System and Method for Determining the Point of Hydration and Proper Time to Apply Potential to a Glucose Sensor

Abstract

According to an embodiment of the invention, a method of determining hydration of a sensor having a plurality of electrodes is disclosed. In particular embodiments, the method couples a sensor electronics device to the sensor and measures the open circuit potential between at least two of the plurality of electrodes. Then, the open circuit potential measurement is compared to a predetermined value. In some embodiments, the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode. In still further embodiments, the open circuit potential between the working electrode and the reference electrode is measured. In other embodiments, the open circuit potential between the working electrode and the counter electrode is measured. In still other embodiments, the open circuit potential between the counter electrode and the reference electrode is measured.

What is claimed is: 
     
         1 . A program code storage device, comprising:
 a machine-readable medium; and   machine-readable program code, stored on the machine-readable medium, the machine-readable program code including instructions, which when executed cause a processor for a sensor electronics device that is operably coupled to a sensor having a plurality of electrodes to:
 receive measurements of successive open circuit potential values between at least two of the plurality of electrodes; 
 calculate the rate of change of the measured open circuit potential values as the change over time between an open circuit potential value measured earlier in time and an open circuit potential value measured later in time; 
 compare the open circuit potential values and the calculated rate of change to respective predetermined thresholds; 
 determine that the sensor is ready for use if said predetermined thresholds are met; 
 repeat, over a specified period of time, the measuring, calculating, and comparing steps if said predetermined thresholds are not met; and 
 if said predetermined thresholds are not met after the specified period of time has been exceeded, determine that the sensor is not useable. 
   
     
     
         2 . The program code storage device of  claim 1 , wherein the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode. 
     
     
         3 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode. 
     
     
         4 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the working electrode and the counter electrode. 
     
     
         5 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the counter electrode and the reference electrode. 
     
     
         6 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode and between the counter electrode and the reference electrode. 
     
     
         7 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the working electrode and the counter electrode and between the counter electrode and the reference electrode. 
     
     
         8 . The program code storage device of  claim 2 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode, between the working electrode and the counter electrode, and between the counter electrode and the reference electrode. 
     
     
         9 . The program code storage device of  claim 1 , wherein said plurality of electrodes are configured to be placed percutaneously or subcutaneously at a selected site in a body of a user. 
     
     
         10 . A program code storage device, comprising:
 a machine-readable medium; and   machine-readable program code, stored on the machine-readable medium, the machine-readable program code including instructions, which when executed cause a processor of a hydration detection circuit that is operably coupled to a sensor having a plurality of electrodes to:
 receive measurements of successive open circuit potential values between at least two of the plurality of electrodes; 
 calculate the rate of change of the measured open circuit potential values as the change over time between an open circuit potential value measured earlier in time and an open circuit potential value measured later in time; 
 compare the open circuit potential values and the calculated rate of change to respective predetermined thresholds; 
 determine that the sensor is hydrated if said predetermined thresholds are met; 
 repeat, over a specified period of time, the measuring, calculating, and comparing steps if said predetermined thresholds are not met; and 
 if said predetermined thresholds are not met after the specified period of time has been exceeded, determine that the sensor will not hydrate. 
   
     
     
         11 . The program code storage device of  claim 10 , wherein the plurality of electrodes includes a working electrode, a reference electrode, and a counter electrode. 
     
     
         12 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode. 
     
     
         13 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the working electrode and the counter electrode. 
     
     
         14 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the counter electrode and the reference electrode. 
     
     
         15 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode and between the counter electrode and the reference electrode. 
     
     
         16 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the working electrode and the counter electrode and between the counter electrode and the reference electrode. 
     
     
         17 . The program code storage device of  claim 11 , wherein said measurements are for open circuit potential values between the working electrode and the reference electrode, between the working electrode and the counter electrode, and between the counter electrode and the reference electrode. 
     
     
         18 . The program code storage device of  claim 10 , wherein said plurality of electrodes are configured to be placed percutaneously or subcutaneously at a selected site in a body of a user.