Method and Device for Determining Elapsed Sensor Life

Abstract

Methods and systems for determining elapsed sensor life in medical systems, and more specifically continuous analyte monitoring systems.

What is claimed is: 
     
         1 . A system, comprising:
 an analyte sensor to measure an analyte level;   a receiving device; and   sensor electronics communicatively coupled to the analyte sensor and the receiving device, the sensor electronics configured to:
 store a first count; 
 periodically increment the first count; 
 detect a fault condition associated with a system failure; and 
 when the fault condition is detected, store a second count associated with a time of re-initiation of the analyte sensor. 
   
     
     
         2 . The system of  claim 1 , wherein the fault condition comprises a condition in which one of the analyte sensor, receiving device or sensor electronics loses power. 
     
     
         3 . The system of  claim 2 , wherein the condition in which one of the analyte sensor, receiving device or sensor electronics loses power comprises a reset, battery replacement, power loss, power shut-down, or fatal error. 
     
     
         4 . The system of  claim 1 , wherein the receiving device is configured to receive the first count and the second count from the sensor electronics, and to compare the first count and the second count to determine a duration of use of the analyte sensor prior to the fault condition, and to determine a remaining sensor life expectancy based on the duration of use of the analyte sensor prior to the fault condition. 
     
     
         5 . The system of  claim 4 , wherein the receiving device is further configured determine that the remaining sensor life expectancy is less than a predetermined amount, and in response to notify a user that the analyte sensor is soon to expire. 
     
     
         6 . The system of  claim 4 , wherein the receiving device is further configured to restart a sensor life timer based on the duration of use. 
     
     
         7 . The system of  claim 1 , wherein the first count is periodically incremented according to a measurement cycle. 
     
     
         8 . The system of  claim 1 , wherein the analyte sensor comprises a plurality of electrodes including a working electrode comprising an analyte-responsive enzyme bonded to a polymer disposed on the working electrode. 
     
     
         9 . The system of  claim 8 , wherein the analyte-responsive enzyme is chemically bonded to the polymer. 
     
     
         10 . The system of  claim 8 , wherein the working electrode further comprises a mediator. 
     
     
         11 . The system of  claim 1 , wherein the analyte sensor comprises a plurality of electrodes including a working electrode comprising a mediator bonded to a polymer disposed on the working electrode. 
     
     
         12 . The system of  claim 11 , wherein the mediator is chemically bonded to the polymer. 
     
     
         13 . A method, comprising:
 providing an analyte sensor to measure an analyte level;   providing sensor electronics communicatively coupled to the analyte sensor and a receiving device;   storing a first count;   periodically incrementing the first count;   detecting a fault condition associated with a system failure; and   when the fault condition is detected, storing a second count associated with a time of re-initiation of the analyte sensor.   
     
     
         14 . The method of  claim 13 , wherein the fault condition comprises a condition in which one of the analyte sensor, receiving device or sensor electronics loses power. 
     
     
         15 . The method of  claim 14 , wherein the condition in which one of the analyte sensor, receiving device or sensor electronics loses power comprises a reset, battery replacement, power loss, power shut-down, or fatal error. 
     
     
         16 . The method of  claim 13 , wherein the analyte sensor comprises a plurality of electrodes including a working electrode comprising an analyte-responsive enzyme bonded to a polymer disposed on the working electrode. 
     
     
         17 . The method of  claim 16 , wherein the analyte-responsive enzyme is chemically bonded to the polymer. 
     
     
         18 . The method of  claim 16 , wherein the working electrode further comprises a mediator. 
     
     
         19 . The method of  claim 13 , wherein the analyte sensor comprises a plurality of electrodes including a working electrode comprising a mediator bonded to a polymer disposed on the working electrode. 
     
     
         20 . The method of  claim 19 , wherein the mediator is chemically bonded to the polymer.