JP6720524B2 - catheter - Google Patents

Description

The present invention relates to catheters.

As a catheter used by being introduced into a body cavity, in recent years, a catheter that can be operated in the direction of entry into the body cavity by bending a distal end has been provided.

For example, Patent Document 1 describes a catheter in which two auxiliary lumens (wire lumens in the same document) having a smaller diameter than the main lumen (the central lumen in the same document) are provided around the main lumen. .. An operation wire (a turning wire in the same document) is inserted inside the sub-lumen, and the distal end of the catheter is bent by operating the operation handle on the proximal end side to pull the operation wire. ..

JP, 2006-192269, A

However, in the catheter as described in Patent Document 1, the tip portion locally bends with an excessive curvature, so that good operability is obtained when the catheter is advanced from a thick blood vessel to a thin blood vessel. Sometimes I can't.

The present invention has been made in view of the above-mentioned problems, and provides a catheter with better operability.

The present invention has a sheath main body, a lumen having a through hole formed inside the sheath main body, and an operation wire inserted into the lumen and connected to a distal end portion of the sheath main body. A catheter in which the distal end portion is bent by pulling the operation wire,
The sliding resistance between the peripheral wall of the lumen and the operating wire is larger at the distal end portion than at the intermediate portion between the distal end portion and the proximal end portion of the sheath body. A catheter is provided.

According to the present invention, the operability of the catheter can be improved.

It is a longitudinal cross-sectional view of the catheter according to the first embodiment. It is a cross-sectional view of the catheter according to the first embodiment. It is an expanded longitudinal cross-sectional view of the catheter which concerns on 1st Embodiment. It is a schematic diagram for demonstrating the behavior of the catheter which concerns on embodiment. It is a schematic diagram for demonstrating the behavior of the catheter which concerns on a comparison form. It is a longitudinal section of a catheter concerning a 2nd embodiment. It is a longitudinal section of a catheter concerning a 3rd embodiment. It is a longitudinal section of a catheter concerning a 4th embodiment. It is a longitudinal section of a catheter concerning a 5th embodiment. It is explanatory drawing of the measuring method of the sliding resistance of the peripheral wall of a sublumen (lumen), and the operating wire.

Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, the same constituents will be referred to with the same signs, while omitting their overlapping descriptions.

[First Embodiment]
1 to 3 are views showing a catheter 100 according to the first embodiment, of which FIG. 1 is a cross-sectional view (longitudinal cross-sectional view) taken along the longitudinal direction of the catheter 100, and FIG. 2 is a catheter. It is sectional drawing (transverse sectional view) which cut|disconnected 100 to the perpendicular|vertical direction with respect to a longitudinal direction, and FIG. 1 is a sectional view taken along line I-I of FIG. 2, and FIG. 2 is a sectional view taken along line II-II of FIG. Further, in FIG. 3, the left side is the distal side (tip side), and the right side is the proximal side (base end side). In addition, in FIG. 3, in the configuration shown in FIG. 1, one sub-tube 40, an operation wire 60 inserted in the sub-tube 40, and a sub-lumen 42 which is an internal space of the sub-tube 40. , The outer layer 50 around the sub-tube 40 is selectively shown, and other structures are not shown.

The catheter 100 of the present embodiment has a sheath main body (tubular main body 10), a lumen formed in the inside of the sheath main body (sub-lumen 42 in the present embodiment), and a sheath inserted into the lumen. A catheter having an operating wire 60 connected to the distal end of the main body, and the distal end being bent by pulling the operating wire 60.
The sliding resistance between the peripheral wall of the lumen and the operating wire 60 is larger at the distal end portion than at the intermediate portion between the distal end portion and the proximal end portion of the sheath body.
As a result, it is possible to prevent the distal end portion of the sheath body from locally bending with an excessive curvature (an excessively small radius of curvature), so that the orientation of the distal end of the tubular body 10 can be easily adjusted and the tubular body 10 can be easily adjusted. It becomes easy to introduce the tip into a desired body cavity.
Here, the sliding resistance between the peripheral wall of the lumen and the operating wire 60 is the resistance when the operating wire 60 is moved in the axial direction relative to the lumen of the unit length in a state where the sheath body is bent. Means the size of.

As shown in FIGS. 1 and 3, in the case of the present embodiment, the inner diameter of the sub-lumen 42 at the distal end of the tubular body 10 () is smaller than the inner diameter of the sub-lumen 42 at the middle portion of the tubular body 10. As a result, the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger at the distal end portion than at the intermediate portion.
More specifically, the inner diameter of the sub-lumen 42 is constant from the middle portion to the base end portion of the tubular body 10, and locally reduced at the tip end portion.

In the case of the present embodiment, the sub-lumen 42 is formed by the internal space of the sub-tube 40 embedded in the tubular body 10. The inner diameter of the sub tube 40 at the tip of the tubular body 10 is smaller than the inner diameter of the sub tube 40 at the middle portion of the tubular body 10. Such a configuration can be realized, for example, by selectively heating and pressurizing the distal end portion of the tubular body 10 using a heat-shrinkable tube or the like and crushing the sub-tube 40 at the distal end portion.
That is, the catheter 100 includes a tube (subtube 40) embedded in the tubular body 10, the inner space of the tube constitutes a lumen, and the tube is crushed at the tip of the tubular body 10.
With such a configuration, in the catheter 100 of the type having the sub-lumen 42 formed by the sub-tube 40, the inner diameter of the sub-lumen 42 at the tip portion is larger than the inner diameter of the sub-lumen 42 at the intermediate portion. A small configuration can be realized.

Hereinafter, the present embodiment will be described in more detail. The catheter 100 of the present embodiment is an intravascular catheter used by inserting the tubular body 10 into the blood vessel.

The tubular main body 10 is a hollow tubular long member having a main lumen (main lumen) 20 formed therein. More specifically, tubular body 10 is formed with an outer diameter and length that allows it to enter any of the eight subsections of the liver.

The tubular body 10 has a laminated structure. As shown in FIG. 2, the tubular body 10 is configured by laminating the inner layer 24, the first outer layer 52, and the second outer layer 54 in order from the inner diameter side around the main lumen 20. A hydrophilic layer (not shown) is formed on the outer surface of the second outer layer 54. The inner layer 24, the first outer layer 52, and the second outer layer 54 are made of a flexible resin material and each have an annular shape and a substantially uniform thickness. The first outer layer 52 and the second outer layer 54 may be collectively referred to as the outer layer 50.

The inner layer 24 is the innermost layer of the tubular body 10 and its inner wall surface defines the main lumen 20. The cross-sectional shape of the main lumen 20 is not particularly limited, but is circular in this embodiment. In the case of the main lumen 20 having a circular cross section, its diameter may be uniform over the longitudinal direction of the tubular body 10 or may vary depending on its longitudinal position. For example, in a part or the entire length region of the tubular body 10, the diameter of the main lumen 20 may be continuously tapered from the distal end to the proximal end.

Examples of the material of the inner layer 24 include a fluorine-based thermoplastic polymer material. Specific examples of the fluorine-based thermoplastic polymer material include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and perfluoroalkoxy fluororesin (PFA). By configuring the inner layer 24 with such a fluorine-based polymer material, the deliverability when supplying a drug solution or the like through the main lumen 20 is improved. Further, when the guide wire is inserted into the main lumen 20, the sliding resistance of the guide wire is reduced.

The outer layer 50 occupies most of the thickness of the tubular body 10. The outer layer 50 of the present embodiment includes a first outer layer 52 having an annular cross section that encloses the holding wire 70, and a second outer layer that has an annular cross section that is provided around the first outer layer 52 and encloses the second reinforcing layer 80. 54, and are included.

Inside the first outer layer 52, which is the inner layer of the outer layer 50, the wire reinforcing layer 30, the sub-tube (tube) 40, and the holding wire 70 are provided in order from the inner diameter side. A second reinforcing layer 80 is provided inside the second outer layer 54 which is an outer layer of the outer layer 50. The second reinforcing layer 80 is in contact with the outer surface of the first outer layer 52. The wire reinforcing layer 30 and the second reinforcing layer 80 are arranged coaxially with the tubular body 10. The second reinforcing layer 80 is arranged apart from the wire reinforcing layer 30 and the sub tube 40 so as to surround the wire reinforcing layer 30 and the sub tube 40.

As the material of the outer layer 50, a thermoplastic polymer material can be used. Examples of the thermoplastic polymer material include polyimide (PI), polyamide imide (PAI), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), polyamide elastomer (PAE), polyether block amide (PEBA), and the like. Mention may be made of nylon elastomer, polyurethane (PU), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC) or polypropylene (PP).
An inorganic filler may be mixed in the outer layer 50. Examples of inorganic fillers include contrast agents such as barium sulfate and bismuth subcarbonate. By mixing the outer layer 50 with the contrast agent, the X-ray contrast property of the tubular body 10 in the body cavity can be improved.

The first outer layer 52 and the second outer layer 54 are made of the same or different resin materials. Although the boundary surface between the first outer layer 52 and the second outer layer 54 is clearly shown in FIG. 2, the present invention is not limited to this. When the first outer layer 52 and the second outer layer 54 are made of the same type of resin material, the two layers may be naturally fused together and do not have a clear boundary surface. That is, in the outer layer 50 of the present embodiment, the first outer layer 52 and the second outer layer 54 may be configured in a multi-layer that can be distinguished from each other, or the first outer layer 52 and the second outer layer 54 are integrated. It may be constructed as a single layer.

The wire reinforcement layer 30 is a protective layer that is provided on the inner diameter side of the tubular body 10 with respect to the operation wire 60 and protects the inner layer 24. The presence of the wire reinforcing layer 30 on the inner diameter side of the operating wire 60 prevents the operating wire 60 from breaking the first outer layer 52 and the inner layer 24 and exposing the operating wire 60 to the main lumen 20.
The wire reinforcing layer 30 is formed by winding a reinforcing wire 32. Examples of the material of the reinforcing wire 32 include metal materials such as tungsten (W), stainless steel (SUS), nickel titanium alloy, steel, titanium, copper, titanium alloy or copper alloy, as well as the inner layer 24 and the first outer layer 52. Also, a resin material such as polyimide (PI), polyamide imide (PAI) or polyethylene terephthalate (PET) having high shear strength can be used. In the present embodiment, a stainless steel thin wire is used as the reinforcing wire 32.

The wire reinforcing layer 30 is configured by winding the reinforcing wire 32 in a coil or braiding in a mesh shape. The number of streaks of the reinforcing wire 32, the coil pitch, and the number of meshes are not particularly limited. Here, the number of meshes of the wire reinforcing layer 30 refers to the number of crosses (the number of meshes) per unit length (1 inch) viewed in the extending direction of the reinforcing wire 32.

The reinforcing wire 32 is obliquely wound around the inner layer 24. The angle formed by the extending direction of the reinforcing wire 32 with respect to the radial direction of the inner layer 24 is referred to as the pitch angle of the reinforcing wire 32. When the reinforcing wire 32 is wound at a fine pitch, the pitch angle becomes a small angle. Conversely, when the reinforcing wire 32 is wound at a shallow angle along the axis of the tubular body 10, the pitch angle becomes a large angle close to 90 degrees. The pitch angle of the reinforcing wire 32 of the present embodiment is not particularly limited, but can be 30 degrees or more, preferably 45 degrees or more and 75 degrees or less.

As the wire reinforcing layer 30 of this embodiment, a braid layer in which a reinforcing wire 32 is braided is illustrated. The first outer layer 52 is impregnated between the wire reinforcing layer 30 and the sub tube 40.

The second reinforcing layer 80 is a protective layer which is provided on the outer diameter side of the tubular body 10 with respect to the operation wire 60 and protects the second outer layer 54. The presence of the second reinforcing layer 80 on the outer diameter side of the operating wire 60 prevents the operating wire 60 from breaking the second outer layer 54 and the hydrophilic layer (not shown) and exposing the outside of the tubular body 10. To do.
The second reinforcing layer 80 is formed by winding a second reinforcing wire 82 in a coil or braiding it in a mesh shape. The material described above as the reinforcing wire 32 of the wire reinforcing layer 30 can be used for the second reinforcing wire 82. The second reinforcing wire 82 and the reinforcing wire 32 may be made of the same material or different materials. In the present embodiment, as the second reinforcing wire 82, a blade layer in which a fine wire made of the same material as the reinforcing wire 32 (stainless steel) is braided in a mesh shape is illustrated.

The wire diameters of the second reinforcing wire 82 and the reinforcing wire 32 may be the same or different. In the present embodiment, the second reinforcing wire 82 and the reinforcing wire 32 have the same wire diameter.
Further, the number of threads of the reinforcing wire 32 configuring the wire reinforcing layer 30 and the number of threads of the second reinforcing wire 82 configuring the second reinforcing layer 80 are not particularly limited, but they are the same in this embodiment. In FIG. 2, both the wire reinforcing layer 30 and the second reinforcing layer 80 are shown as a blade layer composed of 16 wires (reinforcing wire 32, second reinforcing wire 82).

The sub-tube 40 is a hollow tubular member that defines a sub-lumen 42. The sub-tube 40 is embedded inside the outer layer 50 (first outer layer 52). The subtube 40 can be made of, for example, a thermoplastic polymer material. Examples of the thermoplastic polymer material include low friction resin materials such as polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), and tetrafluoroethylene/hexafluoropropylene copolymer (FEP).
The sub-tube 40 is made of a material having higher flexural rigidity and tensile modulus than the outer layer 50.

The outer surface of the subtube 40 is subjected to etching treatment such as metallic sodium treatment or plasma treatment. This improves the adhesion between the sub tube 40 and the outer layer 50.

As shown in FIG. 2, two sub tubes 40 are arranged around the wire reinforcing layer 30 so as to face each other by 180 degrees, and the operation wires 60 are inserted into the two sub tubes 40, respectively. The two sub-tubes 40 are parallel to the axial direction of the tubular body 10.

The two sub tubes 40 are arranged on the same circumference so as to surround the main lumen 20. Instead of the present embodiment, three or four sub-tubes 40 may be arranged around the main lumen 20 at equal intervals. In this case, the operation lines 60 may be arranged on all the sub tubes 40, or the operation lines 60 may be arranged on some of the sub tubes 40.

The operation wire 60 is slidably inserted into the sub tube 40. The tip portion of the operation wire 60 is fixed to the distal portion DE of the tubular body 10. By pulling the operation wire 60 toward the proximal end side, a tensile force is applied to a position eccentric to the axial center of the tubular body 10, so that the tubular body 10 bends. Since the operating wire 60 of this embodiment is extremely thin and highly flexible, even if the operating wire 60 is pushed distally, substantially no pushing force is applied to the distal portion DE of the tubular body 10.

The operation wire 60 may be made of a single wire material, but may be a twisted wire made by twisting a plurality of thin wires. The number of thin wires that compose one twisted wire of the operating wire 60 is not particularly limited, but is preferably three or more. A suitable example of the number of thin wires is 7 or 3.

Here, the operation wire 60 is, for example, a twisted wire in which a plurality of (seven in the present embodiment) element wires are twisted together. More specifically, for example, 7 strands are integrally formed by spirally winding 6 strands (peripheral strands) around one strand (center strand) They are twisted together. The six peripheral strands are arranged at the vertices of a hexagon centered on the central strand. The wire diameter of the operation wire 60 refers to the diameter of a circumscribed circle including seven wires (a center wire and a peripheral wire).

Alternatively, the operation wire 60 may be formed by twisting three wires together. The diameter of the operating wire 60 in this case also refers to the diameter of the circumscribing circle including the three strands. When a plurality of strands having the same diameter are twisted together to form the operating wire 60, the number of strands is preferably 3 or 7. By setting these numbers, the wires are in a state of being most closely twisted so that the wires are closely attached to each other in the circumferential direction and the radial direction.

As the operation wire 60 (element wire), low carbon steel (piano wire), stainless steel (SUS), steel wire coated with corrosion resistance, titanium or titanium alloy, or metal wire such as tungsten can be used. In addition, as the operating wire 60 (strand wire), polyvinylidene fluoride (PVDF), high density polyethylene (HDPE), poly(paraphenylene benzobisoxazole) (PBO), polyether ether ketone (PEEK), polyphenylene sulfide Polymer fibers such as (PPS), polybutylene terephthalate (PBT), polyimide (PI), polytetrafluoroethylene (PTFE), or boron fiber can be used.

The holding wire 70 winds the sub tube 40 and the wire reinforcing layer 30 together. The holding wire 70 is formed by winding a coil around the sub tube 40 or braiding it in a mesh shape. Of these, the holding wire 70 is a coil, and more specifically, is a coil in which a plurality of strands are wound in multiple turns (multi-strand coil).

The holding wire 70 is spirally wound so as to surround the outside of the pair of sub-tubes 40 that are arranged to face each other around the main lumen 20. The winding shape of the holding wire 70 of the present embodiment is a substantially elliptical shape or a substantially rhombic shape whose major axis direction is the direction in which the sub tubes 40 are arranged. In FIG. 2, the holding wire 70 having a substantially rhombic winding shape is shown by a broken line. The holding wire 70 is in contact with the peripheral surface of the sub tube 40, specifically, the outer surface of the main lumen 20 opposite to the axis thereof. Here, the substantially diamond shape means that the first diagonal line is longer than the second diagonal line, and the first diagonal line and the second diagonal line are substantially orthogonal to each other. The approximate rhombus here includes a rhombus, a kite shape (a kite shape), and a flat polygon such as a flat hexagon and a flat octagon. In addition, the substantially elliptical shape includes an eccentric circle such as an oval as well as an oval shape and an oval.

In the present embodiment, the main lumen 20 is circular and is arranged at the center of the tubular main body 10, and the two sub-tubes 40 are arranged 180 degrees opposite to each other around the main lumen 20, but three or more are arranged. The (N) sub-tubes 40 may be evenly arranged around the main lumen 20. In this case, the winding shape of the holding wire 70 may be a rounded N-sided shape having each sub-tube 40 as a corner.

The holding wire 70 is in contact with the outer surface of the wire reinforcing layer 30 on both sides or one side in the minor axis direction orthogonal to the major axis direction. In this embodiment, as shown in FIG. 2, 16 reinforcing wires 32 are braided by spirally winding eight reinforcing wires in opposite directions, and the number of intersections of the reinforcing wires 32 is eight in the circumferential direction of the inner layer 24. Has been formed. The holding wire 70 of the present embodiment is in contact with the reinforcing wires 32 so as to ride on the intersections of the reinforcing wires 32 at positions corresponding to both sides of the substantially rhombic winding shape in the minor axis direction.

The inner surface of the subtube 40 is in contact with the outer surface of the wire reinforcing layer 30 (see FIG. 1). That is, the holding wire 70 is spirally wound in contact with the outer surface of the pair of sub-tubes 40 and the wire reinforcing layer 30 corresponding to the hard point. In particular, the holding wire 70 of the present embodiment is in contact with the outer surface of the wire reinforcing layer 30 on both sides in the minor axis direction. As a result, the holding wire 70 causes the sub-tube 40 and the wire reinforcing layer 30 to be closely wound without loosening and wound together. Therefore, the sub-tube 40 can be kept in parallel with the wire reinforcing layer 30 with high accuracy even after the molding process of the outer layer 50. That is, the holding wire 70 has an elliptical shape, and the holding wire 70 is wound by applying tension to the wire reinforcing layer 30 and the sub tube 40 so as to hold the sub tube 40 at both ends of its major axis. This prevents the sub-tube 40 from being displaced in the circumferential direction of the wire reinforcing layer 30.

The holding wire 70 is wound over substantially the entire length of the sub-tube 40 as viewed in the longitudinal direction of the tubular body 10. Thereby, the relative position between the wire reinforcement layer 30 and the subtube 40 is fixed by the holding wire 70 while the pair of subtubes 40 are kept parallel to the axial direction of the tubular body 10 along the surface of the wire reinforcement layer 30. Has been done.

As the material of the holding wire 70, any of the above-mentioned metal material or resin material that can be used as the reinforcing wire 32 can be used. In the present embodiment, the holding wire 70 is made of a material different from that of the reinforcing wire 32. The ductility of the holding wire 70 is preferably higher than the ductility of the reinforcing wire 32. Specifically, austenite soft stainless steel (W1 or W2), which is a blunting material, or copper or a copper alloy is used for the holding wire 70, while tungsten or stainless spring steel can be used for the reinforcing wire 32. ..
By using a highly ductile material for the holding wire 70, the holding wire 70 is loosened when the holding wire 70 is coiled around the sub tube 40 or braided in a mesh shape (coil winding in the present embodiment). Without fixing, the sub tube 40 is fixed by being plastically stretched and deformed. On the other hand, since the wire reinforcement layer 30 is a member that prevents the occurrence of kinks in the tubular body 10 as described later, it is preferable to use a spring material having a high elastic restoring force.

The tubular main body 10 includes a second reinforcing layer 80 formed by winding a second reinforcing wire 82 in a circular cross section on the outer side of the holding wire 70. The second reinforcing layer 80 of the present embodiment is a blade layer formed by braiding fine metal wires in a mesh shape. That is, the tubular body 10 of the present embodiment includes three metal layers of the wire reinforcing layer 30, the holding wire 70, and the second reinforcing layer 80.

The second reinforcing layer 80 is a member that imparts bending elasticity to the tubular body 10 together with the wire reinforcing layer 30. After the distal portion DE of the tubular body 10 is bent by the pulling operation of the operation wire 60, the tubular body 10 is preferably elastically restored when the tensile load of the operation wire 60 is removed. For this reason, in the tubular main body 10 of the present embodiment, it is preferable to use a springy metallic material for the wire reinforcing layer 30 (reinforcing wire 32) and the second reinforcing layer 80 (second reinforcing wire 82). Therefore, the ductility of the holding wire 70 is higher than that of both the reinforcing wire 32 and the second reinforcing wire 82.

The distal portion DE of the tubular body 10 is provided with a first marker 14 and a second marker 16 located on the proximal side of the first marker 14. The first marker 14 and the second marker 16 are ring-shaped members made of a material that is impermeable to radiation such as X-rays such as platinum. By using the positions of the two markers of the first marker 14 and the second marker 16 as indices, the position of the tip of the tubular main body 10 in the body cavity (blood vessel) can be visually recognized under observation of radiation (X-ray). This makes it possible to easily determine the optimum timing for performing the bending operation of the catheter 100.

The tip portion of the operation wire 60 is fixed to a portion of the tubular body 10 on the distal side of the second marker 16. By pulling the operation wire 60, the portion of the distal portion DE on the distal side of the second marker 16 is bent. In the catheter 100 of this embodiment, the distal end portion of the operation wire 60 is fixed to the first marker 14. The mode of fixing the operation wire 60 to the first marker 14 is not particularly limited, and examples thereof include solder joining, heat fusion, adhesion with an adhesive, and mechanical locking of the operation wire 60 and the first marker 14. ..

The inner diameter of the second marker 16 is larger than the inner diameter of the first marker 14. The first marker 14 is arranged so as to contact or almost contact the outer surface of the wire reinforcing layer 30. The inner diameter of the first marker 14 is larger than the outer diameter of the wire reinforcing layer 30 and smaller than the inner diameter of the second reinforcing layer 80.
The radial positional relationship between the inner wall surface and outer peripheral surface of the first marker 14 and the sub-tube 40 is not particularly limited. When fixing the operation wire 60 to the outer peripheral surface of the first marker 14, as shown in FIG. 1, the first marker 14 is placed so that the outer peripheral surface of the first marker 14 is located inside the disposition position of the tip of the sub tube 40. The outer diameter of 14 can be set. In addition, when the operation wire 60 is fixed to the end face of the first marker 14 on the base end side, the end face may overlap the tip end of the sub tube 40 in the radial direction. In this case, the outer peripheral surface of the first marker 14 may be located on the outer diameter side with respect to the disposition position of the tip of the sub tube 40.
The second marker 16 is arranged so as to contact or almost contact the outer surface of the second reinforcing layer 80. The inner diameter of the second marker 16 is larger than the outer diameter of the second reinforcing layer 80.

As shown in FIG. 2, the distal end of the wire reinforcement layer 30 reaches the area where the first marker 14 is disposed. The disposition region of the first marker 14 is a length region in which the first marker 14 is formed as viewed in the axial direction of the tubular body 10. The same applies to the second marker 16. The distal end of the wire reinforcing layer 30 is located on the distal side of the tubular body 10 with respect to the proximal end of the first marker 14. Further, the distal end of the wire reinforcing layer 30 is located near the distal end of the first marker 14. In this way, the wire reinforcing layer 30 reaches the disposition region of the first marker 14, so that the discontinuity of the bending rigidity of the tubular body 10 at the proximal end of the first marker 14 is alleviated and the kink of It prevents the occurrence.

The distal end of the second reinforcing layer 80 is proximal to the proximal end of the first marker 14 and distal to the proximal end of the area where the second marker 16 is disposed. The distal end of the second reinforcing layer 80 is located near the distal end of the second marker 16. This causes discontinuity in the bending rigidity of the tubular body 10 at the distal end of the second marker 16. Therefore, when the operating wire 60 is pulled, the tubular body 10 can be bent sharply slightly distal to the second marker 16. Even when the tubular body 10 is sharply bent as described above, since the wire reinforcing layer 30 is continuously formed up to the area where the first marker 14 is disposed as described above, a kink is generated in the tubular body 10. Never. In other words, one of the wire reinforcement layer 30 and the second reinforcement layer 80 is continuously formed up to the vicinity of the distal end of the tubular body 10 to prevent kinks, and the other end is terminated in the middle of the distal portion DE. The bending position is clearly defined by causing discontinuity in bending rigidity of the main body 10.

The proximal ends of the wire reinforcing layer 30 and the second reinforcing layer 80 are located at the proximal end of the tubular body 10, that is, inside the operating portion 90.

The distal end of the inner layer 24 may reach the distal end of the tubular body 10 or may terminate proximal to the distal end. The position where the inner layer 24 ends may be inside the area where the first marker 14 is provided.

Here, as described above, the catheter 100 includes the first marker (marker) 14 made of a radiopaque material.
Then, the distal end of the sub-lumen 42, that is, the distal end of the sub-tube 40 ends at a position overlapping the first marker 14 or at a position closer to the proximal end side than the first marker 14 in the front proximal direction of the tubular body 10. ing. Note that FIG. 1 shows an example in which the base end of the first marker 14 and the tip of the sub-tube 40 are aligned.
Further, as described above, the sliding resistance between the peripheral wall of the sub-lumen 42 (that is, the inner peripheral surface of the sub-tube 40) and the operating wire 60 is larger at the distal end portion than at the intermediate portion of the tubular body 10. Large sliding resistance. In other words, the sliding resistance in the length region of at least a part of the distal end portion of the tubular body 10 is larger than the sliding resistance in the middle portion of the tubular body 10. Here, in the present embodiment, at least a part of the length region of the tip portion is the length of a portion of the subtube 40 of the tip portion having a smaller diameter than the subtube 40 in the middle portion.
Then, in the case of the present embodiment, as shown in FIG. 1, in the front proximal direction of the tubular body 10, the length of at least a part of the length region of the distal end portion of the tubular body 10 is equal to that of the first marker 14. Longer than length.
This makes it possible to increase the sliding resistance between the operating wire 60 and the peripheral wall of the sub-lumen 42 in a sufficient length region.

The present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope of achieving the object of the present invention are included in the present invention.
In the above-described embodiment, the wire reinforcement layer 30 is a blade layer, and the first outer layer 52 impregnates the inside of the openings of the wire reinforcement layer 30 from the periphery of the subtube 40 to form the inner layer 24, the wire reinforcement layer 30, and It is illustrated that the sub-tube 40 is integrally fixed. Alternatively, the first outer layer 52, which is the inner layer of the outer layer 50, may not be substantially impregnated between the wire reinforcing layer 30 and the sub tube 40.

The hydrophilic layer formed on the outer surface of the second outer layer 54 constitutes the outermost layer of the catheter 100. The hydrophilic layer may be formed over the entire length of the tubular body 10, or may be formed only in a partial length region on the tip side including the distal portion DE. The hydrophilic layer is made of, for example, a maleic anhydride-based polymer such as polyvinyl alcohol (PVA), a copolymer thereof, or a hydrophilic resin material such as polyvinylpyrrolidone.

Typical dimensions of the constituent elements of the catheter 100 of this embodiment will be described.
The diameter of the main lumen 20 may be 400 μm to 600 μm (including the upper limit value and the lower limit value, the same applies hereinafter), the thickness of the inner layer 24 may be 5 μm to 30 μm, and the thickness of the outer layer 50 may be 10 μm to 200 μm. The wall thickness of the sub-tube 40 may be smaller than that of the inner layer 24 and may be 1 μm to 10 μm. The inner diameter of the wire reinforcing layer 30 is 410 μm to 660 μm, the outer diameter of the wire reinforcing layer 30 is 450 μm to 740 μm, the inner diameter of the second reinforcing layer 80 is 560 μm to 920 μm, and the outer diameter of the second reinforcing layer 80 is 600 μm to 940 μm. You can
The inner diameter of the first marker 14 can be 450 μm to 740 μm, the outer diameter of the first marker 14 can be 490 μm to 820 μm, the inner diameter of the second marker 16 can be 600 μm to 940 μm, and the outer diameter of the second marker 16 can be 640 μm to 960 μm. .. The width dimension of the first marker 14 (dimension in the longitudinal direction of the tubular body 10) can be 0.3 mm to 2.0 mm, and the width dimension of the second marker 16 can be 0.3 mm to 2.0 mm.
The radius (distance) from the axial center of the catheter 100 to the center of the subtube 40 may be 300 μm to 450 μm, the inner diameter (diameter) of the subtube 40 may be 40 μm to 100 μm, and the thickness of the operating wire 60 may be 25 μm to 60 μm. ..
The tubular body 10 has a diameter of 700 μm to 980 μm, that is, an outer diameter of less than 1 mm, and can be inserted into a blood vessel such as a celiac artery.

When one of the two operation wires 60 included in the catheter 100 is pulled toward the proximal end side, a tensile force is applied to the distal end portion of the catheter 100 via the one operation wire 60. Given. As a result, the distal portion DE of the tubular body 10 bends toward the side of the sub-tube 40 through which the one operation wire 60 is inserted with the axial center of the tubular body 10 as a reference. When the other operation wire 60 is pulled toward the proximal end side, a tensile force is applied to the distal portion DE of the catheter 100 via the other operation wire 60. As a result, the distal portion DE of the tubular body 10 bends toward the side of the sub-tube 40 through which the other operation wire 60 is inserted, with the axial center of the tubular body 10 as a reference.
Here, the bending of the tubular body 10 includes a mode in which the tubular body 10 is bent in an “L” shape and a mode in which the tubular body 10 is curved in a bow.

According to the first embodiment as described above, as described above, the sliding resistance between the peripheral wall of the sub-lumen 42 (the inner peripheral surface of the sub-tube 40) and the operating wire 60 is the intermediate portion of the tubular body 10. The sliding resistance at the tip of the tubular body 10 is greater than the sliding resistance at.
As a result, it is possible to prevent the distal end portion of the tubular body 10 from locally bending with an excessive curvature (an excessively small radius of curvature), so that the orientation of the distal end of the tubular body 10 can be easily adjusted and the tubular body 10 can be easily adjusted. It becomes easy to introduce the tip of the into the desired body cavity.
That is, the operability of the catheter 100 can be improved.

Here, in the conventional intravascular catheter, when the operating wire is pulled, first, the entire body and the distal end portion bend. The intermediate portion and the proximal end portion are held to some extent by the blood vessel (thick blood vessel from which branching) or the parent catheter, and the distal end portion is bent at the branch portion (thin blood vessel) of the blood vessel. With the tip bent about 90 degrees, point the tip toward the intended branch vessel and push the catheter in as it is. The tip is just caught in the branch vessel, so the entire catheter is inside the large blood vessel. It loses the force to go straight and the tip falls off from the branch vessel.
Then, when the catheter is pushed while increasing the pulling length of the operation line with the bent distal end hooked on the branch blood vessel, the intermediate portion bends into the branch blood vessel following the distal end of the catheter. It is thought that the catheter can successfully enter the target branch vessel. However, when the pulling length of the operation wire is increased in this way, the curvature of the distal end portion becomes excessive when the intermediate portion of the catheter bends. When the bending angle of the distal end portion is 180 degrees, the distal end portion is directed toward the proximal end side (that is, the branching origin side when viewed from the branch blood vessel), and when the catheter is pushed in, the tip end portion is easily dropped from the branch blood vessel.

On the other hand, in the catheter 100 according to the present embodiment, the force for pulling the operation wire 60 is consumed by the sliding resistance at the tip portion of the tubular body 10, and as a result, the pulling force applied to the tip portion is suppressed. Therefore, it is possible to prevent the distal end of the tubular body 10 from being locally bent with an excessive curvature (an excessively small radius of curvature), and to gently bend the range including the distal end and the intermediate portion. ..
Therefore, by pushing the catheter 100 with the distal end of the tubular body 10 hooked on the branch blood vessel, the catheter 100 can be easily advanced in the target direction without falling off from the branch blood vessel.

Here, the mechanism will be described with reference to FIGS. 4 and 5.
FIG. 4 is a schematic diagram for explaining the behavior of the catheter 100 according to the embodiment, of which (a) and (b) are the moment (a) when the tubular body 10 has a small curvature and the tip of the tubular body 10. The cumulative value (b) obtained by integrating the moment from the (distal end) toward the hand (proximal end) side is shown, and (c) and (d) show the moment (a) and the cumulative value when the tubular body 10 has a large curvature. The value (b) is shown.
On the other hand, FIG. 5 is a schematic diagram for explaining the behavior of the catheter according to the comparative embodiment. Among them, (a) and (b) are the moment (a) and the accumulated value (b) when the curvature of the tubular body 10 is small. ), and (c) and (d) show a moment (a) and a cumulative value (b) when the tubular body 10 has a large curvature.
The catheter according to the comparative form is different from the catheter 100 according to the embodiment in that the diameter of the sub-tube 40 at the distal end portion is the same as the diameter of the sub-tube 40 at the intermediate portion, and in other respects, it is different from the embodiment. It is configured similarly to the catheter 100.

As shown in FIGS. 4A and 4B, and FIGS. 5A and 5B, when the tubular body 10 has a small curvature (when the force for pulling the operating wire 60 is weak), In both the embodiment and the comparative embodiment, since the rubbing between the peripheral wall of the sub-lumen 42 and the operation line 60 does not substantially occur, a moment acts locally only on the tip portion and only the tip portion locally bends. Yes (however, the curvature is small).

On the other hand, as shown in FIGS. 4C and 4D, in the case of the present embodiment, when the curvature of the tubular body 10 is large (when the force pulling the operation wire 60 is strong), the sub-lumen 42 is formed. Since the peripheral wall of the and the operation line 60 rub against each other, a moment is dispersed from the tip to the middle (corresponding to the region where the rectangular frame of the alternate long and short dash line is arranged), and the moment acts from the tip to the middle. The tubular body 10 bends gently.

However, as shown in FIGS. 5C and 5D, in the case of the comparative example, when the curvature of the tubular main body 10 is large (when the force pulling the operating wire 60 is strong), the moment is concentrated on the distal end portion. However, the tip portion is mainly bent.

Here, a method of measuring the sliding resistance between the inner peripheral surface of the sub-tube 40 (the peripheral wall of the sub-lumen 42) and the operating wire 60 will be described with reference to FIG. 10.

First, the tubular body 10 is cut out from the distal end portion and the intermediate portion of the catheter, and the tubular body 10 is bent and fixed. The length of the tubular body 10 cut out from the tip portion and the length of the tubular body 10 cut out from the middle portion are equal to each other (hereinafter, this length is referred to as a predetermined length). Further, the bent shape of the tubular body 10 cut out from the tip portion and the bent shape of the tubular body 10 cut out from the middle portion are made equal to each other. It should be noted that both ends of the tubular main body 10 cut out longer than the predetermined length (without cutting the operation line 60) are cut off so that the operation lines 60 are projected from both ends of the tubular main body 10 of the predetermined length. The tubular body 10 having a predetermined length is prepared by. The operation wires 60 protruding from both ends of the tubular body 10 are assumed to protrude from the common sub-lumen 42.

Next, the tip of the operation wire 60 protruding from one end of the cut out tubular body 10 is fixed to a load cell (not shown), and the tip of the operation wire 60 protruding from the other end of the cut out tubular body 10 is passed through the pulley 130. The weight 140 is fixed, and the weight 140 is suspended from the pulley 130.
In this state, one end of the operating wire 60 is pulled by the load cell, and the pulling load at that time is measured. The value obtained by subtracting the load due to the weight of the weight 140 (the integrated value of the mass of the weight 140 and the gravitational acceleration) from the measured traction load is measured as the sliding resistance.

[Second Embodiment]
FIG. 6 is a vertical cross-sectional view of the catheter 100 according to the second embodiment.
In the case of the present embodiment, the adhesion of the operating wire 60 to the peripheral wall of the sub-lumen 42 is stronger at the tip portion of the tubular body 10 than at the middle portion of the tubular body 10.
As a result, the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger at the distal end portion than at the intermediate portion.
Here, the adhesion of the operating wire 60 to the peripheral wall of the sub-lumen 42 is a property having a positive correlation with the dynamic friction coefficient between the peripheral wall of the sub-lumen 42 and the operating wire 60.
The adhesion of the operating wire 60 to the peripheral wall of the sub-lumen 42 is determined according to the resin material forming the peripheral wall. Therefore, by making the resin material forming the peripheral wall of the sub-lumen 42 different between the distal end portion and the intermediate portion, the adhesiveness at the distal end portion of the tubular main body 10 is made higher than that at the intermediate portion of the tubular main body 10. A strong structure can be realized.

In the case of the present embodiment, as shown in FIG. 6, the tip of the sub-tube 40 ends in the middle portion of the tubular body 10.
The sub-lumen 42 is formed by the inner space of the sub-tube 40, and the second portion formed in the tubular body 10 on the tip side of the sub-tube 40 and communicating with the first portion 42a. 42b and are comprised.
The peripheral wall of the second portion 42b of the sub-lumen 42 is configured by, for example, the outer layer 50, and more specifically, is configured by, for example, the first outer layer 52 (see FIG. 2). The inner diameter of the second portion 42b is smaller than the inner diameter of the first portion 42a.
The adhesion of the operation wire 60 to the constituent material of the outer layer 50 is stronger than the adhesion of the operation wire 60 to the constituent material of the sub tube 40.
Therefore, the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger than the sliding resistance at the intermediate portion at the tip portion.

Note that the catheter 100 according to the present embodiment is similar to the first embodiment in other configurations, and thus the description thereof is omitted.

[Third Embodiment]
FIG. 7 is a vertical sectional view of the catheter 100 according to the third embodiment.
Also in the case of the present embodiment, the adhesion of the operating wire 60 to the peripheral wall of the sub-lumen 42 is stronger at the distal end portion of the tubular body 10 than at the middle portion of the tubular body 10, and as a result, The sliding resistance between the peripheral wall of the lumen 42 and the operating wire 60 is larger at the distal end portion than at the intermediate portion.

In the case of the present embodiment, as shown in FIG. 7, the sub-tube 40 is connected to the first tube 40a located in the middle portion of the tubular body 10 and the distal end portion of the tubular body 10 connected to the distal end side of the first tube 40a. And a second tube 40b located at.
The first tube 40a and the second tube 40b are made of different materials. That is, the adhesion of the operation wire 60 to the constituent material of the second tube 40b is stronger than the adhesion of the operation wire 60 to the constituent material of the first tube 40a.
Therefore, the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger at the tip portion than at the intermediate portion.

Note that the catheter 100 according to the present embodiment is similar to the first embodiment in other configurations, and thus the description thereof is omitted.

[Fourth Embodiment]
FIG. 8 is a vertical cross-sectional view of the catheter 100 according to the fourth embodiment. Note that, in FIG. 8, as in FIG. 3, illustration of a part of the configuration of the catheter 100 is omitted.
Also in the case of the present embodiment, the adhesion of the operating wire 60 to the peripheral wall of the sub-lumen 42 is stronger at the distal end portion of the tubular body 10 than at the intermediate portion of the tubular body 10, and as a result, The sliding resistance between the peripheral wall of the lumen 42 and the operating wire 60 is larger at the distal end portion than at the intermediate portion.

In the case of the present embodiment, an opening 41 penetrating the inside and the outside of the sub tube 40 is formed in the sub tube 40 at the tip portion of the tubular body 10. The constituent material of the tubular body 10 projects into the sub-tube 40 through the opening 41. More specifically, the constituent material of the outer layer 50 (among others, the first outer layer 52 (FIG. 2), for example) projects into the sub-tube 40 through the opening 41. The presence of the resin material protruding into the sub-tube 40 through the opening 41 increases the sliding resistance at the tip portion. As a result, the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger at the distal end portion than at the intermediate portion.

Note that the catheter 100 according to the present embodiment is similar to the first embodiment in other configurations, and thus the description thereof is omitted.

[Fifth Embodiment]
FIG. 9 is a vertical cross-sectional view of the catheter 100 according to the fifth embodiment. Note that in FIG. 9, as in FIG. 3, illustration of a part of the configuration of the catheter 100 is omitted.
As shown in FIG. 9, in the case of this embodiment, unevenness (fine unevenness) is formed on the inner surface of the sub-tube 40 at the tip portion of the tubular body 10. On the other hand, in the middle portion of the tubular body 10, the inner surface of the sub-tube 40 is formed smoothly (at least smoother than the tip portion).
More specifically, for example, when the sub-tube 40 is compressed in the axial direction, the sub-tube 40 is formed in a bellows shape at the distal end portion of the tubular body 10, and as a result, irregularities 47 are formed on the inner surface and the outer surface of the sub-tube 40. Are formed.
This realizes a configuration in which the sliding resistance between the peripheral wall of the sub-lumen 42 and the operating wire 60 is larger at the tip portion than at the intermediate portion.

It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications, improvements, etc. as long as the object of the present invention is achieved.

It should be noted that the various constituent elements of the present invention do not have to be independent. A plurality of constituent elements are formed as one member, one constituent element is formed by a plurality of members, one constituent element is a part of another constituent element, one constituent element It is allowed that a part overlaps with a part of other components.

The above embodiment includes the following technical ideas.
(1) A sheath main body, a lumen having a through hole formed inside the sheath main body, and an operation wire inserted into the lumen and connected to a distal end portion of the sheath main body. A catheter in which the distal end portion is bent by pulling a wire,
The sliding resistance between the peripheral wall of the lumen and the operating wire is larger at the distal end portion than at the intermediate portion between the distal end portion and the proximal end portion of the sheath body. catheter.
(2) The catheter according to (1), wherein the inner diameter of the lumen at the tip portion is smaller than the inner diameter of the lumen at the intermediate portion.
(3) A tube embedded in the sheath body is provided,
The inner space of the tube constitutes the lumen,
The catheter according to (2), wherein the tube is crushed at the tip portion.
(4) A tube embedded in the sheath body is provided,
The inner space of the tube constitutes the lumen,
The catheter according to any one of (1) to (3), wherein unevenness is formed on the inner surface of the tube at the tip portion.
(5) The adhesion of the operating wire to the peripheral wall of the lumen is stronger than the adhesion at the intermediate portion, and the adhesion at the tip portion is stronger (1) to (4). catheter.
(6) A tube embedded in the sheath body is provided,
The tip of the tube is terminated at the intermediate portion,
The lumen is
A first portion constituted by the inner space of the tube,
A second portion formed on the sheath body on the distal side of the tube and communicating with the first portion;
The catheter according to (5), which comprises:
(7) A tube embedded in the sheath body is provided,
The inner space of the tube constitutes the lumen,
The tube is
A first tube located in the intermediate portion,
A second tube connected to the tip side of the first tube and located at the tip portion;
Including
The catheter according to (5), wherein the first tube and the second tube are made of different materials.
(8) A tube embedded in the sheath body is provided,
The inner space of the tube constitutes the lumen,
An opening is formed in the tip portion to penetrate the inside and outside of the tube,
The catheter according to (5), wherein the constituent material of the sheath body projects into the tube through the opening.
(9) A marker made of a radiopaque material is provided,
The distal end of the lumen is terminated at a position overlapping the marker or a position closer to the proximal end side than the marker in the front proximal direction of the sheath body,
The sliding resistance in the length region of at least a part of the tip portion is larger than the sliding resistance in the intermediate portion,
The catheter according to any one of (1) to (8), wherein the length of the at least part of the length region of the distal end portion is longer than the length of the marker in the front proximal direction of the sheath body. ..

10 Tubular body (sheath body)
14 1st marker 16 2nd marker 20 Main lumen 24 Inner layer 30 Wire reinforcement layer 32 Reinforcement wire 40 Sub tube (tube)
40a 1st tube 40b 2nd tube 41 Opening 42 Secondary lumen 42a 1st part 42b 2nd part 50 Outer layer 52 1st outer layer 54 2nd outer layer 60 Operation wire 70 Retaining wire 80 2nd reinforcement layer 82 2nd reinforcement wire 100 Catheter 130 pulley 140 weight DE distal part

Claims (7)

A sheath main body, a lumen having a through hole formed inside the sheath main body, and an operation wire that is inserted into the lumen and is connected to a distal end portion of the sheath main body, and the operation wire is pulled. A catheter in which the distal end portion is bent by being
The sliding resistance between the peripheral wall of the lumen and the operation line when moving the operation line in the axial direction relative to the lumen having a unit length in a state where the sheath body is bent is determined by the sheath. The sliding resistance at the tip portion is larger than the sliding resistance at the intermediate portion between the tip portion and the base end portion of the main body,
The catheter comprises a tube embedded in the sheath body,
The inner space of the tube constitutes the lumen,
A catheter in which irregularities are formed on the inner surface of the tube at the distal end portion. The adhesion of the operation line to the peripheral wall of the lumen, which has a positive correlation with the dynamic friction coefficient between the peripheral wall of the lumen and the operation line, is higher at the tip portion than at the intermediate portion. The catheter according to claim 1, wherein the adhesion is strong. A sheath main body, a lumen having a through hole formed inside the sheath main body, and an operation wire that is inserted into the lumen and is connected to a distal end portion of the sheath main body, and the operation wire is pulled. A catheter in which the distal end portion is bent by being
The sliding resistance between the peripheral wall of the lumen and the operation line when moving the operation line in the axial direction relative to the lumen having a unit length in a state where the sheath body is bent is determined by the sheath. The sliding resistance at the tip portion is larger than the sliding resistance at the intermediate portion between the tip portion and the base end portion of the main body,
The catheter comprises a tube embedded in the sheath body,
The inner space of the tube constitutes the lumen,
The tube is
A first tube located in the intermediate portion,
A second tube connected to the tip side of the first tube and located at the tip portion;
Including
The first tube and the second tube are made of different materials from each other,
The adhesion of the operation line to the peripheral wall of the lumen, which has a positive correlation with the dynamic friction coefficient between the peripheral wall of the lumen and the operation line, is higher at the tip portion than at the intermediate portion. The catheter with strong adhesion. A sheath main body, a lumen having a through hole formed inside the sheath main body, and an operation wire that is inserted into the lumen and is connected to a distal end portion of the sheath main body, and the operation wire is pulled. A catheter in which the distal end portion is bent by being
The sliding resistance between the peripheral wall of the lumen and the operation line when moving the operation line in the axial direction relative to the lumen having a unit length in a state where the sheath body is bent is determined by the sheath. The sliding resistance at the tip portion is larger than the sliding resistance at the intermediate portion between the tip portion and the base end portion of the main body,
The catheter comprises a tube embedded in the sheath body,
The inner space of the tube constitutes the lumen,
An opening is formed in the tip portion to penetrate the inside and outside of the tube,
Through the opening, the constituent material of the sheath body is projected into the tube,
The adhesion of the operation line to the peripheral wall of the lumen, which has a positive correlation with the dynamic friction coefficient between the peripheral wall of the lumen and the operation line, is higher at the tip portion than at the intermediate portion. The catheter with strong adhesion. The inner diameter of the lumen in the tip, the catheter according to any one of 4 claims 1 smaller than the inner diameter of the lumen in the intermediate section. The catheter according to claim 5 , wherein the tube is collapsed at the tip portion. With a marker made of radiopaque material,
The distal end of the lumen is terminated at a position overlapping the marker or a position closer to the proximal end side than the marker in the front proximal direction of the sheath body,
The sliding resistance in the length region of at least a part of the tip portion is larger than the sliding resistance in the intermediate portion,
The catheter according to any one of claims 1 to 6 , wherein a length of the at least a part of the length region of the distal end portion is longer than a length of the marker in a front proximal direction of the sheath body.

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