System to prevent stent damage caused by laser cutting

Abstract

Apparatus, method and system for cutting a polymeric stent including the use of a polymeric mandrel as a laser shielding device. The polymeric mandrel is allowed to roll freely within a polymeric tube that is cut into a polymeric stent.

1 . (canceled) 
     
     
         2 . A stent cutting apparatus, comprising:
 a polymeric tube having a working outer tube and an inner tube surface defining an inside diameter of the polymeric tube, the polymeric tube having a first end and a second end;   a polymeric mandrel having an outer surface defining an outer diameter that is smaller than the inside diameter of the polymeric tube;   a support adapted to hold the polymeric tube only at the first end, with the polymeric mandrel therewithin, in operative association with a laser for providing a laser beam for laser cutting the polymeric tube to form a stent out of the polymeric tube; and   a nozzle near a laser beam cutting point adapted to dispense pressurized gas, thereby forming a jet of pressurized gas to force debris out of a laser cut kerf toward the second end of the polymeric tube,   wherein the polymeric mandrel is positioned longitudinally within the polymeric tube such that the outer surface of the polymeric mandrel is in contact with the inner tube surface of the polymeric tube.   
     
     
         3 . The method of  claim 2 , wherein during the cutting the polymeric tube is configured to rotate and the polymeric mandrel is allowed to roll on the inside surface of the polymeric tube in response to an angular force from rotation of the polymeric tube, and wherein there are imperfections including bumps on an inside surface of the polymeric tube or on an outer surface of the polymeric mandrel contacting the polymeric tube which cause the polymeric mandrel to have a bouncy, irregular, motion when the polymeric mandrel is allowed to roll. 
     
     
         4 . The method of  claim 2 , wherein the polymeric mandrel is hollow. 
     
     
         5 . The method of  claim 2 , wherein the polymeric mandrel is a solid rod that is not hollow. 
     
     
         6 . The method of  claim 2 , wherein the polymeric tube and the polymeric mandrel are formed from at least one of poly(L-lactide) and poly(L-lactide-co-glycolide). 
     
     
         7 . The method of  claim 2 , wherein the polymeric tube and the polymeric mandrel are formed from the same bioerodable polymer. 
     
     
         8 . A stent cutting apparatus, comprising:
 a polymeric tube having a working outer tube and an inner tube surface defining an inside diameter of the polymeric tube, the polymeric tube having a first end and a second end;   a polymeric mandrel having an outer surface defining an outer diameter that is smaller than the inside diameter of the polymeric tube;   a support adapted to hold the polymeric tube, with the polymeric mandrel therewithin, in operative association with a laser for providing a laser beam for laser cutting the polymeric tube to form a stent out of the polymeric tube; and   a nozzle near a laser beam cutting point adapted to dispense pressurized gas, thereby forming a jet of pressurized gas to force debris out of a laser cut kerf toward the second end of the polymeric tube,   wherein the polymeric mandrel is positioned longitudinally within the polymeric tube such that the outer surface of the polymeric mandrel is in contact with the inner tube surface of the polymeric tube,   wherein during the cutting the polymeric tube is configured to rotate and the polymeric mandrel is allowed to roll on the inside surface of the polymeric tube in response to an angular force from rotation of the polymeric tube, and   wherein there are imperfections including bumps on an inside surface of the polymeric tube or on an outer surface of the polymeric mandrel contacting the polymeric tube which cause the polymeric mandrel to have a bouncy, irregular, motion when the polymeric mandrel is allowed to roll.