Abstract: A stent for use in a lumen in a human or animal body, has a generally tubular body formed from a shape memory alloy which has been treated so that it exhibits enhanced elastic properties with a point of inflection in the stress-strain curve on loading, enabling the body to be deformed inwardly to a transversely compressed configuration for insertion into the lumen and then revert towards its initial configuration, into contact with and to support the lumen. The shape memory alloy comprises nickel, titanium and from about 3 at. % to about 20 at. %, based on the weight of the total weight of the alloy composition, of a ternary element selected from the group consisting of niobium, hafnium, tantalum, tungsten and gold. The ratio of the stress on loading to the stress on unloading at the respective inflection points on the loading and unloading curves is at least about 2.5:1, and the difference between the stresses on loading and unloading at the inflection points at least about 250 MPa.

Abstract: A stent having marker tabs formed from a micro-alloyed combination of materials provides for more precise placement and post-procedural visualization in a vessel, by increasing the radiopacity of the stent under X-ray fluoroscopy. A unique micro-alloying process is utilized to form the tabs, comprising a first alloy and a second alloy, wherein one of these alloys is radiopaque. This substantially eliminates the possibility of galvanic action between the tab and the stent. This process is also applicable to other medical devices.

Abstract: In accordance with the present invention, there is provided a stent, preferably a self-expanding Nitinol stent, for insertion into a vessel of a patient. The stent is made from a tubular member a thickness, front and back open ends, and a longitudinal axis extending therebetween. The member has a first smaller diameter for insertion into a vessel, and a second larger diameter for deployment into a vessel. The tubular member has a plurality of adjacent hoops extending between its front and back ends. The hoops are formed of a plurality of longitudinal struts, each having opposing ends and a center therebetween. The ends of the struts are shaped to form a plurality of loops which connect adjacent struts at the ends of the struts. The member further includes a plurality of bridges connecting adjacent hoops to one another. Each of the struts has a width which is greater at its ends than at its center. Preferably, the width continuously tapers from a greater width at the ends to a smaller width at the centers.

Abstract: A composite stent device comprises a shape memory alloy stent sleeve which is treated so that it can exert an outward force on a lumen in which the stent device is to be deployed, and a restraint element which restricts the maximum transverse dimension to which the stent sleeve can expand outwardly. The restraint sleeve can minimize damage to a lumen by a stent located within it. It can be arranged to allow the stent device to be deformed in a bending mode, for example when the lumen in which the device is located is subjected to a transverse flattening deformation, relying on the enhanced elastic properties of the shape memory alloy stent sleeve to recover to the open, generally rounded configuration.

Abstract: In accordance with the present invention, there is provided a stent for insertion into a vessel of a patient the stent is a tubular member with a predetermined a thickness. The member has front and back open ends and a longitudinal axis extending therebetween. The stent has a first smaller diameter for insertion into the vessel, and a second larger diameter for deployment into the vessel. The tubular member includes a plurality of adjacent hoops extending between the front and back ends. The hoops are made from a plurality of longitudinal struts and a plurality of loops connecting adjacent struts. The member further includes a plurality of bridges connecting adjacent hoops to one another. The individual struts have lengths, as measured parallel to the longitudinal axis. The stent is constructed so that the ratio of the number of struts per hoop to the length of a strut, as measured in inches, is greater than about 400.

Abstract: A composite stent device comprises a shape memory alloy stent sleeve which is treated so that it can exert an outward force on a lumen in which the stent device is to be deployed, and a restraint element which restricts the maximum transverse dimension to which the stent sleeve can expand outwardly. The restraint sleeve can minimize damage to a lumen by a stent located within it. It can be arranged to allow the stent device to be deformed in a bending mode, for example when the lumen in which the device is located is subjected to a transverse flattening deformation, relying on the enhanced elastic properties of the shape memory alloy stent sleeve to recover to the open, generally rounded configuration.

Abstract: A method of treating a component formed from a Ni--Ti based shape memory alloy, so that the component exhibits superelasticity, comprises cold working the component, annealing the alloy while the component is restrained in the configuration resulting from the cold working step, and exposing the component to a temperature that is less than the solvus temperature of the alloy and greater than the temperature to which it is exposed in the annealing step to cause the A.sub.f temperature to be reduced.

Abstract: A composite material in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the composite material.

Abstract: Very finely granular metal powders are produced by atomizing a liquid jet of metal by means of a gas jet which, in addition to a continuous band of sound frequencies, contains at least one discrete sound frequency which is at least 5 decibel above the average intensity of this band, and which is generated in a rotationally symmetrical device by means of a nozzle (4) which has the shape of a hollow cone and by means of an annular resonance space (7) with an annular edge (6) and is projected concentrically against the liquid jet of metal at a total opening angle of an average 35.degree. to 55.degree.. The atomization zone of the gas jet should preferably contain at least three discrete sound frequencies which are each at least 10 decibel above the sound intensity of the continuous band.

Abstract: An article in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the article.

Abstract: Very finely granular metal powders are produced by atomizing a liquid jet of metal by means of a gas jet which, in addition to a continuous band of sound frequencies, contains at least one discrete sound frequency which is at least 5 decibel above the average intensity of this band, and which is generated in a rotationally symmetrical device by means of a nozzle (4) which has the shape of a hollow cone and by means of an annular resonance space (7) with an annular edge (6) and is projected concentrically against the liquid jet of metal at a total opening angle of an average 35.degree. to 55.degree.. The atomization zone of the gas jet should preferably contain at least three discrete sound frequencies which are each at least 10 decibel above the sound intensity of the continuous band.

Abstract: Material, in the form of bars, tubes, profiles, wires, sheets, or bands, which is, at least partially, composed of a constituent showing a one-way shape memory effect, and a further inactive constituent hindering the one-way effect of the first, and which collectively exhibits a significant two-way effect. The one-way shape memory constituent can be a Cu-Al-Ni, Cu-Al, TiV, Ti-Nb, Ni-Ti, or Ni-Ti-Cu alloy. Production of bi- or multi-constituent components by brazing, welding, roll bonding, extruding, powder metallurgical methods, hot isostatic pressing, or gluing, or by the application of metallic coatings (2) onto a core material (1) and subsequent diffusion treatment to produce an inactive surface layer (3).

Abstract: Process to produce a reversible two-way shape memory effect in Cu-Al-Ni and Cu-Al memory alloys by heat treating said alloy while applying an external lead (G) after the martensite formation accomplished by the conventional steps: solution treatment, quench (1,2) and deformation (3). Additional improvements by optional Martensite Stabilization (10) and Two-way Effect Zero-point Stabilization (12) in the form of further heat treatments.

Abstract: A process for manufacturing a component from a mechanically unstable .beta.-titanium alloy which exhibits 3 shape-related memory effects which all differ from one another: a one-way effect, a two-way effect (resembling a bi-metal), this effect being virtually hysteresis-free but occurring continuously over a wide phase-transformation temperature range, and an irreversible effect, which is isothermal. Utilization of the effects in thermal triggering elements (electrical switches) as well as in fixed or detachable connecting elements for components.

Abstract: A noticeable two-way effect can be induced in a component consisting of a shape memory alloy exhibiting only a one-way effect by inhomogeneous deformation of the cross-section so that one part of the component cross-section is deformed sufficiently to hinder the free movement of the one-way effect in the lesser deformed part. Component in the form of a tension/compression (6/8), bending (3), or torsion rod.

Abstract: A notable two-way effect can be induced in components made of a memory alloy exhibiting only a one-way effect by applying an external force which gives rise to an internal stress opposing the one-way effect. Component made of a memory alloy in the form of a tension, compression bending, or torsion rod (helical spring 2). External force by weight or spring (counter-spring 3).