Catheter

Abstract

A catheter (10A) comprises a valve fixing structure (32A) for fixing a valve body (18A) to a catheter hub (16A). The valve fixing structure (32A) comprises a fixing part (36A) formed from a swelling material and provided on an outer surface (281) of the valve body (18A).

Description

Catheter

[0001] The present disclosure relates to a catheter.

[0002] Japanese National Publication of International Patent Application No. 2016-509915 discloses a catheter assembly. The catheter assembly includes a catheter and a needle member. The catheter includes a catheter main body, a catheter hub fixed to a proximal end of the catheter main body, and a valve body disposed inside the catheter hub. When using the catheter assembly, after puncturing a living body with the distal end of the needle member, the catheter main body is advanced relative to the inner needle, whereby the catheter main body is inserted into a blood vessel. The inner needle of the needle member is withdrawn from the catheter, and the valve body prevents blood leakage from the catheter hub.

[0003] Japanese National Publication of International Patent Application No. 2016-509915

[0004] In many cases, catheters are used by being inserted into veins, but there are also cases where catheters are inserted into arteries. Since arterial pressure is higher than venous pressure, when a catheter designed for venous indwelling is used for arterial indwelling, a higher pressure than expected is applied to the valve body, which may cause the valve body to shift from its predetermined position in the catheter hub. If the valve body shifts, blood may leak out from the catheter hub.

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

[0006] (1) An aspect of the present disclosure is a catheter comprising: a hollow catheter main body; a catheter hub having a hub lumen communicating with the catheter main body and fixed to a proximal end portion of the catheter main body; a valve body disposed between a distal space portion and a proximal space portion of the hub lumen, the valve body being capable of switching the communication state between the distal space portion and the proximal space portion; and a valve fixing structure that fixes the valve body to the catheter hub, wherein the valve fixing structure includes a fixing portion provided on either one of an inner surface of the catheter hub and an outer surface of the valve body, the fixing portion being formed of a swellable material.

[0007] With this catheter, when liquid is introduced into the tip space of the catheter hub, the fixation part swells upon contact with the liquid, thereby increasing the fixing force of the valve body to the catheter hub. As a result, the valve body can be effectively fixed to the catheter hub. Therefore, even when high pressure (e.g., arterial pressure) is applied to the valve body, displacement of the valve body from its predetermined position within the catheter hub is effectively suppressed.

[0008] (2) The catheter described in (1) above is provided with an engaging portion on the other of the inner surface of the catheter hub and the outer surface of the valve body, with which the fixing portion is engaged, and when the fixing portion swells, the swollen fixing portion and the engaging portion may fit together.

[0009] This configuration allows the valve body to be more effectively fixed to the catheter hub by bringing the swollen fixing portion into close contact with the engaged portion.

[0010] (3) In the catheter described in (2) above, the engaged portion may be a recess, and the fixing portion may be a convex portion that protrudes toward the recess and is inserted into the recess.

[0011] This configuration allows the valve body to be more effectively fixed to the catheter hub.

[0012] (4) In the catheter described in (1) or (2) above, a channel may be provided between the inner surface of the catheter hub and the outer surface of the valve body that communicates with at least the tip space.

[0013] This configuration allows the liquid introduced into the tip space to be introduced into the flow path, thereby effectively swelling the fixed part with the liquid.

[0014] (5) In the catheter described in (4) above, the flow path may communicate with the proximal space.

[0015] This configuration allows the liquid introduced into the tip space to effectively swell the fixing part, and also allows the gas inside the hub lumen to be discharged towards the base end via the flow path.

[0016] (6) In the catheter described in (4) or (5) above, the flow path and the fixing portion may each extend along the axial direction of the catheter hub, and the flow path and the fixing portion may be adjacent to each other in the circumferential direction of the valve body.

[0017] This configuration allows the fixed part to swell more effectively with the liquid flowing through the channel.

[0018] (7) In the catheter described in (2) above, the fixing portion may be provided on the outer surface of the valve body, and the engaging portion may be provided on the inner surface of the catheter hub.

[0019] This configuration allows for easy formation of both the fixed portion and the engaged portion.

[0020] (8) In the catheter described in any one of (1) to (7) above, the fixing portion may extend along the axial direction of the catheter hub.

[0021] This configuration allows for the implementation of a valve fixing structure with a simple design.

[0022] (9) In the catheter described in any one of (1) to (7) above, the fixing portion may extend in the circumferential direction of the catheter hub.

[0023] This configuration allows for the implementation of a valve fixing structure with a simple design.

[0024] (10) In the catheter described in (9) above, the valve body may be provided with a communication hole that connects the engaged portion and the tip space portion to each other.

[0025] This configuration allows the liquid introduced into the tip space through the communication hole to be effectively directed toward the fixed part.

[0026] (11) In the catheter described in any one of (1) to (10) above, the swelling material may be an absorbent polymer.

[0027] This configuration allows for the implementation of a valve fixing structure at a low cost.

[0028] According to this disclosure, when liquid is introduced into the tip space of the catheter hub, the fixing portion swells upon contact with the liquid, thereby increasing the fixing force of the valve body to the catheter hub. As a result, the valve body can be effectively fixed to the catheter hub. Therefore, even when high pressure (e.g., arterial pressure) is applied to the valve body, displacement of the valve body from its predetermined position within the catheter hub is effectively suppressed.

[0029] Figure 1 is a cross-sectional view of a catheter according to the first embodiment of this disclosure. Figure 2 is an enlarged cross-sectional view showing the area around the valve fixation structure in Figure 1. Figure 3 is a cross-sectional view along the line III-III in Figure 1. Figure 4 is a perspective view of the valve body. Figure 5 is a plan view of the valve body shown in Figure 4. Figure 6 is an enlarged cross-sectional view of the valve fixation structure showing the fixation portion in a swollen state. Figure 7 is an explanatory diagram showing the catheter during puncture. Figure 8 is a cross-sectional view of a catheter according to the second embodiment of this disclosure. Figure 9 is a cross-sectional view along the line IX-IX in Figure 8. Figure 10 is a perspective view of the valve body. Figure 11 is an enlarged cross-sectional view of the valve fixation structure showing the fixation portion in a swollen state. Figure 12 is a cross-sectional view of a catheter according to the third embodiment of this disclosure. Figure 13 is a cross-sectional view along the line XIII-XIII in Figure 12. Figure 14 is a perspective view of the valve body. Figure 15 is an enlarged cross-sectional view of a modified valve fixation structure.

[0030] The catheter 10A shown in Figure 1, according to the first embodiment, is a vascular access device inserted into a blood vessel BV. The catheter 10A is combined with a needle member 12 to form a catheter assembly 100. The catheter assembly 100 can be configured as a peripheral arteriovenous indwelling needle, a dialysis indwelling needle, a PICC, a midline catheter, a CV catheter, etc.

[0031] The catheter 10A comprises a hollow catheter body 14, a catheter hub 16A, and a valve body 18A.

[0032] The catheter body 14 is a flexible tube. The constituent material of the catheter body 14 is not particularly limited. Examples of constituent materials for the catheter body 14 include ETFE, PTFE, PFA, PE, PU, ​​etc. In the initial state of the catheter assembly 100, the inner needle 121 of the needle member 12 is inserted into the lumen 141 of the catheter body 14.

[0033] The catheter hub 16A is a hollow cylindrical member. The tip of the catheter hub 16A holds the proximal end of the catheter body 14. That is, the proximal end of the catheter body 14 is fixed to the tip of the catheter hub 16A. As shown in Figure 2, the catheter hub 16A has a hub lumen 161. The hub lumen 161 is the inner space of the catheter hub 16A. The hub lumen 161 communicates with the lumen 141 of the catheter body 14. The catheter hub 16A has an inner surface 162 surrounding the hub lumen 161. The catheter hub 16A is attached to the skin S of a living body A with tape or the like and is placed in the living body A together with the catheter body 14 (see Figure 7).

[0034] The inner surface 162 of the catheter hub 16A is provided with a valve retaining portion 20. The valve retaining portion 20 is provided to hold the valve body 18A. The valve retaining portion 20 is an annular groove recessed radially outward on the inner surface 162 of the catheter hub 16A (see Figure 3). A stepped portion 22 is provided on the tip side of the valve retaining portion 20. The stepped portion 22 is a wall that constitutes the tip side of the valve retaining portion 20. The wall surface of the stepped portion 22 is perpendicular to the axis of the catheter hub 16A. A locking projection 24 is provided on the base end side of the valve retaining portion 20. The locking projection 24 is an annular projection that protrudes radially inward from the inner surface 162 of the catheter hub 16A. The locking projection 24 is not limited to an annular projection, but may be composed of a plurality of projections spaced apart from each other in the circumferential direction.

[0035] Examples of materials that can be used to construct the catheter hub 16A include thermoplastic resins such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer, polyurethane, acrylic resin, and ABS resin. As shown in Figure 1, in the initial state of the catheter assembly 100, the inner needle hub 122 of the needle member 12 is fitted to the proximal end of the catheter hub 16A. The inner needle hub 122 is detachable from the proximal end of the catheter hub 16A.

[0036] The valve body 18A is positioned in the hub lumen 161 of the catheter hub 16A. The valve body 18A is fixed to the inner surface 162 of the catheter hub 16A. The valve body 18A divides the hub lumen 161 into a tip space 261 and a proximal space 262. The tip space 261 is positioned towards the tip of the valve body 18A. The tip space 261 communicates with the lumen 141 of the catheter body 14. The proximal space 262 is positioned towards the proximal end of the valve body 18A. In the axial direction of the catheter hub 16A, the tip space 261 and the proximal space 262 are positioned on opposite sides of each other with the valve body 18A in between. The valve body 18A can switch the communication state between the tip space 261 and the proximal space 262 of the hub lumen 161.

[0037] The valve body 18A allows fluid to flow toward the tip of the catheter hub 16A. Therefore, the valve body 18A can allow fluid to flow from the catheter hub 16A to the catheter body 14. The valve body 18A prevents fluid from flowing toward the proximal end of the catheter hub 16A. Therefore, the valve body 18A prevents fluid (e.g., blood B) that has entered the catheter hub 16A via the catheter body 14 from flowing toward the proximal end beyond the valve body 18A.

[0038] The valve body 18A is made of an elastic material. The constituent material of the valve body 18A is not particularly limited. Examples of constituent materials for the valve body 18A include various rubber materials such as natural rubber, butyl rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, and silicone rubber, as well as various thermoplastic elastomers such as polyurethane, polyester, polyamide, olefin, and styrene, or mixtures thereof.

[0039] As shown in Figure 4, the valve body 18A has a contact portion 28 and a valve portion 30. The contact portion 28 constitutes the base end of the valve body 18A. As shown in Figure 2, the contact portion 28 is held by an annular valve retaining portion 20 provided on the inner surface 162 of the catheter hub 16A. The contact portion 28 is annular in shape (see Figure 4). The tip of the contact portion 28 contacts the stepped portion 22 of the valve retaining portion 20. The contact portion 28 contacts the valve retaining portion 20 and adheres to it in a liquid-tight manner. Note that the configuration is not limited to the outer surface 281 of the contact portion 28 being in liquid-tight contact with the inner surface 162 of the valve retaining portion 20. For example, it is sufficient if the tip surface 282 of the contact portion 28 is in liquid-tight contact with the base end surface of the stepped portion 22, or if the base end of the outer circumference of the contact portion 28 is in liquid-tight contact with the locking projection 24.

[0040] As shown in Figure 4, the valve portion 30 extends from the contact portion 28 toward the tip. The outer diameter of the valve portion 30 is smaller than the outer diameter of the contact portion 28 (see Figure 3). Therefore, the contact portion 28 protrudes radially outward from the outer surface of the valve portion 30. The valve portion 30 has a duckbill structure. The duckbill structure has a pair of bill portions 301 that approach each other toward the tip. The duckbill structure includes an openable and closable slit 302. The slit 302 extends from the tip of the duckbill structure toward the base. The valve portion 30 is not limited to a duckbill structure; for example, it may be a disc structure (circular disc structure).

[0041] As shown in Figure 3, the catheter 10A further comprises a valve fixing structure 32A and a flow path 34A.

[0042] The valve fixing structure 32A fixes the valve body 18A to the catheter hub 16A. The valve fixing structure 32A includes a fixing portion 36A provided on either one of the outer surface 281 of the valve body 18A and the inner surface 162 of the catheter hub 16A, and an engaged portion 38A. The fixing portion 36A is formed of a swellable material. The swellable material is, for example, a superabsorbent polymer. Examples of the superabsorbent polymer include crosslinked sodium polyacrylate, vinyl acetate-methyl acrylate copolymer, carboxymethyl cellulose, starch-polyacrylonitrile hydrolysate, starch-polyacrylate, isobutylene-maleic anhydride copolymer, and polyethylene oxide-based polymer.

[0043] A plurality of the fixing portions 36A are provided at intervals in the circumferential direction of the valve body 18A. The plurality of fixing portions 36A are provided at equal intervals in the circumferential direction. Hereinafter, a case where four fixing portions 36A are provided will be described. Note that only one fixing portion 36A may be provided. Two or three fixing portions 36A may be provided. Five or more fixing portions 36A may be provided. The number of the fixing portions 36A is preferably three or more.

[0044] As shown in FIG. 5, each fixing portion 36A is provided on the outer surface 281 of the valve body 18A. Each fixing portion 36A is fixed to the outer surface 281 of the contact portion 28 in the valve body 18A. Each fixing portion 36A has a convex portion 40 protruding radially outward from the outer surface 281 of the contact portion 28. Each fixing portion 36A extends along the axial direction of the valve body 18A (see FIG. 3). Note that each fixing portion 36A is not limited to a configuration extending in the axial direction, and may be, for example, a pin shape protruding from the outer surface 281 of the contact portion 28.

[0045] As shown in FIG. 3, in a cross section orthogonal to the axial direction of the valve body 18A, the tip end of each fixing portion 36A has an arc shape that is convex outward in the radial direction. Note that the cross-sectional shape of each fixing portion 36A may be triangular, rectangular, or the like.

[0046] Each fixing portion 36A is not limited to a configuration fixed to the outer surface 281 of the valve body 18A. For example, the entire valve body 18A including the fixing portion 36A may be formed of a swellable material. Further, each fixing portion 36A may be formed by coating the surface of the convex portion 40 with a swellable material.

[0047] The engaged portion 38A is formed on the inner surface 162 of the catheter hub 16A. The engaged portion 38A is formed on the inner surface 162 of the hub lumen 161. The engaged portion 38A opens radially inward on the inner surface 162 of the hub lumen 161. The fixing portion 36A of the valve fixing structure 32A is inserted into the engaged portion 38A.

[0048] A plurality of the engaged portions 38A are provided at intervals in the circumferential direction. The plurality of engaged portions 38A are provided at equal intervals in the circumferential direction. Hereinafter, a case where four engaged portions 38A are provided will be described. The number of engaged portions 38A is the same as the number of fixing portions 36A. Note that only one engaged portion 38A may be provided. Two or three engaged portions 38A may be provided. Five or more engaged portions 38A may be provided. The number of engaged portions 38A is preferably three or more.

[0049] In the initial state before the catheter 10A is used, each engaged portion 38A and each fixing portion 36A are engaged with each other. At this time, there is a gap between each fixing portion 36A and each engaged portion 38A. Note that, in the initial state, each fixing portion 36A and each engaged portion 38A may abut against each other without a gap therebetween.

[0050] Each engaged portion 38A has a recess 42 that is recessed radially outward from the inner surface 162 of the hub lumen 161. Each engaged portion 38A extends in the axial direction of the catheter hub 16A (see FIG. 3). In a cross section perpendicular to the axial direction of the catheter hub 16A, each engaged portion 38A has a substantially semicircular shape that is convex toward radially outward. Note that the cross-sectional shape of each engaged portion 38A is not limited to a substantially semicircular shape. The convex portion 40 of each fixing portion 36A protrudes toward the recess 42 of each engaged portion 38A and is inserted into the recess 42. When a liquid (blood B) is introduced into the hub lumen 161 and the fixing portions 36A swell, the swollen fixing portions 36A and the engaged portions 38A fit with each other.

[0051] The flow path 34A is provided at least between the inner surface 162 of the catheter hub 16A and the outer surface 281 of the valve body 18A. As shown in Figure 2, the flow path 34A communicates with the tip space 261 and the proximal space 262 of the hub lumen 161. Note that the flow path 34A only needs to communicate with at least the tip space 261.

[0052] As shown in Figure 3, the flow path 34A includes a groove 44A provided on the outer surface 281 of the valve body 18A. As shown in Figure 5, the groove 44A is recessed radially inward from the contact portion 28 of the valve body 18A. The groove 44A extends in the axial direction of the valve body 18A (see Figure 4). In the circumferential direction of the valve body 18A, the groove 44A and the fixed portion 36A are adjacent to each other. The groove 44A is arranged on both sides of the fixed portion 36A in the circumferential direction of the valve body 18A. That is, there are two grooves 44A, and the two grooves 44A and the fixed portion 36A are in parallel. Note that the number of grooves 44A is not limited to two. For example, there may be one groove 44A, or there may be three or more grooves 44A. Also, it is not limited to the case that the grooves 44A and the fixed portion 36A are arranged adjacent to each other in the circumferential direction of the valve body 18A. For example, the groove 44A and the fixing portion 36A may be spaced apart from each other in the circumferential direction of the valve body 18A.

[0053] As shown in Figure 3, the radially outward side of each groove 44A is covered by the inner surface 162 (valve holding portion 20) of the catheter hub 16A. A flow path 34A is formed from each groove 44A and the inner surface 162 of the catheter hub 16A.

[0054] The fixing portion 36A is not limited to being provided on the outer surface 281 of the valve body 18A. For example, the fixing portion 36A may be provided on the inner surface 162 of the catheter hub 16A.

[0055] The flow path 34A is further provided with a communication groove 46A. The communication groove 46A is provided in the direction of the tip of the groove portion 44A. The communication groove 46A is formed on the tip surface 282 of the contact portion 28. The communication groove 46A extends radially along the tip surface 282. The communication groove 46A is formed as a recess from the tip surface 282. The radial outer end of the communication groove 46A is connected to and communicates with the groove portion 44A. In other words, there are multiple communication grooves 46A. To put it another way, the communication grooves 46A are connected to the tip of each groove portion 44A and extend radially inward. A portion of the communication groove 46A faces the tip space portion 261 (see Figure 2).

[0056] Next, as shown in Figure 7, we will describe the case in which catheter 10A is placed in the body A for intravenous fluid administration. Below, we will describe the case in which the tip of catheter 10A is placed in a blood vessel BV. Blood vessel BV is, for example, an artery. The fluid is blood B. Note that the site in which catheter 10A is placed is not limited to blood vessels. For example, catheter 10A may be used to administer intravenous fluid by placing it in a lumen of the body other than blood vessel BV. In this case, the fluid is a fluid other than blood B.

[0057] The user inserts the tip of the inner needle 121 of the catheter assembly 100 into the skin S of the living body A. The tip of the inner needle 121 of the needle member 12 is inserted into the blood vessel BV.

[0058] Next, the user advances the catheter 10A while fixing the position of the internal needle hub 122, inserting the tip of the catheter 10A to the target position within the blood vessel BV. The tip of the catheter body 14 is open within the blood vessel BV.

[0059] Blood B (liquid) in the blood vessel BV flows from the tip of catheter 10A through the lumen 141 of the catheter body 14 into the lumen 161 of the catheter hub 16A. At this time, the air present in the tip space 261 of the catheter hub 16A is pushed towards the proximal end by the inflow pressure of blood B. This air is discharged from the tip space 261 to the proximal space 262 through eight flow channels 34A (see Figure 3). As the air is discharged to the outside from the proximal space 262 of the catheter hub 16A, blood B gradually flows into the tip space 261 through the catheter body 14.

[0060] When the inner needle 121 is withdrawn from the valve body 18A towards the proximal end while the position of the catheter 10A is maintained, the slit 302 through which the inner needle 121 passed is closed by the elasticity of the valve portion 30 of the valve body 18A.

[0061] As shown in Figure 2, as blood B fills the tip space 261, a portion of the blood B flows into the valve fixing structure 32A. Specifically, as a portion of the blood B flows from the tip space 261 into the eight flow channels 34A (from each communication groove 46A to each groove 44A), the blood B comes into contact with each fixing part 36A adjacent to each groove 44A, and as a result, each fixing part 36A swells by absorbing moisture from the blood B. As shown in Figure 6, each fixing part 36A swells radially outward and circumferentially relative to the outer surface 281 of the valve body 18A. The outer circumference of each swollen fixing part 36A comes into close contact with the inner surface of each engaged part 38A, thereby fitting each fixing part 36A and each engaged part 38A together. It should be noted that a portion of each flow channel 34A may be blocked by each swollen fixing part 36A.

[0062] After removing the inner needle 121 and inner needle hub 122 from the catheter body 14 and catheter hub 16A, the user inserts a connector of an infusion tube (not shown) through the proximal opening of the catheter hub 16A. By passing a portion of the connector through the slit 302 of the valve body 18A, it becomes possible to deliver infusion fluid from the infusion tube (not shown) into the blood vessel BV of the living body A. Note that the slit 302 of the valve body 18A is not limited to opening when a portion of the connector passes through it. For example, the slit 302 of the valve body 18A may open due to the pressure of the infusion fluid supplied from the infusion tube.

[0063] The first embodiment provides the following effects.

[0064] As shown in Figure 2, the catheter 10A includes a valve fixing structure 32A that fixes the valve body 18A to the catheter hub 16A. The valve fixing structure 32A includes a fixing portion 36A formed from a swellable material.

[0065] With this catheter 10A, when liquid (blood B) is introduced into the tip space 261 of the catheter hub 16A, the fixing portion 36A swells upon contact with the liquid, thereby increasing the fixing force of the valve body 18A to the catheter hub 16A. As a result, the valve body 18A can be effectively fixed to the catheter hub 16A. Therefore, even when high pressure (e.g., arterial pressure) is applied to the valve body 18A, displacement of the valve body 18A from its predetermined position within the catheter hub 16A is suppressed.

[0066] As shown in Figure 6, the inner surface 162 of the catheter hub 16A is provided with an engaging portion 38A into which the fixing portion 36A engages, and when the fixing portion 36A swells, the swollen fixing portion 36A and the engaging portion 38A fit together.

[0067] With this configuration, the valve body 18A can be more effectively fixed to the catheter hub 16A by bringing the swollen fixing portion 36A into close contact with the engaged portion 38A.

[0068] As shown in Figure 3, the engaged portion 38A is a recess 42, and the fixing portion 36A is a protrusion 40 that protrudes toward the recess 42 and is inserted into the recess 42.

[0069] This configuration allows the valve body 18A to be fixed to the catheter hub 16A more effectively. When assembling the catheter 10A, the fixing portion 36A is not swollen, and there is a gap between the fixing portion 36A and the engaged portion 38A. Therefore, the catheter 10A can be easily assembled.

[0070] Between the inner surface 162 of the catheter hub 16A and the outer surface 281 of the valve body 18A, there is a flow path 34A that communicates with at least the tip space 261.

[0071] With this configuration, the liquid introduced into the tip space 261 is introduced into the flow path 34A, thereby effectively swelling the fixed portion 36A.

[0072] As shown in Figure 2, the flow path 34A communicates with the base end space 262.

[0073] With this configuration, the liquid introduced into the tip space 261 effectively swells the fixing portion 36A, and the flow path 34A pushes the gas (air) in the hub lumen 161 toward the base end for discharge.

[0074] Each of the flow path 34A and the fixed portion 36A extends along the axial direction of the catheter hub 16A. As shown in Figure 3, the flow path 34A and the fixed portion 36A are adjacent to each other in the circumferential direction of the valve body 18A.

[0075] With this configuration, the liquid flowing through the channel 34A can more effectively swell the fixed portion 36A.

[0076] The fixing portion 36A is provided on the outer surface 281 of the valve body 18A, and the engaged portion 38A is provided on the inner surface 162 of the catheter hub 16A. With this configuration, the fixing portion 36A and the engaged portion 38A can be easily formed.

[0077] As shown in Figure 2, the fixing portion 36A extends along the axial direction of the catheter hub 16A. With this configuration, the valve fixing structure 32A can be realized with a simple structure.

[0078] As shown in Figure 6, the swelling material is a water-absorbing polymer. This configuration allows for the inexpensive realization of the valve fixing structure 32A.

[0079] As shown in Figure 8, the catheter 10B according to the second embodiment comprises a catheter hub 16B and a valve fixing structure 32B. As shown in Figure 9, the valve fixing structure 32B comprises a fixing portion 36B and an engaging portion 38B.

[0080] As shown in Figure 10, the fixing portion 36B is provided on the outer surface 281 of the valve body 18B. The fixing portion 36B is provided on the outer surface 281 of the contact portion 28 of the valve body 18B. As shown in Figure 11, the fixing portion 36B has a recess 50 that is recessed radially inward from the outer surface 281 of the contact portion 28. The recess 50 opens radially outward. The fixing portion 36B extends along the axial direction of the valve body 18B. The fixing portion 36B is formed from a swelling material.

[0081] The engaged portion 38B is provided on the inner surface 162 (valve holding portion 20) of the catheter hub 16B and engages with the fixing portion 36B.

[0082] As shown in Figure 11, the engaged portion 38B has a protrusion 52 that projects radially inward from the valve holding portion 20 of the catheter hub 16B. The engaged portion 38B extends in the axial direction of the catheter hub 16B. The protrusion 52 of the engaged portion 38B protrudes toward the recess 50 of the fixing portion 36B and is inserted into the recess 50. As shown in Figure 9, in the initial state before the catheter 10B is used, the engaged portion 38B and the fixing portion 36B are engaged with each other. As shown in Figure 11, when liquid (blood B) is introduced into the hub lumen 161 and the fixing portion 36B swells, the swollen fixing portion 36B and the engaged portion 38B fit together.

[0083] As shown in Figure 9, the catheter 10B further includes a flow path 34B. The flow path 34B is provided at least between the inner surface 162 of the catheter hub 16B and the outer surface 281 of the valve body 18B. The flow path 34B communicates with the tip space 261 and the proximal space 262 of the hub lumen 161. The flow path 34B includes a groove 44B provided on the outer surface 281 of the valve body 18B (see Figure 10).

[0084] As shown in Figure 10, the groove 44B is recessed radially inward from the contact portion 28 of the valve body 18B. The groove 44B that constitutes the flow path 34B also serves as the recess 50 of the fixing portion 36B. As shown in Figure 9, when the engaged portion 38B is inserted into the fixing portion 36B in the initial state, both sides of the fixing portion 36B in the circumferential direction of the valve body 18B become the flow path 34B. The flow path 34B and the fixing portion 36B are in parallel. The radially outward side of each groove 44B is covered by the inner surface 162 (valve holding portion 20) of the catheter hub 16B. The flow path 34B is formed from each groove 44B and the inner surface 162 of the catheter hub 16B, respectively.

[0085] As shown in Figure 10, the flow path 34B is further provided with a communication groove 46B. The communication groove 46B is provided in the direction of the tip of the groove portion 44B. The communication groove 46B is formed on the tip surface 282 of the contact portion 28. The communication groove 46B extends radially along the tip surface 282. The communication groove 46B is formed as a recess from the tip surface 282. The radial outer end of the communication groove 46B is connected to and communicates with the groove portion 44B. In other words, there are multiple communication grooves 46B. A portion of the communication groove 46B faces the tip space portion 261.

[0086] The fixing portion 36B is not limited to being provided on the outer surface 281 of the valve body 18B. For example, the fixing portion 36B may be provided on the inner surface 162 of the catheter hub 16B.

[0087] When using catheter 10B, blood B (liquid) flows into the tip space 261 of catheter hub 16B through the lumen 141 of catheter body 14. Air present in tip space 261 is pushed out to proximal space 262 through each channel 34B and discharged by the inflow pressure of blood B.

[0088] A portion of the blood B introduced into the tip space 261 of the catheter hub 16B flows into each channel 34B (from the communication groove 46B to the groove 44B) and comes into contact with each fixing part 36B. As a result, each fixing part 36B absorbs moisture from the blood B and swells. Specifically, each fixing part 36B swells inward toward the engaged part 38B. The inner circumference of each swollen fixing part 36B tightly surrounds the outer surface of each engaged part 38B, causing each fixing part 36B and each engaged part 38B to fit together. Each channel 34B is blocked by the swollen fixing part 36B. This prevents the blood B from the tip space 261 from flowing into the proximal space 262 through each channel 34B.

[0089] The second embodiment provides the following effects.

[0090] As shown in Figure 9, the catheter 10B includes a valve fixing structure 32B that fixes the valve body 18B to the catheter hub 16B. The valve fixing structure 32B is provided on the outer surface 281 of the valve body 18B and includes a fixing portion 36B formed from a swellable material. With this configuration, when liquid (blood B) is introduced into the tip space 261 of the catheter hub 16B, as shown in Figure 11, the fixing portion 36B swells upon contact with the liquid, causing the inner surface 162 of the catheter hub 16B and the outer surface 281 of the valve body 18B to adhere tightly. As a result, the valve body 18B can be effectively fixed to the catheter hub 16B.

[0091] As shown in Figure 9, the catheter hub 16B has an engaging portion 38B provided on its inner surface 162, into which the fixing portion 36B engages. When the fixing portion 36B swells, the swollen fixing portion 36B and the engaging portion 38B fit together.

[0092] With this configuration, the valve body 18B can be more effectively fixed to the catheter hub 16B by bringing the swollen fixing portion 36B into close contact with the engaged portion 38B.

[0093] As shown in Figure 10, the fixing portion 36B extends along the axial direction of the catheter hub 16B. With this configuration, the valve fixing structure 32B can be realized with a simple structure.

[0094] As shown in Figure 12, the catheter 10C according to the third embodiment comprises a catheter hub 16C and a valve fixing structure 32C.

[0095] As shown in Figure 13, the valve fixing structure 32C comprises a fixing portion 36C and an engaged portion 38C. As shown in Figure 14, the fixing portion 36C is provided on the outer surface 281 of the valve body 18C. The fixing portion 36C has a protrusion 60 that projects radially outward from the outer surface 281 of the contact portion 28. The fixing portion 36C extends circumferentially along the outer surface 281 of the contact portion 28. As shown in Figure 12, in a cross-section along the axial direction of the valve body 18C, the tip of the fixing portion 36C is an arc shape that is convex radially outward. The cross-sectional shape of the fixing portion 36C may be triangular, rectangular, or the like. The fixing portion 36C may also be formed only on a part of the outer surface 281 of the valve body 18C so as to follow the outer surface 281.

[0096] As shown in Figure 13, the engaged portion 38C is formed on the inner surface 162 of the catheter hub 16C. The engaged portion 38C is formed on the inner surface 162 of the hub lumen 161. The engaged portion 38C opens radially inward on the inner surface 162 of the hub lumen 161. The fixed portion 36C of the valve body 18C is inserted into the engaged portion 38C (see Figure 12). The engaged portion 38C has a recess 62 that is recessed radially outward from the inner surface 162. The engaged portion 38C is formed in an annular shape and extends circumferentially on the inner surface 162 of the catheter hub 16C. In the initial state before the catheter 10C is used, the engaged portion 38C and the fixed portion 36C are engaged with each other.

[0097] As shown in Figure 12, the protrusion 60 of the fixing portion 36C protrudes toward the recess 62 of the engaged portion 38C and is inserted into the recess 62. When liquid (blood B) is introduced into the hub lumen 161 and the fixing portion 36C swells, the swollen fixing portion 36C and the engaged portion 38C fit together (see Figure 13).

[0098] The fixing portion 36C may also be configured such that a circumferential portion extending in the circumferential direction of the outer surface 281 of the contact portion 28 intersects with an axial portion extending in the axial direction of the outer surface 281 of the contact portion 28.

[0099] As shown in Figure 12, the catheter 10C further includes a flow path 34C. The flow path 34C is provided at least between the inner surface 162 of the catheter hub 16C and the outer surface 281 of the valve body 18C. The flow path 34C communicates with the tip space 261 and the base space 262 of the hub lumen 161. As shown in Figure 14, the flow path 34C includes a groove 44C provided on the outer surface 281 of the valve body 18C. The groove 44C is recessed radially inward from the contact portion 28 of the valve body 18C. Multiple grooves 44C are provided spaced apart from each other in the circumferential direction of the valve body 18C. The groove 44C has a V-shaped cross-section that tapers radially inward. Note that the shape of the groove 44C is not limited to a V-shaped cross-section.

[0100] Note that the number of flow paths 34C (grooves 44C) is not limited to multiple paths. For example, there may be only one flow path 34C (groove 44C). The radially outward side of each groove 44C is covered by the inner surface 162 (valve holding portion 20) of the catheter hub 16C. Each groove 44C and the inner surface 162 of the catheter hub 16C form a flow path 34C. On the outer surface 281 of the valve body 18C, fixing portions 36C are arranged between each of the multiple grooves 44C.

[0101] The flow path 34C is further provided with a communication groove 46C. The communication groove 46C is provided in the direction of the tip of the groove portion 44C. The communication groove 46C is formed on the tip surface 282 of the contact portion 28. The communication groove 46C extends radially along the tip surface 282. The communication groove 46C is formed as a recess from the tip surface 282. The radial outer end of the communication groove 46C is connected to and communicates with the groove portion 44C. In other words, there are multiple communication grooves 46C. A portion of the communication groove 46C faces the tip space portion 261 (see Figure 12).

[0102] When using the catheter 10C, blood B as a liquid flows into the tip space 261 of the catheter hub 16C through the catheter body 14, and the air in the tip space 261 is pushed out to the proximal space 262 through each channel 34C.

[0103] A portion of the blood B introduced into the tip space 261 of the catheter hub 16C flows into each channel 34C (from the communication groove 46C to the groove 44C) and comes into contact with each fixing part 36C. As a result, as shown in Figure 13, the blood B in each channel 34C comes into contact with each fixing part 36C, causing each fixing part 36C to absorb water and swell. Specifically, each fixing part 36C swells radially outward from the outer surface 281 of the valve body 18C. The outer circumference of the swollen fixing part 36C comes into close contact with the inner surface of each engaged part 38C, causing each fixing part 36C and each engaged part 38C to fit together.

[0104] The third embodiment provides the following effects.

[0105] As shown in Figure 13, the fixing portion 36C extends in the circumferential direction of the catheter hub 16C. This allows for the realization of a valve fixing structure 32C with a simple configuration. By engaging each fixing portion 36C with each engaged portion 38C, the valve body 18C is positioned in a predetermined position relative to the catheter hub 16C, and axial movement of the valve body 18C relative to the catheter hub 16C is effectively suppressed.

[0106] Furthermore, as shown in Figure 15, the modified catheter 10C comprises a valve body 18D and a valve fixing structure 32C. The valve body 18D is provided with a communication hole 70. The communication hole 70 connects the tip space 261 of the hub lumen 161 and the engaged portion 38C to each other. The communication hole 70 is provided in the contact portion 28 of the valve body 18D. The tip of the communication hole 70 opens to the tip surface 282 of the contact portion 28 of the valve body 18D. The base end of the communication hole 70 opens to the contact portion 28 of the valve body 18C. Note that there may be one or more communication holes 70. The communication hole 70 is positioned between each flow path 34C in the contact portion 28 of the valve body 18C (see the dashed line shape in Figure 14).

[0107] When using the catheter 10C, a portion of the blood B that flows into the tip space 261 of the catheter hub 16C is introduced into the engaged portion 38C through the communication hole 70. The blood B flows circumferentially along the engaged portion 38C in the direction of the valve body 18D. When the blood B introduced into the engaged portion 38C comes into contact with the fixing portion 36C, the fixing portion 36C swells and is fitted into the engaged portion 38C.

[0108] The following effects are produced by the torture method:

[0109] As shown in Figure 15, the valve body 18D is provided with a communication hole 70 that connects the engaged portion 38C and the tip space portion 261 to each other. With this configuration, the liquid (blood B) introduced into the tip space portion 261 can be effectively introduced toward the fixed portion 36C through the communication hole 70. By providing the communication hole 70, the cross-sectional area of ​​the flow path 34C can be made smaller.

[0110] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

Claims

1. A catheter comprising: a hollow catheter body; a catheter hub having a hub lumen communicating with the catheter body and fixed to the proximal end of the catheter body; a valve body disposed between the tip space and the proximal space of the hub lumen and capable of switching the communication state between the tip space and the proximal space; and a valve fixing structure for fixing the valve body to the catheter hub, wherein the valve fixing structure comprises a fixing portion provided on either the inner surface of the catheter hub or the outer surface of the valve body and formed from a swelling material.

2. A catheter according to claim 1, wherein the catheter hub is provided with an engaging portion on the other of the inner surface and the outer surface of the valve body, the fixing portion being engaged with the engaging portion, and when the fixing portion swells, the swollen fixing portion and the engaging portion fit together with each other.

3. A catheter according to claim 2, wherein the engaged portion is a recess, and the fixing portion is a convex portion that protrudes toward the recess and is inserted into the recess.

4. A catheter according to claim 2, wherein a channel is provided between the inner surface of the catheter hub and the outer surface of the valve body that communicates with at least the tip space.

5. A catheter according to claim 4, wherein the flow path communicates with the proximal space.

6. A catheter according to claim 4 or 5, wherein each of the flow path and the fixing portion extends along the axial direction of the catheter hub, and the flow path and the fixing portion are adjacent to each other in the circumferential direction of the valve body.

7. A catheter according to claim 2, wherein the fixing portion is provided on the outer surface of the valve body, and the engaging portion is provided on the inner surface of the catheter hub.

8. A catheter according to claim 1 or 2, wherein the fixing portion extends along the axial direction of the catheter hub.

9. A catheter according to claim 1 or 2, wherein the fixing portion extends in the circumferential direction of the catheter hub.

10. A catheter according to claim 9, wherein the valve body has a communication hole that connects the engaged portion and the tip space portion to each other.

11. A catheter according to claim 1, wherein the swelling material is a water-absorbing polymer.

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