Venous valve with sinus

Abstract

A venous valve-with a structural member and valve leaflets that provide a sinus.

1 . A venous valve, comprising: 
 a structural member having an inlet region that defines an inlet cross sectional area, a middle region that defines a middle cross sectional area, and an outlet region that defines an outlet cross sectional area, the inlet cross sectional area being different than the middle cross sectional area, and the inlet cross sectional area being at least approximately equal to the outlet cross sectional area;    a first valve leaflet connected to the structural member, the first valve leaflet including a first inflow surface and a first outflow surface opposite the first inflow surface, and being configured to shift between an open position and a closed position; and    a sinus defined by a volume between the structural member at the middle cross sectional area and the first outflow surface of the first valve leaflet in the open position.    
   
   
       2 . The venous valve of  claim 1 , including a second valve leaflet connected to the structural member opposite the first valve leaflet, where the first valve leaflet and the second valve leaflet have free edges in the sinus that in the open position form a free edge cross sectional area.  
   
   
       3 . The venous valve of  claim 2 , where the inlet cross sectional area is approximately equal to the outlet cross sectional area, is greater than the free edge cross sectional area, and is less than the middle cross sectional area.  
   
   
       4 . The venous valve of  claim 2 , where the middle cross sectional area is greater than the inlet cross sectional area and is approximately equal to the outlet cross sectional area and the inlet cross sectional area is greater than the free edge cross sectional area.  
   
   
       5 . The venous valve of  claim 2 , where the inlet cross sectional area is approximately equal to both the free edge cross sectional area and the outlet cross sectional area, and the inlet cross sectional area is less than the middle cross sectional area.  
   
   
       6 . The venous valve of  claim 2 , where the inlet cross sectional area is approximately equal to the outlet cross sectional area, the inlet cross sectional area is greater than the middle cross sectional area, and the middle cross sectional area is greater than the free edge cross sectional area.  
   
   
       7 . The venous valve of  claim 2 , where the structural member provides for a longitudinal center axis extending from the inlet region to the outlet region, the free edge of the first and second valve leaflet extending from an attachment location on the structural member at a distance at least twenty-five (25) percent from the inlet region along the longitudinal center axis.  
   
   
       8 . The venous valve of  claim 7 , where the attachment location on the structural member ranges from a distance fifty (50) percent from the inlet region to eighty (80) percent from the inlet region along the longitudinal center axis.  
   
   
       9 . The venous valve of  claim 2 , where the structural member provides for a longitudinal center axis, where the free edge of the first or second valve leaflet in the open position and the middle region of the structural member define a gap having a maximum distance ranging from 0.5 to four (4) millimeters (mm) measured perpendicular to the longitudinal center axis.  
   
   
       10 . The venous valve of  claim 9 , where the gap has a maximum distance ranging from one (1) to three (3) mm.  
   
   
       11 . The venous valve of  claim 10 , where the maximum distance ranges from 1.5 to 2.5 mm.  
   
   
       12 . The venous valve of  claim 2 , where the first and second valve leaflets have a valve leaflet length (L) along the inflow surface measured at a greatest length distance between the free edge and an attachment location to the structural member perpendicular to the free edge, where the inlet cross sectional area has an inlet radius (r i ), and where the valve leaflet length (L) is a function of the inlet radius (r i ) and is at least approximately equal to the inlet radius (r i ).  
   
   
       13 . The venous valve of  claim 12 , where the valve leaflet length (L) is a function of the inlet radius (r i ) that ranges from L=1.2r i  to L=8r i .  
   
   
       14 . The venous valve of  claim 13 , where the function ranges from L=1.5r i  to L=5r i .  
   
   
       15 . The venous valve of  claim 2 , where the structural member provides for a longitudinal center axis, where the first and second valve leaflets have a valve leaflet width (W) measured at a greatest width distance between attachment locations to the structural member existing on a plane extending perpendicularly from the longitudinal center axis, and where the first and second valve leaflets have a valve leaflet length (L) along the inflow surface measured at a greatest length distance between the free edge and an attachment location to the structural member perpendicular to the free edge, and the ratio of valve leaflet length (L) to the valve leaflet width (W) ranges from 0.75:1 to 1.5:1.  
   
   
       16 . The venous valve of  claim 15 , where the ratio of valve leaflet length (L) to valve leaflet width (W) is between 0.75:1 and 1.5:1.  
   
   
       17 . The venous valve of  claim 1 , where the first valve leaflet is formed of a material selected from the group comprising urinary bladder matrix (UBM), expanded polytetrafluoroethylene (ePTFE), polyurethane, silicone, polystyrene, and a cellurized tissue from a human, an animal, or a plant source.  
   
   
       18 . The venous valve of  claim 16 , where the material is reinforced with a metal mesh.  
   
   
       19 . A method, comprising: 
 forming a middle region in a venous valve frame with an inlet region and a outlet region, the middle region being substantially different than the inlet region, and the inlet region being at least approximately equal to the outlet region; and    coupling valve leaflets to the venous valve frame, where a free edge of the valve leaflets are located adjacent the middle region to form a sinus between the middle region in the venous valve frame and the valve leaflets.    
   
   
       20 . The method of  claim 19 , including configuring an opening defined by the valve leaflet to create a Bernoulli effect across the valve leaflet.  
   
   
       21 . The method of  claim 19 , where coupling the valve leaflet to the venous valve frame includes providing a gap of at least a predetermined distance between the free edge of the valve leaflet and the middle region in the venous valve frame.  
   
   
       22 . The method of  claim 21 , where coupling the valve leaflet to the venous valve frame includes maintaining at least the gap between the free edge of the valve leaflet and the middle region in the venous valve frame as the valve leaflet cycles between an open position and a closed position.  
   
   
       23 . The method of  claim 19 , where the venous valve frame resists flexing and can withstand a high expansion force on the middle region and a low expansion force on the inlet region and outlet region.  
   
   
       24 . The method of  claim 19 , where the venous valve frame is flexible and the valve leaflet is made of an elastomeric material.  
   
   
       25 . The method of  claim 19 , where the venous valve frame is flexible and the valve leaflet is large enough to maintain the closed position when the venous valve frame is compressed.