Apparatus for electropolishing a stent

• US 6,679,980 B1
• Filed: 06/13/2001
• Issued: 01/20/2004
• Est. Priority Date: 06/13/2001
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Andreacchi, Anthony
• Primary Examiner(s): Nguyen, Nam
• Assistant Examiner(s): Mutschler, Brian L
• Application Number:
  US09/881,166
• Time in Patent Office: 951 Days
• Field of Search: 204/194, 204/242, 204/272, 204/280
• US Class Current: 204/272
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: C25F 3/22 of heavy metals
• CPC Class Codes: C25F 7/00 Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects for both electrolytic coating and removal C25D; Servicing or operating

Abstract

The invention is directed to an apparatus and a process for electropolishing a product or metallic device made from a metal alloy. The electropolishing apparatus includes a cathode formed of a tubular member and an anode formed by the metallic device to be electropolished. Both the tubular member and the metallic device are positioned within an electrolytic solution and current is passed through the anode to effect the electropolishing process. The invention is useful for electropolishing metal stents formed of metallic alloys, such as cobalt-chromium-tungsten, in which the stent is positioned within the tubular member and immersed in an electrolytic solution for a predetermined time. The electropolishing process using the apparatus of the invention provides an ultrasmooth and shiny metallic surface on the metallic device for metal stents.

Claims

1. An apparatus for electropolishing a stent, comprising:

a continuous cathode formed by a tubular member having a first end and a second end defining a length, a diameter, and an opening therethrough;

a current conducting member attached to the tubular member first end and second end;

an anode formed by a metallic stent having a first end and a second end defining a length, and a diameter, the stent being positioned within the tubular member opening;

the ratio of the length of the tubular member to the length of the stent ranges from about 1;

1 to about 8;

1 and the ratio the tubular member diameter to the stent diameter ranges from about 5;

1 to about 10;

1;

an electrolytic solution; and

the tubular member and the stent being substantially submerged in the electrolytic solution and a current source attached to the stent to conduct a current through the stent for a predetermined time to electropolish the stent.

2. The apparatus of claim 1, wherein the tubular member is formed from a metal wire shaped in a helical coil configuration.

3. The apparatus of claim 1, wherein the tubular member is formed from a wire mesh.

4. The apparatus of claim 1, wherein the tubular member is formed from at least one metal wire shaped in a ring configuration.

5. The apparatus of claim 1, wherein the tubular member is cylindrical.

6. The apparatus of claim 1, wherein the tubular member is non-circular.

7. The apparatus of claim 1, wherein the tubular member has an hourglass configuration.

8. The apparatus of claim 1, wherein the stent is made from a metal alloy taken from the group of metal alloys including stainless steel, cobalt-chromium, cobalt-chromium-tungsten, nickel-titanium, titanium, tantalum, and tungsten.

9. The apparatus of claim 1, wherein means for circulating the electrolytic solution is provided.

10. The apparatus of claim 9, wherein a pump circulates the electrolytic solution.

11. The apparatus of claim 9, wherein the electrolytic solution is circulated mechanically.

12. An apparatus for electropolishing a stent, comprising:

a continuous cathode formed by a tubular member having a first end and a second end defining a length, a diameter, and an opening therethrough, the tubular member having a wall surface between the first end and the second end and a plurality of apertures formed in the wall surface;

a current conducting member attached to the tubular member first end and second end;

an anode formed by a metallic stent having a first end and a second end defining a length, and a diameter, the stent being positioned within the tubular member opening;

the ratio of the length of the tubular member to the length of the stent ranges from about 1;

1 to about 8;

1 and the ratio the tubular member diameter to the stent diameter ranges from about 5;

1 to about 10;

1;

an electrolytic solution for flowing through the tubular member apertures; and

the tubular member and the stent being substantially submerged in the electrolytic solution and a current source attached to the stent to conduct a current through the stent for a predetermined time to electropolish the stent.

13. The apparatus of claim 12, wherein means for circulating the electrolytic solution is provided.

14. An apparatus for electropolishing a stent, comprising:

a continuous cathode formed by a wire mesh tubular member having a first end and a second end defining a length, a diameter, and an opening therethrough;

a current conducting member attached to the tubular member first end and second end;

an anode formed by a metallic stent having a length and a diameter, the stent being positioned within the tubular member opening;

the ratio of the length of the tubular member to the length of the stent ranges from about 1;

1 to about 8;

1 and the ratio the tubular member diameter to the stent diameter ranges from about 5;

1 to about 10;

1;

an electrolytic solution; and

the tubular member and the stent being substantially submerged in the electrolytic solution and a current source attached to the stent to conduct a current through the anode for a predetermined time to electropolish the stent.