Patent ID: 7575568

Claim:
A catheter comprising, a proximal portion, a distal portion, the distal portion terminating at a distal end, a shaft, the shaft having a proximal portion, a distal portion, the distal portion terminating at a distal end, and a conduit there though, and a distal tip layer, the distal tip layer being in the form of a tube and being positioned about the distal portion of the shaft, the distal tip layer having a proximal end and a distal end, wherein the distal end of the distal tip layer extends distally to at least the distal end of the shaft and forms at least a portion of the distal end of the catheter such that the distal tip layer is at least distally coextensive with the shaft, the catheter further comprising a medical balloon, the balloon having a body portion position between a proximal waist and a distal waist, wherein the distal waist is connected to the distal portion of the shaft and is positioned at least adjacent to the proximal end of the distal tip layer and wherein the distal tip layer is circumferentially between the distal waist and the shaft, such that the distal waist is not in contact with the shaft, and wherein the shaft extends distally beyond the distal waist, the distal end of the shaft having a first longitudinal portion having a first diameter, wherein in the first longitudinal portion is radially at least partially within the body portion of the balloon, and a second longitudinal portion having a second diameter, the second longitudinal portion being immediately adjacent to the first longitudinal portion, wherein the first diameter is greater than the second diameter, the second longitudinal portion forming a circumferentially stepped down portion from the first longitudinal portion, wherein the distal tip layer is positioned around and conforms to the circumferentially stepped down portion.