Electrokinetic Actuator to Titrate Fluid Flow

Abstract

An electrokinetic actuator for fluid flow titration including two chambers separated from one another by a porous dielectric disposed therebetween. A plurality of electrodes are disposed about a perimeter of the first and second chambers. Polar electrolyte disposed within the actuator is able to pass through the porous dielectric between the first and second chambers upon the application of an electric field or electric potential to the plural electrodes. A mechanical valve actuation mechanism connected to the second chamber allows for fine titration of fluid flow using electro-osmosis, including full-flow and/or complete cut-off. The polar electrolyte is isolated to prohibit intermixing with a fluid being titrated such as cerebrospinal fluid.

1 . An electrokinetic actuator for fluid flow titration comprising:
 a first chamber having a closed proximal end and an opposite open distal end;   a second chamber having an open proximal end and an opposite open distal end, the open distal end of the first chamber being separated from the open proximal end of the second chamber by a porous dielectric disposed therebetween;   a plurality of electrodes disposed about a perimeter of the first and second chambers; and   polar electrolyte disposed within the actuator and adapted to pass through the porous dielectric between the first and second chambers upon the application of an electric field or electric potential to the plural electrodes; and   a mechanical valve actuation mechanism connected to the open distal end of the second chamber for fine titration of a fluid using electro-osmosis of the polar electrolyte isolated to prohibit intermixing with the fluid being titrated.   
     
     
         2 . The electrokinetic actuator in accordance with  claim 1 , wherein the actuator imposes a hydraulic force of less than approximately 500 mbar. 
     
     
         3 . The electrokinetic actuator in accordance with  claim 1 , wherein the fine titration of fluid flow caused by the mechanical actuator mechanism is not limited to only two flow states of full fluid flow and fluid flow cut off completely. 
     
     
         4 . A method for fine titration of a fluid flow using the electrokinetic actuator in accordance with  claim 1 , comprising the step of:
 imposing a mechanical force via the mechanical valve actuation mechanism on an opening of a valve member to adjust fluid flow therethrough.   
     
     
         5 . The method in accordance with  claim 4 , wherein the imposing step comprises the steps of:
 applying an electric potential or electric field to the plural electrodes to produce electro-osmosis that displaces the electrolyte between the two chambers through the porous dielectric;   expanding/contracting a bellows connected to the second chamber as a result of the electro-osmosis of the electrolyte;   linearly displacing an actuator pin connected to the bellows as a result of the expansion/contraction of the bellows;   adjusting a force imposed on the opening of the valve member based on the linear displacement of the actuator pin.   
     
     
         6 . The method in accordance with  claim 4 , wherein the imposing step comprises the steps of:
 applying an electric potential or electric field to the plural electrodes to produce electro-osmosis that displaces the electrolyte between the two chambers through the porous dielectric;   expanding/contracting a bellows connected to the second chamber as a result of the displacement of the electrolyte;   adjusting a force imposed on a flexible tubing through which fluid flows therethrough thereby deforming a cross-sectional area of the flexible tubing.   
     
     
         7 . An implantable shunt system comprising:
 a proximal catheter;   a drainage catheter;   a valve apparatus disposed between the proximal or drainage catheters; and   an electrokinetic actuator in accordance with  claim 1  for finely titrating cerebrospinal fluid from the proximal catheter to the drainage catheter by controlling an opening pressure and/or diameter of the valve apparatus, wherein fine titration includes full fluid flow and/or complete cut off of fluid flow.   
     
     
         8 . A drainage system comprising:
 a proximal catheter;   a drainage catheter;   a valve apparatus disposed between the proximal or drainage catheters; and   an electrokinetic actuator in accordance with  claim 1  for finely titrating fluid from the proximal catheter to the drainage catheter by controlling an opening pressure and/or diameter of the valve apparatus, wherein fine titration includes full fluid flow and/or complete cut off of fluid flow.