Patent ID: 8021387

Claim:
A device comprising: an elongated, generally flexible tubular body; and a dilating tip slidably mounted on a distal end of the tubular body and comprising: a segmented surface comprising a plurality of segments having proximal and distal ends, wherein the plurality of segments is configured to move between a closed configuration in which the segments combine to form the segmented surface and an open configuration in which the segments separate from one another; a plurality of generally rigid tube segments, each tube segment extending distally from a segment of the segmented surface, and wherein, when the plurality of generally rigid tube segments is in the closed configuration, the plurality of generally rigid tube segments combine to form a generally rigid tube having a sharp distal end configured to puncture tissue, and when the segments of the segmented surface are in the open configuration, the generally rigid tube segments have free distal ends that are separate from each other; and a ring slidably mounted on the tubular body, wherein the proximal ends of the segments of the segmented surface are hingedly attached to the ring; wherein proximal movement of the ring relative to the tubular body exerts a force on the segmented surface to thereby open the segmented surface.