Apparatus, systems and methods for medical device expansion

Abstract

A system and method for manufacturing a medical device. The system can include a thermal chamber and an expander at least partially positioned within the thermal chamber. The expander can be configured to uniformly expand a medical device as the medical device is advanced over the heated expander and heat set the expanded medical device while the medical device is positioned on the heated expander. The method can include forming a medical device from a tube having a first diameter; uniformly expanding the medical device from the first diameter to a second diameter at which the medical device can be left within a body vessel, the medical device being expanded from the first diameter to the second diameter while being continuously positioned on an expander; and heat setting the expanded medical device at the second diameter while the medical device is positioned on the expander.

What is claimed is: 
     
         1 . A system for uniformly expanding and heat setting a medical device, the system comprising:
 a thermal chamber; and   an expander at least partially positioned within the thermal chamber, the thermal chamber maintaining the expander at a predetermined elevated temperature, the expander being configured to:
 uniformly expand a medical device as the medical device is advanced over the heated expander; and 
 heat set the expanded medical device while the medical device is positioned on the heated expander. 
   
     
     
         2 . The system of  claim 1 , wherein the expander extends longitudinally between a proximal end and a distal end, the expander having an outer surface with a plurality of transport guides formed thereon that extend longitudinally from the proximal end toward the distal end; and the system further comprises:
 a transport assembly extending between a proximal end and a distal end, the transport assembly comprising a plurality of transport mechanisms each extending longitudinally between the proximal and distal ends of the transport assembly, the distal ends of the transport mechanisms being receivable within and slidable along the transport guides, the transport assembly being configured to receive a medical device thereon and position the medical device radially over the expander, and the expander being configured to radially expand the medical device while the medical device remains on the transport assembly.   
     
     
         3 . The system of  claim 2 , further comprising an axial guide that longitudinally guides the transport assembly when the transport mechanisms of the transport assembly are received within and slide longitudinally along the transport guides. 
     
     
         4 . The system of  claim 3 , wherein the expander has a guide opening extending distally thereinto from a proximal end face, and the axial guide is receivable within the guide opening to longitudinally guide the transport mechanisms of the transport assembly to the wire guides and to guide the transport mechanisms as the transport mechanisms slide longitudinally along the transport guides. 
     
     
         5 . The system of  claim 3 , further comprising means for rotationally aligning the axial guide and the expander. 
     
     
         6 . The system of  claim 5 , wherein the means for rotationally aligning the axial guide and the expander comprises:
 the axial guide and the expander having mating shapes; or   mating keys formed on the axial guide and the expander.   
     
     
         7 . The system of  claim 2 , wherein the expander has a tapered portion positioned between the proximal and distal portions, the tapered portion having a cross sectional area that transitions between the cross sectional area of the proximal portion and the cross sectional area of the distal portion. 
     
     
         8 . The system of  claim 2 , wherein the transport guides are circumferentially distributed about the outer surface of the expander. 
     
     
         9 . The system of  claim 2 , wherein the transport mechanisms and the transport guides are configured so that the medical device is physically separated from the expander when the medical device is positioned radially over the expander and expanded by the expander. 
     
     
         10 . The system of  claim 2 , wherein the plurality of transport mechanisms comprises a plurality of wires, the transport assembly comprises an array of the wires, and the plurality of transport guides comprises a plurality of wire guides. 
     
     
         11 . A method of manufacturing a medical device, the method comprising:
 forming a medical device from a tube having a first diameter;   uniformly expanding the medical device from the first diameter to a second diameter at which the medical device can be left within a body vessel, the medical device being expanded from the first diameter to the second diameter while being continuously positioned on an expander; and   heat setting the expanded medical device at the second diameter while the medical device is positioned on the expander.   
     
     
         12 . The method of  claim 11 , wherein heat setting the expanded medical device comprises maintaining the expanded medical device at the second diameter on the expander for a predetermined period of time while the expander is maintained at a predetermined heat-setting temperature. 
     
     
         13 . The method of  claim 12 , wherein the expander is positioned within a thermal chamber that maintains the expander at the predetermined heat-setting temperature during the steps of uniformly expanding the medical device and heat setting the expanded medical device. 
     
     
         14 . The method of  claim 11 , wherein the medical device is comprised of a shape-memory material. 
     
     
         15 . The method of  claim 11 , wherein the medical device is physically separated from the expander when the medical device is positioned on the expander. 
     
     
         16 . The method of  claim 11 , further comprising:
 preheating the medical device within a thermal chamber before uniformly expanding the medical device; and   maintaining heat on the medical device within the thermal chamber during radial expansion of the medical device.   
     
     
         17 . A method of manufacturing a medical device, the method comprising:
 positioning a medical device on a transport assembly having a plurality of transport mechanisms, the transport mechanisms being arranged generally parallel to a central longitudinal axis;   positioning a portion of the transport assembly on an expander so that the medical device becomes positioned radially over the expander;   radially expanding the medical device with the expander while the medical device is positioned on the transport assembly; and   heat setting the expanded medical device while the medical device is positioned on the expander, the acts of radially expanding the medical device and heat setting the expanded medical device being performed while the medical device is positioned in a heated thermal chamber.   
     
     
         18 . The method of  claim 17 , wherein positioning the portion of the transport assembly on the expander comprises:
 positioning ends of the transport mechanisms of the transport assembly in transport guides formed on the expander; and   moving the transport assembly longitudinally with respect to the expander so that the transport mechanisms slide along the transport guides until the medical device is positioned radially over the expander.   
     
     
         19 . The method of  claim 18 , wherein positioning the portion of the transport assembly on the expander further comprises:
 inserting an axial guide into a guide opening extending longitudinally through the expander, the transport assembly being attached to the axial guide so as to move therewith, and   wherein the steps of positioning the ends of the transport mechanisms in the transport guides and moving the transport assembly longitudinally are accomplished by moving the axial guide along the guide opening.   
     
     
         20 . The method of  claim 17 , wherein radially expanding the medical device with the expander comprises moving the medical device relative to the expander from a first position on a first portion of the expander to a second position on a second portion of the expander, the first and second portions of the expander respectively having first and second cross sectional areas, the second cross sectional area being greater than the first cross sectional area, the medical device being radially expanded as the medical device moves from the first position to the second position.