Balloon catheter

Abstract

A balloon catheter comprises a balloon, an outer tube connected to a proximal end of the balloon, an inner tube disposed inside the outer tube and having a distal end attached to a distal end of the balloon, a protruded-depressed portion formed on an outer periphery of the inner tube, and a core wire disposed between the outer tube and the inner tube. The core wire has a bulged portion sandwiched between the outer tube and a depressed portion of the protruded-depressed portion. The balloon catheter can transmit a force from the core wire to both the outer tube and the inner tube regardless of whether the force is generated by pushing or pulling a proximal end portion of the balloon catheter. Additionally, the core wire can move appropriately to maintain the flexibility of the balloon catheter even when the balloon catheter bends.

What is claimed is: 
     
         1 . A catheter comprising:
 an outer tube;   an inner tube disposed inside the outer tube;   a protruded-depressed portion provided on an outer periphery of the inner tube, the protruded-depressed portion including a plurality of protruded portions and a plurality of depressed portions alternately arranged along a longitudinal direction of the inner tube; and   a core wire disposed between the outer tube and the inner tube, and having a bulged portion,   wherein a periphery of the bulged portion is disposed between a first protruded portion and a second protruded portion, which are two of the plurality of protruded potions that are located adjacent each other.   
     
     
         2 . The catheter according to  claim 1 , wherein the bulged portion is provided at a distal end of the core wire. 
     
     
         3 . The catheter according to  claim 1 , wherein the bulged portion is freely movable relative to the outer tube and the first and second protruded portions. 
     
     
         4 . The catheter according to  claim 1 , wherein:
 the bulged portion is connected to a distal end of a distal end portion of the core wire; and   a diameter of the bulged portion is larger than a wire diameter of the distal end portion of the core wire.