Analyte sensor
Systems and methods of use for continuous analyte measurement of a host's vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host's circulatory system.
1. A method for evaluating a change in a sensitivity of an implanted analyte sensor over a predetermined time period, comprising:
receiving sensor data from an analyte sensor implanted in a host, wherein the implanted sensor is configured to generate sensor data, wherein the sensor data comprises one or more sensor analyte values measured in a biological sample of a host;
intermittently calculating a sensitivity of the analyte sensor; and
evaluating, using an electronic device, a change in sensitivity by evaluating a plurality of time-spaced sensitivity calculations over a predetermined time period, wherein evaluating a change in sensitivity is based at least in part on using a priori sensitivity information throughout a sensor session, wherein the a priori sensitivity information comprises sensitivity information that is used to generate an expected sensitivity profile that is a function of time.
2. The method of claim 1 , wherein the predetermined time period is less than or equal to about 30 minutes.
3. The method of claim 1 , wherein the predetermined time period is less than or equal to about 20 minutes.
4. The method of claim 1 , wherein the predetermined time period is less than or equal to about 10 minutes.
5. The method of claim 1 , wherein evaluating a change in sensitivity comprises evaluating at least two sensitivity measurements during the predetermined time period.
6. The method of claim 5 , further comprising averaging and/or filtering the at least two sensitivity measurements prior to evaluating the at least two sensitivity measurements.
7. The method of claim 1 , wherein evaluating a change in sensitivity comprises comparing the change in sensitivity with one or more criteria.
8. The method of claim 7 , further comprising using a most recent sensitivity calculation evaluated to calibrate the analyte sensor when the change in sensitivity meets one or more criteria.
9. The method of claim 7 , further comprising not using a most recent sensitivity calculation evaluated to calibrate the analyte sensor when the change in sensitivity does not meet one or more criteria.
10. The method of claim 1 , wherein evaluating a change in sensitivity is iteratively performed on the plurality of time-spaced sensitivity calculations over the predetermined time period.
11. The method of claim 1 , wherein the predetermined time period is at least about 30 minutes.
12. The method of claim 1 , wherein the predetermined time period is at least about 60 minutes.
13. The method of claim 1 , wherein the predetermined time period is at least about 120 minutes.
14. The method of claim 1 , wherein evaluating a change in sensitivity comprises evaluating all sensitivity calculations over a sensor session.