Variable rate closed loop control and methods

• US 8,622,988 B2
• Filed: 08/31/2008
• Issued: 01/07/2014
• Est. Priority Date: 08/31/2008
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Hayter, Gary
• Primary Examiner(s): Lucchesi, Nicholas
• Assistant Examiner(s): Zhang, Jenna
• Application Number:
  US12/202,306
• Publication Number:
  US 20100056992A1
• Time in Patent Office: 1,955 Days
• Field of Search: 604/65, 604/66, 604/503, 604/504, 604/131
• US Class Current: 604/503
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61M 5/50 having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile retractable needles or needle protectors with means for preventing re-use A61M5/321
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 20/60 relating to nutrition control, e.g. diets
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

Methods, system and devices for monitoring a closed loop control operation including signal levels received from an analyte sensor at a predetermined frequency, determining a variation in the monitored analyte level, determining a medication delivery rate adjustment frequency to deliver a medication based on the determined variation in the monitored analyte level, and adjusting the closed loop control operation to modify the medication delivery rate frequency are provided.

Claims

1. A method, comprising:

determining periodically at a first medication delivery rate adjustment frequency whether to adjust a medication delivery rate;

monitoring a closed loop control operation including an analyte level associated with signal levels received from an analyte sensor at a predetermined frequency;

determining a variation in the monitored analyte level;

modifying the first medication delivery rate adjustment frequency to a second medication delivery rate adjustment frequency based on the determined variation in the monitored analyte level; and

determining periodically at the second medication delivery rate adjustment frequency whether to adjust the medication delivery rate;

wherein the modification to the first medication delivery rate adjustment frequency is performed dynamically based in part on the determined variation in the monitored analyte level.

2. The method of claim 1 wherein the predetermined frequency associated with the monitored signal levels received from the analyte sensor is greater than both the first medication delivery rate adjustment frequency and the second medication delivery rate adjustment frequency.

3. The method of claim 1 wherein the analyte sensor includes a glucose sensor.

4. The method of claim 1 wherein the modification to the first medication delivery rate adjustment frequency is based on one or more of an anticipated carbohydrate intake, an anticipated exercise event, or an anticipated change in a physiological condition.

5. The method of claim 1 wherein the modification to the first medication delivery rate adjustment frequency is performed to minimize power consumption level associated with medication delivery.

6. The method of claim 1 wherein the medication includes one or more of insulin or glucagon.

7. The method of claim 1 wherein the variation in the monitored analyte level is associated with a carbohydrate intake event.

8. The method of claim 1 wherein the modification of the first medication delivery rate adjustment frequency to the second medication delivery rate adjustment frequency is based on a rate of change of the monitored analyte level.

9. The method of claim 1 wherein the second medication delivery rate adjustment frequency corresponds to the predetermined frequency when the variation in the monitored analyte level exceeds a predetermined threshold.

10. The method of claim 1 wherein the modification of the first medication delivery rate adjustment frequency to the second medication delivery rate adjustment frequency is based on the monitored analyte level.

11. The method of claim 1 wherein when the determined variation in the monitored analyte level is within a threshold level, the medication delivery rate is not adjusted at the first medication delivery rate adjustment frequency such that the second medication delivery rate adjustment frequency is the same as the first medication delivery rate adjustment frequency.

12. The method of claim 1 wherein the analyte sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises an analyte-responsive enzyme and a mediator, wherein at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.

13. A device, comprising:

one or more processors; and

a memory operatively coupled to the one or more processors, the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to determine periodically at a first medication delivery rate adjustment frequency whether to adjust a medication delivery rate, monitor a closed loop control operation including an analyte level associated with signal levels received from an analyte sensor at a predetermined frequency, determine a variation in the monitored analyte level, modify the first medication delivery rate adjustment frequency to a second medication delivery rate adjustment frequency based on the determined variation in the monitored analyte level, and determine periodically at the second medication delivery rate adjustment frequency whether to adjust the medication delivery rate, wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to dynamically perform the modification to the first medication delivery rate adjustment frequency based in part on the determined variation in the monitored analyte level.

14. The device of claim 13 wherein the predetermined frequency associated with the monitored signal levels received from the analyte sensor is greater than both the first medication delivery rate adjustment frequency and the second medication delivery rate adjustment frequency.

15. The device of claim 13 wherein the analyte sensor includes a glucose sensor.

16. The device of claim 13 wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to modify the first medication delivery rate adjustment frequency based on one or more of an anticipated carbohydrate intake, an anticipated exercise event, or an anticipated change in a physiological condition.

17. The device of claim 13 wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to modify the first medication delivery rate adjustment frequency to minimize power consumption level associated with medication delivery.

18. The device of claim 13 wherein the medication includes one or more of insulin or glucagon.

19. The device of claim 13 wherein the variation in the monitored analyte level is associated with a carbohydrate intake event.

20. The device of claim 13 wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to transmit the second medication delivery rate adjustment frequency to a medication delivery unit.

21. The device of claim 20 wherein the medication delivery unit includes an insulin pump.

22. The device of claim 20 wherein the second medication delivery rate adjustment frequency is transmitted wirelessly to the medication delivery unit.

23. The device of claim 13 further including a strip port to receive a blood glucose test strip including a blood sample, wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to determine a blood glucose value based on the blood sample.

24. The device of claim 13 wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to modify the first medication delivery rate adjustment frequency to the second medication delivery rate adjustment frequency based on a rate of change of the monitored analyte level.

25. The device of claim 13 wherein the second medication delivery rate adjustment frequency corresponds to the predetermined frequency when the variation in the monitored analyte level exceeds a predetermined threshold.

26. The device of claim 13 wherein the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to associate the second medication delivery rate adjustment frequency with the monitored analyte level and adjust the first medication delivery rate adjustment frequency to the second medication delivery rate adjustment frequency when the monitored analyte level is detected.

27. The device of claim 13 wherein when the determined variation in the monitored analyte level is within a threshold level, the memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to not adjust the medication delivery rate at the first medication delivery rate adjustment frequency such that the second medication delivery rate adjustment frequency is the same as the first medication delivery rate adjustment frequency.

28. The device of claim 13 wherein the analyte sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises an analyte-responsive enzyme and a mediator, wherein at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.