Abstract: Medical devices, such as stents, and methods of making the devices are disclosed. In some embodiments, a medical device includes an alloy having tantalum, tungsten, zirconium and niobium. For example, the alloy can include from about 20% to about 40% by weight of tantalum, from about 0.5% to about 9% by weight of tungsten, and from about 0.5% to about 10% by weight of zirconium.

Abstract: Medical devices, such as stents, and methods of making the devices are disclosed. In some embodiments, a medical device includes an alloy having tantalum, tungsten, zirconium and niobium. For example, the alloy can include from about 20% to about 40% by weight of tantalum, from about 0.5% to about 9% by weight of tungsten, and from about 0.5% to about 10% by weight of zirconium.

Abstract: Medical devices, such as stents, and methods of making the devices are disclosed. In some embodiments, a medical device includes an alloy having tantalum, tungsten, zirconium and niobium. For example, the alloy can include from about 20% to about 40% by weight of tantalum, from about 0.5% to about 9% by weight of tungsten, and from about 0.5% to about 10% by weight of zirconium.

Abstract: Medical devices may be made of shape-memory materials portions of which have been heat treated to exhibit spatial variations in the stiffness of the material. Devices including stents, vena cava filters and guidewires may be constructed from such materials. Devices may also be made from shape-memory materials which have been locally heat treated such that the superelasticity of the treated portion is destroyed while the remainder of the shape-memory material can transition between the martensitic and austenitic states.

Abstract: An endoluminal device, such as a stent or a vena cava filter, comprising at least one superelastic section and at least one plastically deformable section. The superelastic section may comprise, for example, a superelastic grade of nitinol, whereas the plastically deformable section may comprise, for example, gold, platinum, tantalum, titanium, stainless steel, tungsten, a nickel alloy, a cobalt ally, a titanium alloy, or a combination thereof. Each plastically deformable section may merely comprise a constrained portion of the superelastic section comprising a plastically deformable material, such as gold.

Abstract: A thrombosis filter which can be securely affixed at a selected location in the vascular system of a patient and removed when no longer required. An embodiment of the thrombosis filter includes a plurality of struts formed of a shape memory material. A change in temperature can cause the struts to extend and engage a wall of a blood vessel.

Abstract: The inventive stent delivery system includes a catheter having a retractable outer sheath near its distal end. A shape memory contraction member having a memorized contracted shape is connected to the retractable outer sheath. A heat generating device connected to the shape memory contraction member causes the shape memory contraction member to heat up to its transition temperature and assume its contracted position, retracting the retractable outer sheath. Another embodiment utilizes 2 springs, a “normal” spring and a shape memory alloy (SMA) spring, the two springs selected and designed so that the “normal” has an expansion force which is less than SMA spring when the SMA spring is austenitic, but greater than the SMA spring when the SMA spring is martensitic.

Abstract: Medical devices may be made of shape-memory materials portions of which have been heat treated to exhibit spatial variations in the stiffness of the material. Devices including stents, vena cava filters and guidewires may be constructed from such materials. Devices may also be made from shape-memory materials which have been locally heat treated such that the superelasticity of the treated portion is destroyed while the remainder of the shape-memory material can transition between the martensitic and austenitic states.

Abstract: A thrombosis filter which can be securely affixed at a selected location in the vascular system of a patient and removed when no longer required. A first embodiment of the thrombosis filter includes a plurality of struts having a first grouping and a second grouping. The first grouping of struts and the second grouping of struts radiate in opposite directions. The free ends of the struts include anchoring elements which anchor into the walls of a blood vessel. At least one grouping of struts is comprised of a shape memory material. When these struts are at body temperature, their free ends engage the wall of the blood vessel. When the temperature of the shape memory alloy struts is selectively varied from body temperature, the struts retract into the body portion of the thrombosis filter.

Abstract: A process for treating nitinol so that desired mechanical properties are achieved. In one embodiment, the process comprises the steps of exposing the nitinol to a primary annealing temperature within the range of approximately 475° C. to 525° C. for a first time period, and thereafter exposing the nitinol to a secondary annealing temperature within the range of approximately 550° C. to 800° C. for a second time period. The invention also includes nitinol articles made by the process of the invention.

Abstract: A thrombosis filter which can be securely affixed at a selected location in the vascular system of a patient and removed when no longer required, and method for removing the thrombosis filter. An embodiment of the thrombosis filter includes a plurality of struts made from a shape memory alloy which changes shape at a temperature other than body temperature, thereby allowing removal of the filter.

Abstract: A process for treating nitinol so that desired mechanical properties are achieved. In one embodiment, the process comprises the steps of exposing the nitinol to a primary annealing temperature within the range of approximately 475° C. to 525° C. for a first time period, and thereafter exposing the nitinol to a secondary annealing temperature within the range of approximately 550° C. to 800° C. for a second time period. The invention also includes nitinol articles made by the process of the invention.

Abstract: Medical devices may be made of shape-memory materials portions of which have been heat treated to exhibit spatial variations in the stiffness of the material. Devices including stents, vena cava filters and guidewires may be constructed from such materials. Devices may also be made from shape-memory materials which have been locally heat treated such that the superelasticity of the treated portion is destroyed while the remainder of the shape-memory material can transition between the martensitic and austenitic states.

Abstract: A welding method for improving the durability and strength of fusion weld joints in metal structures; the method is especially beneficial for metal structures fabricated from nickel-titanium alloy (nitinol) and for medical devices.

Abstract: The inventive stent delivery system includes a catheter having a retractable outer sheath near its distal end. A shape memory contraction member having a memorized contracted shape is connected to the retractable outer sheath. A heat generating device connected to the shape memory contraction member causes the shape memory contraction member to heat up to its transition temperature and assume its contracted position, retracting the retractable outer sheath. Another embodiment utilizes 2 springs, a “normal” spring and a shape memory alloy (SMA) spring, the two springs selected and designed so that the “normal” has an expansion force which is less than SMA spring when the SMA spring is austenitic, but greater than the SMA spring when the SMA spring is martensitic.

Abstract: The inventive stent delivery system includes a catheter having a retractable outer sheath near its distal end. A shape memory contraction member having a memorized contracted shape is connected to the retractable outer sheath. A heat generating device connected to the shape memory contraction member causes the shape memory contraction member to heat up to its transition temperature and assume its contracted position, retracting the retractable outer sheath. Another embodiment utilizes 2 springs, a “normal” spring and a shape memory alloy (SMA) spring, the two springs selected and designed so that the “normal” has an expansion force which is less than SMA spring when the SMA spring is austenitic, but greater than the SMA spring when the SMA spring is martensitic.

Abstract: A welding method for improving the durability and strength of fusion weld joints in metal structures; the method is especially beneficial for metal structures fabricated from nickel-titanium alloy (nitinol) and for medical devices.

Abstract: A process for treating nitinol so that desired mechanical properties are achieved. In one embodiment, the process comprises the steps of exposing the nitinol to a primary annealing temperature within the range of approximately 475.degree. C. to 525.degree. C. for a first time period, and thereafter exposing the nitinol to a secondary annealing temperature within the range of approximately 550.degree. C. to 800.degree. C. for a second time period. The invention also includes nitinol articles made by the process of the invention.

Abstract: A welding method for improving the durability and strength of fusion weld joints in metal structures; the method is especially beneficial for metal structures fabricated from nickel-titanium alloy (nitinol) and for medical devices.