Pulsed fiber laser cutting system for medical implants

• US 20050035101A1
• Filed: 09/21/2004
• Published: 02/17/2005
• Est. Priority Date: 06/14/2001
• Status: Abandoned Application

• Current Assignee: Brad Whitney, Jason Fox, Klaus Kleine, Stephen Jones, Yu-Chun Ku
• Original Assignee: Brad Whitney, Jason Fox, Klaus Kleine, Stephen Jones, Yu-Chun Ku
• Inventors: Fox, Jason, Jones, Stephen, Ku, Yu-Chun, Whitney, Brad, Kleine, Klaus
• Application Number:
  US10/946,223
• Publication Number:
  US 20050035101A1
• Time in Patent Office: Days
• US Class Current: 219/121.720
• 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: B23K 2101/06 Tubes
• CPC Class Codes: B23K 2103/05 Stainless steel
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/06 Shaping the laser beam, e.g. by masks or multi-focusing
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/08 Devices involving relative movement between laser beam and workpiece
• CPC Class Codes: B23K 26/123 in an atmosphere of particular gases
• CPC Class Codes: B23K 26/14 using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor B23K26/12 takes precedence
• CPC Class Codes: B23K 26/142 for the removal of by-products
• CPC Class Codes: B23K 26/1436 for pressure control
• CPC Class Codes: B23K 26/1438 for directional control
• CPC Class Codes: B23K 26/146 the fluid stream containing a liquid
• CPC Class Codes: B23K 26/1476 Features inside the nozzle for feeding the fluid stream through the nozzle
• CPC Class Codes: B23K 26/16 Removal of by-products, e.g. particles or vapours produced during treatment of a workpiece by a fluid stream B23K26/142
• CPC Class Codes: B23K 26/18 using absorbing layers on the workpiece, e.g. for marking or protecting purposes
• CPC Class Codes: B23K 26/38 by boring or cutting

Abstract

An improved expandable stent for implantation in a body lumen, such as an artery, and an improved method for making it from a single length of tubing. The stent consists of a plurality of radially expandable cut cylindrical elements generally aligned on a common axis and interconnected by one or more interconnective elements, the elements having a rectangular cross-section from cut-to-cut. The individual radially expandable cylindrical elements are disposed in an undulating pattern. The stent is manufactured by direct laser cutting from a single metal tube using a finely focused laser beam originating from a diode pumped fiber laser with an external pulse generator and passing through a coaxial gas jet structure to impinge on the working surface of the tube as the linear and rotary velocity of the tube is precisely controlled. To optimize the cut, the laser parameters may be adjusted and/or the laser pulse may be shaped.

Claims

1-11. -11. (Cancel)

12. An assembly for making a stent comprising:

a fiber laser having an optical fiber and two or more mirrors;

a diode pump for pumping the fiber laser; and

the fiber laser configured for operating at a cutting speed within a range of about 3.0 to about 5.0 mm per second (about 0.12 to 0.20 inch per second).

13. The assembly of claim 12, wherein a pulse generator is used to gate the diode pump.

14. The assembly of claim 13, wherein the pulse generator is configured to deliver pulses at a frequency in the range of about 1,205 Hertz to about 1,750 Hertz.

15. The assembly of claim 13, wherein the pulse generator is configured to pulse the laser in pulse lengths between about 0.05 ms and about 0.10 ms.

16. The assembly of claim 12, wherein the fiber laser incorporates a coaxial gas jet configured to release compressed gas at a pressure in a range between about 130 kPa to over about 345 kPa (about 20 psi to over about 50 psi).

17. The assembly of claim 13, wherein the pulse generator provides laser pulses having pulse lengths in increments as small as about 0.005 ms.