SHAPE-MEMORY ALLOY HEART VALVE CLAMPING DEVICE

AN OVERWHELMING MAJORITY OF MECHANICAL HEART VALVES ARE CONSTRUCTED USING PARTS COATED WITH PYROLYTIC CARBON BECAUSE OF ITS INCREDIBLE WEAR CHARACTERISTICS, BIOCOMPATIBILITY, AND NONTHROMBOGENICITY. UNFORTUNATELY, CURRENT DESIGNS REQUIRE THAT THE PYROLYTIC CARBON COMPONENTSBE DEFORMED (STRESSED) AND HANDLED EXCESSIVELY IN ORDER TO COMPLETE VALVE ASSEMBLY. THESE MANIPULATIONS MAY CAUSE DEFECTS THAT CAN RESULT IN THROMBOSIS OR PREMATURE MECHANICAL FAILURE OF THE VALVE. NEWER DESIGNS ARE ATTEMPTING TO CIRCUMVENT THIS PROBLEM BY ADDING A STIFFENING RING TO THE VALVES. THE ADDITION OF A STIFFENING RING SIMPLIFIES THE ASSEMBLY PROCESS AND MINIMIZES HANDLING. THE ADVANTAGES INHERENT IN USING A STIFFENING RING CAN BE OPTIMIZED IF THE ATTACHMENT MECHANISM IS PROPERLY DESIGNED. TINI ALLOY COMPANY PLANS TO DEVELOP AN INNOVATIVE MECHANISM FOR THE ATTACHMENT OF A STIFFENING RING TO A MECHANICAL HEART VALVE PROTHESIS USING AN INTERMEDIATE LOCKING RING MADE FROM NICKEL-TITANIUM SHAPE-MEMORY ALLOY. THE PURPOSE OF THE NOVEL DESIGN IS TO PERMIT A SLIP-FIT ASSEMBLY OF A STIFFENING RING AROUND A HEART VALVE HOUSING. THE LOCKING RING'S SHAPE-MEMORY PROPERTIES WILL SECURE THE STIFFENING RING TO THE VALVE HOUSING WHILE MINIMIZING VALVE HANDLING AND STRESS. THIS DEVELOPMENT WILL IMPROVE HEART VALVE QUALITY AND RELIABILITY.