Patent ID: 12257396

DETAILED DESCRIPTION

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

First Embodiment

A catheter assembly10according to a first embodiment is a medical device that is used in a case where infusion, blood transfusion, or the like is performed on a patient (living body) and constructs an inlet and an outlet for a liquid (liquid medicine or blood) by means of puncturing with a catheter30and insertion and placement of the catheter30into the patient's body. The catheter assembly10is configured to insert a catheter (such as a central venous catheter, a PICC, and a midline catheter) that is longer than a peripheral venous catheter. It should be noted that the catheter assembly10may insert a peripheral venous catheter that is shorter than a central venous catheter. In addition, the catheter assembly10may insert an arterial catheter such as a peripheral arterial catheter without being limited to venous catheters.

As illustrated inFIG.1, the catheter assembly10is provided with an inner needle12, a housing20(inner needle hub) fixing and holding the inner needle12, the catheter30disposed outside the inner needle12, and a catheter hub50fixing and holding the catheter30. Further, the catheter assembly10is provided with a catheter operation member60operating the catheter30and the catheter hub50for advancing and retracting movements and a guide wire70and a guide wire operation member80guiding the advancement of the catheter30.

In addition, the catheter30according to the present embodiment is configured as a multi-lumen catheter incorporating a plurality of (two in the present embodiment) lumens31(see alsoFIG.2). In a pre-use assembled state (pre-puncture state), the catheter assembly10forms a multi-structure needle11with the inner needle12inserted through and disposed in a main lumen34of one of the plurality of lumens31and the guide wire70accommodated in the inner needle12.

As for the multi-structure needle11, a needle tip13of the inner needle12protrudes beyond the distal end of the catheter and the guide wire70is disposed in the inner needle12in the pre-puncture state. The proximal end side of the multi-structure needle11is accommodated in the housing20. The catheter hub50, the catheter operation member60, and the guide wire operation member80are accommodated in the housing20together.

In using the catheter assembly10, a user such as a doctor and a nurse grips the housing20and punctures a patient's body with the multi-structure needle11. Further, the guide wire70is sent out from the inner needle12into a blood vessel with the punctured state maintained and the catheter30is inserted into the blood vessel along the guide wire70. Then, the catheter30is indwelled into the blood vessel by the inner needle12being retracted and removed with respect to the catheter30. In the indwelling state, the catheter30allows the two lumens31to communicate with each other in the blood vessel. As a result, the catheter30allows treatments such as separate administration of a plurality of types of drugs and blood sampling during drug administration. Hereinafter, each configuration of the catheter assembly10will be described in detail.

As illustrated inFIGS.1and2, the inner needle12is configured as a rigid hollow tube capable of puncturing the skin of a living body and the sharp needle tip13is provided at the distal end of the inner needle12. A hollow portion12ais provided along the axial direction of the inner needle12in the inner needle12. It should be noted that the inner needle12may be a solid structure that is not provided with the hollow portion12a.

The needle tip13has a blade surface15that is inclined at a predetermined angle with respect to the axial center of the inner needle12by a cylindrical tube being obliquely cut. The blade surface15has an elliptical shape surrounding a distal end opening15acommunicating with the hollow portion12a. When the catheter assembly10is used, the blade surface15is directed in the direction that faces the user (upward direction in a case where the surface of a patient's body is a lower side). As a result, the edge of the blade surface15cuts the skin and is inserted into the body during puncturing.

Hereinafter, the direction and the position of each configuration of the catheter assembly10will be described based on the direction of the blade surface15unless otherwise specified (see also the arrow directions inFIG.1). Especially, the disposition of the plurality of lumens31of the catheter30will be described in relation to the blade surface15.

It should be noted that the shape of the blade surface15is not particularly limited althoughFIGS.1and2exemplify the blade surface15that is simply cut obliquely with respect to the axial center of the inner needle12. For example, the needle tip13may have a lancet-type configuration in which two inclined left and right blade surfaces15form a distal end (peak) at the center in the width direction or a back-cut configuration in which the opposite side of the blade surface15is cut.

The inner needle12is provided with a hole portion14penetrating the outer surface and the hollow portion12a. In other words, the inner needle12constitutes an introduction path for blood flashback confirmation during puncturing with the multi-structure needle11by means of the distal end opening15a, the hollow portion12a, and the hole portion14.

Examples of the constituent material of the inner needle12include a hard resin, ceramics, and a metal material such as stainless steel, aluminum or an aluminum alloy, and titanium or a titanium alloy. The inner needle12is firmly fixed to the housing by appropriate fixing means such as fusion, adhesion, and insert molding.

The housing20of the catheter assembly10is an inner needle hub19fixing and holding the inner needle12and moving integrally with the inner needle12and constitutes a grip part that a user grips. The housing20has an elongated bowl shape as a whole. The housing20is designed so as to have a moderate size (thickness and length) such that a user grips the housing20with ease.

The housing20is provided with an accommodating space20aaccommodating the catheter hub50, the catheter operation member and the guide wire operation member80. A pair of side walls21sandwiching the accommodating space20aextend in parallel in the longitudinal direction. The side walls21have groove-shaped rail portions21ain the inner surfaces that are on the distal end side, which is formed higher than the proximal end side. The pair of rail portions21aslidably accommodate a side edge61aof the catheter operation member60. The distal end side of one of the pair of side walls21(side wall21in the leftward direction inFIG.1) has a bulging portion22, which bulges outward in the width direction. A support member91, which is a deflection suppression mechanism90, is attached to a disposition recess22aof the bulging portion22.

The support member91has a sliding contact support portion92that allows the accommodating space20aof the housing20to protrude in the rightward direction and is rotatably and pivotally supported by the side wall21. The sliding contact support portion92rubs against the catheter30when the catheter30(multi-structure needle11) held by the catheter operation member advances. The sliding contact support portion92may not be in contact with the catheter30before the catheter30is used or during a movement of the catheter30relative to the housing20. In addition, the support member91has, in the upper end portion of the support member91, a groove portion (not illustrated) accommodating the side edge61aof the catheter operation member in a state where the catheter operation member60is accommodated in the housing20. The presence of the side edge61ain the groove portion results in regulation of rotation and standing by for the catheter30to be supportable. When the catheter operation member advances, the support member91becomes rotatable by the side edge61acoming out of the groove portion. Further, the support member91rotates toward the outside of the side wall21by contact of the catheter operation member60. As a result, the catheter hub and the catheter operation member60are smoothly sent out from the housing20with the support member91(sliding contact support portion92) remaining in the housing20.

The housing20is provided with a block-shaped needle holding portion24, which holds the inner needle12at the axially intermediate position of the accommodating space20a. A guide mechanism (not illustrated) is provided on the side of the housing that is closer to the proximal end than the needle holding portion24. The guide mechanism guides sliding of the guide wire operation member80and regulates detachment of the guide wire operation member80. Further, a rear wall25closing the accommodating space20ais provided on the most proximal end side of the housing20.

The constituent material of the housing20is not particularly limited. For example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and a methacrylate-butylene-styrene copolymer may be applied. It should be noted that the housing20may be formed in a square tube shape in which, for example, the accommodating space20ais covered with an upper wall although the housing20has a configuration in which the upper surface of the accommodating space20ais exposed in the illustrated example.

The catheter30of the catheter assembly10is formed in the shape of a perfect circle in a cross-sectional view orthogonal to the axial direction and extends with an appropriate length along the axial direction. The length of the catheter30is not particularly limited and can be appropriately designed in accordance with applications, conditions, and so on. For example, the catheter30has a set length of approximately 14 to 500 mm.

As illustrated inFIG.2, a main body portion32and a soft tip33(flexible portion) constitute the catheter30. The main body portion32constitutes most of the catheter30in the axial direction. The soft tip33is provided at the distal end of the main body portion32and is softer than the main body portion32. The main body portion32and the soft tip33are firmly fixed by an appropriate fixing method such as heat fusion and adhesion, and the outer peripheral surfaces of the main body portion32and the soft tip33are continuously formed in series. The main body portion32and the soft tip33have connection boundary portions overlapping each other in a tapered shape. As a result, the physical properties of the catheter30are gradually changed.

The plurality of lumens31in the catheter30include the main lumen34(first lumen) in which the inner needle12is inserted through and disposed in the pre-puncture state and a sub lumen41(second lumen) extending in parallel with the main lumen34. Each of the main lumen34and the sub lumen41is formed in the shape of a perfect circle in a cross-sectional view orthogonal to the axis of the catheter30.

The main lumen34is provided over the entire axial length of the catheter30and communicates with a first distal end opening34a(main opening) formed at the distal end of the catheter30and a first proximal end opening34bformed at the proximal end of the catheter30. The first distal end opening34aexposes the needle tip13of the inner needle12.

The inner peripheral surface of the catheter30that constitutes the main lumen34is divided into a first inner peripheral surface36and a second inner peripheral surface38based on a predetermined axial position P. In this embodiment, there is no gap between the first inner peripheral surface36and an outer peripheral surface16of the inner needle12. A gap39is formed between the second inner peripheral surface38and the outer peripheral surface16of the inner needle12. A tapered inner peripheral surface37interconnecting the first inner peripheral surface36and the second inner peripheral surface38is formed at the distal end of the second inner peripheral surface38.

The diameter of the first inner peripheral surface36is equal to or slightly smaller than the outer diameter of the outer peripheral surface16of the inner needle12. As a result, the first inner peripheral surface36forms a close contact portion35coming into close contact with the outer peripheral surface16of the inner needle12and closes the gap39of the second inner peripheral surface38. Accordingly, the diameter of the first inner peripheral surface36may be designed in accordance with the outer diameter of the inner needle12and may range, for example, from 0.3 mm to 1.8 mm. The longitudinal (axial) length of the first inner peripheral surface36may range, for example, from 0.1 mm to 4.0 mm so that the distal end of the catheter30is inserted well.

The soft tip33and the main body portion32constitute the distal end of the catheter30. The inside of the distal end of the catheter30forms the first inner peripheral surface36(close contact portion35). The most distal end of the first inner peripheral surface36of the soft tip33forms the first distal end opening34a. The most distal end that is on the outer peripheral surface side of the soft tip33is formed in, for example, a distal end tapered portion40, which has the same inclination as the blade surface15of the needle tip13(or is less inclined than the blade surface15).

The tapered inner peripheral surface37of the main lumen34has a diameter that gradually decreases toward the distal direction (first inner peripheral surface36) in a short axial range. A second inner peripheral surface38constitutes the inner peripheral surface of most of the main lumen34in the axial direction.

The diameter of the second inner peripheral surface38is formed so as to be larger than the outer diameter of the outer peripheral surface16of the inner needle12. As a result, the inner needle12and the catheter30can be slid well. In the pre-puncture state, the hole portion14of the inner needle12faces the second inner peripheral surface38and communicates with the gap39of the second inner peripheral surface38. Accordingly, blood flashback can be performed well in the gap between the inner needle12and the catheter30. The designed diameter of the second inner peripheral surface38may be, for example, approximately 1.02 to 1.33 times the diameter of the first inner peripheral surface36.

The sub lumen41is provided separately from the main lumen34along the axial direction of the catheter30. In other words, the main lumen34and the sub lumen41extend in the catheter30along mutually parallel axes. The sub lumen41is bent radially outward at a midway position on the distal end side of the catheter30and communicates with a second lateral opening41a(sub opening) formed in the outer peripheral surface (side) of the catheter30.

The second lateral opening41ais positioned closer to the proximal end side than the first distal end opening34a. Preferably, the distance between the first distal end opening34aand the second lateral opening41ais 17 mm or more.

In the catheter assembly10, the distance between the first distal end opening34aand the second lateral opening41ais 17 mm or more, and thus a drug flowing out from one of the first distal end opening34aand the second lateral opening41ais mixed with a drug flowing out from the other after mixing with blood in a blood vessel. In other words, combination contraindications can be administered well with the single catheter30. It should be noted that the proximal end side of the sub lumen41communicates with a second proximal end opening41band the second proximal end opening41bis adjacent to the first proximal end opening34b.

In the present embodiment, the diameter of the inner peripheral surface of the sub lumen41is set to a dimension that is smaller than the diameter of the inner peripheral surface of the main lumen34(first inner peripheral surface36). In other words, the plurality of lumens31are constituted by the large-diameter main lumen34where the inner needle12is disposed and the small-diameter sub lumen41where nothing is disposed. Further, the inscribed circle diameter of the sub lumen41is constant along the axial direction of the catheter30whereas the diameter of the main lumen34changes along the axial direction. The diameter of the sub lumen41is not particularly limited insofar as a drug is allowed to flow in from the second proximal end opening41band the drug can be guided to the second lateral opening41a. For example, the sub lumen41has a diameter ranging from 0.3 to 1.2 mm.

The outer peripheral surface of the catheter30has a distal end-to-predetermined position P range formed in the first outer peripheral surface42with a small-outer diameter. For example, the first outer peripheral surface42is one size larger in outer diameter than the inner needle12. In addition, the outer peripheral surface of the catheter30has a tapered outer peripheral surface43increasing in thickness from the predetermined position P toward the proximal direction and the second outer peripheral surface44continuous with the proximal end of the tapered outer peripheral surface43and thicker than the first outer peripheral surface42. The second outer peripheral surface44is provided at the position where the sub lumen41is formed.

In the catheter30, the first inner peripheral surface36and the first outer peripheral surface42overlap each other, the tapered inner peripheral surface37and the tapered outer peripheral surface43overlap each other, and the second inner peripheral surface38and the second outer peripheral surface44overlap each other in the axial direction of the catheter30. Accordingly, in this configuration, the thickness of the main body portion32itself does not change in the vicinity of the predetermined position P. In other words, in the vicinity of the predetermined position P, continuity is provided with the thickness of the main body portion32constant even if the shape of the main body portion32becomes thin. In addition, a continuous inclined surface45, which is inclined continuously with the tapered outer peripheral surface43and is continuous with the second outer peripheral surface44, is provided at the position where the outer diameter increases to the same extent as the formation of the sub lumen41.

The constituent material of the main body portion32is not particularly limited. A soft resin material is preferable as the constituent material of the main body portion32. Examples of the constituent material of the main body portion32include fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxy fluorine resin (PFA), olefin-based resins such as polyethylene and polypropylene or mixtures of the resins, polyurethane, polyester, polyamide, a polyether nylon resin, and a mixture of an olefin-based resin and an ethylene-vinyl acetate copolymer. The constituent material of the soft distal end33is not particularly limited. For example, a resin material such as polyurethane may be applied as the constituent material of the soft tip33.

Preferably, the catheter30is formed of a material having transparency. Then, a user can visually and satisfactorily recognize the flashback of the blood that has flowed into the main lumen34and the sub lumen41. It should be noted that the catheter30may have a configuration in which the flesh portion that constitutes the main lumen34has transparency and the flesh portion that constitutes the sub lumen41has opacity. This is because a user can visually recognize the blood by the blood flowing around into the gap39. In an alternative configuration, the flesh portion that constitutes the sub lumen41may have transparency and the flesh portion that constitutes the main lumen34may have opacity. The flashback can be confirmed with the catheter assembly10even in a configuration in which the inner needle12does not have the hole portion14(notch). This is because blood flows into the main lumen34at a stage in which contact between the distal end side of the inner needle12and the inner peripheral surface of the main lumen34of the catheter30has disappeared as the catheter30advances relative to the inner needle12.

The proximal end portion of the catheter30is fixed to the distal end portion in the catheter hub50by appropriate fixing means such as caulking, fusion, and adhesion. The catheter hub50is exposed on a patient's skin in a state where the catheter30is inserted in the patient's blood vessel, is affixed with a tape or the like, and is indwelled together with the catheter30. The material that constitutes the catheter hub50is not particularly limited. For example, the materials listed for the housing20may be appropriately adopted.

As illustrated inFIGS.1and2, the catheter hub50has a main hub51(first catheter hub) and a sub hub52(second catheter hub). The main hub51is formed in the shape of a tube tapered in the distal direction. The sub hub52is connected to the side surface of the main hub51. The main hub51constitutes a main port allowing one of two types of drugs to flow in during infusion or the like. The sub hub52constitutes a sub port allowing the other of the drugs to flow in.

The main hub51fixes and holds the catheter30in the distal end portion of the main hub51and is provided with a main space51a(first space) on the proximal end side of the fixing part. The main space51acommunicates with the main lumen34. In the pre-puncture state, the inner needle12is inserted through the main space51a. A flow path53is provided in the main hub51, communicates with the sub lumen41of the catheter30, and communicates with a sub space52ain the sub hub52. The sub space52aand the flow path53constitute a communication path55communicating with the sub lumen41.

The sub hub52is formed in a tubular shape having the sub space52atherein. The sub hub52is provided above the main space51acorrespondingly to the disposition relationship between the sub lumen41and the main lumen34of the catheter30. As a result, the main hub51can be easily manufactured in a shape in which the flow path53and the main space51aare separate from each other. In addition, the housing20can be configured to be thin in the width direction and a user can easily grip the housing20during puncturing.

The main hub51and the sub hub52are connecting portions to which an infusion tube connector can be connected (for example, a flange portion54protruding radially outward is provided at the proximal end or the inner peripheral surface of the sub space52aor the main space51ais formed into a luer taper). It should be noted that the main space51aof the main hub51and the sub space52aof the sub hub52may accommodate, for example, a hemostatic valve (not illustrated) that prevents blood from flowing back and a plug (not illustrated) that allows infusion by penetrating a hemostatic valve as an infusion tube connector is inserted.

The catheter operation member60operates the catheter30and the catheter hub50for a movement relative to the inner needle12and the housing20as illustrated inFIG.1. The catheter operation member60directly holds the catheter30and accommodates and holds the catheter hub50. The catheter operation member60has an operation plate portion61extending in the longitudinal direction of the housing20and a hub storage portion62continuous with the proximal end of the operation plate portion61and storing the catheter hub50.

The operation plate portion61is a part that a user advances and retracts with his or her finger. In the pre-puncture state, a pair of the side edges61aof the operation plate portion61are disposed in the pair of rail portions21aof the housing20and the upper surfaces of the pair of side walls21. At least one catheter holding portion including a pair of projecting pieces (not illustrated) is provided along the longitudinal direction on the lower surface of the operation plate portion61and bites the catheter30in each place.

In other words, as illustrated inFIGS.1and2, the midway position of the multi-structure needle11(catheter30) in the axial direction is supported by the deflection suppression mechanism90that the support member91and the operation plate portion61constitute. The place of the support by the support member91(deflection suppression mechanism90) is positioned closer to the proximal end side than the tapered outer peripheral surface43or the continuous inclined surface45and closer to the proximal end side than the second lateral opening41a. The support member91is capable of supporting the catheter30in the vicinity of the closest second lateral opening41aand on the distal end side that is beyond the support member91.

More specifically, the support member91is capable of supporting the catheter30on the distal end side that is beyond the support member91and at the position that is at a distance of 5 mm or less from the closest second lateral opening41a. Here, it is preferable that the deflection suppression mechanism90is provided as close as possible to the distal end side from the viewpoint of suppressing the distal end-side deflection of the inner needle12and the catheter30. As for the catheter30having the main lumen34and the sub lumen41, each opening needs to be provided at a certain distance such that a liquid medicine discharged from each opening is mixed in blood. The deflection suppression mechanism90being present closer to the distal end side than the second lateral opening41amay lead to damage or the like attributable to contact between the deflection suppression mechanism90and the catheter30in the vicinity of the second lateral opening41a. Accordingly, both the mixing in blood and deflection suppression can be achieved by the deflection suppression mechanism90being provided in the vicinity of the second lateral opening41aand at the limit distance for the mixing of the liquid medicine in blood subsequent to the discharge from each opening.

The hub storage portion62constitutes a storage chamber storing the catheter hub50by means of an upper plate63continuous with the operation plate portion61and a pair of side plates (not illustrated). The upper plate63is provided with a disposition hole63a, which is notched in a substantially isosceles triangle shape in accordance with the shape of the catheter hub50and causes the sub hub52to protrude. The hub storage portion62holds the flange portion54of the catheter hub50so as to be separable by an appropriate frictional force by means of the pair of side plates and an arch portion64providing circular arc-shaped bridging on the proximal end side.

As illustrated inFIGS.1and2, the guide wire70of the catheter assembly10is disposed in the hollow portion12aof the inner needle12and extends along the axial direction of the inner needle12. The guide wire70extends from the proximal end opening (not illustrated) of the inner needle12and is fixed to the guide wire operation member80. The guide wire70is formed so as to be axially longer than the inner needle12and has appropriate rigidity and flexibility.

In the pre-puncture state, the distal end of the guide wire70is disposed closer to the proximal end side than the hole portion14of the inner needle12. As a result, the blood that has flowed into the hollow portion12afrom a blood vessel during puncturing with the inner needle12flows out well to the outside of the inner needle12via the hole portion14and a user can visually recognize the flashback. In a state of being punctured with the inner needle12, the guide wire70advances into the blood vessel by being sent out from the distal end opening15aof the inner needle12under the operation of the guide wire operation member80by the user.

Returning toFIG.1, the guide wire operation member80of the catheter assembly10has a holding block81fixing and holding the guide wire70on the proximal end side of the housing20and an operation arm82extending in the distal direction from the holding block81. The distal end portion of the operation arm82is provided with an operation projection83operated by direct contact with a user and is placed so as to be capable of sliding with respect to the flat upper surface of the guide wire operation member80. In other words, the holding block81advances in conjunction with advancement of the operation arm82and the guide wire70is pushed out in the distal direction as a result. The guide wire70is sent out from the distal end opening15aof the inner needle12in accordance with the amount of advancement of the guide wire operation member80.

The catheter assembly10according to the first embodiment is basically configured as described above. The actions and effects of the catheter assembly10will be described below.

The catheter assembly10is used in constructing an introduction portion for infusion to a patient as described above. In using the catheter assembly10, a user grips the housing20and performs puncturing on the patient with the multi-structure needle11. At this time, the support member91of the housing20supports the second outer peripheral surface44of the catheter30(place where the plurality of lumens31extend) and satisfactorily ensures the linearity of the catheter30. During puncturing, the catheter30is inserted into the body after the inner needle12is inserted by the skin and a blood vessel being cut with the blade surface15.

As illustrated inFIG.2, during the insertion, the sufficiently thin first outer peripheral surface42is inserted first, and thus the catheter30undergoes a sufficiently low piercing resistance. In addition, the first inner peripheral surface36including the soft tip33is in close contact with the inner needle12, and thus the first inner peripheral surface36is not deflected radially inward. As a result, axial shrinkage of the distal end of the catheter30is suppressed as well and the catheter30is inserted with ease. Especially, a thick needle can be adopted as the inner needle12disposed in the main lumen34, and thus deflection of the catheter30is reduced.

When a blood vessel is punctured, the distal end of the guide wire70is positioned on the proximal end side of the hole portion14. Accordingly, the blood that has flowed into the hollow portion12aof the inner needle12flows through the hole portion14to the main lumen34of the catheter30(gap39of the second inner peripheral surface38). As a result, a user can visually recognize the flashback of the blood and confirm that the main lumen34has secured the blood vessel.

Once the catheter30is further inserted, the catheter30moves from the predetermined position P to the tapered outer peripheral surface43. Although the biological tissue spreads at this time, the catheter30can be smoothly inserted along the tapered outer peripheral surface43. In addition, the smooth insertion of the catheter30can be continuously performed by the inclination of the continuous inclined surface45even after the continuous inclined surface45is reached. Especially, the sub lumen41has a small diameter and the rate of change in the outer diameter of the second outer peripheral surface44with respect to the first outer peripheral surface42is small as well, and thus the piercing resistance of the catheter30is significantly suppressed. Accordingly, the catheter30can be smoothly inserted up to the second outer peripheral surface44.

After the multi-structure needle11is somewhat inserted into the blood vessel, the user advances the guide wire operation member and sends out the guide wire70from the distal end opening15aof the inner needle12. Subsequently, the user advances the catheter30and the catheter hub50along the guide wire70by advancing the catheter operation member60. At this time, the sliding resistance between the inner needle12and the catheter is low because the gap39is formed between the inner needle12and the second inner peripheral surface38of the main lumen34. As a result, the catheter30can be smoothly moved relative to the inner needle12.

After the multi-structure needle11is somewhat inserted into the blood vessel, blood flows into the sub lumen41from the second lateral opening41a. As a result, the user can satisfactorily recognize that the sub lumen41has secured the blood vessel as well.

Once the needle tip13of the inner needle12moves to the proximal end side beyond the second inner peripheral surface38of the catheter30in particular, it is possible to easily retract the inner needle12relative to the catheter30. The catheter30and the catheter hub50are indwelled into the patient once the catheter30and the catheter hub50are sent out from the inner needle12and the housing20. During the indwelling, an infusion tube is connected to each of the main hub51and the sub hub52. As a result, a first drug is administered to the patient via the main space51aand the main lumen34and a second drug is administered to the patient via the sub space52a, the flow path53, and the sub lumen41.

As described above, in the catheter assembly10according to the first embodiment, while the first inner peripheral surface36on the distal end side of the main lumen34is in close contact with the outer peripheral surface16of the inner needle12, the gap39is formed between the outer peripheral surface16of the inner needle12and the second inner peripheral surface38, which is closer to the proximal end side than the first inner peripheral surface36. Accordingly, at the position where the first inner peripheral surface36is formed, the catheter30is reliably supported by the inner needle12even if pressure is received from a biological tissue during puncturing, and thus deflection, shrinkage, and the like of the catheter30are suppressed. Accordingly, the distal end of the catheter30is smoothly inserted into the body. In addition, the gap39of the second inner peripheral surface38smoothens the relative movements of the inner needle12and the catheter30by suppressing the sliding resistance between the catheter30and the inner needle12, and thus the operability of the catheter30during insertion and indwelling is improved. Further, a user can satisfactorily recognize blood vessel securing because the hole portion14is disposed. In other words, the catheter30having the plurality of lumens31can be easily inserted with the catheter assembly10and various treatments such as administration of a plurality of types of drugs and blood sampling can be carried out well with the catheter assembly10.

The distal end side of the catheter30can be reduced in thickness in terms of outer shape and is more reliably supported by the inner needle12as the first inner peripheral surface36forms the close contact portion35with the inner needle12. Accordingly, the insertion performance of the catheter30is significantly enhanced. In the catheter30, the first outer peripheral surface42is thinner than the second outer peripheral surface44, and thus the catheter30can be easily inserted into a blood vessel from the distal end. The tapered outer peripheral surface43is inserted subsequently to the first outer peripheral surface42, and then the second outer peripheral surface44is inserted. Accordingly, the thick second outer peripheral surface44can be inserted with ease.

Further, in the catheter30having the soft tip33, the soft tip33that is in contact with the wall of the blood vessel is easily deflected and curved along the blood vessel during insertion into the blood vessel, and thus inflammation or damage occurrence with respect to the blood vessel wall can be significantly reduced. Especially, the first inner peripheral surface36of the catheter30is supported by the inner needle12, and thus the occurrence of deflection or shrinkage of the soft tip33can be effectively suppressed during the insertion that is performed before the blood vessel is reached.

In the catheter assembly10, the second lateral opening41aof the sub lumen41is positioned closer to the proximal end side than the hole portion14. Accordingly, the vicinity of the distal end of the catheter30can be reduced in thickness and insertability improvement can be achieved. In addition, the blood that flows into the main lumen34can be quickly confirmed. The second lateral opening41aof the sub lumen41is capable of suppressing mixing of drugs immediately when the plurality of types of drugs are administered to the blood vessel.

The catheter assembly10has the deflection suppression mechanism90(support member91, holding portion of the catheter operation member60) on the proximal end side that is beyond the second lateral opening41a. As a result, it is possible to reduce the sliding resistance of the catheter30with respect to the deflection suppression mechanism90during advancement of the catheter30. The deflection suppression mechanism90supports the catheter30on the proximal end side that is beyond the tapered outer peripheral surface43or the continuous inclined surface45of the catheter30. As a result, the sliding resistance of the catheter30with respect to the deflection suppression mechanism during advancement of the catheter30can be further reduced. Further, deflection of the inner needle12can be prevented with a constant force by damage to the deflection suppression mechanism attributable to hitting against the second lateral opening41aor the tapered outer peripheral surface43being prevented and a step attributable to the second lateral opening41aor the tapered outer peripheral surface43being eliminated in the contact place and the planned contact place of the deflection suppression mechanism90.

It should be noted that the present invention is not limited to the embodiment described above and various modifications can be made in line with the gist of the invention.

For example, an example in which the guide wire70is applied as an insertion assistance mechanism assisting with insertion of the catheter30has been described in the above embodiment. The insertion assistance mechanism is not limited thereto, and various configurations may be adopted as the insertion assistance mechanism. For example, the insertion assistance mechanism may be configured such that the guide wire70can be used in a retrofitted manner by exposure of the proximal end opening of the inner needle12from the inner needle hub19. Further, the insertion assistance mechanism may be configured such that the guide wire70is automatically retractable into the hollow portion12aafter exposure from the needle tip13. Alternatively, the catheter assembly10may be configured without the guide wire70and the guide wire operation member80.

The insertion assistance mechanism may be configured such that the guide wire70extends at least twice with respect to the amount of operation of the guide wire operation member80. For example, a configuration in which the guide wire70is folded back in the housing20and the guide wire operation member80advances and retracts the folded portion of the guide wire70may be adopted as this type of structure.

The catheter assembly10may be provided with a safety mechanism (not illustrated) for preventing erroneous puncturing with the inner needle12during removal of the inner needle12. For example, applicable as the safety mechanism is a full cover-type mechanism causing a tubular member (such as a telescopic member) to protrude from the inner needle hub19during removal of the inner needle12and accommodating the inner needle12inside. In addition, the safety mechanism may be a covering member that partially covers the needle distal end13of the inner needle12and the periphery of the needle tip13. Further, the safety mechanism may be a mechanism that automatically or manually pulls the inner needle12into the housing20(inner needle hub19) during removal of the inner needle12.

Alternatively, the safety mechanism may be configured to cause a blunt needle having a distal end with which the skin is hardly pierced to protrude from the needle tip13during removal of the inner needle12. With the blunt needle configured to protrude from the needle tip13during advancement of the catheter with respect to the inner needle12, piercing of the catheter with the inner needle12can be prevented as well.

The catheter assembly10may be provided with a hemostatic mechanism (not illustrated) preventing leakage of reverse blood from a patient. For example, a hemostatic valve accommodated in the catheter hub50can be an example of the hemostatic mechanism. In addition, the hemostatic valve may be a cap-type valve that is detachably attached to the proximal end of the catheter hub50. Alternatively, the hemostatic mechanism may be a gas-permeable and liquid-impermeable air vent member attached to a predetermined position (such as the proximal end) of the inner needle12.

The catheter assembly10may be provided with a catheter hub rotation mechanism (not illustrated) that allows the catheter hub to rotate with respect to the inner needle12in order to eliminate sticking of the catheter30to the inner needle12before puncturing with the multi-structure needle11. For example, the catheter hub rotation mechanism can be configured by a notch being formed in at least one of the leftward and rightward directions of the position that corresponds to the sub hub52in the pre-puncture state and is in the axial direction of the housing20and the catheter operation member60.

The catheter30may adopt various mechanisms in addition to the flexible mechanism that is based on the soft tip33. For example, a rigid mechanism that prevents crushing of the catheter30can be applied by, for example, a blade or a ring-shaped, mesh-shaped, or coil-shaped reinforcing material being embedded in the catheter30.

Further, a kink prevention mechanism (not illustrated) may be applied to the catheter assembly10so that the catheter30is prevented from kinking. A deformable configuration of the distal end part of the catheter hub50can be an example of the kink prevention mechanism.

In the present embodiment, the catheter assembly10is constituted by a separation mechanism (separate member) that separates the catheter hub50and the catheter operation member60when the catheter hub50is detached from the inner needle12. Alternatively, the catheter assembly10may be a configuration (non-separation mechanism) with which the catheter hub50and the catheter operation member60cannot be separated and can be integrally indwelled.

In an alternative configuration, the first inner peripheral surface36defining the main lumen34may be smaller in diameter than the second inner peripheral surface38, and a gap between the first inner peripheral surface36and the outer peripheral surface16of the inner needle12may not be zero (that is, the close contact portion35may not be formed). This is because the inner needle12is capable of satisfactorily supporting the catheter30under inward pressure during puncturing even in this configuration.

Other embodiments and other configuration examples of the present invention will be described with reference toFIGS.3to18. In the following description, identical configurations or functionally identical configurations will be denoted by the same reference numerals so that detailed descriptions of the configurations can be omitted. It is a matter of course that the above-described mechanisms of the catheter assembly (insertion assistance mechanism, safety mechanism, hemostatic mechanism, catheter hub rotation mechanism, flexible mechanism, rigid mechanism, kink prevention mechanism, separation mechanism, and non-separation mechanism) can be appropriately adopted for the following embodiments and configuration examples.

Second Embodiment

As illustrated inFIG.3, a catheter assembly110according to a second embodiment is different from the catheter assembly10according to the first embodiment in terms of the structure of a multi-structure needle111(inner needle112and catheter130). Specifically, in the catheter130, the diameter of a sub lumen141is larger than that of a main lumen134through which the inner needle112is inserted and disposed, and the inner needle112is formed so as to be thin correspondingly to the main lumen134.

The inner needle112has a groove portion113as a blood flashback-realizing introduction path. The groove portion113is notched by a predetermined length from the blade surface15toward the proximal direction. The proximal end portion of the groove portion113communicates with a gap139. An outer peripheral surface116of the inner needle112and the inner peripheral surface of the main lumen134(second inner peripheral surface138) constitute the gap139.

As in the first embodiment, the catheter130is constituted by a main body portion132and a soft tip133(flexible portion) provided at the distal end of the main body portion132. However, the soft tip133is provided in the range from the distal end of the main lumen134to the proximal end side that is slightly beyond the distal end of the sub lumen141(second distal end opening141a). A stylet170is disposed in the sub lumen141.

The main lumen134of the catheter130is provided with a first inner peripheral surface136and the second inner peripheral surface138. The diameter of the first inner peripheral surface136is almost equal to the outer diameter of the inner needle112. The diameter of the second inner peripheral surface138is slightly larger than the outer diameter of the inner needle112including a tapered inner peripheral surface137(diameter of the first inner peripheral surface136). The first inner peripheral surface136forms a close contact portion135between the first inner peripheral surface136and the outer peripheral surface116of the inner needle112other than the groove portion113(gap being zero). The gap139is formed between the second inner peripheral surface138and the outer peripheral surface116of the inner needle112.

The sub lumen141is positioned in the direction that the blade surface15faces (upward direction). The sub lumen141extends (in parallel with the main lumen134) along the axial direction of the catheter130and communicates with the second distal end opening141a, which is positioned closer to the proximal end side than a first distal end opening134aof the main lumen134.

The outer peripheral surface of the catheter130has a first outer peripheral surface142at a position overlapping the first inner peripheral surface136and a second outer peripheral surface144having an outer diameter corresponding to the sub lumen141at a position overlapping the second inner peripheral surface138. The distal end of the second outer peripheral surface144is continuous with an inclined end surface145, which is inclined with respect to the axial center of the catheter130. The second distal end opening141ais formed in the inclined end surface145and the distal end of the inclined end surface145is continuous with the proximal end of a tapered outer peripheral surface143.

The stylet170disposed in the sub lumen141is a solid rod-shaped member formed so as to be larger in diameter than the inner needle112and enhances the insertion performance of the catheter130for insertion into a living body by providing stiffness to the catheter130as a whole. The distal end of the stylet170is inclined to substantially the same extent as the inclined end surface145of the catheter130. In the pre-puncture state, the distal end of the stylet170is disposed slightly closer to the proximal end side than the second distal end opening141a. As a result, the distal end of the stylet170suppresses clogging of the sub lumen141with biological tissue pieces.

The stylet170extends in the sub lumen141and is inserted through a sub space152aof a sub hub152, which is connected to a main hub151(catheter hub150), via a communication path153from the sub lumen141. The proximal end of the stylet170is fixed and held by a stylet holding member171attached to the protruding end of the sub hub152. Accordingly, with the catheter130somewhat inserted in a blood vessel, a user can remove the stylet170from the catheter130by gripping the stylet holding member171.

An appropriate gap is provided between the outer surface of the stylet170and the inner surface of the sub lumen141, and thus the stylet170can be slid with respect to the catheter130. In addition, it can be seen that the distal end of the sub lumen141is inserted in a blood vessel by blood flowing into the gap between the stylet170and the sub lumen141. Although a cross section of the stylet170may have a shape in which the sub lumen141is reduced in a similar shape, the flashback can be confirmed better by means of groove installation. In addition, the stylet170may be made of a hollow transparent material. The flashback can be confirmed better by means of this configuration as well.

As described above, the catheter assembly110according to the second embodiment is capable of obtaining effects similar to those of the catheter assembly10according to the first embodiment. In other words, deflection or shrinkage of the catheter130is suppressed by the catheter130having a distal end supported by the outer peripheral surface116of the inner needle112, and thus the catheter130can be smoothly inserted into the body. In a case where the inner needle112is formed so as to be thin in particular, a patient's wound can be reduced during puncturing with the inner needle112and hemostasis in the case of erroneous puncturing is facilitated.

As for the second distal end opening141aof the sub lumen141facing the distal direction of the catheter130, blocking by the wall of a blood vessel in a state of being indwelled in the blood vessel is suppressed. Accordingly, blood can be suctioned well from the second distal end opening141aof the sub lumen141. Further, in the catheter assembly110, the stylet170is detachably disposed in the sub lumen141, and thus the rigidity and the straightness of the catheter130can be improved by the stylet170.

Third Embodiment

As illustrated inFIG.4, a catheter assembly210according to a third embodiment is different from the catheter assemblies and110according to the first and second embodiments in terms of the structures of a multi-structure needle211(catheter230) and a catheter hub250. Specifically, in a side cross-sectional view of the catheter230, a main lumen234is provided on the upward direction side of a sub lumen241and the inner needle12is inserted through and disposed in the main lumen234. In the third embodiment, the diameter of the main lumen234(second inner peripheral surface238) is larger than that of the sub lumen241. It should be noted that configurations similar to those of the second embodiment are adopted for the soft tip (flexible portion) and the main body portion constituting the catheter230and the soft tip is provided in the range from the distal end of the catheter230to a second outer peripheral surface244.

As in the case of the main lumen34of the first embodiment, the main lumen234of the catheter230has the second inner peripheral surface238including a first inner peripheral surface236and a tapered inner peripheral surface237. Although the outer peripheral surface of the catheter230has a first outer peripheral surface242, a tapered outer peripheral surface243, and the second outer peripheral surface244, the sub lumen241extends from the second outer peripheral surface244to the range in which the tapered outer peripheral surface243and the first outer peripheral surface242are formed. The sub lumen241is provided in the downward direction on the side opposite to the direction that the blade surface15of the inner needle12faces. A second distal end opening241aof the sub lumen241is disposed at substantially the same axial position as the first distal end opening234aof the main lumen234.

Accordingly, the lower portion side of the first distal end opening234aat the distal end of the catheter230(side where the sub lumen241is formed) is formed on an inclined end surface245continuous with the distal end tapered portion40although the outer shape of the catheter230is thick as a whole. The inclined end surface245is inclined at an appropriate angle on the lower side of the blade surface15of the inner needle12, and thus insertion of the distal end of the catheter230(first outer peripheral surface242) is smoothened. The second distal end opening241ais provided in the inclined end surface245. Although not illustrated, insertion of the distal end of the catheter230can be smoothened in a more satisfactory manner by the inner diameter of the distal end portion of the sub lumen241being reduced.

A main hub251of the catheter hub250forms a first space251aso as to communicate with the main lumen234in the upper portion of the catheter230. The main hub251has a bypass communication path253that allows communication between the sub lumen241provided on the lower portion side of the catheter230and a second space252aof a sub hub252connected to the upper portion side of the main hub251. The bypass communication path253is provided so as to curve in the peripheral wall that surrounds the first space251aof the main hub251and communicates with the second space252a.

As described above, the catheter assembly210according to the third embodiment is capable of obtaining effects similar to those of the catheter assembly10. With the catheter assembly210in particular, it is possible to quickly confirm that blood has flowed into the sub lumen241. This is because the second distal end opening241aof the sub lumen241is positioned closer to the distal end side than the hole portion14of the inner needle12.

Fourth Embodiment

As illustrated inFIG.5, a catheter assembly310according to a fourth embodiment is different from the catheter assemblies110, and210according to the first to third embodiments in terms of the structures of a multi-structure needle311(catheter330) and a catheter hub350. Specifically, in a plan cross-sectional view of the catheter330, a sub lumen341and a main lumen334extend in parallel to each other with the sub lumen341adjacent in the lateral direction of the main lumen334(rightward direction inFIG.5). The guide wire70is slidably disposed in the sub lumen341while the inner needle12is inserted through and disposed in the main lumen334.

In the fourth embodiment, the diameter of the main lumen334is larger than that of the sub lumen341. Configurations similar to those of the second embodiment are adopted for the soft tip (flexible portion) and the main body portion constituting the catheter330and the soft tip is provided in the range from the distal end of the catheter330to a second outer peripheral surface344.

As in the case of the main lumen34of the first embodiment, the main lumen334of the catheter330has a second inner peripheral surface338that includes a first inner peripheral surface336and a tapered inner peripheral surface337and communicates with a distal end opening334a. The outer peripheral surface of the catheter330has a first outer peripheral surface342, a tapered outer peripheral surface343, and the second outer peripheral surface344.

The sub lumen341is provided in the place where the second outer peripheral surface344is formed. The diameter of the sub lumen341is set to an appropriate dimension in accordance with the outer diameter of the guide wire70. An inclined end surface345continuous with the tapered outer peripheral surface343is formed at the distal end of the second outer peripheral surface344, and a second distal end opening341ais formed in the inclined end surface345.

The catheter hub350has a main hub351and a sub hub352, and the sub hub352is connected to the side of the main hub351. The main hub351has a first space350acommunicating with the main lumen334and a communication path353communicating with a second space352aof the sub hub352. In other words, the guide wire70is inserted so as to be slidable with respect to the sub lumen341via the second space352aand the communication path353.

As described above, the catheter assembly310according to the fourth embodiment is capable of obtaining effects similar to those of the catheter assembly10. In the catheter assembly310in particular, the guide wire70is slidably disposed in the sub lumen341, and thus the guide wire70reinforces the catheter330during insertion of the multi-structure needle311and the insertion performance of the catheter330can be enhanced. The guide wire70is capable of guiding insertion of the catheter330well by being inserted into a blood vessel from the sub lumen341.

The catheter assemblies10,110,210, and310and the following catheter assemblies510,610,710,810,910, and1010are not particularly limited as to the disposition relationship between main and sub lumens. In other words, adoptable are all of the disposition relationships between a main lumen α and a sub lumen β in catheters430A to430F according to first to sixth configuration examples illustrated inFIGS.6A to6F.

Specifically, the catheter430A illustrated inFIG.6Ais the disposition relationship between the main lumen34and the sub lumen41described in the first embodiment. In other words, the diameter of the main lumen α is larger than that of the sub lumen β and the sub lumen β is disposed above the main lumen α. The cross-sectional shape of the catheter430A that is orthogonal to the axial direction may be a shape other than the elliptical shape illustrated inFIG.6A. Examples of the shape include the shape of a perfect circle. The same applies to the catheters430B to430F.

The positions of disposition of the main lumen α and the sub lumen β will be described based on the blade surface15of the inner needle12disposed in the main lumen α as an index. In other words and as described above, the blade surface15of the inner needle12is operated in terms of posture so as to face the upward direction in a case where the patient's body surface is the lower side during puncturing. Accordingly, the sub lumen β being present above the main lumen α means that the sub lumen β is positioned in the upward direction that the blade surface15faces and constitutes the circumferential direction of the catheter430A.

The catheter430A illustrated inFIG.6Ais capable of performing flashback confirmation by using the sub lumen β. In addition, suppressed in this catheter430A is the place of formation of the distal end of the sub lumen β (inclined end surface) being caught by a blood vessel wall on the side opposite to the insertion place in a blood vessel and disturbed in terms of movement during blood vessel insertion. Accordingly, inflammation in or damage to the blood vessel wall can be suppressed as well. Furthermore, it is possible to suppress a decrease in flow rate attributable to the second distal end opening of the sub lumen β being closed by the blood vessel wall.

The catheter430B illustrated inFIG.6Bis the disposition relationship between the main lumen334and the sub lumen341described in the fourth embodiment. In other words, the diameter of the main lumen α is larger than that of the sub lumen β and the sub lumen β is disposed in the lateral direction of the main lumen α that constitutes the circumferential direction of the catheter430B (direction orthogonal to the direction that the blade surface faces). Effects similar to those of the disposition relationship illustrated inFIG.6Acan be obtained with this configuration. In addition, the flashback of the main lumen α can be confirmed well.

The catheter430C illustrated inFIG.6Cis the disposition relationship between the main lumen234and the sub lumen241described in the third embodiment. In other words, the diameter of the main lumen α is larger than that of the sub lumen β and the sub lumen β is disposed below the main lumen α in the circumferential direction of the catheter430C (direction opposite to the direction that the blade surface15faces). With this configuration, the flashback of the main lumen α can be confirmed better.

The catheter430D illustrated inFIG.6Dis the disposition relationship between the main lumen134and the sub lumen141described in the second embodiment. In other words, the diameter of the sub lumen β is larger than that of the main lumen α and the sub lumen β is disposed above the main lumen α in the circumferential direction of the catheter430D. In the430E illustrated inFIG.6E, the diameter of the sub lumen β is larger than that of the main lumen α and the sub lumen β is disposed in the lateral direction of the main lumen α. In the catheter430F illustrated inFIG.6F, the diameter of the sub lumen β is larger than that of the main lumen α and the sub lumen β is disposed below the main lumen α. Sufficient effects can be obtained, as in the case of the catheters430A to430C, with the catheters430D to430F illustrated inFIGS.6D to6F.

The cross-sectional shapes of the lumens are not particularly limited although the main lumen α and the sub lumen β have the shape of a perfect circle in cross section inFIGS.6A to6F. As an example, the lumen that is smaller in flow path cross-sectional area (such as the sub lumen) may have a shape (such as a C-shape, a U-shape, an elliptical shape, and a polygonal shape) surrounding a part of the circumferential outside of the main lumen α. Then, it is possible to reduce the outer diameters of all of the catheters430A to430F.

The catheter assembly may be configured to have three or more lumens431as in catheters430G and430H according to seventh and eighth configuration examples illustrated inFIGS.7A and7B. Specifically, in the catheter430G illustrated inFIG.7A, first and second sub lumens β1and β2are disposed above the main lumen α and side by side in the width direction (direction orthogonal to the direction that the blade surface15faces). In the catheter430H illustrated inFIG.7B, the main lumen α is disposed in the axial center portion of the catheter430H, the first sub lumen β1is disposed above the main lumen α (in the direction that the blade surface15faces), and the second sub lumen β2is disposed below the main lumen α (in the direction opposite to the direction that the blade surface15faces).

The catheter assembly may be configured such that the flashback can be confirmed in the order of the main lumen α and the sub lumen β by the diameter and the length of each flashback flow path being appropriately set. Then, the flashback of the lumen that has a distal end opening portion can be confirmed first, and thus a user is unlikely to feel discomfort. Alternatively, the catheter assembly may be configured such that the flashback can be confirmed in the order of the sub lumen β and the main lumen a by the diameter and the length of each flashback flow path being appropriately set. Then, the catheter assembly can be used with ease on the part of a user who thinks that the main lumen α is naturally in a blood vessel with the sub lumen β in the blood vessel.

Fifth Embodiment

As illustrated inFIGS.8to10, the catheter assembly510according to a fifth embodiment includes a catheter530having three lumens531as in the case of the seventh and eighth configuration examples and is configured such that a multi-structure needle511can be supported by a deflection suppression mechanism590of an inner needle hub519. Specifically, in a side cross-sectional view along the axial direction, the catheter530has a main lumen534disposed on the lower side, an intermediately disposed first sub lumen540, and a second sub lumen545disposed on the upper side.

The inner needle hub519of the catheter assembly510has a pair of extending portions520bifurcating from a base portion521, which is at the center in the width direction. The inner needle hub519holds a catheter hub550in a state of upward and downward exposure. It should be noted that the inner needle hub519may have the shape of a housing with the lower and upper sides of the pair of extending portions520covered. In a case where the upper side is covered, the upper cover may be provided with a slit so that a tab can be exposed from the housing and operated.

The deflection suppression mechanism590has a pair of openable and closable support arms591and a restraining portion592that is capable of restraining the pair of support arms591in a closed state and is capable of releasing the restraint. The pair of support arms591are pivotally supported by a pair of support pins593and can be opened and closed in the leftward-rightward direction with respect to the pair of extending portions520of the inner needle hub519.

Each support arm591is provided with a support groove591afor holding the inner needle12in the closed state. The pair of support grooves591aconstitute a support hole594supporting the multi-structure needle511. In the initial state of the catheter assembly510, the wall surface that constitutes the support hole594functions as a sliding contact support portion595rubbing against the catheter530when the catheter530advances with respect to the inner needle12. In the pre-puncture state, a slight gap is formed between the outer surface of the catheter530and the inner surface of the sliding contact support portion595. In addition, the sliding contact support portion595surrounds the entire circumferential direction of the catheter530contactably.

Each support arm591is provided with a bent engagement groove591bin a front view in the closed state. The restraining portion592has a head portion592acorresponding to the shape in which the pair of engagement grooves591bare continuous. In the pre-puncture state, the restraining portion592closes each support arm591by mutual engagement. The restraint with respect to the pair of support arms591is released by the pressing against the catheter hub550resulting from the advancement of the catheter hub550.

The main lumen534, the first sub lumen540, and the second sub lumen545extend in parallel to one another in the catheter530. The main lumen534, the first sub lumen540, and the second sub lumen545overlap each other in steps on the distal end side of the catheter530.

Specifically, the main lumen534is formed so as to be longer than the first and second sub lumens540and545and communicates with a first distal end opening534a(main opening) at the most distal end of the catheter530and the first proximal end opening (not illustrated) at the most proximal end of the catheter530. The catheter530has a first tapered outer peripheral surface535, which has an outer diameter gradually decreasing toward the first distal end opening534a. A first lateral opening534b(main opening) communicating with the main lumen534is provided at the midway position of the catheter530(between the first tapered outer peripheral surface535and a second distal end opening540ato be described later).

The first sub lumen540is formed so as to be shorter than the main lumen534and longer than the second sub lumen545. Here, the distal end side of the catheter530is increased in thickness (outer diameter) by the first sub lumen540overlapping the main lumen534and a second tapered outer peripheral surface541(tapered portion) constituting a step portion is provided at the most distal end of the first sub lumen540. The first sub lumen540communicates with the second distal end opening540a(sub opening) formed in the second tapered outer peripheral surface541. The first sub lumen540communicates with the second proximal end opening (not illustrated) at the most proximal end of the catheter530(positioned coaxially with the first proximal end opening). A second lateral opening540b(sub opening) communicating with the first sub lumen540is provided between the second tapered outer peripheral surface541of the catheter530and a third distal end opening545a, which will be described later.

The second sub lumen545is formed so as to be shortest. The distal end side of the catheter530is further increased in thickness (outer diameter) by the second sub lumen545overlapping the main lumen534and the first sub lumen540and a third tapered outer peripheral surface546(tapered portion) constituting a step portion is provided at the most distal end of the second sub lumen545. The second sub lumen545communicates with the third distal end opening545a(sub opening) formed in the third tapered outer peripheral surface546. The second sub lumen545communicates with the third proximal end opening (not illustrated) at the most proximal end of the catheter530(positioned coaxially with the first proximal end opening). A third lateral opening545b(sub opening) communicating with the second sub lumen545is provided on the proximal end side of the third tapered outer peripheral surface546of the catheter530.

The first lateral opening534band the second distal end opening540aare set at positions that are apart from each other at a distance of 17 mm or more. Likewise, the second lateral opening540band the third distal end opening545aare set at positions that are apart from each other at a distance of 17 mm or more.

In the present embodiment, the sliding contact support portion595of the deflection suppression mechanism590is positioned closer to the proximal end side than the third lateral opening545bof the catheter530in the pre-puncture state. More specifically, the sliding contact support portion595is provided so as to be capable of supporting a position in the vicinity of the third lateral opening545b(at a distance of, for example, 5 mm or less on the proximal end side), which is the sub opening of the two sub lumens540and545that is on the most proximal end side.

In the initial state of the catheter assembly510, the sliding contact support portion595may be provided closer to the distal end side than the third distal end opening545aof the second sub lumen545(see the two-dot chain line inFIG.9). Specifically, the sliding contact support portion595is capable of supporting the proximal end side that is beyond the second distal end opening540a(sub opening of the two sub lumens540and545that is on the most distal end side). Damage to the second tapered outer peripheral surface541and the second distal end opening540aof the first sub lumen540and the like can be suppressed also with the above-described configuration in which the deflection suppression mechanism590supports the distal end side that is beyond the third distal end opening545a. In addition, the deflection suppression effect of the inner needle12is improved.

The catheter hub550of the catheter assembly510has a main hub551functioning as a port of the main lumen534. In addition, the catheter hub550has a first sub port552functioning as a port of the first sub lumen540and a second sub port553functioning as a port of the second sub lumen545. A hub operation portion551a, on which a user puts his or her finger, is provided at the distal end of the main hub551. The hub operation portion551ahas a surface pushing out the restraining portion592. The hub operation portion551amay be configured so as to be removable from the main hub551.

Each of the first and second sub ports552and553has a connecting part for the main hub551, a soft flexible tube554(soft portion) fixed to the connecting part, and a sub hub555continuous with the proximal end of the flexible tube554. The sub hub555is configured as a connector to which a medical device is connected. A first communication path552acommunicating with the first sub lumen540is formed in the first sub port552(main hub551, flexible tube554, and sub hub555). Likewise, a second communication path553acommunicating with the second sub lumen545is formed in the second sub port553.

The catheter assembly510according to the fifth embodiment is basically configured as described above. As for the catheter assembly510, the deflection suppression mechanism590provides support in the vicinity of the proximal end of the third lateral opening545bduring puncturing with the multi-structure needle511. Accordingly, puncturing with the multi-structure needle511can be performed with deflection of the inner needle12suppressed well.

As illustrated inFIG.10, after puncturing with the multi-structure needle511, a user advances the catheter530relative to the inner needle12by advancing the catheter hub550. The catheter530can be smoothly advanced, without being caught, at this time because the deflection suppression mechanism590supports the proximal end side of the third lateral opening545bof the second sub lumen545. In addition, the catheter hub550pushes out the restraining portion592during the advancement, and thus the pair of support arms591are opened in the leftward-rightward direction. As a result, the support of the multi-structure needle511by the deflection suppression mechanism590can be released with ease and the catheter530and the catheter hub550can be detached from the inner needle12.

As described above, the catheter assembly510is capable of obtaining effects similar to those of the catheter assembly10. For example, the catheter assembly510is capable of easily supplying a liquid medicine or blood to the main lumen534and the first and second sub lumens540and545by a medical device being connected to the main hub551and the sub hub555during indwelling of the catheter530. After the catheter530is indwelled, different types of liquid medicines are allowed to flow well and be administered into a blood vessel by the main lumen534and the first and second sub lumens540and545extending in parallel to each other.

The deflection suppression mechanism590supports the proximal end side of the second distal end opening540a(sub opening at the most distal end) even in the configuration in which the catheter assembly510has a plurality of lumens, that is, the main lumen534and the first and second sub lumens540and545. As a result, damage to the catheter530can be reduced and deflection of the inner needle12can be suppressed at the same time.

It is preferable that the deflection suppression mechanism590supports a place close to the needle tip13of the inner needle12for deflection of the inner needle12to be suppressed. For example, with the deflection suppression mechanism590configured to support the distal end side that is beyond the plurality of sub openings, the possibility of damage to the catheter530attributable to contact with the sub opening during a movement of the catheter530increases. In contrast to this, in the catheter assembly510according to the present embodiment, the position of formation of the sub opening and the support position of the deflection suppression mechanism590are appropriately disposed, and thus both deflection prevention for the inner needle12and catheter mobility can be achieved.

In the catheter assembly510, the deflection suppression mechanism590supports the proximal end side that is beyond the third lateral opening545b(sub opening on the most proximal end side), and thus damage to the catheter530can be prevented in a more reliable manner. Further, because the deflection suppression mechanism590supports the proximal end side that is beyond the third tapered outer peripheral surface546, it is possible to prevent the deflection suppression mechanism590from being caught by the third tapered outer peripheral surface546. Accordingly, the mobility of the catheter530can be further enhanced.

In the catheter assembly510, the sub openings include the second and third lateral openings540band545b. Accordingly, the liquid medicine or blood that has flowed in the first and second sub lumens540and545can be discharged well into a blood vessel. In addition, damage to the vicinity of the third lateral opening545bis suppressed because the deflection suppression mechanism590is positioned on the proximal end side that is beyond the third lateral opening545b.

In the catheter assembly510, the first distal end opening534aand the second distal end opening540aare apart from each other at a distance of 17 mm or more. Accordingly, the liquid medicines flowing out from the first distal end opening534aand the second distal end opening540acan be mixed in a blood vessel. In other words, combination contraindications can be administered well with the single catheter530.

In the catheter assembly510, the deflection suppression mechanism590is capable of supporting the position at a distance of 5 mm or less on the proximal end side of the third lateral opening545b. Accordingly, the distance from the needle tip13of the inner needle12to the deflection suppression mechanism590is shortened. Accordingly, deflection of the inner needle12can be suppressed with more firmness.

In the catheter assembly510, the deflection suppression mechanism590surrounding the entire circumferential direction of the catheter530is capable of reliably suppressing upward, downward, leftward, and rightward shaking of the inner needle12(such as deviation from the deflection suppression mechanism590and deflection of the inner needle12).

The catheter assembly510is provided with the first and second sub ports552and553including the sub hub555and the flexible tube554, and thus the sub hub555can be freely placed in terms of position and posture. Accordingly, a user can satisfactorily carry out puncturing with the multi-structure needle511and insertion of the catheter530.

It should be noted that the main opening that the main lumen534communicates with and the sub opening that the first and second sub lumens540and545communicate with are not limited to the configurations described above (first distal end opening534a, first lateral opening534b, second distal end opening540a, second lateral opening540b, third distal end opening545a, third lateral opening545b) and various configurations are adoptable instead. For example, the first distal end opening534amay constitute the main opening alone.

The sub opening of the first sub lumen540may be only one of the second distal end opening540aand the second lateral opening540b. Likewise, the sub opening of the second sub lumen545may be only one of the third distal end opening545aand the third lateral opening545b.

In a case where the second lateral opening540bconstitutes the sub opening of the first sub lumen540alone and the third lateral opening545bconstitutes the sub opening of the second sub lumen545alone, for example, the second tapered outer peripheral surface541and the third tapered outer peripheral surface546constitute a step portion of the catheter530that is blocked. In this configuration, the deflection suppression mechanism590may provide support in the vicinity of the proximal end of the second tapered outer peripheral surface541or the third tapered outer peripheral surface546. Even with this configuration, it is possible to satisfactorily avoid catching of the deflection suppression mechanism590with respect to the second tapered outer peripheral surface541or the third tapered outer peripheral surface546.

Various configurations can be adopted for the deflection suppression mechanism590. For example, the inner surface of the support hole594constituting the sliding contact support portion595may be formed in a tapered shape so as to be tapered toward the distal direction. Then, it is possible to reduce catching of the third tapered outer peripheral surface546with respect to the sliding contact support portion595even with a configuration having a tapered portion (such as the third tapered outer peripheral surface546) as in the case of the catheter530and having the sliding contact support portion595on the distal end side.

It is a matter of course that the configuration of the deflection suppression mechanism590and the configuration of the sub lumen (including the tapered portion) in the catheter530are applicable to the following embodiments.

Sixth Embodiment

As illustrated inFIGS.11,12A, and12B, a catheter630of the catheter assembly610according to a sixth embodiment is configured such that a main lumen634and a sub lumen641are disposed in the upward-downward direction and the two lumens are partitioned by a partition wall640. The partition wall640is configured to be deformable in response to the pressure of the main lumen634and the sub lumen641.

Specifically, the main lumen634of the catheter630communicates with a distal end opening634aformed at the distal end of the catheter630and communicates with the proximal end opening (not illustrated) formed at the proximal end of the catheter630. In the pre-puncture state, the inner needle12is detachably disposed in the main lumen634.

The sub lumen641of the catheter630is positioned below the main lumen634and extends in parallel with the main lumen634. The sub lumen641communicates with a lateral opening641a, which is formed at the midway position on the lower side of the catheter630.

The partition wall640extends along the axial direction of the catheter630and separates the main lumen634and the sub lumen641from each other. Although the partition wall640is connected at a position shifted in phase by approximately 180° with respect to a tubular wall portion639of the catheter630in a cross-sectional view orthogonal to the axial direction of the catheter630, the partition wall640has a length exceeding the diameter of the tubular wall portion639(has a margin). The partition wall640is configured so as to be more flexible than the tubular wall portion639and can be deformed by receiving a predetermined positive pressure or more pressure from a liquid medicine.

As illustrated inFIG.12A, for example, the partition wall640is capable of spreading downward and allowing the inner needle12to be disposed well in a state where the inner needle12is inserted through the main lumen634. As illustrated inFIG.12B, for example, the partition wall640increases the flow path cross-sectional area of the main lumen634in a case where a liquid medicine is allowed to flow in quantity through the main lumen634. In a case where a liquid medicine is allowed to flow in quantity through the sub lumen641, the partition wall640increases the flow path cross-sectional area of the sub lumen641as indicated by the two-dot chain line in the illustrated example.

Returning toFIG.11, the catheter assembly610fixes and holds the proximal end of the catheter630by means of a catheter hub650. The catheter hub650has a sub hub652protruding upward from a main hub651as in the first embodiment.

A catheter operation member660is a long plate corresponding to the elongated inner needle12and the catheter630(multi-structure needle611). The catheter operation member660is fixed so as to be rotatable with respect to the catheter hub650. The catheter operation member660has a pressing portion661capable of pressing the part between the proximal end and the distal end of the catheter630. The pressing portion661constitutes a part of a deflection suppression mechanism690. The catheter operation member660has a plurality of non-slip ribs662, which are spaced apart from one another on the upper surface of the catheter operation member660.

A housing620of the catheter assembly610is formed in an elongated bowl shape, accommodates the proximal end side of the multi-structure needle611, and movably accommodates the catheter hub650. The housing620has a bottom plate621and left and right side walls622extending upward from the left and right sides of the bottom plate. The housing620is open upward and to the distal end side. The distal end portion of the bottom plate621is a sliding contact support portion691rubbing against the catheter630when the catheter630advances with respect to the inner needle12.

The sliding contact support portion691and the pressing portion661constitute the deflection suppression mechanism690. The deflection suppression mechanism690is capable of supporting the inner needle12and the catheter630(multi-structure needle611) between the sliding contact support portion691and the pressing portion661when the catheter630advances with respect to the inner needle12. In the pre-puncture state, the sliding contact support portion691is disposed at a position where the proximal end side that is beyond the lateral opening641aof the catheter630can be supported.

The catheter assembly610according to the sixth embodiment is basically configured as described above. In using the catheter assembly610, a user performs puncturing by pressing the distal end portion of the catheter assembly610(distal end portion of the catheter630through which the inner needle12is inserted) against a patient while pressing the distal end portion of the catheter operation member660with the index finger of one hand. The catheter630is sandwiched and supported between the pressing portion661and the distal end portion (sliding contact support portion691) of the housing620in a state where the midway part of the catheter630is pressed with the catheter operation member660(pressing portion661). As a result, deflection of the multi-structure needle611is suppressed.

Then, the distal end of the catheter630is inserted to a target position in a blood vessel by the catheter operation member660being advanced relative to the inner needle12and the housing620. When the catheter630moves in the distal direction with respect to the inner needle12, the catheter630slides with respect to the sliding contact support portion691. Subsequently, the housing620is pulled in the proximal direction while the catheter operation member660is pressed with the other hand. As a result, the catheter630and the catheter hub650can be indwelled in the patient by detachment of the inner needle12from the catheter hub650and removal of the catheter operation member660.

The catheter assembly610is capable of obtaining effects similar to those of the other embodiments described above. In other words, the deflection suppression mechanism690supports a position (proximal end position at a distance of, for example, 5 mm or less) in the vicinity of the proximal end side of the lateral opening641aof the sub lumen641(sub opening at the most distal end). As a result, damage to the catheter630can be reduced and deflection of the inner needle12can be suppressed at the same time.

In the catheter assembly610in particular, the main lumen634and the sub lumen641are partitioned from each other by the partition wall640, which can be deformed in response to pressure. Accordingly, in the pre-puncture state, the relative movements of the catheter630and the inner needle12can be simplified by the main lumen634being enlarged. During drug or blood administration, the partition wall640is appropriately deformed by the fluid pressure resulting from the administration. For example, a flow path cross-sectional area can be ensured with ease even in a case where the liquid medicine of the sub lumen641is caused to flow by a relatively larger amount than the liquid medicine of the main lumen634.

Seventh Embodiment

As illustrated inFIG.13, a catheter730of the catheter assembly710according to a seventh embodiment is similar in configuration to the catheter30of the first embodiment and a main lumen734and a sub lumen741are provided in the catheter730. A deflection suppression mechanism790suppressing deflection of the inner needle12and the catheter730(multi-structure needle711) is provided on the distal end side of the catheter assembly710.

Specifically, an inner needle hub719has an upper housing720and a lower housing721. In the pre-puncture state, the upper housing720and the lower housing721overlap each other in the upward-downward direction. Respective distal end portions720aand721aof the upper housing720and the lower housing721are held so as to be embraced by a guide wire operation member780, which will be described later, and upward-downward expansion is regulated as a result. A slit722, which extends in the longitudinal direction, is formed between the upper housing720and the lower housing721in the left and right side portions of the inner needle hub719. The upper housing720has a pair of side grip portions720bobliquely inclined with respect to the slit722. The pair of side grip portions720bare gripped by a user during puncturing with the multi-structure needle711.

The distal end portion720aof the upper housing720and the distal end portion721aof the lower housing721constitute the deflection suppression mechanism790. A holding groove723having a semicircular cross section is formed in the facing surfaces of the distal end portions720aand721aof the upper housing720and the lower housing721. The wall portion that constitutes the holding groove723constitutes a hole-shaped sliding contact support portion791, which rubs against the catheter730when the catheter730advances with respect to the inner needle12. In the initial state of the catheter assembly710, a slight gap is formed between the outer surface of the catheter730and the sliding contact support portion791.

The catheter730has a distal end opening734acommunicating with the main lumen734at the distal end of the catheter730and has a lateral opening741aof the sub lumen741at a predetermined distance (such as 17 mm or more) from the distal end opening734a. The catheter730is fixed and held by a catheter hub750.

The catheter hub750includes a main hub751communicating with the main lumen734and a sub port752provided on the side surface of the main hub751. In this case, the sub port752has a sub hub753, a hard tube754, and a soft tube755. A medical device can be connected to the sub hub753. The hard tube754is connected to the main hub751and protrudes to the outside of the inner needle hub719. The soft tube755extends between the hard tube754and the sub hub753and is softer than the hard tube754. The sub port752is exposed to the outside via the slit722of the inner needle hub719with the hard tube754of the main hub751protruding in the lateral direction.

A catheter operation member760is attached to the proximal end side of the catheter hub750that is beyond the sub port752. The catheter operation member760has a middle base portion761detachably connected to the proximal end portion of the catheter hub750and a pair of finger hook portions762extending to both sides in the leftward-rightward direction from the middle base portion761. In the pre-puncture state, the middle base portion761is accommodated in the inner needle hub719and the finger hook portion762protrudes outward in the leftward-rightward direction via the slit722.

In the pre-puncture state of the catheter assembly710, the deflection suppression mechanism790(sliding contact support portion791) is positioned on the proximal end side that is beyond the lateral opening741aof the sub lumen741. The sliding contact support portion791is provided closer to the proximal end side than the lateral opening741apositioned on the most distal end side.

A guide wire770extends in the axial direction in the inner needle12, protrudes from the proximal end opening (not illustrated) of the inner needle12, and is connected to the proximal end portion of the guide wire operation member780via the connecting portion (not illustrated) that is disposed in the inner needle hub719. The guide wire operation member780is provided so as to be displaceable in the forward-rearward direction with respect to inner needle hub719. The guide wire operation member780has a pair of regulating arms781embracing the distal end portion of the inner needle hub719in the pre-puncture state. The guide wire operation member780has a finger hook tab782and a plurality of non-slip ribs783.

When the catheter assembly710configured as described above is used, a user performs puncturing on a patient with the multi-structure needle711(inner needle12, catheter730). At this time, the deflection suppression mechanism790suppresses deflection by supporting the multi-structure needle711. Subsequently, the user operates the guide wire operation member780in the distal direction and causes the guide wire770to protrude from the distal end of the inner needle12for insertion into a blood vessel. Once the pair of regulating arms781move to the distal end side beyond the distal end portion of the inner needle hub719as the guide wire operation member780is moved in the distal direction, the regulation of the upward-downward expansion of the distal end portion of the upper housing720and the distal end portion of the lower housing721is released.

Subsequently, the user advances the catheter730and the catheter hub750by operating the catheter operation member760in the distal direction. During this movement, the upper housing720is opened with respect to the lower housing721by the pair of side grip portions720bcoming into contact with the hard tube754of the catheter hub750and being pressed upward. As a result, the catheter operation member760is allowed to move in the distal direction and the catheter730can be inserted well into the blood vessel.

The user removes the inner needle12from the catheter730by pulling the inner needle hub719in the proximal direction with respect to the catheter730and the catheter hub750. As a result, the catheter730and the catheter hub750are indwelled on the patient side.

As described above, the catheter assembly710according to the seventh embodiment is capable of obtaining effects similar to those of the embodiments described above. In other words, the deflection suppression mechanism790supports the proximal end side of the lateral opening741aof the sub lumen741(sub opening at the most distal end). As a result, damage to the catheter730can be reduced and deflection of the inner needle12can be suppressed at the same time.

In the catheter assembly710, the inner needle hub719has the slit722, and thus the sub port752can be easily moved along the slit722even in the configuration in which the catheter hub750is provided with the sub port752. In other words, a movement of the catheter730with respect to the inner needle12can be performed with smoothness. In the catheter assembly710in particular, the sub port752protrudes in the lateral direction of the inner needle hub719, and thus the sub port752becoming a hindrance during puncturing with the multi-structure needle711or the like can be suppressed and a user's work can be facilitated. Further, the sub port752of the catheter assembly710allows the catheter hub750to be smoothly moved because the hard tube754is placed at the position coming into contact with the inner needle hub719.

Eighth Embodiment

As illustrated inFIGS.14and15, the catheter assembly810according to an eighth embodiment is configured by a catheter hub850extending to the proximal end side beyond a catheter operation member860and a sub port852being provided at the extending part of the catheter hub850. It should be noted that a catheter830has a main lumen834and a sub lumen841as in the first embodiment and constitutes a multi-structure needle811by accommodating the inner needle12in the pre-puncture state. The catheter830has a distal end opening834acommunicating with the main lumen834at the distal end of the catheter830. The catheter830has a lateral opening841acommunicating with the sub lumen841at a predetermined distance (such as 17 mm or more) from the distal end opening834a.

The sub port852of the catheter hub850has a sub hub853and a soft tube855interconnecting a main hub851and the sub hub853.

As in the seventh embodiment, an inner needle hub819of the catheter assembly810has an upper housing820and a lower housing821overlapping each other in the upward-downward direction. In the pre-puncture state, distal end portions820aand821aof the upper housing820and the lower housing821are closed. A slit822extending in the longitudinal direction of the inner needle hub819is formed between the upper housing820and the lower housing821. The distal end portion821aof the lower housing821has a right side distal end portion823R and a left side distal end portion823L and is configured to be capable of expanding in the leftward-rightward direction.

The distal end portion820aof the upper housing820has a regulating portion824, which regulates leftward-rightward opening of the right side distal end portion823R and the left side distal end portion823L of the lower housing821in the pre-puncture state. The regulating portion824is configured to hold the left and right sides of the right side distal end portion823R and the left side distal end portion823L with a pair of plate portions (not illustrated) and interconnect the upper sides of the pair of plate portions (not illustrated) with a bridging portion.

The catheter assembly810constitutes a deflection suppression mechanism890by means of the right side distal end portion823R and the left side distal end portion823L. A holding groove825is formed in each of the right side distal end portion823R and the left side distal end portion823L. The wall portion that constitutes the two holding grooves825constitutes a hole-shaped sliding contact support portion891, which rubs against the catheter830when the catheter830advances with respect to the inner needle12. In the initial state of the catheter assembly810, a slight gap is formed between the outer surface of the catheter830and the inner surface of the sliding contact support portion891. The sliding contact support portion891(deflection suppression mechanism890) supports the proximal end side that is beyond the lateral opening841aof the sub lumen841(sub opening positioned on the most distal end side).

Further, the upper housing820is provided with a guide passage826extending in the longitudinal direction. The sub port852(soft tube855) of the catheter hub850is exposed from the inside of the upper housing820to the outside of the upper housing820via the guide passage826.

The catheter operation member860has a middle base portion861detachably connected to the proximal end portion of the catheter hub850and a pair of finger hook portions862extending to both sides in the leftward-rightward direction from the middle base portion861. The pair of finger hook portions862are inclined upward toward the outer side in the leftward-rightward direction. The lower surface of the finger hook portion862is provided with a plurality of non-slip projections862a.

The catheter assembly810has a guide wire870and a guide wire operation member880. A plurality of finger hook ribs881are provided on the upper surface of the guide wire operation member880. The guide wire operation member880is connected to the proximal end portion of the guide wire870via the intermediate connecting portion (not illustrated) that is disposed in the inner needle hub819. The guide wire operation member880is provided so as to be displaceable in the forward-rearward direction with respect to upper housing820.

When the catheter assembly810configured as described above is used, a user performs puncturing on a patient with the multi-structure needle811(inner needle12, catheter830). At this time, the deflection suppression mechanism890suppresses deflection by supporting the multi-structure needle811. Subsequently, the user operates the guide wire operation member880in the distal direction and causes the guide wire870to protrude from the distal end of the inner needle12for insertion into a blood vessel.

Subsequently, the user advances the catheter830and the catheter hub850by operating the catheter operation member860in the distal direction. During this movement, the upper housing820is opened with respect to the lower housing821by being pressed upward by the catheter operation member860. By the upper housing820being detached, the right side distal end portion823R and the left side distal end portion823L of the lower housing821can be further separated from each other in the leftward-rightward direction. As a result, the catheter operation member860is allowed to move in the distal direction and the catheter830can be inserted well into the blood vessel.

The user removes the inner needle12from the catheter830by pulling the inner needle hub819in the proximal direction with respect to the catheter830and the catheter hub850. As a result, the catheter830and the catheter hub850are indwelled on the patient side.

As described above, the catheter assembly810according to the eighth embodiment is capable of obtaining effects similar to those of the embodiments described above. In other words, the deflection suppression mechanism890supports the proximal end side of the lateral opening841aof the sub lumen841(sub opening at the most distal end). As a result, damage to the catheter830can be reduced and deflection of the inner needle12can be suppressed at the same time.

Further, in the catheter assembly810, the sub port852protrudes in the upward direction of the upper housing820. As a result, gripping of the inner needle hub819can be simplified and operability can be enhanced for users.

Ninth Embodiment

As illustrated inFIG.16, the catheter assembly910according to a ninth embodiment is basically similar in configuration to the catheter assembly810according to the eighth embodiment and is provided with the inner needle12, an inner needle hub919, a catheter930, a catheter hub950, a catheter operation member960, a guide wire970, a guide wire operation member980, and a deflection suppression mechanism990.

The catheter930has a main lumen934and a sub lumen941and constitutes a multi-structure needle911by accommodating the inner needle12in the pre-puncture state. The catheter930has a distal end opening934acommunicating with the main lumen934at the distal end of the catheter930. The catheter930has a lateral opening941acommunicating with the sub lumen941at a predetermined distance (such as 17 mm or more) from the distal end opening934a.

The catheter hub950is disposed on the proximal end side that is beyond the catheter operation member960. The catheter hub950is configured to be provided with a main hub951and a sub port952at the extending part of the main hub951. The sub port952has a sub hub953and a soft tube955interconnecting the main hub951and the sub hub953.

The inner needle hub919of the catheter assembly910has an upper housing920and a lower housing921overlapping each other in the upward-downward direction. In the pre-puncture state, distal end portions920aand921aof the upper housing920and the lower housing921are closed. A slit922extending in the longitudinal direction of the inner needle hub919is formed between the upper housing920and the lower housing921. In the present embodiment, the slit922extends to the proximal end side beyond the initial position of the catheter operation member960in the pre-puncture state.

The lower housing921has a right side distal end portion and a left side distal end portion, which can be separated to the left and right outer sides with separation from the upper housing920. The right side distal end portion and the left side distal end portion constitute the deflection suppression mechanism990. As in the eighth embodiment, the deflection suppression mechanism990constitutes a sliding contact support portion991by means of the holding grooves (not illustrated) of the right side distal end portion and the left side distal end portion. In addition, the deflection suppression mechanism990is positioned closer to the proximal end side than the lateral opening941apositioned on the most distal end side.

The catheter operation member960is supported by the upper housing920of the inner needle hub919so as to be slidable in the forward-rearward direction. A finger hook projection961is provided on the upper surface of the catheter operation member960. The guide wire operation member980is displaceable with respect to the upper housing920and is connected to the proximal end portion of the guide wire970via the intermediate connecting portion (not illustrated) that is disposed in the inner needle hub919. A plurality of finger hook ribs981are provided on the upper surface of the guide wire operation member980.

In the catheter assembly910, distances Xa, Xb, and Xc are set to be Xa<Xb<Xc. Xa is the distance from the distal end of the inner needle hub919to the projection961of the catheter operation member960. Xb is the distance from the projection961to the rib981. Xc is the distance from the rib981to the proximal end of the inner needle hub919. As a result, with the catheter assembly910, the position of a finger can be disposed well with respect to each operation member during single-hand operation by a user.

When the catheter assembly910configured as described above is used, a user performs puncturing on a patient with the multi-structure needle911(inner needle12, catheter930). At this time, the deflection suppression mechanism990suppresses deflection by supporting the multi-structure needle911. Subsequently, the user operates the guide wire operation member980in the distal direction and causes the guide wire970to protrude from the distal end of the inner needle12for insertion into a blood vessel.

Subsequently, the user advances the catheter930and the catheter hub950by operating the catheter operation member960in the distal direction. During this movement, the upper housing920is opened with respect to the lower housing921by being pressed upward by the catheter operation member960. By the upper housing920being detached, the right side distal end portion and the left side distal end portion of the lower housing921can be further separated from each other in the leftward-rightward direction. As a result, the catheter operation member960is allowed to move in the distal direction and the catheter930can be inserted well into the blood vessel.

The user removes the inner needle12from the catheter930by pulling the inner needle hub919in the proximal direction with respect to the catheter930and the catheter hub950. As a result, the catheter930and the catheter hub950are indwelled on the patient side.

As described above, the catheter assembly910according to the ninth embodiment is capable of obtaining effects similar to those of the embodiments described above. In other words, the deflection suppression mechanism990supports the proximal end side of the lateral opening941aof the sub lumen941(sub opening at the most distal end). As a result, damage to the catheter930can be reduced and deflection of the inner needle12can be suppressed at the same time.

Tenth Embodiment

As illustrated inFIG.17, the catheter assembly1010according to a tenth embodiment is provided with the inner needle12, a catheter1030, a catheter hub1050connected to the catheter1030, a catheter operation member1060moving the catheter hub1050in the distal direction, an inner needle hub1019connected to the inner needle12, a guide wire (not illustrated) inserted through the inner needle12, a guide wire operation member1080connected to the guide wire, and a deflection suppression mechanism1090suppressing deflection of the inner needle12during puncturing. The inner needle12and the catheter1030form a multi-structure needle1011in the pre-puncture state.

The catheter1030is similar in configuration to the fifth embodiment. In other words, the catheter1030has a main lumen1034, a first sub lumen1040, and a second sub lumen1045. The main lumen1034communicates with a first distal end opening1034aand a first lateral opening1034bon the distal end side of the catheter1030and communicates with the proximal end opening (not illustrated) that is at the proximal end of the catheter1030. The first sub lumen1040communicates with a second distal end opening1040aand a second lateral opening1040bon the distal end side of the catheter1030and communicates with the proximal end opening (not illustrated) that is at the proximal end of the catheter1030. The second sub lumen1045communicates with a third distal end opening1045aand a third lateral opening1045bon the distal end side of the catheter1030and communicates with the proximal end opening (not illustrated) that is at the proximal end of the catheter1030.

The catheter hub1050is fixed to the proximal end portion of the catheter1030. The catheter hub1050is accommodated in the inner needle hub1019in the pre-puncture state of the catheter assembly1010. The catheter hub1050has a main hub1051connected to the catheter1030and a first side port1052and a second side port1053protruding in the lateral direction (horizontal direction perpendicular to the axis of the main hub1051) from the main hub1051. The first and second side ports1052and1053have a soft tube1054connected to the main hub1051via a hard tube1051aand a sub hub1055connected to the other end of the soft tube1054. A clamp1056, which is capable of opening and closing the communication path in the soft tube1054, is attached to the soft tube1054.

The catheter assembly1010has a slide member1057, which slides integrally with the catheter hub1050along a housing1020(lower side extending portion1022). The slide member1057has a pair of holding projecting portions1057a, which are gripped by a user during detachment of the catheter hub1050from the housing1020.

The slide member1057has an accommodating groove1057baccommodating the distal end side of the catheter hub1050. Especially, the catheter hub1050according to the present embodiment has a pair of wings1058extending outward in the width direction from the outer peripheral surface on the distal end side and the accommodating groove1057bis formed in a shape that allows the pair of wings1058to be stored. The wing1058is provided with a small hole (not illustrated). The convex portion (not illustrated) that is provided in the accommodating groove1057bis inserted into the small hole. The accommodating groove1057bis open upward, and the catheter hub1050can be detached upward.

The catheter operation member1060is an annular member supported so as to be slidable in the forward-rearward direction in the distal end portion of the housing1020of the inner needle hub1019, which will be described later. The catheter operation member1060is provided with a finger hook portion1061protruding in a flange shape. A side wall1062of the catheter operation member1060is provided with a recess portion1063open in the distal direction. The second side port1053of the catheter hub1050protrudes in the lateral direction via the recess portion1063.

The inner needle hub1019has the housing1020functioning as a grip portion for a user and an upper side extending portion1021and the lower side extending portion1022extending in parallel to each other in the distal direction from the distal end portion of the housing1020. In the pre-puncture state of the catheter assembly1010, the catheter1030and the catheter hub1050are disposed between the upper side extending portion1021and the lower side extending portion1022.

The deflection suppression mechanism1090is provided in the distal end portion of the inner needle hub1019. Specifically, the deflection suppression mechanism1090is provided with a support member1091, which is supported by the upper side extending portion1021so as to be rotatable about an axis in the leftward-rightward direction. The support member1091has a sliding contact support portion1092, which rubs against the catheter1030when the catheter1030advances with respect to the inner needle12. An upper portion1091uof the support member1091is provided with a shaft portion1093. The shaft portion1093is pivotally supported by the upper side extending portion1021. The distal end portion of the guide wire operation member1080is positioned closer to the distal end side than the upper portion1091uof the support member1091. Accordingly, upward rotation of the support member1091is regulated by the guide wire operation member1080.

As illustrated inFIG.18, the sliding contact support portion1092has an upper support portion1094capable of supporting the catheter1030from above and left and right lateral support portions1095capable of supporting the catheter1030from the lateral direction. The lateral support portions1095protrude downward from the left and right end portions of the upper support portion1094. Accordingly, the sliding contact support portion1092is formed in an inverted U-shape as viewed from the longitudinal direction of the catheter assembly1010. In the pre-puncture state, a slight gap is formed between the outer surface of the catheter1030and the sliding contact support portion1092.

As illustrated inFIG.17, in the initial state of the catheter assembly1010, the sliding contact support portion1092supports the proximal end side that is beyond the third lateral opening1045bpositioned on the most distal end side.

The guide wire operation member1080is an operation portion for performing guide wire insertion into a patient's blood vessel prior to insertion of the catheter1030into the blood vessel. A finger hook projection1081and a plurality of non-slip ribs1082are provided at the distal end of the guide wire operation member1080. The guide wire operation member1080is supported so as to be slidable in the forward-rearward direction on the upper surface of the upper side extending portion1021. One end portion of the guide wire is disposed in the vicinity of the distal end of the inner needle12and the other end portion of the guide wire is connected to the guide wire operation member1080. The intermediate portion of the guide wire is folded back in the housing1020.

A patient's skin is punctured with the catheter assembly1010when the catheter assembly1010is used. A user performs the skin puncturing toward a puncturing target blood vessel by pressing the distal end portion of the catheter assembly1010against the patient with the housing1020in the pre-puncture state illustrated inFIG.17gripped. As a result, the skin is punctured with the respective distal end portions of the inner needle12and the catheter1030.

Once the user subsequently moves the guide wire operation member1080in the proximal direction, the guide wire intermediately folded back in the housing1020moves in the distal direction in the inner needle12. As a result, the guide wire protrudes from the distal end of the inner needle12and is inserted into the blood vessel. As the guide wire operation member1080is moved in the proximal direction, the distal end portion of the guide wire operation member1080moves in the proximal direction beyond the upper portion of the support member1091. As a result, the regulation of upward rotation of the support member1091by the guide wire operation member1080is released.

After the distal end of the guide wire is inserted into the target position in the blood vessel, the user advances the catheter1030, the catheter hub1050, and the slide member1057by operating the catheter operation member1060in the distal direction with the position of the inner needle hub1019fixed. As a result, the catheter1030is inserted into the target position in the blood vessel. At this time, the support member1091rotates upward by being pressed by the slide member1057moving in the distal direction. As a result, the catheter1030is allowed to be detached in the distal direction from the inner needle hub1019.

Subsequently, the user pulls the housing1020in the proximal direction with the positions of the catheter1030, the catheter hub1050, and the slide member1057held by pressing the pair of holding projecting portions1057aof the slide member1057. As a result, the catheter1030, the catheter hub1050, and the slide member1057completely come out of the inner needle hub1019and the inner needle12is removed in the proximal direction from the catheter1030. Subsequently, the catheter hub1050is removed from the slide member1057. Then, a tape or the like (not illustrated) is attached to the pair of wings1058of the catheter hub1050. As a result, the catheter1030and the catheter hub1050are indwelled in the patient's blood vessel.

As described above, the catheter assembly1010according to the tenth embodiment is capable of obtaining effects similar to those of the embodiments described above. In other words, the deflection suppression mechanism1090supports the proximal end side of the third lateral opening1045bof the second sub lumen1045(sub opening at the most proximal end). As a result, damage to the catheter1030can be reduced and deflection of the inner needle12can be suppressed at the same time.

The sliding contact support portion1092, in particular, has the upper support portion1094capable of supporting the catheter1030from above and the lateral support portion1095capable of supporting the catheter1030from the lateral direction (FIG.18) and the third lateral opening1045bis provided in any place in the upper and lateral portions of the catheter1030. With this configuration, it is possible to effectively suppress damage to the third lateral opening1045band an increase in sliding resistance during advancement of the catheter1030.

It should be noted that each of the configurations described in the first to tenth embodiments and the first to eighth configuration examples of the present invention can be partially taken out and applied to another embodiment or another configuration example without departing from the technical idea of the present invention.