of puncture, the inner needle 12 is first inserted by cutting the skin and blood vessel with the blade surface 15, and then the catheter 30 is inserted into the body.

[0055] As shown in Fig. 2, when the catheter 30 is inserted, since the tip outer peripheral surface 42, which is sufficiently thin, is inserted first, it receives a sufficiently low piercing resistance. Further, since the tip inner peripheral surface 36 including the soft tip 33 is in close contact with the inner needle 12, it does not bend radially inward. As a result, the tip of the catheter 30 is also prevented from shrinking in the axial direction, and the catheter 30 can be easily inserted. In particular, since the inner needle 12 disposed in the main lumen 34 can be thick, the bending of the catheter 30 is further reduced.

[0056] Furthermore, when puncturing the blood vessel, since the tip of the guide wire 70 is located on the proximal end side of the hole 14, the blood that has flowed into the hollow portion 12a of the inner needle 12 flows through the hole 14 into the main lumen 34 (the gap 39 of the basic inner peripheral surface 38) of the catheter 30. As a result, the user can visually confirm the blood flashback and confirm that the main lumen 34 has secured the blood vessel.

[0057] When the catheter 30 is further inserted, it transitions from the predetermined position P to the tapered outer peripheral surface 43. At this time, the living tissue expands, but it is possible to smoothly insert the catheter 30 along the tapered outer peripheral surface 43, and even when reaching the continuous inclined surface 45, the smooth insertion of the catheter 30 can be continued due to the inclination. In particular, since the sub-lumen 41 has a small diameter and the rate of change of the outer diameter of the basic outer peripheral surface 44 with respect to the tip outer peripheral surface 42 is also small, the piercing resistance of the catheter 30 is significantly suppressed. Therefore, the catheter 30 can be smoothly inserted up to the basic outer peripheral surface 44.

[0058] When the multi-structured needle 11 is inserted into the blood vessel to a certain extent, the user advances the guide wire operating member 80 to send out the guide wire 70 from the tip opening 15a of the inner needle 12. Then, the user advances the catheter operating member 60 to advance the catheter 30 and the catheter hub 50 along the guide wire 70. At this time, since the basic inner peripheral surface 38 of the main lumen 34 forms a gap 39 with the inner needle 12, the sliding resistance between the inner needle 12 and the catheter 30 is low, and the catheter 30 can be smoothly moved relative to the inner needle 12.

[0059] Also, when the multi-structured needle 11 is inserted into the blood vessel to a certain extent, blood flows into the sub-lumen 41 from the second lateral opening 41a. As a result, the user can also well recognize that the sub-lumen 41 has secured the blood vessel.

[0060] In particular, when the tip 13 of the inner needle 12 moves to the proximal side of the basic inner peripheral surface 38 of the catheter 30, it becomes possible to easily retract the inner needle 12 relative to the catheter 30. The catheter 30 and the catheter hub 50 are left in the patient when they are sent out from the inner needle 12 and the housing 20. At the time of leaving in the body, infusion tubes are connected to the main hub 51 and the sub-hub 52 respectively. Thereby, the first drug is administered to the patient through the main space portion 51a and the main lumen 34, and the second drug is administered to the patient through the sub-space portion 52a, the flow path 53, and the sub-lumen 41.

[0061] As described above, in the catheter assembly 10 according to the first embodiment, the tip inner peripheral surface 36 on the tip side of the main lumen 34 is in close contact with the outer peripheral surface 16 of the inner needle 12, while a gap 39 is formed between the basic inner peripheral surface 38 on the proximal side of the tip inner peripheral surface 36 and the outer peripheral surface 16 of the inner needle 12. Therefore, at the formation position of the tip inner peripheral surface 36, even when the catheter 30 is compressed by living tissue during puncture, the catheter 30 is surely supported by the inner needle 12, and the deflection and shrinkage of the catheter 30 are suppressed. Thus, the tip of the catheter 30 is smoothly inserted into the body. Further, the gap 39 of the basic inner peripheral surface 38 suppresses the sliding resistance between the catheter 30 and the inner needle 12 and smooths the relative movement between the inner needle 12 and the catheter 30, improving the operability when the catheter 30 is inserted and left in the body. Furthermore, by arranging the hole 14, the user can well recognize the securing of the blood vessel. That is, the catheter assembly 10 enables the catheter 30 having a plurality of lumens 31 to be easily inserted, and can well perform various treatments such as administration of a plurality of types of drugs or blood sampling.

[0062] In addition, by forming the close contact portion 35 between the tip inner peripheral surface 36 and the inner needle 12, the tip side of the catheter 30 can be formed to have a thinner outer shape and is more reliably supported by the inner needle 12. Therefore, the insertion performance of the catheter 30 is significantly improved. And since the tip outer peripheral surface 42 of the catheter 30 is thinner than the basic outer peripheral surface 44, it can be easily inserted into the blood vessel from the tip. Also, since the tapered outer peripheral surface 43 is inserted following the tip outer peripheral surface 42 and then the basic outer peripheral surface 44 is inserted, it becomes possible to easily insert the thick basic outer peripheral surface 44.

[0063] Furthermore, in the catheter 30 having the soft tip 33, when inserted into the blood vessel, the soft tip 33 in contact with the blood vessel wall easily bends and curves along the blood vessel, and the occurrence of inflammation and damage to the blood vessel wall can be significantly reduced. In particular, since the tip inner peripheral surface 36 of the catheter 30 is supported by the inner needle 12, the occurrence of bending and shrinking of the soft tip 33 during the puncture before reaching the blood vessel can be effectively suppressed.

[0064] Moreover, in the catheter assembly 10, since the second lateral opening 41a of the sub-lumen 41 is located on the proximal side of the hole 14, the vicinity of the tip of the catheter 30 can be made thinner, and the insertability can be improved. Also, the blood flowing into the main lumen 34 can be quickly confirmed. The second lateral opening 41a of the sub-lumen 41 can suppress the immediate mixing of multiple types of drugs when administered to the blood vessel.

[0065] Further, the catheter assembly 10 has a bending suppression mechanism 90 (support member 91, holding portion of the catheter operating member 60) on the proximal side of the second lateral opening 41a. Thereby, the sliding resistance of the catheter 30 against the bending suppression mechanism 90 when the catheter 30 is advanced can be reduced. Further, the bending suppression mechanism 90 supports the catheter 30 on the proximal side of the tapered outer peripheral surface 43 and the continuous inclined surface 45 of the catheter 30. Thereby, the sliding resistance of the catheter 30 against the bending suppression mechanism 90 when the catheter 30 is advanced can be further reduced. Furthermore, it is possible to prevent the bending suppression mechanism 90 from hitting and damaging the second lateral opening 41a and the tapered outer peripheral surface 43, and by eliminating the step due to the second lateral opening 41a and the tapered outer peripheral surface 43 at the contact portion and the planned contact portion of the bending suppression mechanism 90, the bending of the inner needle 12 can be prevented with a certain force.

[0066] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made along the gist of the invention.

[0067] For example, in the above-described embodiment, an example in which the guide wire 70 is applied as an insertion assisting mechanism for assisting the insertion of the catheter 30 has been described. The insertion assisting mechanism is not limited to this, and various configurations may be adopted. For example, the insertion assisting mechanism may be configured such that the guide wire 70 can be used retroactively by exposing the proximal opening of the inner needle 12 from the inner needle hub 19. Further, the insertion assisting mechanism may be configured to be able to automatically draw the guide wire 70 exposed from the needle tip 13 into the hollow portion 12a. Alternatively, the catheter assembly 10 may be configured not to include the guide wire 70 and the guide wire operating member 80.

[0068] The insertion assisting mechanism may be configured to extend the guide wire 70 by two times or more with respect to the operation amount of the guide wire operating member 80. For example, as this type of structure, the guide wire 70 may be folded back in the housing 20, and the guide wire operating member 80 may be configured to advance and retreat the folded-back portion.

[0069] Further, the catheter assembly 10 may be provided with a safety mechanism (not shown) for preventing accidental puncture by the inner needle 12 when the inner needle 12 is removed. For example, the safety mechanism may be of a full-cover type that projects a tubular member (such as a telescopic type) from the inner needle hub 19 and houses the inner needle 12 therein when the inner needle 12 is removed. The safety mechanism may also be a covering member that partially covers the tip 13 of the inner needle 12 and its peripheral portion. 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 project a blunt needle having a tip that is difficult to pierce the skin from the needle tip 13 when the inner needle 12 is removed. If this blunt needle is configured to project from the needle tip 13 when the catheter 30 is advanced relative to the inner needle 12, it is also possible to prevent the inner needle 12 from piercing the catheter 30.

[0071] The catheter assembly 10 may be provided with a hemostasis mechanism (not shown) for preventing leakage of blood that has backflowed from the patient. For example, as the hemostasis mechanism, there is a hemostasis valve housed in the catheter hub 50. The hemostasis valve may also be of a cap type that is detachably attached to the proximal end of the catheter hub 50. Alternatively, the hemostasis mechanism may be an air vent member that is attached to a predetermined position (such as the proximal end) of the inner needle 12 and allows gas to pass through while not allowing liquid to pass through.

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

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

[0074] Furthermore, the catheter assembly 10 may apply a kink prevention mechanism (not shown) for preventing kinking of the catheter 30. For example, as the kink prevention mechanism, the tip portion of the catheter hub 50 may be configured to be deformable.

[0075] In the present embodiment, when the catheter hub 50 is detached from the inner needle 12, the catheter assembly 10 is configured by a separation mechanism (separate member) that separates the catheter hub 50 and the catheter operating member 60. However, the catheter assembly 10 may also be configured such that the catheter hub 50 and the catheter operating member 60 cannot be separated and can be left in place integrally (non-separation mechanism).

[0076] Furthermore, the inner peripheral surface 36 at the tip of the main lumen 34 may have a smaller diameter than the basic inner peripheral surface 38, and may be configured such that the distance from the outer peripheral surface 16 of the inner needle 12 is not zero (that is, the close contact portion 35 is not formed). Even with this configuration, during puncture, the inner needle 12 can favorably support the catheter 30 that is compressed inward.

[0077] In addition, other embodiments and other configuration examples of the present invention will be described with reference to FIGS. 3 to 18. In the following description, the same reference numerals are given to configurations having the same configuration or the same function, and detailed descriptions thereof are omitted. Also, in the following embodiments and configuration examples, it goes without saying that the mechanisms of the catheter assembly described above (insertion assist 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.

[0078] 〔Second Embodiment〕 As shown in FIG. 3, the catheter assembly 110 according to the second embodiment is different from the catheter assembly 10 according to the first embodiment in the structure of the multi-structured needle 111 (inner needle 112 and catheter 130). Specifically, the diameter of the sub-lumen 141 of the catheter 130 is formed larger than the diameter of the main lumen 134 through which the inner needle 112 is inserted and disposed, and the inner needle 112 is formed thinner corresponding to this main lumen 134.

[0079] Further, the inner needle 112 has a groove portion 113 that is notched by a predetermined length from the blade surface 15 toward the proximal end direction as an introduction path for realizing blood flashback. And the proximal end portion of the groove portion 113 communicates with a gap 139 formed by the outer peripheral surface 116 of the inner needle 112 and the inner peripheral surface (basic inner peripheral surface 138) of the main lumen 134.

[0080] On the other hand, the catheter 130 is composed of a main body portion 132 and a soft tip 133 (flexible portion) provided at the tip of the main body portion 132, similar to the first embodiment. However, the soft tip 133 is provided in a range from the tip of the main lumen 134 to slightly proximal side from the tip of the sub-lumen 141 (second tip opening 141a). And a stylet 170 is disposed in the sub-lumen 141.

[0081] The main lumen 134 of the catheter 130 is provided with a tip inner peripheral surface 136 having a diameter approximately the same as the outer diameter of the inner needle 112, and a basic inner peripheral surface 138 including a tapered inner peripheral surface 137 and having a diameter slightly larger than the outer diameter of the inner needle 112 (the diameter of the tip inner peripheral surface 136). The tip inner peripheral surface 136 forms a close contact portion 135 with the outer peripheral surface 116 of the inner needle 112 other than the groove portion 113 (with a zero interval). The basic inner peripheral surface 138 forms a gap 139 between the outer peripheral surface 116 of the inner needle 112.

[0082] On the other hand, the sub lumen 141 is located in the direction (upward direction) facing the blade surface 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 distal opening 141a provided on the proximal side of the first distal opening 134a of the main lumen 134.

[0083] The outer peripheral surface of the catheter 130 has a distal outer peripheral surface 142 at a position overlapping the distal inner peripheral surface 136 and a basic outer peripheral surface 144 with an outer diameter corresponding to the sub lumen 141 at a position overlapping the basic inner peripheral surface 138. The distal end of the basic outer peripheral surface 144 is connected to an inclined end surface 145 inclined with respect to the axis of the catheter 130. And a second distal opening 141a is formed in the inclined end surface 145, and the distal end of the inclined end surface 145 is connected to the proximal end of the tapered outer peripheral surface 143.

[0084] The stylet 170 disposed in the sub lumen 141 is a solid rod-shaped member formed with a larger diameter than the inner needle 112, and gives rigidity to the entire catheter 130 to enhance the insertion performance of the catheter 130 into the living body. The distal end of the stylet 170 is inclined to the same extent as the inclined end surface 145 of the catheter 130 and is disposed slightly on the proximal side of the second distal opening 141a in the state before puncture. Thereby, the distal end of the stylet 170 suppresses the clogging of the living tissue pieces in the sub lumen 141.

[0085] Also, the stylet 170 extends in the sub lumen 141 and is inserted from the sub lumen 141 into a sub space portion 152a of a sub hub 152 connected to a main hub 151 (catheter hub 150) through a communication passage 153. And 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 141. Therefore, at the stage where the catheter 130 is inserted into the blood vessel to a certain extent, the user can remove the stylet 170 from the catheter 130 by gripping and operating the stylet holding member 171.

[0086] An appropriate gap is provided between the outer surface of the stylet 170 and the inner surface of the sub-lumen 141, and the stylet 170 is slidable with respect to the catheter 130. Further, when blood flows into the gap between the stylet 170 and the sub-lumen 141, it is possible to know that the tip of the sub-lumen 141 has been inserted into the blood vessel. The cross-section of the stylet 170 may be a shape that is smaller than the sub-lumen 141 in a similar shape, but by providing a groove, flashback can be confirmed better. Also, the stylet 170 may be made of a hollow transparent material, and flashback can be confirmed well with this configuration as well.

[0087] As described above, even in the catheter assembly 110 according to the second embodiment, the same effects as those of the catheter assembly 10 according to the first embodiment can be obtained. That is, since the tip of the catheter 130 is supported by the outer peripheral surface 116 of the inner needle 112, bending and shrinking are suppressed, and thus it can be smoothly inserted into the body. In particular, when the inner needle 112 is formed thin, the patient's wound can be made small during puncture of the inner needle 112, and hemostasis in case of accidental puncture becomes easy.

[0088] Also, the second tip opening 141a of the sub-lumen 141 facing the tip direction of the catheter 130 is suppressed from being blocked by the blood vessel wall in the indwelling state in the blood vessel. Therefore, blood can be satisfactorily aspirated from the second tip opening 141a of the sub-lumen 141. Further, in the catheter assembly 110, since the stylet 170 is detachably arranged in the sub-lumen 141, the rigidity and straightness of the catheter 130 can be improved by the stylet 170.

[0089] 〔Third Embodiment〕 As shown in FIG. 4, in the catheter assembly 210 according to the third embodiment, the structures of the multi-structure needle 211 (catheter 230) and the catheter hub 250 are different from those of the catheter assemblies 10 and 110 according to the first and second embodiments. Specifically, in a side cross-sectional view of the catheter 230, a main lumen 234 through which the inner needle 12 is inserted and disposed is provided on the upper side of the sub-lumen 241. Also, in the third embodiment, the diameter of the main lumen 234 (basic inner peripheral surface 238) is formed larger than the diameter of the sub-lumen 241. Note that the main body and the soft tip (flexible portion) constituting the catheter 230 have the same configuration as in the second embodiment, and the soft tip is provided in the range from the tip of the catheter 230 to the basic outer peripheral surface 244.

[0090] Similar to the main lumen 34 of the first embodiment, the main lumen 234 of the catheter 230 has a basic inner peripheral surface 238 including a tip inner peripheral surface 236 and a tapered inner peripheral surface 237. The outer peripheral surface of the catheter 230 has a tip outer peripheral surface 242, a tapered outer peripheral surface 243, and a basic outer peripheral surface 244, and the sub-lumen 241 extends from the basic outer peripheral surface 244 to the formation ranges of the tapered outer peripheral surface 243 and the tip outer peripheral surface 242. Also, the sub-lumen 241 is provided downward on the side opposite to the direction in which the blade surface 15 of the inner needle 12 faces. The second tip opening 241a of the sub-lumen 241 is disposed at substantially the same axial position as the first tip opening 234a of the main lumen 234.

[0091] Therefore, the outer shape of the catheter 230 is thick as a whole, but the lower side of the first tip opening 234a at the tip (the side where the sub-lumen 241 is formed) is formed as an inclined end surface 245 that continues to the tip tapered portion 40. The inclined end surface 245 is inclined at an appropriate angle below the blade surface 15 of the inner needle 12, thereby smoothing the insertion of the tip (tip outer peripheral surface 242) of the catheter 230. The second tip opening 241a is provided in this inclined end surface 245. Also, although not shown, by making the inner diameter of the tip portion of the sub-lumen 241 smaller, the insertion of the tip of the catheter 230 can be made smoother.

[0092] On one hand, the main hub 251 of the catheter hub 250 forms a first space portion 251a so as to communicate with the main lumen 234 at the upper part of the catheter 230. Further, the main hub 251 has a detour communication passage 253 that communicates the sub-lumen 241 provided on the lower side of the catheter 230 and the second space portion 252a of the sub-hub 252 connected to the upper side of the main hub 251. The detour communication passage 253 is provided so as to wind around within the peripheral wall surrounding the first space portion 251a of the main hub 251 and communicates with the second space portion 252a.

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

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

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

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

[0097] The sub-lumen 341 is provided at the location where the basic outer peripheral surface 344 is formed. The diameter of the sub-lumen 341 is set to an appropriate dimension according to the outer diameter of the guide wire 70. At the tip of this basic outer peripheral surface 344, an inclined end surface 345 connected to the tapered outer peripheral surface 343 is formed, 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, and the sub-hub 352 is connected to the side of the main hub 351. This main hub 351 has a first space portion 350a communicating with the main lumen 334, and also has a communication passage 353 communicating with the second space portion 352a of the sub-hub 352. That is, the guide wire 70 is slidably inserted into the sub-lumen 341 via the second space portion 352a and the communication passage 353.

[0099] As described above, also in the catheter assembly 310 according to the fourth embodiment, the same effects as those of the catheter assembly 10 can be obtained. In particular, the catheter assembly 310 can enhance the insertion performance of the catheter 330 by slidably disposing the guide wire 70 in the sub-lumen 341 so that the guide wire 70 reinforces the catheter 330 when the multi-structured needle 311 is inserted. And the guide wire 70 can guide the insertion of the catheter 330 well by being inserted into the blood vessel from the sub-lumen 341.

[0100] The above-described catheter assemblies 10, 110, 210, 310, and the catheter assemblies 510, 610, 710, 810, 910, 1010 to be described later are not particularly limited with respect to the arrangement relationship between the main lumen and the sub-lumen. That is, all of the arrangement relationships between the main lumen α and the sub-lumen β in the catheters 430A to 430F according to the first to sixth configuration examples shown in FIGS. 6A to 6F can be adopted.

[0101] Specifically, the catheter 430A shown in FIG. 6A has the arrangement relationship between the main lumen 34 and the sub-lumen 41 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 disposed above the main lumen α. Note that the cross-sectional shape perpendicular to the axial direction of the catheter 430A may be a shape other than the elliptical shape shown in FIG. 6A, and may be formed, for example, in a circular shape. The same applies to the other catheters 430B to 430F.

[0102] Note that the arrangement positions of the main lumen α and the sub-lumen β are described with reference to the cutting edge surface 15 of the inner needle 12 disposed in the main lumen α. That is, as described above, the cutting edge surface 15 of the inner needle 12 is positioned so as to face upward when the body surface of the patient is on the lower side during puncture. Therefore, the fact that the sub-lumen β is above the main lumen α means that the sub-lumen β is located in the upward direction facing the cutting edge surface 15 in the circumferential direction of the catheter 430A.

[0103] In the catheter 430A shown in FIG. 6A, flashback can be confirmed using the sub-lumen β. Further, in this catheter 430A, when inserted into a blood vessel, it is possible to suppress the tip (inclined end surface) of the sub-lumen β from being caught by the blood vessel wall on the side opposite to the insertion site in the blood vessel and being obstructed from moving. Therefore, it is also possible to suppress the occurrence of inflammation and damage to the blood vessel wall. Furthermore, it is possible to suppress the second tip opening of the sub-lumen β from being closed by the blood vessel wall and the flow rate from decreasing.

[0104] The catheter 430B shown in FIG. 6B has the arrangement relationship between the main lumen 334 and the sub-lumen 341 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 arranged in the lateral direction of the main lumen α (the direction orthogonal to the direction in which the blade surface 15 faces) in the circumferential direction of the catheter 430B. By configuring in this way, the same effect as the arrangement relationship shown in FIG. 6A can be obtained, and moreover, the flashback of the main lumen α can be confirmed well.

[0105] The catheter 430C shown in FIG. 6C has the arrangement relationship between the main lumen 234 and the sub-lumen 241 described in the third 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 arranged below the main lumen α (the opposite direction to the direction in which the blade surface 15 faces) in the circumferential direction of the catheter 430C. By configuring in this way, it becomes possible to confirm the flashback of the main lumen α better.

[0106] The catheter 430D shown in FIG. 6D has the arrangement relationship between the main lumen 134 and the sub-lumen 141 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 arranged above the main lumen α in the circumferential direction of the catheter 430D. Also, the catheter (430E) shown in FIG. 6E has the diameter of the main lumen α smaller than the diameter of the sub-lumen β, and the sub-lumen β is arranged in the lateral direction of the main lumen α. Further, the catheter 430F shown in FIG. 6F has the diameter of the main lumen α smaller than the diameter of the sub-lumen β, and the sub-lumen β is arranged below the main lumen α. Even with the catheters 430D to 430F in FIGS. 6D to 6F, sufficient effects can be obtained in the same manner as the above catheters 430A to 430C.

[0107] In FIGS. 6A to 6F, the cross-sectional shapes of the main lumen α and the sub-lumen β are formed into circular shapes, but the cross-sectional shapes of these lumens are not particularly limited. As an example, the lumen with a smaller flow path cross-sectional area (for example, the sub-lumen) may be formed in a shape (C-shaped, U-shaped, elliptical, polygonal, etc.) that surrounds a part of the outer side in the circumferential direction of the main lumen α. Thereby, the overall outer diameter of the catheters 430A to 430F can be made smaller.

[0108] Also, like the catheters 430G and 430H according to the seventh and eighth configuration examples shown in FIGS. 7A and 7B, the catheter assembly may be configured to have three or more lumens 431. Specifically, in the catheter 430G shown in FIG. 7A, the first and second sub-lumens β1 and β2 are arranged side by side in the width direction (the direction orthogonal to the direction in which the blade surface 15 faces) above the main lumen α. In the catheter 430H shown in FIG. 7B, the main lumen α is arranged at the axial center of the catheter 430H, the first sub-lumen β1 is arranged above it (in the direction in which the blade surface 15 faces), and the second sub-lumen β2 is arranged below it (in the direction opposite to the direction in which the blade surface 15 faces).

[0109] Also, the catheter assembly may be configured such that flashback can be confirmed in the order of the main lumen α and the sub-lumen β by appropriately setting the flashback flow path lengths and lengths. Thereby, since the flashback of the lumen with an opening at the tip can be confirmed first, it is less likely to cause discomfort to the user. Alternatively, the catheter assembly may be configured such that flashback can be confirmed in the order of the sub-lumen β and the main lumen α by appropriately setting the flashback flow path lengths and lengths. Thereby, for a user who considers that if the sub-lumen β has entered the blood vessel, the main lumen α has naturally entered the blood vessel, it becomes easy to use.

[0110] 〔Fifth Embodiment〕 As shown in FIGS. 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 such that the multi-structure needle 511 can be supported by the bending suppression mechanism 590 of the inner needle hub 519. Specifically, 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 extending portions 520 branched into two from the base portion 521 at the center in the width direction. This inner needle hub 519 holds the catheter hub 550 in a state where it is exposed above and below. Note that the inner needle hub 519 may be covered on the lower side or the upper side of the pair of extending portions 520 to form a housing shape. When covering the upper side, a slit may be provided in the upper cover in order to expose the tab from the housing so that it can be operated.

[0112] The bending suppression mechanism 590 has a pair of support arms 591 that can be opened and closed, and a restraint portion 592 that can restrain the pair of support arms 591 in a closed state and can release the restraint. The pair of support arms 591 are pivotally supported by a pair of support pins 593 and can be opened and closed in the left-right direction with respect to the pair of extending portions 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. The pair of support grooves 591a constitute a support hole 594 for supporting the multi-structure 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 when the catheter 530 advances relative to the inner needle 12. In the state before puncture, a slight gap is formed between the outer surface of the catheter 530 and the inner surface of the sliding contact support portion 595. Further, the sliding contact support portion 595 surrounds the entire circumference of the catheter 530 so as to be able to contact it.

[0114] And each support arm 591 is provided with a bent engagement groove 591b when viewed from the front in the closed state. On the other hand, the restraint portion 592 has a head 592a corresponding to the shape connecting the pair of engagement grooves 591b, and closes each support arm 591 by engaging with each other in the state before puncture. Then, as the catheter hub 550 is pushed by the catheter hub 550 as it advances, the restraint on the pair of support arms 591 is released.

[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 inside the catheter 530. Also, at the distal end side 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 formed longer than the first and second sub-lumens 540 and 545, and communicates with the first distal opening 534a (main opening) at the foremost end of the catheter 530 and the first proximal opening (not shown) at the most proximal end of the catheter 530. The catheter 530 also has a first tapered outer peripheral surface 535 whose outer diameter gradually decreases toward the first distal opening 534a. A first lateral opening 534b (main opening) communicating with the main lumen 534 is provided at an intermediate position of the catheter 530 (between the first tapered outer peripheral surface 535 and the second distal opening 540a described later).

[0117] The first sub lumen 540 is formed shorter than the main lumen 534 and longer than the second sub lumen 545. Here, the tip side of the catheter 530 has an increased thickness (outer diameter) due to the overlap of the first sub lumen 540 with the main lumen 534, and at the foremost end of the first sub lumen 540, it has a second tapered outer peripheral surface 541 (taper portion) that constitutes a stepped portion. The first sub lumen 540 communicates with a second tip opening 540a (sub opening) formed on the second tapered outer peripheral surface 541. Also, the first sub lumen 540 communicates with a second base end opening (not shown) at the most proximal end of the catheter 530 (coaxial with the first base end opening). Between the second tapered outer peripheral surface 541 of the catheter 530 and a third tip opening 545a described later, a second lateral opening 540b (sub opening) communicating with the first sub lumen 540 is provided.

[0118] The second sub lumen 545 is formed to be the shortest. The tip side of the catheter 530 has an even further increased thickness (outer diameter) due to the overlap of the second sub lumen 545 with the main lumen 534 and the first sub lumen 540, and at the foremost end of the second sub lumen 545, it has a third tapered outer peripheral surface 546 (taper portion) that constitutes a stepped portion. The second sub lumen 545 communicates with a third tip opening 545a (sub opening) formed on the third tapered outer peripheral surface 546. Also, the second sub lumen 545 communicates with a third base end opening (not shown) at the most proximal end of the catheter 530 (coaxial with the first base end opening). On the base end side of the third tapered outer peripheral surface 546 of the catheter 530, a third lateral opening 545b (sub opening) communicating with the second sub lumen 545 is provided.

[0119] Also, the distance between the first lateral opening 534b and the second tip opening 540a is set at a position separated by 17 mm or more. Similarly, the distance between the second lateral opening 540b and the third tip opening 545a is also set at a position separated by 17 mm or more.

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

[0121] In the initial state of the catheter assembly 510, the sliding contact support portion 595 may be provided on the distal side of the third distal opening 545a of the second sub-lumen 545 (see the dashed-dotted line in FIG. 9). Specifically, the sliding contact support portion 595 can support the proximal side of the second distal opening 540a (the most distal sub-opening among the two sub-lumens 540 and 545). Even in the configuration where the bending suppression mechanism 590 supports the distal side of the third distal opening 545a, damage to the second distal opening 540a of the first sub-lumen 540 and the second tapered outer peripheral surface 541 can be suppressed, and moreover, the bending 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 of the main lumen 534. Further, the catheter hub 550 has a first sub-port 552 that functions as a port of the first sub-lumen 540 and a second sub-port 553 that functions as a port of the second sub-lumen 545. At the tip of the main hub 551, a hub operation portion 551a for the user to place a finger is provided, and this hub operation portion 551a has a surface for pushing out the above-described restraint portion 592. The hub operation portion 551a may be configured to be removable from the main hub 551.

[0123] Each of the first and second sub-ports 552 and 553 has a connecting portion of the main hub 551, a flexible soft tube 554 (soft portion) fixed to this connecting portion, and a sub-hub 555 connected to the proximal end of the soft tube 554. The sub-hub 555 is configured as a connector to which a medical device is connected. Inside the first sub-port 552 (main hub 551, soft tube 554, sub-hub 555), a first communication passage 552a communicating with the first sub-lumen 540 is formed. Similarly, inside the second sub-port 553, a second communication passage 553a communicating with the second sub-lumen 545 is formed.

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

[0125] After the multi-structured needle 511 is punctured, as shown in FIG. 10, the user advances the catheter hub 550 to advance the catheter 530 relative to the inner needle 12. At this time, since the bending suppression mechanism 590 supports the proximal end side of the third lateral opening 545b of the second sub-lumen 545, the catheter 530 can be smoothly advanced without being caught. Further, when the catheter hub 550 advances, by pushing out the restraining portion 592, the pair of support arms 591 open in the left-right direction. Thereby, the support of the multi-structured needle 511 by the bending suppression mechanism 590 can be easily released, and the catheter 530 and the catheter hub 550 can be detached from the inner needle 12.

[0126] Thus, even with the catheter assembly 510, the same effects as those of the catheter assembly 10 can be obtained. For example, when the catheter 530 is being inserted, by connecting a medical device to the main hub 551 and the sub-hub 555, it is possible to easily supply a drug solution or blood to the main lumen 534, the first and second sub-lumens 540, 545. Further, after the catheter 530 is inserted, due to the main lumen 534, the first and second sub-lumens 540, 545 that extend parallel to each other, different types of drug solutions can flow well and be administered into the blood vessel.

[0127] Also, even in the configuration where the catheter assembly 510 has a plurality of lumens such as the main lumen 534, the first and second sub-lumens 540, 545, the deflection suppression mechanism 590 supports the proximal end side of the second tip opening 540a (the most distal sub-opening). Thereby, while suppressing the deflection of the inner needle 12, it is possible to reduce damage to the catheter 530.

[0128] That is, in order to suppress the deflection of the inner needle 12, it is preferable that the deflection suppression mechanism 590 supports a location close to the needle tip 13 of the inner needle 12. However, if the deflection suppression mechanism 590 is configured to support the distal end side of the plurality of sub-openings, there is an increased possibility of the catheter 530 being damaged by contacting the sub-openings during the movement of the catheter 530. In contrast, the catheter assembly 510 according to the present embodiment can achieve both prevention of the deflection of the inner needle 12 and the mobility of the catheter by appropriately arranging the formation position of the sub-opening and the support position of the deflection suppression mechanism 590.

[0129] Moreover, the catheter assembly 510 can more reliably prevent damage to the catheter 530 by the deflection suppression mechanism 590 supporting the proximal end side of the third lateral opening 545b (the most proximal sub-opening). Further, since the deflection suppression mechanism 590 supports the proximal end side of the third tapered outer peripheral surface 546, it is possible to prevent the deflection suppression mechanism 590 from being caught by the third tapered outer peripheral surface 546. Therefore, it is possible to further enhance the mobility of the catheter 530.

[0130] In addition, since the catheter assembly 510 includes sub-openings that include the second and third lateral openings 540b and 545b, the chemical solution and blood that have flowed through the first and second sub-lumen 540 and 545 can be discharged well into the blood vessel. Moreover, since the bending suppression mechanism 590 is located on the proximal side of the third lateral opening 545b, damage near the third lateral opening 545b can also be suppressed.

[0131] Here, since the distance between the first tip opening 534a and the second tip opening 540a of the catheter assembly 510 is separated by 17 mm or more, the chemical solution flowing out from the first tip opening 534a and the chemical solution flowing out from the second tip opening 540a can be mixed within the blood vessel. That is, drugs with incompatible formulations can be well administered with a single catheter 530.

[0132] And, since the bending suppression mechanism 590 can support a position 5 mm or less on the proximal side of the third lateral opening 545b of the catheter assembly 510, the distance from the needle tip 13 of the inner needle 12 to the bending suppression mechanism 590 is shortened. Therefore, the bending of the inner needle 12 can be more strongly suppressed.

[0133] Furthermore, the catheter assembly 510 can reliably suppress the deviation (such as deviation from the bending suppression mechanism 590 and bending of the inner needle 12) of the inner needle 12 in the vertical and horizontal directions by the bending suppression mechanism 590 that surrounds the entire circumferential direction of the catheter 530.

[0134] Moreover, since the catheter assembly 510 includes first and second sub-ports 552 and 553 that include a sub-hub 555 and a flexible tube 554, the sub-hub 555 can be arranged in a free position and posture. Therefore, the user can perform the puncture of the multi-structured needle 511 and the insertion of the catheter 530 well.

[0135] Note that the main opening communicating with the main lumen 534 and the sub-openings communicating with the first and second sub-lumens 540 and 545 are not limited to the above configuration (the first tip opening 534a, the first lateral opening 534b, the second tip opening 540a, the second lateral opening 540b, the third tip opening 545a, the third lateral opening 545b), and various configurations can be adopted. For example, the main opening may be constituted by only the first tip opening 534a.

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

[0137] For example, when the sub-openings of the first and second sub-lumens 540 and 545 are respectively constituted by only the second lateral opening 540b and the third lateral opening 545b, the second tapered outer peripheral surface 541 and the third tapered outer peripheral surface 546 constitute a stepped portion of the closed catheter 530. In this configuration, the bending suppression mechanism 590 may be configured to support a position near the proximal end of the second tapered outer peripheral surface 541 or the third tapered outer peripheral surface 546. Even in this configuration, the catching of the bending suppression mechanism 590 with respect to the second tapered outer peripheral surface 541 or the third tapered outer peripheral surface 546 can be favorably avoided.

[0138] Also, the bending suppression mechanism 590 may adopt 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 tapers toward the distal end direction. Thereby, even in a configuration having a tapered portion (for example, the third tapered outer peripheral surface 546) like the catheter 530 and having the sliding contact support portion 595 on the distal end side thereof, the catching of the third tapered outer peripheral surface 546 with respect to the sliding contact support portion 595 can be reduced.

[0139] Note that the configuration of the sub-lumen (including the tapered portion) in the catheter 530 as described above and the configuration of the bending suppression mechanism 590 are of course applicable also in the embodiments described later.

[0140] 〔Sixth Embodiment〕 As shown in FIGS. 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, and the two lumens are partitioned by a partition wall 640. This partition wall 640 is configured to be deformable according to the pressures in the main lumen 634 and the sub-lumen 641.

[0141] Specifically, the main lumen 634 of the catheter 630 communicates with a distal opening 634a formed at the distal end of the catheter 630 and also communicates with a proximal opening (not shown) formed at the proximal end of the catheter 630. In this main lumen 634, the inner needle 12 is detachably arranged in the pre-puncture state.

[0142] The sub-lumen 641 of the catheter 630 is located below the main lumen 634 and extends in parallel with this main lumen 634. The sub-lumen 641 communicates with a lateral opening 641a formed at an intermediate position on the lower side of the catheter 630.

[0143] The partition wall 640 extends along the axial direction of the catheter 630 and separates the main lumen 634 and the sub-lumen 641. This partition wall 640 is connected at a position where the phase is shifted by approximately 180° with respect to the tubular wall portion 639 of the catheter 630 in a cross-sectional view perpendicular to the axial direction of the catheter 630, but is formed longer (with a margin) than the diameter of the tubular wall portion 639. Moreover, the partition wall 640 is configured to be more flexible than the tubular wall portion 639 and can be deformed by receiving a positive pressure equal to or greater than a predetermined value from the chemical solution.

[0144] For example, as shown in FIG. 12A, the partition wall 640 can spread downward with the inner needle 12 inserted into the main lumen 634, and the inner needle 12 can be well arranged. Also, for example, as shown in FIG. 12B, when a large amount of chemical solution is made to flow in the main lumen 634, the partition wall 640 increases the cross-sectional area of the flow path of the main lumen 634. On the other hand, when a large amount of chemical solution is made to flow in the sub-lumen 641, the cross-sectional area of the flow path of the sub-lumen 641 is increased as shown by the two-dot chain line in the illustrated example.

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

[0146] The catheter operation member 660 is formed in a long plate shape corresponding to the long inner needle 12 and the catheter 630 (multi-structured needle 611), and is rotatably fixed to the catheter hub 650. The catheter operation member 660 has a pressing portion 661 that can press a portion between the proximal end and the distal end of the catheter 630. The pressing portion 661 forms part of the deflection suppressing mechanism 690. Also, the catheter operation member 660 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, houses the proximal end side of the multi-structured needle 611, and 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 the left and right sides of the bottom plate, and is open at the upper and distal ends. The distal end portion of the bottom plate 621 is a sliding contact support portion 691 that rubs against the catheter 630 when the catheter 630 advances with respect to the inner needle 12.

[0148] ]> The folding contact support portion 691 constitutes a bending suppression mechanism 690 together with the pressing portion 661. When the catheter 630 advances relative to the inner needle 12, the bending suppression mechanism 690 enables the support of the inner needle 12 and the catheter 630 (the multi-structure needle 611) between the folding contact support portion 691 and the pressing portion 661. And the folding contact support portion 691 is arranged at a position capable of supporting the proximal end side of the catheter 630 relative to the lateral opening 641a in the state before puncture.

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

[0150] Then, by advancing the catheter operating member 660 relative to the inner needle 12 and the housing 620, the tip of the catheter 630 is inserted to the target position within the blood vessel. When the catheter 630 moves in the tip direction relative to the inner needle 12, the catheter 630 slides relative to the folding contact support portion 691. Then, while holding the catheter operating member 660 with the other hand, the housing 620 is pulled in the proximal direction. Thereby, the inner needle 12 is detached from the catheter hub 650, and by removing the catheter operating member 660, the catheter 630 and the catheter hub 650 can be left in the patient.

[0151] The above catheter assembly 610 can obtain the same effects as those of the other embodiments described above. That is, the bending suppression mechanism 690 supports the vicinity of the proximal end side (for example, the proximal end position within 5 mm) of the lateral opening 641a of the sub-lumen 641 (the most distal sub-opening). Thereby, while suppressing the bending of the inner needle 12, the damage to the catheter 630 can be reduced.

[0152] In particular, this catheter assembly 610 is partitioned into a main lumen 634 and a sub-lumen 641 by a partition wall 640 that is deformable according to pressure. In the state before puncture, the main lumen 634 can be enlarged, and the relative movement between the inner needle 12 and the catheter 630 can be simplified. The partition wall 640 is appropriately deformed by the flow pressure when administering a drug or blood. For example, even when a relatively large amount of the drug solution in the sub-lumen 641 flows relative to the drug solution in the main lumen 634, it is possible to easily secure the cross-sectional area of the flow path.

[0153] 〔Seventh Embodiment〕 As shown in FIG. 13, the catheter 730 of the catheter assembly 710 according to the seventh embodiment is configured in the same manner as the catheter 30 of the first embodiment, and has a main lumen 734 and a sub-lumen 741 inside. A bending suppression mechanism 790 for suppressing the bending of the inner needle 12 and the catheter 730 (multi-structure needle 711) is provided on the tip side of the catheter assembly 710.

[0154] Specifically, the inner needle hub 719 has an upper housing 720 and a lower housing 721, and in the state before puncture, the upper housing 720 and the lower housing 721 overlap vertically. The tip portions 720a and 721a of the upper housing 720 and the lower housing 721 are held so as to be sandwiched by a guide wire operating member 780 described later, thereby restricting the vertical expansion. Longitudinal slits 722 are formed between the upper housing 720 and the lower housing 721 on the left and right side portions of the inner needle hub 719. The upper housing 720 has a pair of side gripping portions 720b that are inclined obliquely with respect to the slit 722, and the user grips the pair of side gripping portions 720b when puncturing the multi-structure needle 711.

[0155] The deflection suppression mechanism 790 is composed of the tip 720a of the upper housing 720 and the tip 721a of the lower housing 721. On the opposing surfaces of the tips 720a and 721a of the upper housing 720 and the lower housing 721, holding grooves 723 with a semi-circular cross-section are formed. A hole-shaped sliding support portion 791 that rubs against the catheter 730 when the catheter 730 advances relative to the inner needle 12 is formed by the wall portions constituting the holding groove 723. In the initial state of the catheter assembly 710, a slight gap is formed between the outer surface of the catheter 730 and the sliding support portion 791.

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

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

[0158] A catheter operation member 760 is attached to the proximal side of the sub-port 752 in the catheter hub 750. The catheter operation member 760 has a central base portion 761 detachably connected to the proximal end portion of the catheter hub 750 and a pair of finger-hooking portions 762 extending from the central base portion 761 to both sides in the left-right direction. In the state before puncture, the central base portion 761 is housed in the inner needle hub 719, and the finger-hooking portions 762 protrude outward in the left-right direction through the slit 722.

[0159] And in the pre-puncture state, the catheter assembly 710 has a bending suppression mechanism 790 (sliding contact support portion 791) located on the proximal side of the lateral opening 741a of the sub-lumen 741. The sliding contact support portion 791 is provided on the proximal side of the most distal lateral opening 741a.

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

[0161] In use, the catheter assembly 710 configured as described above is punctured into the patient by the user with the multi-structured needle 711 (inner needle 12, catheter 730). At this time, the bending suppression mechanism 790 supports the multi-structured needle 711 and suppresses bending. Next, the user operates the guide wire operating member 780 in the distal direction to project the guide wire 770 from the tip of the inner needle 12 and insert it into the blood vessel. As the guide wire operating member 780 moves in the distal direction, when the pair of restricting arms 781 move to the distal side of the tip portion of the inner needle hub 719, the vertical expansion restriction between the tip portion of the upper housing 720 and the tip portion of the lower housing 721 is released.

[0162] Next, the user operates the catheter operating member 760 in the distal direction to advance the catheter 730 and the catheter hub 750. During this movement, the upper housing 720 opens with respect to the lower housing 721 when the pair of lateral gripping portions 720b contact the rigid tube 754 of the catheter hub 750 and are pushed upward. As a result, the movement of the catheter operating member 760 in the distal direction is permitted, and the catheter 730 can be inserted well into the blood vessel.

[0163] Then, the user pulls the inner needle hub 719 in the proximal direction with respect to the catheter 730 and the catheter hub 750 to remove the inner needle 12 from the catheter 730. As a result, the catheter 730 and the catheter hub 750 are left on the patient side.

[0164] As described above, the catheter assembly 710 according to the seventh embodiment can also obtain the same effects as those of the above-described embodiments. That is, the bending suppression mechanism 790 supports the proximal side of the lateral opening 741a (the most distal sub-opening) of the sub-lumen 741. Thereby, while suppressing the bending of the inner needle 12, the damage to the catheter 730 can be reduced.

[0165] Further, in the catheter assembly 710, since the inner needle hub 719 has the slit 722, even in the configuration in which the sub-port 752 is provided in the catheter hub 750, the sub-port 752 can easily move along the slit 722. That is, the movement of the catheter 730 with respect to the inner needle 12 can be performed smoothly. In particular, in the catheter assembly 710, since the sub-port 752 protrudes in the lateral direction of the inner needle hub 719, it is possible to suppress the sub-port 752 from getting in the way during the puncture of the multi-structured needle 711 or the like, and to facilitate the work of the user. Furthermore, the sub-port 752 of the catheter assembly 710 can smoothly move the catheter hub 750 by disposing the rigid tube 754 at the position where it contacts the inner needle hub 719.

[0166] 〔Eighth Embodiment〕 As shown in FIGS. 14 and 15, the catheter assembly 810 according to the eighth embodiment has a catheter hub 850 extending from the proximal side of the catheter operation member 860, and a sub-port 852 is provided at the extending portion of the catheter hub 850. The catheter 830 has a main lumen 834 and a sub-lumen 841, as in the first embodiment, and constitutes a multi-structure needle 811 by accommodating the inner needle 12 in the pre-puncture state. The catheter 830 has a tip opening 834a communicating with the main lumen 834 at the tip, and a lateral opening 841a communicating with the sub-lumen 841 at a position separated from the tip opening 834a by a predetermined distance (for example, 17 mm or more).

[0167] The sub-port 852 of the catheter hub 850 includes a sub-hub 853 and a flexible tube 855 connecting between the main hub 851 and the sub-hub 853.

[0168] The inner needle hub 819 of the catheter assembly 810 has an upper housing 820 and a lower housing 821 that overlap vertically, and the tip portions 820a and 821a thereof are 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. The tip portion 821a of the lower housing 821 has a right tip portion 823R and a left tip portion 823L, and is configured to be expandable 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 the left and right sides of the right tip portion 823R and the left tip portion 823L by a pair of plate portions (not shown), and the upper sides of the pair of plate portions (not shown) are connected by a bridging portion.

[0170] The catheter assembly 810 constitutes a deflection suppression mechanism 890 with a right distal end portion 823R and a left distal end portion 823L. Holding grooves 825 are respectively formed in the right distal end portion 823R and the left distal end portion 823L. Wall portions constituting the two holding grooves 825 form a hole-shaped sliding contact support portion 891 that rubs against the catheter 830 when the catheter 830 advances relative to the inner needle 12. In the initial state of the catheter assembly 810, a slight gap is formed between the outer surface of the catheter 830 and the inner surface of the sliding contact support portion 891. Further, the sliding contact support portion 891 (deflection suppression mechanism 890) supports the proximal side of the lateral opening 841a (the most distal sub-opening) of the sub-lumen 841.

[0171] Furthermore, the upper housing 820 is provided with a guide passage 826 extending in the longitudinal direction. The sub-port 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 operation member 860 has a central base portion 861 detachably connected to the proximal end portion of the catheter hub 850, and a pair of finger hooks 862 extending from the central base portion 861 to both sides in the left and right directions. The pair of finger hooks 862 incline upward toward the outer side in the left and right directions. A plurality of protrusions 862a for anti-slip are provided on the lower surface of the finger hook 862.

[0173] The catheter assembly 810 also has a guide wire 870 and a guide wire operation member 880. A plurality of ribs 881 for finger hanging are provided on the upper surface of the guide wire operation member 880. The guide wire operation member 880 is connected to the proximal end portion of the guide wire 870 through an intermediate connection portion (not shown) disposed in the inner needle hub 819. The guide wire operation member 880 is provided so as to be displaceable in the front-rear direction with respect to the upper housing 820.

[0174] The catheter assembly 810 configured as described above, in use, has the multi-structured needle 811 (inner needle 12, catheter 830) punctured into a patient by the user. At this time, the deflection suppression mechanism 890 supports the multi-structured needle 811 to suppress deflection. Next, the user operates the guide wire operating member 880 in the tip direction to project the guide wire 870 from the tip of the inner needle 12 and insert it into the blood vessel.

[0175] Then, the user operates the catheter operating member 860 in the tip direction to advance the catheter 830 and the catheter hub 850. During this movement, the upper housing 820 is pushed upward by the catheter operating member 860 and opens with respect to the lower housing 821. Due to the separation of the upper housing 820, the right tip portion 823R and the left tip portion 823L of the lower housing 821 can be further separated from each other in the left-right direction. Thereby, the movement of the catheter operating member 860 in the tip direction is allowed, and the catheter 830 can be inserted well into the blood vessel.

[0176] Then, the user pulls the inner needle hub 819 in the proximal direction with respect to the catheter 830 and the catheter hub 850 to remove the inner needle 12 from the catheter 830. Thereby, the catheter 830 and the catheter hub 850 are left on the patient side.

[0177] As described above, also in the catheter assembly 810 according to the eighth embodiment, the same effects as those of the above-described embodiments can be obtained. That is, the deflection suppression mechanism 890 supports the proximal side of the lateral opening 841a (the foremost sub-opening) of the sub-lumen 841. Thereby, while suppressing the deflection of the inner needle 12, damage to the catheter 830 can be reduced.

[0178] Furthermore, in this catheter assembly 810, the sub-port 852 protrudes upward from the upper housing 820. Thereby, the gripping of the inner needle hub 819 is simplified, and the operability by the user can be improved.

[0179] 〔Ninth Embodiment〕 As shown in FIG. 16, the catheter assembly 910 according to the ninth embodiment is basically configured in the same manner 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 suppressing mechanism 990.

[0180] The catheter 930 has a main lumen 934 and a sub-lumen 941, and forms a multi-structured needle 911 by accommodating the inner needle 12 in the pre-puncture state. The catheter 930 has a tip opening 934a communicating with the main lumen 934 at the tip, and a lateral opening 941a communicating with the sub-lumen 941 at a position separated from the tip opening 934a by a predetermined interval (for example, 17 mm or more).

[0181] The catheter hub 950 is disposed on the proximal side of the catheter operating member 960, and has a main hub 951 and a sub-port 952 provided at an extended portion of the main hub 951. The sub-port 952 includes a sub-hub 953 and a flexible tube 955 connecting between the main hub 951 and the sub-hub 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, and the tip portions 920a and 921a of each other are 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 the present embodiment, the slit 922 extends to the proximal side of the initial position of the catheter operating member 960 in the pre-puncture state.

[0183] The lower housing 921 has a right tip portion and a left tip portion 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 this right tip portion and left tip portion. Similar to the eighth embodiment, the bending suppression mechanism 990 constitutes a sliding support portion 991 by holding grooves (not shown) of the right tip portion and the left tip portion. Further, the bending suppression mechanism 990 is located on the proximal side with respect to 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. A protrusion 961 for finger hanging is provided on the upper surface of the catheter operation member 960. 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. A plurality of ribs 981 for finger hanging are provided on the upper surface of the guide wire operation member 980.

[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] Then, the user operates the catheter operating member 960 in the distal direction to advance the catheter 930 and the catheter hub 950. During this movement, the upper housing 920 is pushed upward by the catheter operating member 960 and opens with respect to the lower housing 921. Due to the detachment of the upper housing 920, the right and left tip portions of the lower housing 921 can be further separated from each other in the left - right direction. Thereby, the movement of the catheter operating member 960 in the distal direction is allowed, and the catheter 930 can be favorably inserted into the blood vessel.

[0188] Then, the user pulls the inner needle hub 919 in the proximal direction with respect to the catheter 930 and the catheter hub 950 to remove the inner needle 12 from the catheter 930. Thereby, the catheter 930 and the catheter hub 950 are left on the patient side.

[0189] As described above, the catheter assembly 910 according to the eighth embodiment can also obtain the same effects as those of the above - described embodiments. That is, the deflection suppressing mechanism 990 supports the proximal side of the lateral opening 941a (the most distal sub - opening) of the sub - lumen 941. Thereby, while suppressing the deflection of the inner needle 12, the damage to the catheter 930 can be reduced.

[0190] 〔Tenth Embodiment〕 As shown in FIG. 17, the catheter assembly 1010 according to the tenth embodiment includes an inner needle 12, a catheter 1030, a catheter hub 1050 connected to the catheter 1030, a catheter operating member 1060 that moves the catheter hub 1050 in the distal direction, 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 suppressing mechanism 1090 that suppresses the deflection of the inner needle 12 during puncture. And the inner needle 12 and the catheter 1030 form a multi - structure needle 1011 in the state before puncture.

[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 lateral opening 1034b at the tip side of the catheter 1030, and communicates with a base opening (not shown) at the base end of the catheter 1030. The first sub-lumen 1040 communicates with a second tip opening 1040a and a second lateral opening 1040b at the tip side of the catheter 1030, and communicates with a base opening (not shown) at the base end of the catheter 1030. The second sub-lumen 1045 communicates with a third tip opening 1045a and a third lateral opening 1045b at the tip side of the catheter 1030, and communicates with a base opening (not shown) at the base end of the catheter 1030.

[0192] The catheter hub 1050 is fixed to the base end portion of the catheter 1030. The catheter hub 1050 is housed within the inner needle hub 1019 in the state before puncture of the catheter assembly 1010. The catheter hub 1050 has a main hub 1051 connected to the catheter 1030, a first side port 1052, and a second side port 1053 that project laterally (in a horizontal direction perpendicular to the axis of the main hub 1051) from the main hub 1051. The first and second side ports 1052, 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 capable of opening and closing the communication passage within the flexible tube 1054 is attached to the flexible tube 1054.

[0193] Also, the catheter assembly 1010 has a slide member 1057 that slides integrally with the catheter hub 1050 along the housing 1020 (lower extension portion 1022). The slide member 1057 has a pair of holding protrusions 1057a that are gripped by the user when detaching the catheter hub 1050 from the housing 1020.

[0194] Further, the slide member 1057 has a receiving groove 1057b for receiving the distal end side of the catheter hub 1050. In particular, the catheter hub 1050 according to the present embodiment has a pair of wings 1058 extending outward in the width direction from the outer peripheral surface on the distal end side, and the receiving groove 1057b is formed in a shape capable of accommodating the pair of wings 1058. The wings 1058 are provided with small holes (not shown), and convex portions (not shown) provided in the receiving groove 1057b are inserted into the small holes. Further, the receiving groove 1057b is open upward, and the catheter hub 1050 can be detached upward.

[0195] The catheter operating member 1060 is an annular member slidably supported in the front-rear direction at the distal end portion of a housing 1020, which will be described later, of the inner needle hub 1019. The catheter operating member 1060 is provided with a finger hook portion 1061 protruding in a flange shape. A recess 1063 opening in the distal end direction is provided in the side wall 1062 of the catheter operating member 1060. The second side port 1053 of the catheter hub 1050 protrudes laterally through the recess 1063.

[0196] The inner needle hub 1019 has a housing 1020 that functions as a gripping portion for the user to grip, and an upper extending portion 1021 and a lower extending portion 1022 that extend parallel to each other in the distal end direction from the distal end portion of the housing 1020. In the state before puncture of the catheter assembly 1010, the catheter 1030 and the catheter hub 1050 are arranged between the upper extending portion 1021 and the lower extending portion 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 rotatably supported about a horizontal axis on the upper extension portion 1021. 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 portion 1091u of the support member 1091. The shaft portion 1093 is pivotally supported by the upper extension portion 1021. Further, the tip of the guide wire operating member 1080 is located on the tip side of the upper portion 1091u of the support member 1091. Therefore, the support member 1091 is restricted from rotating upward by the guide wire operating member 1080.

[0198] As shown in FIG. 18, the sliding contact 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 lateral direction. The lateral support portions 1095 project downward from both left and right ends of the upper support portion 1094. Therefore, the sliding contact support portion 1092 is formed in an inverted U shape when viewed in the longitudinal direction of the catheter assembly 1010. In the state before puncture, a slight gap is formed between the outer surface of the catheter 1030 and the sliding contact support portion 1092.

[0199] As shown in FIG. 17, in the initial state of the catheter assembly 1010, the sliding contact support portion 1092 supports the proximal side of the third lateral opening 1045b located at the most distal end.

[0200] The guide wire operating member 1080 is an operating portion for performing an operation of inserting a guide wire into a patient's blood vessel prior to the operation of inserting the catheter 1030 into the blood vessel. A finger-hooking projection 1081 is provided at the tip of the guide wire operating member 1080, and a plurality of anti-slip ribs 1082 are provided. The guide wire operating member 1080 is slidably supported in the front-rear direction on the upper surface of the upper extension portion 1021. One end of the guide wire is disposed near the tip of the inner needle 12, the other end is connected to the guide wire operating member 1080, and an intermediate portion thereof is folded back within the housing 1020.

[0201] In the use of the catheter assembly 1010, a puncture operation is performed to puncture the catheter assembly 1010 through the patient's skin. While holding the housing 1020 in the pre-puncture state shown in FIG. 17, the user presses the tip of the catheter assembly 1010 against the patient and punctures the skin toward the blood vessel to be punctured. As a result, the tip portions of the inner needle 12 and the catheter 1030 are punctured through the skin.

[0202] Next, when the user moves the guide wire operating member 1080 in the proximal direction, the guide wire with the middle portion folded back within the housing 1020 moves in the distal direction within the inner needle 12. As a result, the guide wire protrudes from the tip of the inner needle 12 and is inserted into the blood vessel. As the guide wire operating member 1080 moves in the proximal direction, the tip portion of the guide wire operating member 1080 moves in the proximal direction relative to the upper portion of the support member 1091. As a result, the restriction on the upward rotation of the support member 1091 by the guide wire operating member 1080 is released.

[0203] Once the tip of the guide wire has been inserted to the target position within the blood vessel, next, while fixing the position of the inner needle hub 1019, the user operates the catheter operating member 1060 in the distal direction to advance the catheter 1030, the catheter hub 1050, and the slide member 1057. As a result, the catheter 1030 is inserted to the target position within the blood vessel. At this time, the support member 1091 is pushed by the slide member 1057 moving in the distal direction and rotates upward. As a result, detachment of the catheter 1030 from the inner needle hub 1019 in the distal direction is permitted.

[0204] Next, while the user presses the pair of holding protrusions 1057a of the slide member 1057 to hold the positions of the catheter 1030, the catheter hub 1050, and the slide member 1057, the user pulls the housing 1020 in the proximal direction. As a result, the catheter 1030, the catheter hub 1050, and the slide member 1057 completely come out of the inner needle hub 1019, and the inner needle 12 is withdrawn from the catheter 1030 in the proximal direction. Then, the catheter hub 1050 is removed from the slide member 1057. Then, by attaching a tape or the like (not shown) to the pair of wings 1058 of the catheter hub 1050, the catheter 1030 and the catheter hub 1050 are indwelled in the patient's blood vessel.

[0205] As described above, also in the catheter assembly 1010 according to the tenth embodiment, the same effects as those of the above-described embodiments can be obtained. That is, the bending suppression mechanism 1090 supports the proximal side of the third lateral opening 1045b (the most proximal sub-opening) of the second sub-lumen 1045. Thereby, while suppressing the bending of the inner needle 12, the damage to the catheter 1030 can be reduced.

[0206] In particular, the sliding contact support portion 1092 has an upper support portion 1094 capable of supporting the catheter 1030 from above and a lateral support portion 1095 capable of supporting the catheter 1030 from the lateral direction (FIG. 18), and the third lateral opening 1045b is provided at any location of the upper portion and the lateral portion of the catheter 1030. With this configuration, it is possible to effectively suppress the damage to the third lateral opening 1045b and the increase in sliding resistance when the catheter 1030 advances.

[0207] Note that the present invention can be applied to other embodiments and other configuration examples by taking out a part of each configuration exemplified in the first to tenth embodiments and the first to eighth configuration examples without departing from the technical idea thereof.

[0208] Summarizing the above embodiments, the following is obtained.

[0209] The above-described embodiment includes a catheter having a first lumen and a second lumen, and an inner needle inserted into the first lumen. An introduction path for confirming flashback, through which blood can flow between the catheter and the inner needle, is provided in the inner needle. The distance between the inner peripheral surface of the tip of the first lumen connected to the tip of the catheter and the outer peripheral surface of the inner needle is narrower than the distance between the basic inner peripheral surface that constitutes most of the inner peripheral surface of the first lumen on the proximal end side of the tip inner peripheral surface and the outer peripheral surface of the inner needle. A catheter assembly is disclosed with this feature.

[0210] According to such a configuration, in the catheter of the catheter assembly, while the inner peripheral surface of the tip of the first lumen is in close contact with or close to the outer peripheral surface of the inner needle, a gap is formed between the basic inner peripheral surface of the first lumen and the outer peripheral surface of the inner needle. Therefore, at the position of the tip inner peripheral surface, even when the catheter is compressed by biological tissue during puncture, the catheter is surely supported by the inner needle, suppressing bending, shrinking, etc. of the catheter. As a result, the tip of the catheter is smoothly inserted into the body. Also, the gap in the first lumen suppresses the sliding resistance between the catheter and the inner needle and smooths the relative movement between the inner needle and the catheter, improving the operability when inserting the catheter and removing the inner needle. Furthermore, the introduction path can allow blood to flow when the inner needle reaches the blood vessel, enabling the user to well recognize the securing of the blood vessel. That is, the catheter assembly enables easy insertion of a catheter having a plurality of lumens and can favorably perform various treatments such as administration of multiple types of drugs or blood sampling.

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

[0212] According to such a configuration, the tip side of the catheter can form a thinner outer shape by the tip inner peripheral surface forming a close contact portion with the inner needle and is more surely supported by the inner needle. Therefore, the insertion performance of the catheter is significantly enhanced.

[0213] In the above catheter assembly, the outer peripheral surface of the catheter may include a basic outer peripheral surface located at the formation position of the basic inner peripheral surface, a tip outer peripheral surface located at the formation position of the tip inner peripheral surface and having an outer diameter thinner than that of the basic outer peripheral surface, and a tapered outer peripheral surface that tapers from the basic outer peripheral surface toward the tip outer peripheral surface.

[0214] According to such a configuration, since the outer peripheral surface of the tip of the catheter is thinner than the basic outer peripheral surface, the catheter can be easily inserted into the blood vessel from the tip. Further, since the tapered outer peripheral surface is inserted following the tip outer peripheral surface and then the basic outer peripheral surface is inserted, it becomes possible to easily insert the thickly formed basic outer peripheral surface.

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

[0216] According to such a configuration, in the catheter having the flexible portion, when inserted into the blood vessel, the flexible portion in contact with the blood vessel wall easily bends and curves along the blood vessel, improving the blood vessel insertability and significantly reducing the occurrence of inflammation and damage to the blood vessel wall. Further, since the inner peripheral surface of the tip of the catheter is supported by the inner needle, it is possible to effectively suppress the occurrence of bending and contraction of the flexible portion during the puncture before reaching the blood vessel.

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

[0218] According to such a configuration, in the catheter assembly, since the opening on the tip side of the second lumen is located on the tip side of the proximal end of the introduction path, it is possible to quickly confirm that blood has flowed into the second lumen.

[0219] In the above catheter assembly, the opening on the distal end side of the second lumen may be located on the proximal end side of the proximal end of the introduction path in the axial direction of the catheter.

[0220] According to such a configuration, the catheter assembly can make the opening on the distal end side of the second lumen located on the proximal end side of the proximal end of the introduction path, thereby making the vicinity of the distal end of the catheter thinner and improving the insertability. Also, the blood flowing into the first lumen can be quickly confirmed.

[0221] In the above catheter assembly, the opening on the distal end side of the second lumen can be configured to face the side of the catheter.

[0222] According to such a configuration, since the opening on the distal end side of the second lumen faces the side of the catheter, the piercing resistance can be reduced.

[0223] In the above catheter assembly, the opening on the distal end side of the second lumen may be provided so as to face the distal end direction of the catheter.

[0224] According to such a configuration, since the opening on the distal end side of the second lumen faces the distal end direction of the catheter, it is possible to suppress the opening from being blocked by the blood vessel wall in the indwelling state within the blood vessel. In particular, blood can be satisfactorily aspirated from the opening of the second lumen.

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

[0226] According to such a configuration, the catheter can stably flow the drug due to the constant diameter of the second lumen, and also can slidably arrange a guide wire or a stylet.

[0227] In the above catheter assembly, a long bar-shaped member may be detachably arranged in the second lumen in the axial direction.

[0228] According to such a configuration, in the catheter assembly, since the rod-shaped member is detachably disposed in the second lumen, the rigidity and straightness of the catheter can be improved by the rod-shaped member, and the catheter can be inserted more favorably.

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

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

[0231] In the above catheter assembly, the second lumen may be formed in a direction in the circumferential direction of the catheter where the blade surface of the inner needle exposed from the first lumen faces.

[0232] In the above catheter assembly, the second lumen may be formed in a direction orthogonal to the direction in the circumferential direction of the catheter where the blade surface of the inner needle exposed from the first lumen faces.

[0233] In the above catheter assembly, the second lumen may be formed in a direction opposite to the direction in the circumferential direction of the catheter where the blade surface of the inner needle exposed from the first lumen faces.

[0234] According to such a configuration, the catheter assembly can be appropriately designed with respect to the sizes and arrangement relationships of the first lumen and the second lumen in consideration of factors such as the insertability of the catheter, the influence on blood vessels, and the visibility of flashback.

[0235] In the above-described catheter assembly, a first catheter hub that fixedly holds the catheter and has a first space portion communicating with the first lumen, and a second catheter hub that is connected to the first catheter hub and has a second space portion communicating with the second lumen are provided. A communication passage that bypasses the first space portion and communicates the second lumen with the second space portion may be provided in the first catheter hub.

[0236] According to such a configuration, the first and second catheter hubs can enhance the connectivity with a connector of a tube for infusion or blood transfusion. In particular, due to the communication passage, since the second space portion of the second catheter hub and the second lumen of the catheter are communicated, drugs and blood can flow well.

[0237] In the above-described catheter assembly, the catheter assembly includes a deflection suppression mechanism that supports the catheter, and an opening on the distal end side of the second lumen may be on the distal end side of the deflection suppression mechanism in the assembled state.

[0238] According to such a configuration, since the opening on the distal end side of the second lumen of the catheter assembly is on the distal end side of the deflection suppression mechanism, the sliding resistance against the deflection suppression mechanism when the catheter is advanced can be reduced compared to the case where it is on the proximal end side. Also, it is possible to prevent the deflection suppression mechanism from hitting the opening of the second lumen when the catheter moves and damaging the catheter.

[0239] In the above-described catheter assembly, the catheter assembly includes a deflection suppression mechanism that supports the catheter, and the catheter includes a tapered portion whose outer diameter increases in the proximal direction from a position spaced a predetermined distance from the distal end of the catheter. The tapered portion may be on the distal end side of the deflection suppression mechanism in the assembled state.

[0240] According to such a configuration, since the tapered portion of the catheter assembly is located on the distal side of the bending suppression mechanism, similar to the above, the sliding resistance of the catheter can be reduced, and the bending suppression mechanism hits the tapered portion to prevent damage to the catheter. Further, the step can be eliminated to prevent the bending of the inner needle. Further, during the advancement of the catheter, the bending suppression mechanism holds the thick-diameter portion of the catheter instead of the thin-diameter portion of the catheter, and the bending of the inner needle can be effectively prevented.

[0241] The above-described embodiment includes an inner needle, a main lumen through which the inner needle is detachably inserted, a catheter having one or more sub-lumens provided separately from the main lumen, and a bending suppression mechanism that suppresses the bending of the inner needle by supporting the inner needle through the catheter. The catheter assembly is characterized in that the one or more sub-lumens communicate with each of one or more sub-openings formed in the catheter, and the bending suppression mechanism has a sliding contact support portion that rubs against the catheter when the catheter advances relative to the inner needle. The sliding contact support portion is capable of supporting a position on the proximal side of the sub-opening that is the most distal among the one or more sub-openings, or a position on the proximal side of a step portion generated in the catheter due to the formation of the sub-lumen.

[0242] According to such a configuration, even in a catheter assembly having a configuration with a plurality of lumens including a main lumen and one or more sub-lumens, the bending suppression mechanism supports the proximal side of the most distal sub-opening, thereby suppressing the bending of the inner needle and reducing the damage to the catheter. That is, the catheter assembly can achieve both prevention of bending of the inner needle and mobility of the catheter by appropriately arranging the formation position of the sub-opening and the support position of the bending suppression mechanism. Therefore, a catheter having a plurality of lumens can be easily inserted, and thus various treatments such as administration of a plurality of types of drugs or blood sampling can be favorably performed.

[0243] In the above catheter assembly, the bending suppression mechanism may be capable of supporting a position proximal to the most proximal sub-opening among the one or more sub-openings.

[0244] According to such a configuration, the catheter assembly can more reliably prevent damage to the catheter by the bending suppression mechanism by supporting a position proximal to the most proximal sub-opening.

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

[0246] According to such a configuration, the catheter assembly can smoothly flow different types of chemical solutions and administer them into the blood vessel through the main lumen and the sub-lumens that extend parallel to each other.

[0247] In the above catheter assembly, the stepped portion is a tapered portion whose outer diameter gradually decreases in the distal direction, the one or more sub-openings are provided in the tapered portion, and the bending suppression mechanism may be capable of supporting a position proximal to the tapered portion.

[0248] According to such a configuration, the catheter assembly can prevent the bending suppression mechanism from being caught by the tapered portion by the bending suppression mechanism supporting a position proximal to the tapered portion. Therefore, the mobility of the catheter can be further enhanced.

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

[0250] According to such a configuration, the catheter assembly can discharge the chemical solution or blood that has flowed through the sub-lumen into the blood vessel well because the sub-opening includes a lateral opening. Moreover, since the bending suppression mechanism is located proximal to the sub-opening, damage to the lateral opening can also be suppressed.

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

[0252] According to such a configuration, in the catheter assembly, since the distance between the main opening and the one or more sub-openings is separated by 17 mm or more, after the drug flowing out from the sub-opening is mixed with the blood in the blood vessel, it is mixed with the drug flowing out from the main opening. That is, drugs with incompatible formulations can be well administered with one catheter.

[0253] In the above catheter assembly, the bending suppression mechanism may be able to support a position 5 mm or less with respect to the one or more sub-openings that are closer and on the tip side than the bending suppression mechanism.

[0254] According to such a configuration, in the catheter assembly, since the bending suppression mechanism can support a position 5 mm or less on the proximal side of the sub-opening, the distance from the tip of the inner needle to the bending suppression mechanism can be shortened, and the bending of the inner needle can be more strongly suppressed. That is, it is preferable that the bending suppression mechanism is provided as close to the tip side as possible from the viewpoint of suppressing the bending of the tip side of the inner needle and the catheter. On the other hand, a catheter having a plurality of lumens needs to have each opening at a certain distance so that the chemical liquids discharged from the respective openings are mixed in the blood. However, if there is a bending suppression mechanism on the tip side of the opening, there is a possibility that the bending suppression mechanism contacts the catheter near the opening and causes damage or the like. Therefore, as in this characteristic matter, it is the minimum distance at which the chemical liquids discharged from each opening are mixed in the blood, and by providing a bending suppression mechanism near the opening, it is possible to achieve both mixing in the blood and bending suppression.

[0255] In the above catheter assembly, the main lumen and the one or more sub-lumens may be partitioned by a partition wall that is deformable according to pressure.

[0256] According to such a configuration, the catheter assembly partitions the main lumen and one or more sub-lumens by a partition wall that can be deformed according to pressure. Thus, in the state where the inner needle is inserted before catheter insertion, the main lumen can be enlarged, and the relative movement between the inner needle and the catheter can be simplified. Then, the partition wall deforms appropriately by its flow pressure when administering a drug or blood. For example, even when relatively large amounts of the drug solution in the sub-lumen flow relative to the drug solution in the main lumen, it is possible to easily secure the cross-sectional area of the flow path.

[0257] In the above catheter assembly, the deflection suppressing mechanism may surround the entire circumference of the catheter in a manner that allows contact.

[0258] According to such a configuration, the catheter assembly can reliably suppress the deviation in the vertical and horizontal directions of the inner needle (such as deviation from the deflection suppressing mechanism and deflection of the inner needle) by the deflection suppressing mechanism that surrounds the entire circumference of the catheter.

[0259] In the above catheter assembly, it has a catheter hub for fixedly holding the catheter and an inner needle hub for fixedly holding the inner needle. The one or more sub-lumens communicate with communication paths of one or more ports provided in the catheter hub, and the ports may be configured as connectors connectable to medical devices.

[0260] According to such a configuration, by connecting a medical device to the port, it is possible to easily supply a drug solution or blood to the one or more sub-lumens.

[0261] In the above catheter assembly, 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] According to such a configuration, since the housing of the catheter assembly has a slit, even in a configuration where a port is provided in the catheter hub, the port can easily move along the slit. That is, the movement of the catheter relative to the inner needle can be performed smoothly.

[0263] In the above catheter assembly, the housing is separable vertically, the slit forms a part of the boundary of the housing separated vertically, and the port may protrude in the lateral direction of the housing.

[0264] According to such a configuration, since the port of the catheter assembly protrudes in the lateral direction of the housing, it is possible to suppress the port from getting in the way during puncture of the inner needle and the catheter, etc., and facilitate the work of the user.

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

[0266] According to such a configuration, since the port of the catheter assembly protrudes upward from the housing, the gripping of the housing can be simplified and the operability by the user can be improved.

[0267] In the above catheter assembly, the port may include a connection portion connectable to the medical device, and a flexible tube extending between the catheter hub and the connection portion and being softer than the connection portion.

[0268] According to such a configuration, since the catheter assembly includes a port including a connection portion and a flexible tube, the connection portion can be arranged in a free position and posture, and the user can perform puncture and catheter insertion.

[0269] In the above catheter assembly, the port may include a connection portion connectable to the medical device, a rigid tube protruding outside the inner needle hub connected to the catheter hub, and a flexible tube extending between the rigid tube and the connection portion and being softer than the connection portion.

[0270] According to such a configuration, the catheter assembly can arrange the rigid tube at the position contacting the inner needle hub by forming a port with the connection part, the rigid tube, and the flexible tube, and can smoothly move the catheter hub.

Explanation of Signs

[0271] 10, 110, 210, 310, 510, 610, 710, 810, 910, 1010... Catheter assembly 12... Inner needle 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 lumen 41, 141, 241, 341, β, β1, β2, 540, 545, 641, 741, 841, 941... Sub-lumen 90, 590, 690, 790, 890, 990, 1090... Bending suppression mechanism 92, 595, 691, 791, 891, 991, 1092... Folded contact support part (contact support part)

Claims

【Claim 1】 An inner needle, a catheter having a lumen through which the inner needle is removably inserted, a deflection suppression mechanism that suppresses deflection of the inner needle by supporting the inner needle via the catheter, and a catheter assembly comprising the same, wherein the catheter has, one or more side openings of the catheter, and a step portion provided so that the inner diameter and outer diameter of the catheter increase, are formed, the deflection suppression mechanism has a contact support portion that can contact the catheter when the catheter advances with respect to the inner needle, the contact support portion is capable of supporting a proximal end side of a tip portion of the catheter side opening that is the most distal among the one or more catheter side openings, or a proximal end side of the step portion, a catheter assembly.

Images