Artificial, flexible valves and methods of fabricating and serially expanding the same

Abstract

One aspect of the invention provides and artificial, flexible valve indlucding: a stent defining a wall and a plurality of leaflets extending from the wall of the stent. The plurality of leaflets form a plurality of coaptation regions between two adjacent leaflets. The coaptation regions include extensions along a z-axis and adapted and are configured to form a releasable, but substantially complete seal when the leaflets are in a closed position. Another aspect of the invention provides an artificial, flexible valve including: a stent defining a wall and a plurality of leaflets extending from the wall of the stent. Each of the plurality of leaflets terminates in a commissure line. The commissure lines devi-ate from a hyperbola formed in the x-y plane by at least one deviation selected from the group consisting of: a deviation in the z-direction and one or more curves relative to the hyperbola.

1 - 100 . (canceled) 
     
     
         101 . An artificial valve, comprising:
 an expandable frame configured to be implanted within a patient, the expandable frame having a maximum radial extent when the expandable frame is in a fully-expanded configuration in which the valve is in a maximum working condition; and   a plurality of leaflets disposed within and coupled to the frame, each leaflet from the plurality of leaflets extending from the frame and terminating at a free edge, each free edge having a length that is greater than the maximum radial extent of the expandable frame when the expandable frame is in its fully-expanded configuration.   
     
     
         102 . The artificial valve of  claim 101 , wherein a first leaflet from the plurality of leaflets is coupled to a first portion of the frame and a second portion of the frame, a distance along the free edge of the first leaflet between the first portion of the frame and the second portion of the frame being greater than an are distance along the frame between the first portion and the second portion. 
     
     
         103 . The artificial valve of  claim 101 , wherein the expandable frame has a first end, a second end, and a longitudinal z-axis defined therebetween,
 the plurality of leaflets forming a coaptation region having a maximum radial extent in which the leaflets (1) coapt sufficiently to prevent fluid flow along the longitudinal z-axis in a first direction and through the coaptation region, and (2) allow fluid flow along the longitudinal z-axis in a second direction opposite the first direction,   the coaptation region having a radial extent less than the maximum radial extent when the frame is in a partially-expanded configuration such that the plurality of leaflets coapt sufficiently to prevent fluid flow along the longitudinal z-axis in the first direction and through the coaptation region, and (2) allow fluid flow along the longitudinal z-axis in the second direction.   
     
     
         104 . The artificial valve of  claim 101 , wherein each free edge forms a portion of the coaptation region and the leaflet free edges collectively provide a tortuous path for fluid flow to prevent fluid flow in the predefined direction. 
     
     
         105 . The artificial valve of  claim 101 , wherein each leaflet has a variable thickness in which its thickness is reduced from its attachment to the expandable frame towards its free edge. 
     
     
         106 . The artificial valve of  claim 101 , wherein the free edge of each leaflet varies along a longitudinal z-axis of the expandable frame when the expandable frame is in the fully-expanded configuration. 
     
     
         107 . The artificial valve of  claim 106 , wherein the longitudinal z-axis of the expandable frame is defined between a first end of the expandable frame and a second end of the expandable frame, the plurality of leaflets being configured to allow fluid flow from the first end to the second end and restrict fluid flow from the second end to the first end. 
     
     
         108 . The artificial valve of  claim 101 , wherein the plurality of leaflets are formed of polymer. 
     
     
         109 . The artificial valve of  claim 101 , wherein each leaflet from the plurality of leaflets is coupled to the frame along a leaflet attachment line, the leaflet attachment line including a conic portion and a linear portion extending from a point at which the conic portion terminates to the free edge of the leaflet. 
     
     
         110 . The artificial valve of  claim 101 , wherein the maximum working condition is a condition in which the expandable frame is expanded to its largest possible diameter that allows sufficient coaptation between the plurality of leaflets. 
     
     
         111 . An artificial valve, comprising:
 an expandable frame configured to be implanted within a patient, the expandable frame having a maximum radial extent when the expandable frame is in a fully-expanded configuration in which the valve is in a maximum working condition; and   a plurality of leaflets disposed within and coupled to the frame, each leaflet from the plurality of leaflets extending from the frame and terminating at a free edge, each free edge varies along a longitudinal z-axis of the expandable frame when the expandable frame is in its fully-expanded configuration.   
     
     
         112 . The artificial valve of  claim 111 , wherein the longitudinal z-axis of the expandable frame is defined between a first end of the expandable frame and a second end of the expandable frame, the plurality of leaflets being configured to allow fluid flow from the first end to the second end and restrict fluid flow from the second end to the first end. 
     
     
         113 . The artificial valve of  claim 111 , wherein a first leaflet from the plurality of leaflets is coupled to a first portion of the frame and a second portion of the frame, a distance along the free edge of the first leaflet between the first portion of the frame and the second portion of the frame being greater than an are distance along the frame between the first portion and the second portion. 
     
     
         114 . A mandrel, comprising:
 a cylindrical profile having a plurality of recesses configured to define a plurality of valve leaflets,   the plurality of recesses each (1) extending from a valve attachment line and (2) terminating at a commissure line, each commissure line having a length greater than a diameter of the cylindrical profile.   
     
     
         115 . The mandrel of  claim 114 , wherein:
 each commissure line varies along a longitudinal z-axis of the cylindrical profile.   
     
     
         116 . The mandrel of  claim 114 , wherein each commissure line is a first commissure line,
 each valve attachment line being curved until reaching a second commissure line that is defined between the attachment line and the first commissure line, a coaptation region being defined by and linearly extending between the first commissure line and the second commissure line.   
     
     
         117 . The mandrel of  claim 114 , wherein each valve attachment line includes a conic portion and a linear portion that extends from a point at which the conic portion terminates to the commissure line. 
     
     
         118 . The mandrel of  claim 114 , wherein the commissure line extends from the linear portion towards a center of the cylindrical profile, the commissure line varying in height. 
     
     
         119 . The mandrel of  claim 114 , wherein the commissure line extends from the linear portion towards a center of the cylindrical profile, the commissure line varying along a longitudinal z-axis of the cylindrical profile. 
     
     
         120 . A frame for an artificial valve, comprising:
 an expandable cylindrical body having a first end, a second end, and a longitudinal z-axis extending therebetween; and   a plurality of valve leaflets,   
       the expandable cylindrical body being formed by a plurality of posts extending substantially parallel to and circumferentially about the longitudinal z-axis, the plurality of posts including a first set of posts having a first width and a second set of posts having a second width that is greater than the first width, 
       the first set of posts defining a plurality of open cells therebetween that are variable in shape during expansion of the expandable cylindrical body, 
       each post from the second set of posts being disposed at a junction between and coupled to two valve leaflets from the plurality of valve leaflets. 
     
     
         121 . The frame of  claim 120 , wherein each post from the second set of posts defines one or more windows configured to have a fixed shape during expansion of the expandable cylindrical body. 
     
     
         122 . The frame of  claim 121 , wherein the second set of posts includes polymer within its one or more windows, each post from the second set of posts being coupled to the two valve leaflets via the polymer. 
     
     
         123 . The frame of  claim 120 , wherein the plurality of open cells are covered. 
     
     
         124 . The frame of  claim 120 , wherein the plurality of open cells are coated with a polymer. 
     
     
         125 . The frame of  claim 120 , wherein the plurality of windows have a width of about 0.5 mm to about 3 mm, and a height of about 1 mm to about 10 mm. 
     
     
         126 . The frame of  claim 121 , wherein the one or more windows are substantially rectangular. 
     
     
         127 . The frame of  claim 120 , wherein the second set of posts consists of three posts each of which are circumferentially positioned at 120 degree intervals among the expandable cylindrical body, the plurality of valve leaflets consisting of three valve leaflets. 
     
     
         128 . The frame of  claim 120 , wherein the plurality of valve leaflets are coupled to the second set of posts via at least one of a chemical coupling technique, chemical fusing, thermal fusing, or sonic welding. 
     
     
         129 . The frame of  claim 128 , wherein the plurality of valve leaflets are formed of a polymer. 
     
     
         130 . The frame of  claim 120 , wherein the entire external surface of the expandable cylindrical body is coated with a polymer.