A self centering delivery catheter is provided for delivering a filter
into a vessel in a centered manner which aids in the retrieval of the
filter. The delivery catheter generally includes an outer sheath and a
cannula disposed inside the outer sheath and axially translatable
relative thereto. A set of centering legs are attached to the cannula.
The centering legs are operable between a first retracted position and a
second extended position, the centering legs moving radially away from
the cannula as the centering legs move from the retracted position to the
extended position. The relative position of the outer sheath and cannula
control the operation of the centering legs. A control wire is disposed
inside the cannula and is axially translatable relative thereto. Axial
translation of the control wire operates a release mechanism to disengage
the filter for delivering the filter into the vessel.