Highly retractable intravascular stent conveying system

Abstract

A highly retractable intravascular stent delivery system, including a tube assembly and a rotation driving assembly. The tube assembly includes an outer tube, an intermediate tube, and inner tube, wherein an intravascular stentand a stent retaining blockare provided within the outer tube. The rotation driving assembly includes a housing, an outer screw, and an intermediate screwlocated within the housing, as well as a driving member. The driving member allows two screws to rotate at opposite directions, so as to drive the outer tubeto move toward the proximal end, and the intermediate tubepushes the stent retaining blockand the intravascular stentto move toward the distal end. The system uses three-lay tube structure and uses driving gear to drive two screws to move at directions opposite to each other, such that the intermediate tubeand the outer tubeare driven to move to directions opposite to each other. Therefore, the axial retraction of the intravascular stents can be effectively offset and axial movement of the intravascular stents due to axial retraction of the intravascular stents is avoided, thereby accurately implanting the stents into the body.