Devices configured from heat shaped, strain hardened nickel-titanium
First Claim
1. A medical device for use in a body lumen, comprising:
- a self-expanding body formed from struts having a compressed state and an expanded state;
the body including a cold formed nickel-titanium alloy having a transformation temperature greater than a mammalian body temperature, wherein the nickel-titanium alloy exhibits linear pseudoelasticity regardless of stress applied to the body; and
a sheath at least partially enclosing the body in the compressed state.
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Accused Products
Abstract
Cold worked nickel-titanium alloys that have linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite as applied to a medical device having a strut formed body deployed from a sheath is disclosed. In one application, an embolic protection device that employs a linear pseudoelastic nitinol self-expanding strut assembly with a small profile delivery system for use with interventional procedures is disclosed. The expandable strut assembly is covered with a filter element and both are compressed into a restraining sheath for delivery to a deployment site downstream and distal to an interventional procedure. Once at the desired site, the restraining sheath is retracted to deploy the embolic protection device, which captures flowing emboli generated during the interventional procedure. Linear pseudoelastic nitinol is used in the medical device as distinct from non-linear pseudoelastic (i.e., superelastic) nitinol.
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Citations
21 Claims
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1. A medical device for use in a body lumen, comprising:
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a self-expanding body formed from struts having a compressed state and an expanded state;
the body including a cold formed nickel-titanium alloy having a transformation temperature greater than a mammalian body temperature, wherein the nickel-titanium alloy exhibits linear pseudoelasticity regardless of stress applied to the body; and
a sheath at least partially enclosing the body in the compressed state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A medical device for use in a body lumen, comprising:
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a self-expanding body formed from struts;
the body including a cold formed nickel-titanium alloy, wherein the nickel-titanium alloy is in a martensitic phase when the body is stressed into a first shape and when the body is stress relieved to a second shape, and wherein the nickel-titanium alloy has a transformation temperature>
37 degrees C.; and
a sheath at least partially enveloping the body in its first shape. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of providing a medical device for use in a body lumen, comprising:
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providing struts including a cold formed nickel-titanium alloy;
setting a transformation temperature>
37 degrees C.;
cold forming the struts into a body having a shape;
stressing the body into a first shape wherein the nickel-titanium alloy is in a martensitic phase;
providing a sheath;
disposing the body in the first shape at least partially inside the sheath; and
deploying the body from the sheath to stress relieve the body into a second shape, wherein the nickel-titanium alloy remains in the martensitic phase. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification