Method and device for the manufacture of the medical expanding stents

• US 20020023843A1
• Filed: 09/13/2001
• Published: 02/28/2002
• Est. Priority Date: 07/13/2000
• Status: Active Grant

• Current Assignee: Kinneret P.R.C. Technologies Ltd.
• Original Assignee: Discovery Commercial Enterprises Ltd.
• Inventors: Cherkes, David
• Granted Patent: US 6,663,765 B2
• Time in Patent Office: Days
• US Class Current: 205/75
• 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: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: B23H 3/00 Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
• CPC Class Codes: B23H 3/06 Electrode material
• CPC Class Codes: B23H 9/00 Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects heat treatment by cathodic discharge C21D1/38
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10S 623/902 Method of implanting
• CPC Class Codes: Y10S 623/903 Blood vessel
• CPC Class Codes: Y10S 623/909 Method or apparatus for assembling prosthetic

Abstract

Method and device for manufacturing of expandable cylindrical metal meshes for use in expandable stents and in particular for customized manufacturing. The method includes determining the type and size of the stent to be implanted, electrochemically forming the stent with desired pattern of meshes and implanting the stent into patient. The method comprises using a cathode with desired pattern of meshes and a tubular blank, from which the stent is formed. Between the cathode and the blank is delivered an electrolyte and the cathode and the blank are simultaneously rotated during electrochemical forming process.

Claims

1. The method of manufacturing expandable medical stents for implantation into blood and urological vessels of a patient, comprising the steps:

determining the type and size of the stent to be implanted;

electrochemically forming said stents while the patient is being treated; and

implanting said stent into said patient.

2. The method according to claim 1, further including the steps of forming said stent and cutting to a preset length in one operation using a cathode multiple tool which together with a tubular blank, are rotated.

3. The method according to claim 2, further including the step of supplying electrolyte to the external surface of the blank.

4. The method according to claim 3, further including the step of employing centerless method of rotation and supplying electrical current to said blank.

5. The method according to claim 1, wherein the operating parameters of said electrolyte together with the change of condition of said electrodes and stent cross-section, are automatically controlled.

6. Apparatus for electrochemically making stents from a tubular blanks comprising:

a rotator with renewable cathodes;

a current source;

a source of electrolyte;

means for pumping said electrolyte;

means for controlling the electrochemical forming operation;

a mandrel for holding said blank;

said mandrel being made hollow and including a longitudinal slit for supplying electrolyte to the blank;

said blank being positioned inside said mandrel.

7. The apparatus according to claim 6, wherein said mandrel is made with two supporting surfaces matching to the radius of the rotator.

8. The apparatus according to claim 7, wherein inter electrode clearance is provided, said mandrel being made self-aligned with respect to a working cathode, employed for electrochemical forming operation to provide reliable adjacency of the blank to the corresponding cathode surfaces.

9. A method of manufacturing expandable stents for implanting into a body lumen, comprising the steps of:

electrochemically forming said expandable stent just prior to implantation, said electrochemical forming including;

providing a working cathode which includes a desired pattern for producing the stent;

providing a tubular blank adjacent to said working cathode;

delivering an electrolyte between said working cathode and said tubular blank;

relative displacing said tubular blank and said working cathode; and

,

electrochemically producing the stent with said desired pattern

10. The method of claim 9, wherein said tubular blank has a diameter and thickness equal to the stent to be manufactured.

11. The method of claim 10, wherein the ends of said tubular blank are cut after the stent outline is formed, said method for forming a finished stent taking less than about 30 minutes, preferably being less than 15 minutes.

12. The method of claim 9, further including using a mandrel for receiving said tubular blank, said mandrel having a linear slit along its longitudinal length parallel to said tubular blank for the introduction of electrolyte and wherein said linear slit is narrower than the diameter of said tubular blank.

13. The method of claim 9, further including the step of removing an insulating coating on said cathode before electrochemically forming the stent.

14. The method of claim 9, further including the step of customizing said expandable stent according to the needs of a patient being treated.

15. The method of claim 14, further including the step of implanting said stent into the body lumen.

16. The method of claim 9, wherein said electrochemical forming employs a current density of about 50 A/cm², or more.

17. The method of claim 9, wherein said electrolyte is delivered at a velocity of from 8 m/s to 10 m/s.

18. The method of claim 9, wherein said tubular blank is displaced by centerless rotation.

20. The method of claim 19, further including a mandrel for receiving said stent blank, said mandrel having a linear slit along its longitudinal length parallel to said stent blank for the introduction of electrolyte and wherein said linear slit is narrower than the diameter of said stent blank.

21. The method of claim 19, further including the step of removing an insulating coating on said plurality of cathodes before electrochemically forming the stent.

22. The method of claim 19, wherein said electrochemical forming occurs at a current density of about 50 A/cm², or more.

23. The method of claim 19, further including the step of cutting the ends of said electrochemically-formed stent outline.

24. The method of claim 19, wherein said electrolyte is delivered at a velocity of from 8 m/s to 10 m/s.

25. The method of claim 19, wherein said tubular blank is rotated by centerless rotation.

27. The apparatus of claim 26, wherein said working cathode and said tubular blank are separated by a distance not more than 0.05 mm.

28. The apparatus of claim 26, wherein said mandrel includes a linear slit directed parallel to the length of said tubular blank for the delivery of said electrolyte between the working cathode and the tubular blank and wherein said linear slit is narrower than the diameter of said tubular blank.

29. The apparatus of claim 26, wherein said one or more cathodes is made from a metal selected from the group consisting of gold, platinum, stainless steel, brass, copper, or alloys thereof.

30. The apparatus of claim 26, wherein said tubular blank has a diameter and thickness equal to said stent.

31. The apparatus of claim 26, further comprising a housing for containing therein said mandrel, said rotator, said tubular blank, said one or more cathodes, and said conduit and wherein said housing is positionable in an area substantially near a patient being treated for a stent implant.

32. The apparatus of claim 26, wherein said mandrel includes a lateral support comprising two pairs of preferably tubular rests, each of which includes longitudinal slit, for supporting said tubular blank in said mandrel in operative relationship to the working cathodes.

33. The apparatus of claim 26, wherein said mandrel is in a self-aligning relationship to the working cathode.

19. A method of custom-forming an expandable stent in an operating or emergency room for implanting the stent into a body lumen of a patient, comprising the steps of:

providing a plurality of cathodes, at least some of which includes a different stent pattern on a rotator;

providing a plurality of tubular blanks, at least some of which includes a different material, diameter and thickness;

selecting a working cathode from said plurality of cathodes with desired stent pattern;

selecting a stent blank from said plurality of tubular blanks;

mounting said stent blank in an operative relationship to said working cathode;

rotating said rotator while delivering an electrolyte between said working cathode and said stent blank to electrochemically form the stent having the desired stent pattern; and

recovering and preparing the recovered stent for implantation into the patient'"'"'s body lumen.

26. An apparatus for custom-forming an expandable stent in an operating or emergency room during a procedure to implant the stent into a body lumen of a patient for implantation into a body lumen, comprising:

a rotator, for carrying one or more cathodes;

a mandrel positioned parallel to the rotational axis of said rotator, for holding a tubular blank in operative relationship to a working cathode, selected from said one or more cathodes;

a conduit for delivering electrolyte to a working cathode and said tubular blank;

means for simultaneously rotating said rotator and said tubular blank; and

means for supplying electrical voltage to the working cathode and to said tubular blank to produce a stent.