Method and apparatus for point of care osmolarity testing

Abstract

An apparatus and a method are disclosed for providing point of care testing for osmolarity of a bodily fluid. An apparatus is disclosed as having a fluid pathway passing through it for receiving and testing a sample fluid. The invention permits osmolarity testing of a sample fluid wherein the sample fluid has a volume of less than approximately 30 nL, and implements a method and device to measure fluid osmolarity in a clinical setting quickly and accurately, while also reducing evaporation of the fluid.

1 . A sample receiving chip comprising: 
 a substrate having a fluid pathway passing through the substrate for receiving a sample fluid, the fluid pathway including a first port, at least one second port, and a recessed channel, the recessed channel enclosed in the substrate; and    at least two electrodes positioned in the substrate to contact the sample fluid in the recessed channel to measure properties of the sample fluid.    
   
   
       2 . The chip of  claim 1 , wherein the substrate further comprises one of: 
 a) at least two electrode windows to provide access to the at least two electrodes; and    b) the at least two electrodes connected to contacts, the contacts positioned on an external surface of the substrate.    
   
   
       3 . The chip of  claim 1 , wherein the substrate is multilayer.  
   
   
       4 . The chip of  claim 1 , wherein the substrate is cordierite-based glass ceramic and the at least two electrodes are cosintered with copper, nickel, and glass ceramic.  
   
   
       5 . The chip of  claim 1 , wherein the sample fluid has a volume of less than approximately 30 nL.  
   
   
       6 . The chip of  claim 1 , wherein the first port funnels the sample fluid into the recessed chamber and the at least one second port vents the recessed channel.  
   
   
       7 . The chip of  claim 1 , wherein the chip is coupled to a device including a base member; a sample receiving chip fixed to the base member for receiving a sample fluid; and a conduit fixed to the base member for depositing the sample fluid on the sample receiving chip, the conduit including a first end and a second end.