Patent ID: 8109953

Claim:
A medical device for traversing an occlusion in a vessel, comprising: a straightening sleeve positioned at a distal aspect of a catheter; a steering sleeve having an arcuate distal end, said steering sleeve and said straightening sleeve being slidably moveable relative to each other such that in a first position the arcuate distal end of the steering sleeve is straightened within the straightening sleeve and in a second position the steering sleeve extends distally past the straightening sleeve to expose the arcuate distal end; a guidewire disposed through the steering sleeve within the straightening sleeve; a first hub assembly attached to said straightening sleeve, said first hub assembly having a first locking mechanism with a locked condition in which the straightening sleeve and the steering sleeve are secured together, and an unlocked condition in which the straightening sleeve and the steering sleeve are moveable in a linear direction relative to each other; a first motion limiting structure attached to said first locking mechanism for limiting a range of relative linear movement between said straightening sleeve and said steering sleeve when the first locking mechanism is in its unlocked condition, said first motion limiting structure comprising a first set of opposing surfaces that define respective ends of a path of linear movement between said straightening sleeve and said steering sleeve, said first motion limiting structure allowing relative linear movement between said straightening sleeve and said steering sleeve within a limited range defined by said first set of opposing surfaces; a second hub assembly attached to said steering sleeve, said second hub assembly having a second locking mechanism with a locked condition in which the steering sleeve and the guidewire are secured together, and an unlocked condition in which the steering sleeve and the guidewire are moveable in a linear direction relative to each other; and a second motion limiting structure attached to said second locking mechanism for limiting a range of relative linear movement between said steering sleeve and said guidewire when the second locking mechanism is in its unlocked condition, said second motion limiting structure comprising a second set of opposing surfaces that define respective ends of a path of linear movement between said steering sleeve and said guidewire, said second motion limiting structure allowing relative linear movement between said steering sleeve and said guidewire within a limited range defined by said second set of opposing surfaces.