IMPROVED CUTTER DEVICE

摘要

Disclosed herein is a cutter for removing soft and hard tissue when used with an atherectomy catheter (10) of the type having a cutter housing (16) attached to the distal end of a catheter member (12) having a torque cable (26). A circular (5) cutting blade (24) is disposed within the housing (16) and is secured to the distal end of a rotable torque cable (26). An elongated aperture (18) formed along one side of the housing (16) allows the intrusion of stenotic material which may then be severed by rotating and axially translating the cutting blade (24). The cutting blade may be made from a cemented tungsten carbide coumpound of 90 percent (10) tungsten carbide (WC) and 10 percent cobalt (Co) which is heated, injection molded and sintered to produce a hard, durable cutting edge (28). The cutting edge (28) is coated with titanium carbonitride using a physical vapor deposition process to further increase durability and resistance to fragmentation. Cutting edge hardness is further increased by application of an ion implantation (15) of nitrogen using an ion-beam assisted deposition process. A variety of alternative cutter materials, coatings and geometries are devined which improve cutter performance in removing soft and hard lesions.