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US 6,638,372 B1Granted
Superelastic guiding member
AssigneeAdvanced Cardiovascular Systems, Inc.
InventorsRobert M. Abrams, Sepehr Fariabi
Life of this patent
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AssigneeAdvanced Cardiovascular Systems, Inc.
InventorsRobert M. Abrams, Sepehr Fariabi
Estimating the term…
An improved guiding member for use within a body lumen having a unique combination of superelastic characteristics. The superelastic alloy material has a composition consisting of about 30% to about 52% (atomic) titanium, and about 38% to 52% nickel and may have one or more elements selected from the group consisting of iron, cobalt, platinum, palladium, vanadium, copper, zirconium, hafnium and niobium. The alloy material is subjected to thermomechanical processing which includes a final cold working of about 10 to about 75% and then a: heat treatment at a temperature between about 450° and about 600° C. and preferably about 475° to about 550° C. Before the heat treatment the cold worked alloy material is preferably subjected to mechanical straightening. The alloy material is preferably subjected to stresses equal to about 5 to about 50% of the room temperature ultimate yield stress of the material during the thermal treatment. The guiding member using such improved material exhibits a stress-induced austenite-to-martensite phase transformation at an exceptionally high constant yield strength of over 90 ksi for solid members and over 70 ksi for tubular members with a broad recoverable strain of at least about 4% during the phase transformation. An essentially whip free product is obtained.
An elongated intracorporeal member which has superelastic characteristics and which is formed of an alloy containing about 38 to about 52% of nickel and about 30 to about 52% titanium and an amount of platinum up to about 3% such that austenite is the only stable phase at body temperature.
An intracorporeal tubular member which is formed of an alloy containing about 38 to about 52% nickel and about 30 to about 52% titanium and an amount of platinum of up to about 3% such that austenite is the only stable phase at body temperature.
An intracorporeal member comprising a superelastic alloy containing about 38 to about 52% of nickel and about 30 to about 52% titanium and up to 3% platinum such that austenite is the only stable phase at body temperature, wherein the austenite phase is characterized by transforming to the martensite phase at a stress level above 70 ksi.
An intracorporeal member comprising a superelastic alloy containing about 38 to about 52% of nickel and about 30 to about 52% titanium and up to 3% platinum suc that austenite is the only stable phase at body temperature, wherein the austenite phase is characterized by transforming to the martensite phase at a stress level about 90 ksi.
An intracoporeal member comprising a superelastic alloy containing about 38 to about 52% of nickel and about 30 to about 52% titanium and up to 3% platinum such that austenite is the only stable phase at body temperature, wherein the tubular structure has a tensile strength of at least 200 ksi.
An intracorporeal member comprising a superelastic alloy containing about 38 to about 52% of nickel and about 30 to about 52% titanium and up to 3% platinum such that austenite is the only stable phase at body temperature, wherein the alloy exhibits a strain of at least 4% upon the application of stress to transfer the austenite phase to the martensite phase.
Dependencies are inferred from the claim text.