Catheter

1. A catheter comprising:

a balloon extending in an axial direction and comprising an elastic inner layer and an elastic outer layer, the inner and outer layers being tubular and being inflatable and deflatable in a radial direction in response to a change of internal pressure of the balloon;

a tubular reinforcement member positioned between the inner layer and the outer layer in the radial direction;

the reinforcement member comprising a first end portion and a second end portion opposite the first end portion in the axial direction, the reinforcement member comprising an intermediate portion between the first end portion and the second end portion in the axial direction;

at least one of the first end portion and the second end portion being not directly fixed to the inner layer and the outer layer; and

the intermediate portion being not directly fixed to the inner layer and not directly fixed to the outer layer.

2. The catheter according to claim 1 , wherein both the first end portion and the second end portion are not directly fixed to the inner layer and are not directly fixed to the outer layer.

3. The catheter according to claim 1 , wherein inflation of the first end portion and the second end portion in the radial direction is restricted.

4. The catheter according to claim 1 , wherein

the reinforcement member is a tubularly knitted member of one or more wave-shaped threads, and

the wave-shaped threads adjacent to each other in the axial direction are interlaced with each other.

5. The catheter according to claim 1 , wherein the reinforcement member is a fiber possessing a tensile break strength equal to or greater than 2 GPa and an elastic modulus equal to or greater than 50 GPa.

6. The catheter according to claim 1 , wherein

the inner layer comprises a stretchable region that is stretchable during inflation and deflation of the balloon, the stretchable region possessing a length in the axial direction,

the outer layer possesses a length in the axial direction,

the reinforcement member possesses a length in the axial direction,

the length of the reinforcement member in the axial direction is greater than the length of the stretchable region of the inner layer in the axial direction, and

the length of the outer layer in the axial direction is greater than the length of the reinforcement member in the axial direction.

7. The catheter according to claim 1 , wherein

the reinforcement member possesses an inner surface and an outer surface, the reinforcement member comprising multiple gaps penetrating through the inner surface and the outer surface of the reinforcement member,

the catheter further comprising a joint structure that partially joins the inner layer and the outer layer to each other via the multiple gaps penetrating the inner and outer surfaces of the reinforcement member, the joint structure being positioned so that the reinforcement member is restrained from being misaligned in the axial direction with respect to the balloon, and

the joint structure not being fixed to the reinforcement member so that the reinforcement member is movable relative to the balloon.

8. The catheter according to claim 7 , wherein

the joint structure comprises multiple fused portions penetrating the multiple gaps, and

the reinforcement member is movable relative to the fused portions.

9. The catheter according to claim 7 , wherein the joint structure is provided in only a first region of the reinforcement member near the first end portion and a second region of the reinforcement member near the second end portion.

10. The catheter according to claim 7 , wherein the reinforcement member is mesh and the multiple gaps of the reinforcement member are gaps in the mesh.

11. The catheter according to claim 1 , wherein

the reinforcement member comprises one or more wire members, the one or more wire members possessing outer surfaces, and

a lubricant is present on at least the outer surfaces of the one or more wire members to reduce friction between portions of outer surfaces of the one or more wire members that contact each other.

12. The catheter according to claim 1 , wherein the reinforcement member includes multiple gaps spaced apart from one another and penetrating through the reinforcement member, the inner layer of the balloon and the outer layer of the balloon being fused to each other at fused portions each located at one of the gaps.

13. The catheter according to claim 1 , wherein the inner layer of the balloon and the outer layer of the balloon are fused to each other at a plurality of spaced apart fused portions that pass through the reinforcement member, the reinforcement member being movable relative to the inner and outer layers of the balloon at the fused portions.

14. The catheter according to claim 1 , wherein the reinforcement member is comprised of one or more woven threads so that the reinforcement member includes a plurality of spaced apart gaps that pass through the reinforcement member.

15. The catheter according to claim 1 , wherein the inner layer of the balloon and the outer layer of the balloon are made of the same material.

16. The catheter according to claim 1 , further comprising an elongated shaft possessing a distal-most end portion, the distal-most end portion of the elongated shaft possessing a thickness that is reduced relative to an immediately adjacent portion of the elongated shaft, a proximal-most end portion of the inner layer of the balloon being joined to an outer surface of the distal-most end portion of the elongated shaft possessing the thickness that is reduced relative to the immediately adjacent portion of the elongated shaft, a proximal-most end portion of the outer layer of the balloon axially overlying the immediately adjacent portion of the elongated shaft.

17. A catheter comprising:

an elongated shaft extending in an axial direction;

a balloon connected to the shaft, the balloon comprising a tubular elastic inner layer and a tubular elastic outer layer, the inner and outer layers being inflatable and deflatable in response to a change of internal pressure of the balloon, the outer layer possessing an inner surface and the inner layer possessing an outer surface;

at least a portion of the inner surface of the outer layer being spaced radially outwardly from at least a portion of the outer surface of the inner layer;

an accommodation chamber formed by the portion of the inner surface of the outer layer spaced radially outwardly from the portion of the outer surface of the inner layer;

a reinforcement member positioned in the accommodation chamber, the reinforcement member comprising a first end portion and a second end portion opposite the first end portion in the axial direction, the reinforcement member comprising an intermediate portion located between the first end portion and the second end portion in the axial direction;

the reinforcement member comprising a plurality of spaced apart gaps that pass through the reinforcement member; and

the inner layer of the balloon and the outer layer of the balloon being fused to each other at a plurality of spaced apart fused portions each located at one of the gaps.

18. The catheter according to claim 17 , wherein the accommodation chamber is filled with lubricant.

19. The catheter according to claim 17 , wherein

the reinforcement member is a tubular mesh formed by a fiber which possesses a tensile break strength equal to or greater than 2 GPa and an elastic modulus equal to or greater than 50 GPa;

the first end portion is movable relative to both the inner layer and the outer layer; and

the intermediate portion is movable relative to both the inner layer and the outer layer.

20. A catheter comprising:

a balloon extending in an axial direction and comprising an elastic inner layer and an elastic outer layer, the inner and outer layers being tubular and being inflatable and deflatable in a radial direction in response to a change of internal pressure of the balloon;

a tubular reinforcement member positioned between the inner layer and the outer layer in the radial direction;

the reinforcement member comprising a first end portion and a second end portion opposite the first end portion in the axial direction, the reinforcement member comprising an intermediate portion between the first end portion and the second end portion in the axial direction;

at least one of the first end portion and the second end portion being not directly fixed to the inner layer and the outer layer;

the intermediate portion being not directly fixed to the inner layer and are not directly fixed to the outer layer;

the reinforcement member possessing an inner surface and an outer surface, the reinforcement member comprising multiple gaps penetrating through the inner surface and the outer surface of the reinforcement member,

the catheter further comprising a joint structure that partially joins the inner layer and the outer layer to each other via the multiple gaps penetrating the inner and outer surfaces of the reinforcement member, the joint structure being positioned so that the reinforcement member is restrained from being misaligned in the axial direction with respect to the balloon, and

the joint structure not being fixed to the reinforcement member so that the reinforcement member is movable relative to the balloon.