Bubble-free microfluidic valve systems and methods

Abstract

A microfluidic valve for implantation in an eye of a patient is disclosed. The valve may include a chamber formed between a substrate and a flexible membrane. The valve may also include a boss disposed in the chamber and having a top edge in selective contact with the flexible membrane. The top edge includes a relief portion and a non-relief portion, with the relief portion being structurally arranged so that a pressure required to separate the membrane from the relief portion is less than a pressure required to separate the membrane from the non-relief portion. The valve also may include an inlet extending through the boss and the substrate through which fluid enters the chamber and an outlet configured to allow fluid to exit the chamber. Methods for priming a microfluidic valve are also disclosed.

1 . A microfluidic valve for implantation in an eye of a patient, comprising:
 a chamber formed between a substrate and a flexible membrane;   a boss disposed in the chamber and having a top edge in selective contact with the flexible membrane, the top edge including a relief portion and a non-relief portion, the relief portion being structurally arranged so that a pressure required to separate the membrane from the relief portion is less than a pressure required to separate the membrane from the non-relief portion;   an inlet extending through the boss and the substrate through which fluid enters the chamber; and   an outlet configured to allow fluid to exit the chamber.   
     
     
         2 . The microfluidic valve of  claim 1 , wherein the boss is cylindrical. 
     
     
         3 . The microfluidic valve of  claim 2 , wherein the non-relief portion is circular and the relief portion is flat. 
     
     
         4 . The microfluidic valve of  claim 2 , wherein the boss is an elliptical cylinder. 
     
     
         5 . The microfluidic valve of  claim 1 , wherein the chamber is a toroidal chamber. 
     
     
         6 . The microfluidic valve of  claim 1 , wherein the inlet is smaller in diameter than the outlet. 
     
     
         7 . The microfluidic valve of  claim 1 , wherein the boss is offset from a center of the chamber toward the outlet port to form the relief portion. 
     
     
         8 . The microfluidic valve of  claim 1 , wherein the outlet is formed through the substrate. 
     
     
         9 . A microfluidic valve for implantation in an eye of a patient, comprising:
 a chamber having a boundary surface comprising a first wall and a second wall, the second wall opposing the first wall;   a valve portion configured to regulate fluid flow into the chamber;   an inlet configured to allow a fluid to flow through the valve portion and into the chamber; and   an outlet configured to allow the fluid to flow out of the chamber through a location accessible to fluid flowing to the outlet from more than one direction, the outlet being bounded by a first priming block disposed between the outlet and the first wall and by a second priming block disposed between the outlet and the second wall.   
     
     
         10 . The microfluidic valve of  claim 9 , wherein valve portion comprises a membrane that is coupled to a ring that forms the second wall of the chamber. 
     
     
         11 . The microfluidic valve of  claim 9 , wherein valve portion comprises a boss, the first wall being formed by the boss. 
     
     
         12 . The microfluidic valve of  claim 9 , wherein the first and second priming blocks are configured to inhibit the flow of a liquid from one side of the first and second priming blocks to another side within the chamber. 
     
     
         13 . The microfluidic valve of  claim 9 , wherein the relief portion and the outlet port are on opposite sides of the inlet port. 
     
     
         14 . A method of priming a valve in an intraocular device suitable for implantation next to the eye of the patient, the method comprising:
 introducing a pressurized fluid to the valve;   breaking a seal of the valve by displacing a membrane relative to a relief portion of a boss structure so that the pressurized fluid flows into a chamber at the relief portion, while the pressurized fluid is restricted from flowing into the chamber along a non-relief portion of the boss structure; and   directing the pressurized fluid to a valve outlet such that the chamber is filled with the pressurized fluid.   
     
     
         15 . The method of  claim 14 , wherein introducing a pressurized fluid comprises introducing the pressurized fluid through a valve inlet extending through the boss structure. 
     
     
         16 . The method of  claim 14 , wherein the boss structure is configured such that a lower pressure separates the membrane and the relief portion than a pressure that separates the membrane and a non-relief portion such that the relief portion directs the pressurized fluid. 
     
     
         17 . The method of  claim 14 , wherein a position of the boss structure relative to the membrane causes the seal to be broken more easily along the relief portion than along the non-relief portion. 
     
     
         18 - 25 . (canceled) 
     
     
         26 . The method of  claim 14 , wherein directing the pressurized fluid to a valve outlet such that the chamber is filled with the pressurized fluid comprises directing a first portion of the pressurized fluid having a first front and directing a second portion of the pressurized fluid having a second front. 
     
     
         27 . The method of  claim 26 , wherein the boss structure comprises a non-circular cross-section. 
     
     
         28 . A method of priming a valve in an intraocular device suitable for implantation next to the eye of the patient, the method comprising:
 introducing a pressurized fluid to a valve;   breaking a seal of the valve by displacing a membrane relative to a relief portion of a boss structure so that pressurized fluid flows into a chamber and toward a valve outlet in a first flow direction through a first portion of the chamber and toward the valve outlet in a second flow direction through a second portion of the chamber; and   preventing a front of the fluid flowing in the first flow direction from passing into the second portion of the chamber.   
     
     
         29 . The method of  claim 28 , further comprising directing the front of the fluid flowing in the first flow direction to the valve outlet so that the fluid flowing in the first flow direction exits the valve. 
     
     
         30 . The method of  claim 28 , further comprising preventing a front of the fluid flowing in the second flow direction from passing into the first portion of the chamber. 
     
     
         31 . The method of  claim 28 , wherein the chamber is a toroidal chamber. 
     
     
         32 . The method of  claim 28 , comprising a first priming block positioned between the valve outlet and an inside wall of the chamber and a second priming block positioned between the valve outlet and an outside wall of the chamber.