Back to results
US 8,769,794 B2Granted
Specially configured and surface modified medical device with certain design features that utilize the intrinsic properties of tungsten, zirconium, tantalum and/or niobium
AssigneeMICO Innovations, LLC
InventorJoseph G. Furst
Life of this patent
Estimating the term…
Abstract
Medical devices having special geometrical design features and possible surface modifications and can be comprised of niobium, tantalum, zirconium and/or tungsten alloy which is useful in treating a body passageway.
Claims10
A process for producing a stent that has design features that include differentiated wall thicknesses across the length of the stent and geometrically-based shapes to enhance the mechanical properties of said stent, said process comprising the steps of:
- a) providing a non-clad metal tube, about 100 weight percent of said metal tube formed of an alloy of 90-97.5% tantalum and 2.5-10% tungsten, said metal having a grain size of at least about 8 ASTM;
- b) chemically cleaning said metal tube by a solution that includes nitric acid and hydrochloric acid;
- c) annealing said chemically cleaned tube at a temperature of about 2600° F.-2800° F., said step of annealing occurring under a vacuum of no greater that about 10 Torr;
- d) cleaning and polishing said annealed tube by an electro-polishing process, said electro-polishing process including a solution that includes sulfuric acid and hydrofluoric acid having a temperature of about 60-100° F., said electro-polishing process conducted in the presence of a current of 15-30 milliamps, said step of electro-polishing performed in such a manner as to prevent said metal tube from becoming brittle and to prevent excess hydrogen, oxygen and nitrogen from entering said metal tube;
- e) cutting said tube to a desired length after said cleaning and polishing step;
- and,
- f) cutting said tube to form said stent after said tube is cut to said desired length, said step of cutting said tube into said stent includes a laser cutting process in an environment that includes one or more gasses selected from the group consisting of helium and argon, said stent having a plurality of metal support portions and a plurality of metal connecting legs, said metal connecting legs connecting together a plurality of metal support portions, said metal support portions and metal connecting legs forming a mesh in a peripheral wall of said cut tube, a plurality of said metal support portions having an S-shape, a Z-shape, an XZ-shape, a VU shape, an XS shape, or a YU-shape configuration, a plurality of said metal support portions having a thickness of 0.0012-0.007 inch, a plurality of said metal support portions and connecting legs having multiple thicknesses along a longitudinal length of said metal support portions and connecting legs, a thinnest portion of said metal support portions having a thickness as small as about 0.0012 inch and a thickest portion of said metal support portions being about 0.004-0.007 inch, said wall thickness of said metal tube has a thickness so that its physiological presence in a body passage is negligible thereby preventing turbulent flow of fluid as the fluid passes by said stent positioned in the body passageway.
4 more elements
A process for producing a stent that has design features that include differentiated wall thicknesses across the length of the stent and geometrically-based shapes to enhance the mechanical properties of said stent, said process comprising the steps of:
- a) providing a non-clad metal tube, about 100 weight percent of said metal tube formed of an alloy of 90-93% tantalum and 7-10% tungsten, said metal having a grain size of at least about 8 ASTM;
- b) chemically cleaning said metal tube by a solution that includes nitric acid and hydrochloric acid;
- c) annealing said chemically cleaned tube at a temperature of about 2600° F.-2800° F., said step of annealing occurring under a vacuum of no greater that about 10 Torr;
- d) cleaning and polishing said annealed tube by an electro-polishing process, said electro-polishing process including a solution that includes sulfuric acid and hydrofluoric acid having a temperature of about 60-100° F., said electro-polishing process conducted in the presence of a current of 15-30 milliamps, said step of electro-polishing performed in such a manner as to prevent said metal tube from becoming brittle and to prevent excess hydrogen, oxygen and nitrogen from entering said metal tube;
- e) cutting said tube to a desired length after said cleaning and polishing step;
- and,
- f) cutting said tube to form said stent after said tube is cut to said desired length, said step of cutting said tube into said stent includes a laser cutting process in an environment that includes one or more gasses selected from the group consisting of helium and argon, said stent having a plurality of metal support portions and a plurality of metal connecting legs, said metal connecting legs connecting together a plurality of metal support portions, said metal support portions and metal connecting legs forming a mesh in a peripheral wall of said cut tube, a plurality of said metal support portions having a thickness of 0.0012-0.007 inch, a plurality of said metal support portions and connecting legs having multiple thicknesses along a longitudinal length of said metal support portions and connecting legs, a thinnest portion of said metal support portions having a thickness as small as about 0.0012 inch and a thickest portion of said metal support portions being about 0.004-0.007 inch, said wall thickness of said metal tube has a thickness so that its physiological presence in a body passage is negligible thereby preventing turbulent flow of fluid as the fluid passes by said stent positioned in the body passageway.
4 more elements
Dependencies are inferred from the claim text.