Mounting stents on stent delivery systems

Abstract

A system for mounting a stent on a balloon catheter includes two positioning and alignment stations, which are used to prepare a stent and catheter for crimping using the same crimping head. The system is configured for automated assembly of the stent and catheter prior to crimping. A catheter and stent are placed on a computer-controlled carriage that delivers the stent and catheter to the crimper head. Before placing the stent and catheter into the crimper head, an automated alignment system locates the stent between balloon markers.

1 - 21 . (canceled) 
     
     
         22 . An apparatus, comprising:
 a stent comprising a polymer having a glass transition temperature;   a non-stick material;   a crimping station including a crimper head having jaws; and   a processor for crimping the stent, whereupon receiving a user command, the processor causes the crimping station to
 (a) insert the stent into the crimper head, wherein the non-stick material is disposed between the jaws and the stent; 
 (b) heat the stent; and 
 (c) crimp the stent from a first diameter to a second diameter. 
   
     
     
         23 . The apparatus of  claim 22 , wherein the stent is heated to near the glass transition temperature. 
     
     
         24 . The apparatus of  claim 22 , wherein the stent is heated to a temperature between the glass transition temperature (Tg) and 15 degrees Celsius below Tg. 
     
     
         25 . The apparatus of  claim 22 , wherein the stent is on a balloon catheter during step (c), and after step (c) the crimper jaws are held at the second diameter and the balloon is inflated for a dwell period while the stent has the second diameter. 
     
     
         26 . The apparatus of  claim 22 , wherein the stent is made from poly(L-lactide). 
     
     
         27 . The apparatus of  claim 22 , wherein before step (a) the processor accesses crimping parameters defining a crimping sequence for the stent upon receiving an identification code provided with the stent. 
     
     
         28 . The apparatus of  claim 22 , wherein after step (c), the stent is removed from the crimper head, alignment of the stent on a balloon is verified, the stent and balloon are re-inserted into the crimper head, and the stent is crimped to a final crimp diameter that is less than the second diameter. 
     
     
         29 . The apparatus of  claim 22 , wherein the stent before crimping has a diameter about 2.5 times larger than the second diameter. 
     
     
         30 . The apparatus of  claim 22 , wherein the stent is crimped from the first diameter to an intermediate diameter that is the same as a balloon diameter, the stent is removed from the crimper head after crimping to the first diameter, followed by re-inserting the stent into the crimper head wherein the stent disposed upon a balloon and disposed between balloon markers when re-inserted into the crimper head. 
     
     
         31 . The apparatus of  claim 22 , wherein the crimper head jaws are made of metal and the non-stick material is a polymer having a higher compliance than the metal. 
     
     
         32 . The apparatus of  claim 22 , wherein after step (c) the stent is placed in a sheath and the stent and sheath are placed in a refrigeration unit. 
     
     
         33 . An apparatus, comprising:
 a stent made from a polymer material having a glass transition temperature;   a balloon catheter;   a non-stick material;   a crimping station including a crimper head having jaws; and   a processor for crimping the stent to the balloon catheter, whereupon receiving a user command, the processor causes the crimping station to
 (a) insert the stent and balloon catheter into the crimper head; 
 (b) heat the stent; 
 (c) crimp the stent from a first diameter to a second diameter; 
 (d) hold the crimper jaws at the second diameter for a first dwell period to allow for stress relaxation in the polymer material; 
 (e) crimp the stent from the second diameter to a third diameter. 
 (f) hold the crimper jaws at the third diameter for a second dwell period to allow for stress relaxation in the polymer material; and 
 (g) crimp the stent from the third diameter to a fourth diameter. 
   
     
     
         34 . The apparatus of  claim 33 , wherein the first and second dwell periods have durations of between 10 and 200 seconds. 
     
     
         35 . A crimping method, comprising
 providing a stent made from a polymer material having a glass transition temperature, the stent having an initial diameter;   crimping the polymer stent to a polymer balloon, including
 (a) placing the stent over the balloon, 
 (b) removing a static charge between the stent and the balloon, and 
 (c) using a crimping device, crimping the stent from the initial diameter to a first diameter less than the initial diameter while the stent is being heated. 
   
     
     
         36 . The crimping method of  claim 35 , wherein step (b) includes directing anti-static air over the stent and balloon. 
     
     
         37 . The apparatus of  claim 35 , wherein the stent temperature is near the glass transition temperature during step (c). 
     
     
         38 . The apparatus of  claim 35 , wherein the stent temperature is between the glass transition temperature (Tg) and 15 degrees Celsius below Tg during step (c). 
     
     
         39 . The crimping method of  claim 35 , wherein the first diameter equal to an outer diameter of the balloon, further including the steps of
 (e) removing the stent from the crimping device after crimping the stent to the first diameter, and   (f) placing the stent and balloon back into the crimper and crimping the stent to a second diameter less than the first diameter.   
     
     
         40 . The apparatus of  claim 35 , wherein after step (c), the stent and balloon are removed from the crimper head, the stent and balloon are re-inserted into the crimper head, and the stent is crimped to a final crimp diameter that is less than the first diameter. 
     
     
         41 . An apparatus, comprising:
 a crimper head having jaws and a non-stick material arranged for being placed between the jaws and a stent received within the crimper head; and   a first station and a second station disposed adjacent the crimper head and configured to receive, respectively, a first stent and a first balloon catheter assembly and a second stent and a second balloon catheter assembly;   a processor for crimping the first stent to the first balloon catheter and the second stent to the second balloon catheter using the crimper head, whereupon receiving a user command, the processor causes   (a) the first station to insert the first stent and first balloon catheter into the crimper head and the second station to insert the second stent and second balloon catheter into the crimper head, and   (b) the crimper head to perform a crimping sequence including the first stent being crimped to the first balloon catheter and the second stent being crimped to the second balloon catheter.