Method and system for determining analyte levels
Systems, methods, and apparatus are provided for analyte level estimation to improve accuracy thereof. Systems include sensor electronics operatively coupled to an analyte sensor configured for contact with a user's biofluid. A user interface device is configured for communication with the sensor electronics and configured to determine a predicted state estimate using exogenous measurement data and a past state estimate and, thereafter, determine a corrected state estimate, including an estimated analyte level, using the predicted state estimate and current analyte sensor measurement data.
1. A system, comprising:
an analyte sensor comprising sensor electronics operatively coupled thereto and configured to be positioned in fluid contact with biofluid under a skin surface of a user;
a user interface device configured to communicate with the sensor electronics over a wireless electrical communication link, the user interface device including a processor, wherein the processor is configured to:
receive exogenous measurement data;
receive current analyte sensor measurement data from the analyte sensor;
iteratively determine a plurality of present predicted state estimates using the exogenous measurement data and a past state estimate, wherein each subsequent present predicted state estimate is provided as input as the past state estimate;
determine a present corrected state estimate using the iteratively determined plurality of present predicted state estimates and the current analyte sensor measurement data, the present corrected state estimate including an estimated analyte level; and
a medication delivery device system configured for delivery of medication to the user based on the estimated analyte level.
2. The system off claim 1 , wherein the exogenous measurement data includes at least one of: insulin delivery information, meal intake information, or exercise information.
3. The system of claim 1 , wherein at least one of the predicted state estimate or the corrected state estimate is determined using a Kalman filter.
4. The system of claim 1 , wherein the processor is further configured to use an adjustable rate variance filter to filter the exogenous measurement data.
5. The system of claim 4 , wherein the processor is further configured to adjust the rate variance filter in response to a determined insulin delivery level.
6. The system of claim 1 , wherein the biofluid under the skin surface includes interstitial fluid.
7. The system of claim 1 , wherein the exogenous measurement data is data manually received at the user interface device.
8. The system of claim 1 , wherein the analyte level is a glucose level.
9. The system of claim 1 , wherein the processor is further configured to update a medication delivery profile based on the estimated analyte level.
10. The system of claim 9 , wherein the processor is further configured to output the updated medication delivery profile using the user interface device.
11. The system of claim 9 , wherein the processor is further configured transmit the updated medication delivery profile to the medication delivery device system.
12. The system of claim 1 , wherein the analyte sensor is a continuous analyte sensor.
13. The system of claim 1 , wherein the processor is further configured to output the estimated analyte level using the user interface device.
14. A method, comprising:
receiving, by a user interface device, exogenous measurement data;
receiving, by the user interface device, current analyte sensor measurement data from an analyte sensor, the analyte sensor configured to be positioned in fluid contact with biofluid under a skin surface of a user;
iteratively determining, by the user interface device, a plurality of predicated state estimates using the exogenous measurement data and a past state estimate, wherein each subsequent present predicted state estimate is provided as input as the past state estimate;
determining, by the user interface device, a present corrected state estimate using the iteratively determined plurality of present predicted state estimates and the current analyte sensor measurement data, the present corrected state estimate including an estimated analyte level;
delivering, using a medication delivery device system, medication to the user based on the estimated analyte level.
15. The method of claim 14 , further comprising outputting the estimated analyte level to a user interface device.
16. The method of claim 14 , wherein the exogenous measurement data includes at least one of: insulin delivery information, meal intake information, or exercise information.
17. The method of claim 14 , wherein at least one of the predicted state estimate or the corrected state estimate is determined using a Kalman filter.
18. The method of claim 14 , further comprising filtering the exogenous measurement data using an adjustable rate variance filter.
19. The method of claim 14 , wherein the exogenous measurement data is data manually received at the user interface device.
20. The method of claim 14 , further comprising updating a medication delivery profile based on the estimated analyte level.