Patent ID: 7273487

Claim:
A balloon catheter, comprising: a) an elongated shaft comprising, i) a multilayered outer tubular member defining an inflation lumen, and having at least a first layer and a second layer, and the outer tubular member further having a relatively stiff proximal section with the first and second layers extending in a first relative proportion which is substantially constant; a relatively flexible distal section with the first and second layers extending in a second relative proportion which is substantially constant and which is different from the first relative proportion, the distal section having a tapered portion along which the outer diameter of the distal section decreases distally; and a transition section extending between and connecting a distal end of the proximal section and a proximal end of the distal section, along which the relative proportion of the first and second layers inversely cotapers to transition from the first to the second relative proportion, the transition section having a proximal portion, a distal portion, and a tapered portion along which the outer diameter of the transition section decreases distally; and ii) a multilayered inner tubular member extending at least in part in at least a distal section of the inflation lumen, and defining a guidewire lumen, and having a proximal section, a distal section, and a tapered section extending between and connecting a distal end of the proximal section and a proximal end of the distal section and along which the outer diameter of the inner tubular member decreases distally, and wherein a proximal end of the inner tubular member tapered section is radially aligned with a location on the outer tubular member located in the proximal portion of the transition section of the outer tubular member; and b) a balloon secured to the catheter shaft, having an interior in fluid communication with the inflation lumen.