Multiple beam laser system for forming stents

• US 9,199,334 B2
• Filed: 04/01/2015
• Issued: 12/01/2015
• Est. Priority Date: 02/03/2009
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Chen, Li, von Oepen, Randolf
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US14/676,148
• Publication Number:
  US 20150202714A1
• Time in Patent Office: 244 Days
• Field of Search: 219/121.72, 219/121.67, 219/121.68, 219/121.76, 219/121.61, 219/121.75
• US Class Current: 1/1
• 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 first linearly polarized laser beam;

a first beam splitter capable of transmitting and reflecting the first linearly polarized laser beam into a second linearly polarized laser beam and a third linearly polarized laser beam;

a second beam splitter capable of transmitting and reflecting the second linearly polarized laser beam into a fourth linearly polarized laser beam and a fifth linearly polarized laser beam;

a third beam splitter capable of transmitting and splitting the third linearly polarized laser beam into a sixth linearly polarized laser beam and a seventh linearly polarized laser beam;

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

a polarizer disposed in the optical path of each of the fourth, fifth, sixth and seventh laser beams 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 of the fourth, fifth, sixth and seventh laser beams to adjust the size of the laser beam;

a quarter-wave plate disposed in the path of each of the fourth, fifth, sixth and seventh laser beams after the beam splitter and any intervening mirrors for introducing circular polarization into the laser beams; and

a focusing lens for focusing each of the fourth, fifth, sixth and seventh laser beams to a desired spot size; and

wherein a circularly polarized beam spot for each of the fourth, fifth, sixth and seventh laser beams is controlled to accurately cut the stent pattern into the stent work piece upon which each of the fourth, fifth, sixth and seventh laser beam impinges.

2. The laser system of claim 1, wherein the optical path traveling downstream for each of the fourth, fifth, sixth and seventh laser beams includes in order the half wave plate, the polarizer, the adjustable beam expander, the quarter wave plate and the focusing lens.

3. The laser system of claim 2, wherein the spot size is individually controlled for each of the fourth, fifth, sixth and seventh laser beams by individual adjustment of the respective beam expanders and focusing lenses.

4. The laser system of claim 3, wherein for each of the fourth, fifth, sixth and seventh laser beams, a modulator and a switch are used to independently control the repetition rate, power level and on/off control of each laser beam.