Laser system and processing conditions for manufacturing bioabsorbable stents
AssigneeAbbott Cardiovascular Systems Inc.
InventorsJoel Harrington, Ryan Vaughan, Kevin Jow, William Pippey, Yung-Ming Chen
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Abstract
The present invention involves laser machining polymer substrates to form a stent with laser parameters that minimize damage to the substrate in a surface region adjacent to the machined edge surface. The wavelength and pulse width are selected for this unique application and they can be controlled to minimize the surface modifications (such as voids, cracks which are induced by the laser-material interaction) which contribute to the variation in mechanical properties with distance from the edge surface, bulk mechanical properties, or a combination thereof.
Claims11
(canceled)
A method of laser machining a substrate to form a stent, comprising:
- providing a thin-walled polymer substrate;
- laser machining the thin-walled polymer substrate with a laser beam with a pulse width and wavelength that cuts through the wall to form structural elements having a machined edge surface,
- wherein the laser beam modifies the substrate in a surface region adjacent to the machined edge surface,
- wherein the modifications include voids, and characterized by
- selecting the pulse width and wavelength so that the voids are present at no greater than a depth of 2 microns.
A polymer stent body, comprising:
- a plurality of interconnected structural elements formed by laser machining a thin-walled poly(L-Lactide) (PLLA) polymer substrate with a laser beam that cuts through the wall to form the structural elements,
- wherein the structural elements have sidewalls corresponding to machined edge surfaces,
- wherein a surface region adjacent to the sidewalls has damage caused by interaction of the laser beam with the substrate,
- characterized in that the damage comprises voids dispersed in the surface region, wherein the voids dispersed in the surface region are present at no greater than a depth of 2 microns from the edge surface.
Dependencies are inferred from the claim text.