Sheath retractor mechanism and method

Abstract

An actuating mechanism and method for sequentially translating a sheath member relative to an elongate member such as a balloon catheter movably inserted through the sheath includes a coupling structure constructed to enable selectively coupling or uncoupling of a drive member to the sheath member in order to drive translation of the coupled sheath member in one or more translation increments and to enable uncoupling of the drive member following each of said increments of retraction. In a particularly beneficial method of sheath retraction from a portion of an angioplasty balloon catheter on which a stent is mounted, the method includes coupling a drive structure to the sheath and driving translation of the coupled sheath relative to the catheter to expose the stent-mounted portion of the catheter, and then repeating the translational drive of the coupled sheath to further translate the sheath and expose a further incremental portion of the catheter, in order to produce sequential one-way movement of the sheath in controlled increments to attain exposure of the balloon catheter and the stent mounted thereon without disturbing its position.