Patent ID: 7896861

Claim:
A catheter, comprising: an elongated tubular shaft having a proximal end, a proximal shaft section, an intermediate shaft section, a distal shaft section, a distal end, a length extending from the proximal end to the distal end, and an interior lumen adapted to slidably receive a guidewire, each of said proximal, intermediate, and distal shaft sections including an outer layer of material having a different durometer adapted to transition the stiffness of the elongated tubular shaft from a relatively stiff configuration along the proximal shaft section to a relatively flexible configuration along the distal shaft section; wherein the interior lumen of the elongated tubular shaft includes an inner layer or coating of lubricious material; wherein the proximal shaft section extends for at least about 76% of the length of the elongated tubular shaft; an intermediate layer disposed between the elongated tubular shaft and the inner layer or coating, the intermediate layer comprising: a first intermediate layer segment disposed about the inner layer along a portion of the proximal, intermediate, and distal shaft sections; and a second intermediate layer segment disposed about the inner layer along a portion of the distal shaft section, the second intermediate layer segment extending distally from the first intermediate layer segment to a location proximal to the distal end of the elongated tubular shaft; wherein the second intermediate layer segment is more flexible than the first intermediate layer segment; a reinforcement comprising a first coil segment having a plurality of wire coil layers encased within the outer layers of the proximal and intermediate sections and a second coil segment extending distally from the first coil segment, the second coil segment comprising a single wire coil layer encased within the outer layers of the intermediate and distal sections; wherein the first coil segment extends proximally to a strain relief member at the proximal end of the elongate tubular shaft; wherein the first and second coil segments each have a coil pitch, wherein the coil pitch of the second coil segment is greater than the coil pitch of the first coil segment; and a distal tip section having a pre-shaped curved tip configuration.