Multiple beam laser system for forming stents

• US 8,461,478 B2
• Filed: 02/03/2010
• Issued: 06/11/2013
• Est. Priority Date: 02/03/2009
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Chen, Li, Von Oepen, Randolf
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US12/699,391
• Publication Number:
  US 20100193484A1
• Time in Patent Office: 1,224 Days
• Field of Search: 219/121.72, 219/121.75, 219/121.6, 219/121.76, 219/121.68, 219/121.61
• US Class Current: 219/121.6
• 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 2/90 characterised by a net-like or mesh-like structure
• 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: A61M 25/0013 Weakening parts of a catheter tubing, e.g. by making cuts in the tube or reducing thickness of a layer at one point to adjust the flexibility
• CPC Class Codes: B23K 26/0604 by a combination of beams
• CPC Class Codes: B23K 26/0626 Energy control of the laser beam B23K26/0622 takes precedence
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/067 Dividing the beam into multiple beams, e.g. multifocusing
• CPC Class Codes: B23K 26/324 involving non-metallic parts
• CPC Class Codes: B23K 26/36 Removing material B23K26/55, B23K26/57 take precedence
• CPC Class Codes: B23K 26/361 for deburring or mechanical trimming B23K26/351 takes precedence
• CPC Class Codes: B23K 26/362 Laser etching
• CPC Class Codes: B23K 26/38 by boring or cutting

Abstract

A system and method for precision cutting using multiple laser beams is described, The system and method includes a combination of optical components that split the output of a single laser into multiple beams, with the power, polarization status and spot size of each split beam being individually controllable, while providing a circularly polarized beam at the surface of a work piece to be cut by the laser beam. A system and method for tracking manufacture of individual stents is also provided.

Claims

1. A laser system having a plurality of laser beams generated from an output of a single laser for cutting patterns into a plurality of stents at the same time, with each of the plurality of laser beams being controllable to produce a desired power, polarization and spot size and each laser beam directed at a separate stent work piece, comprising:

a laser capable of emitting a linearly polarized laser beam;

at least one partially transmissive and partially reflective beam splitter capable of transmitting and reflecting the laser beam at a nearly linear polarization and which introduces no polarization change to the laser beam and which is capable of dividing the laser beam emitted by the laser into two laser beams;

a half wave plate disposed in an optical path of each of the laser beams, the half wave plate being capable of being rotated to alter the polarization direction each laser beam;

a polarizer disposed in the optical path of each laser beam for adjusting the laser power of the laser beam at a selected polarization direction;

an adjustable beam expander disposed in the optical path of each laser beam to adjust the size of the laser beam;

a quarter-wave plate disposed in each laser beam after the beam splitter and any intervening mirrors for introducing circular polarization into the laser beam; and

a focusing lens for focusing each laser beam to a desired spot size; and

wherein circularly polarized beam spot for each laser beam is controlled to accurately cut the stent pattern into the stent work piece upon which each laser beam impinges.

2. The system of claim 1, wherein the beam expander is disposed in the optical path of each laser beam downstream of the polarizer.

3. The system of claim 1, wherein the beam expander is disposed in the optical path of each laser beam upstream of the polarizer.

4. The system of claim 1, wherein the half wave plate is disposed upstream of the polarizer in the optical path of each laser beam.

5. The system of claim 1, wherein the quarter wave plate is disposed downstream of the polarizer in the optical path of each laser beam.

6. The system of claim 1, further comprising:

a second polarizer disposed in the optical path of at least one of the laser beams; and

a second beam expander disposed in the optical path of the at least one of the laser beams upstream from the second polarizer.

7. The system of claim 1, wherein the polarizer is disposed in between the laser and the at least one partially transmissive and partially reflective mirror.

8. The system of claim 1, wherein a power meter is disposed in the optical path of each of the laser beams to measure the power of the laser beams.

9. The system of claim 1, further comprising:

an achromatic lens;

a camera configured to view a selected one of the laser beams impinging on the work piece through the achromatic lens; and

a dichroic mirror for reflecting the selected one of the laser beams and for providing an optical pathway allowing the camera to view the selected one of the laser beams impinging on the work piece.

10. The system of claim 9, wherein the dichroic mirror is a long wave pass dichroic mirror.