Systems and methods for collecting tear film and measuring tear film osmolarity

Abstract

A sample receiving chip comprising a substrate that receives an aliquot volume of a sample fluid and a sample region of the substrate, sized such that the volume of the sample fluid is sufficient to operatively cover a portion of the sample region. The energy imparted into the sample fluid is transduced by the sample region to produce an output signal that indicates energy properties of the sample fluid. The sample receiving chip also includes a channel formed in the substrate, the channel configured to collect the aliquot volume of a sample fluid and transfer the aliquot volume of sample fluid to the sample region.

1 .- 44 . (canceled) 
     
     
         45 . A device for determining the presence of an analyte in a fluid sample comprising:
 a. a collection chamber containing a hydrophilic polymer;   b. a fluidic channel connected to the collection chamber;   c. a sensing chamber connected to the fluidic channel, wherein the sensing chamber is operably linked to a processor that allows detection of the analyte using electrochemical sensing.   
     
     
         46 . The device of  claim 45 , wherein the processor comprises an electrode system, and wherein the processing of the fluid comprises applying a voltage to the electrode system to induce an electrochemical reaction between the material that specifically detects the analyte and the analyte in the fluid sample and detecting a current produced by the electrochemical reaction. 
     
     
         47 . The device of  claim 45 , wherein detection of the analyte comprises an enzyme modified electrochemical reaction. 
     
     
         48 . The device of  claim 45 , wherein the hydrophilic polymer comprises polyether block amides (PEBA), block-copolyether-esters (PEE), polylactic acid (PLA), polyurethanes (PU) including aliphatic and thermoplastic polyurethanes, polyglycolic acid (PGA) and other polyesters (PE), polycaprolactone (PCL), polyethersulfones (PES), polycarbonate (PC), or a combination thereof. 
     
     
         49 . The device of  claim 45 , wherein the fluid sample is tear fluid. 
     
     
         50 . The device of  claim 49 , wherein volume of the tear fluid is less than 20 μl. 
     
     
         51 . The device of  claim 50 , wherein the volume of the tear fluid is between about 1 μl to about 5 μl. 
     
     
         52 . A method of determining the concentration of an analyte in a fluid sample comprising:
 a. receiving said fluid in a collection chamber comprising a hydrophilic polymer;   b. transferring the liquid collected in step (a) to the sensing chamber of said device to determine the presence of said analyte in said fluid; and   c. correlating the determined presence of the analyte in said liquid with a concentration of said analyte in said liquid.   
     
     
         53 . The method of  claim 52 , wherein the fluid sample is tear fluid. 
     
     
         54 . The method of  claim 52 , wherein the receiving said fluid in the collection chamber comprises placing the tip of the collection chamber well near the eye region of a subject. 
     
     
         55 . The method of  claim 53 , wherein volume of the tear fluid is less than 20 μl. 
     
     
         56 . The method of  claim 55 , wherein the volume of the tear fluid is between about 1 μl to about 5 μl.