Thin-walled scaffolds having radiopaque markers

Abstract

A thin-walled scaffold has a network of rings interconnected by links. A link includes holding a radiopaque marker connects adjacent rings. The link and/or a nearby ring is modified to compensate for the thin walls when the scaffold is crimped to a balloon.

1 - 20 . (canceled) 
     
     
         21 . A medical device, comprising:
 a thin-walled scaffold having a network of rings interconnected by links, wherein each ring has a plurality of crests and each ring extends circumferentially in an undulating fashion along a vertical axis (B-B) perpendicular to a longitudinal axis (A-A); and   a marker link extending between a first ring and a second ring of the network of rings, the marker link comprising:
 a structure forming a hole and a radiopaque material is contained within walls of the hole; 
 a first link portion extending from the structure and connected to a crest of the first ring, 
 a second link portion extending from the structure and connected to a crest of the second ring, and 
 a width of the first link portion is greater than a width of the second link portion. 
   
     
     
         22 . The medical device of  claim 21 , wherein a length of the second link portion is greater than a length of the first link portion. 
     
     
         23 . The medical device of  claim 21 , wherein the structure includes a first hole and a second hole, and each hole contains the radiopaque material. 
     
     
         24 . The medical device of  claim 23 , wherein the first and second holes are aligned with axis A-A. 
     
     
         25 . The medical device of  claim 21 , wherein the width of the second link portion is about 60% less than the width of the first link portion. 
     
     
         26 . The medical device of  claim 21 , wherein the first link portion forms with the first ring crest a W crown and the second link portion forms with the second link portion a Y crown. 
     
     
         27 . The medical device of  claim 21 , wherein a width of the structure is greater than the width of the first link portion. 
     
     
         28 . The medical device of  claim 27 , wherein a width of the structure is about 200% greater than a width of a link that does not hold a radiopaque material. 
     
     
         29 . A medical device, comprising:
 a thin-walled scaffold having a network of rings interconnected by links, wherein each ring has a plurality of crests and each ring extends circumferentially in an undulating fashion along a vertical axis (B-B) perpendicular to a longitudinal axis (A-A);   a marker link extending between a first ring and a second ring of the network of rings, the marker link comprising a structure forming a hole and a radiopaque material is contained within walls of the hole; and   the first ring comprises:
 a first crest joined with a first end of the marker link, 
 the first ring has n crests and n wavelengths, wherein a wavelength is a length between adjacent crests of the first ring measured along the axis B-B, 
 a first of the n wavelengths is measured from the first crest to a crest located above and adjacent the first crest, 
 a second of the n wavelengths is measured from the first crest to a crest located below and adjacent the first crest, and 
 the length of either the first wavelength or the second wavelength is greater than a length of one of the other n−2 wavelengths. 
   
     
     
         30 . The medical device of  claim 29 , wherein n is at least 6 and not more than 12. 
     
     
         31 . The medical device of  claim 29 , wherein the first wavelength and the second wavelength have the same length. 
     
     
         32 . The medical device of  claim 29 , wherein each of the other n−2 wavelengths all have the same length. 
     
     
         33 . The medical device of  claim 29 , wherein the medical device further comprises:
 a non-marker link, devoid of the radiopaque material, extends between the first and second ring, and the first ring further comprises
 a second crest joined with a first end of the non-marker link, 
 a third of the n wavelengths is measured from the second crest to a crest located above and adjacent the second crest, 
 a fourth of the n wavelengths is measured from the second crest to a crest located below and adjacent the second crest, and 
 the lengths of the first wavelength or the second wavelength is greater than a length of the third wavelength or the fourth wavelength. 
   
     
     
         34 . The medical device of  claim 29 , wherein a first end of the marker link forms with the first crest a W crown, and a second end of the marker link is connected to a second crest of the second ring and forms with the second crest a Y crown. 
     
     
         35 . The medical device of  claim 29 , wherein the first ring is adjoined to the second ring by only three links including the marker link. 
     
     
         36 . The medical device of  claim 35 , wherein the other two links do not hold a radiopaque material. 
     
     
         37 . A medical device, comprising:
 a scaffold having proximal and distal end portions formed by a network of rings interconnected by links;   the scaffold has a wall thickness less than 125 microns; and   a marker link extends between a first ring and a second ring of the network of rings, the marker link comprising:
 a structure having a hole and a radiopaque material is contained within walls of the hole, and 
 the marker link has an aspect ratio (AR) of between 2.8 and 4.5, where AR is defined as a maximum width of the structure divided by the wall thickness. 
   
     
     
         38 . The medical device of  claim 37 , wherein the scaffold is crimped to a balloon and the scaffold has an outer diameter of about D-min, wherein
     D -min=(1/π)×[( n ×strut_width)+( m ×link_width)]+2* t,  
   “n” is the number of struts in a ring,   “strut_width” is the width of a strut,   “m” is the number of links adjoining adjacent rings,   “link_width” is the width of a link, and   “t” is the wall thickness.   
     
     
         39 . The medical device of  claim 37 , wherein the wall thickness is equal to, or less than 100 microns. 
     
     
         40 . The medical device of  claim 37 , wherein the structure includes a first hole and a second hole, and each hole contains the radiopaque material. 
     
     
         41 . The medical device of  claim 40 , wherein the first and second holes are aligned with axis B-B or axis A-A. 
     
     
         42 . The medical device of  claim 37 , wherein the marker link further comprises a first link portion connecting the structure to the first ring and forming a W crown with a first ring crest, and a second link portion connecting the structure to the second ring and forming a Y crown with a second ring crest. 
     
     
         43 . The medical device of  claim 42 , wherein a length of the first link portion is greater than a length of the second link portion. 
     
     
         44 . The medical device of  claim 37 , wherein the network of rings includes a third ring having a third crest, and wherein a first distance measured from the first crest to the second crest is greater than a second distance measured from the third crest to the second crest. 
     
     
         45 . The medical device of  claim 37 , wherein the marker link has an aspect ratio (AR) of between 3.2 and 4.5.