CLOSED-LOOP GLUCOSE CONTROL STARTUP

• US 20110208155A1
• Filed: 02/19/2010
• Published: 08/25/2011
• Est. Priority Date: 02/19/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Roy, Anirban, Palerm, Cesar C.
• Granted Patent: US 8,579,879 B2
• Time in Patent Office: Days
• US Class Current: 604/503
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 40/60 for the operation of medical equipment or devices

Abstract

Disclosed are methods, systems, etc. for closed-loop glucose control startup. In certain example embodiments, a request for entry of an automatic mode of operation of a glucose monitoring and insulin delivery system for a patient may be detected. An entry of the automatic mode of operation may be controlled based, at least in part, on a detected rate of change of blood glucose concentration of the patient. In certain other example embodiments, initiation of a continual phase of an automatic mode of operation may be controlled based, at least in part, on a time since a most recent manual delivery of a bolus, on a detected rate of change of blood glucose concentration, on a targeted fixed set point, a combination thereof, and so forth.

Claims

1. A method comprising:

detecting at a controller a request for entry of an automatic mode of operation of a glucose monitoring and insulin delivery system for a patient; and

controlling said entry of said automatic mode of operation based, at least in part, on a detected rate of change of blood glucose concentration of the patient.

2. The method of claim 1, wherein said detected rate of change of blood glucose concentration is based, at least in part, on measurements from one or more glucose sensors.

3. The method of claim 1, wherein said controlling comprises:

delaying initiation of a continual phase of said automatic mode of operation at least until said detected rate of change of blood glucose concentration of the patient is less than a predetermined rate of blood glucose change.

4. The method of claim 3, wherein said delaying comprises:

delaying initiation of said continual phase of said automatic mode of operation at least until said detected rate of change of blood glucose concentration of the patient indicates that the blood glucose concentration of the patient is not increasing.

5. The method of claim 1, wherein said controlling comprises:

delaying initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin.

6. The method of claim 1, wherein said controlling comprises:

initiating a continual phase of said automatic mode of operation if a measured blood glucose concentration of the patient does not exceed a target blood glucose concentration for the patient.

7. The method of claim 1, wherein said controlling comprises:

calculating a correction bolus of insulin based, at least in part, on an insulin-on-board value and a target blood glucose concentration for the patient; and

delivering said correction bolus of insulin to the patient if an amount of said correction bolus of insulin exceeds a predetermined minimum bolus amount.

8. The method of claim 7, wherein said calculating further comprises:

calculating said correction bolus of insulin based, at least in part, on said detected rate of change of blood glucose concentration of the patient.

9. The method of claim 1, wherein said controlling comprises:

initiating a continual phase of said automatic mode of operation if said detected rate of change of blood glucose concentration of the patient does not exceed a first predetermined rate of blood glucose change.

10. The method of claim 9, wherein said controlling further comprises:

waiting a predetermined period of time if said detected rate of change of blood glucose concentration of the patient exceeds said first predetermined rate of blood glucose change; and

after expiration of said predetermined period of time, determining if a correction bolus of insulin is to be delivered based, at least in part, on an insulin-on-board value.

11. The method of claim 9, wherein said controlling further comprises:

comparing said detected rate of change of blood glucose concentration of the patient to a second predetermined rate of blood glucose change if said detected rate of change of blood glucose concentration of the patient exceeds said first predetermined rate of blood glucose change;

if said detected rate of change of blood glucose concentration of the patient exceeds said second predetermined rate of blood glucose change, waiting a first predetermined period of time;

if said detected rate of change of blood glucose concentration of the patient does not exceed said second predetermined rate of blood glucose change, waiting a second predetermined period of time; and

after expiration of said first or second predetermined period of time, determining if a measured blood glucose concentration of the patient exceeds a target blood glucose concentration for the patient.

12. The method of claim 1, wherein said controlling comprises:

establishing a reference trajectory for a set point of said automatic mode of operation;

initiating a continual phase of said automatic mode of operation; and

attempting to cause a measured blood glucose concentration of the patient to track said reference trajectory.

13. The method of claim 1, wherein said controlling comprises:

determining a time at which to exit a transitional phase of said automatic mode of operation and enter a continual phase of said automatic mode of operation.

14. The method of claim 13, further comprising:

providing insulin in accordance with a basal rate and delivering at least one bolus of insulin in accordance with measured blood glucose concentration of the patient during said transitional phase of said automatic mode of operation; and

providing insulin in accordance with said current measured blood glucose concentration of the patient during said continual phase of said automatic mode of operation.

15. The method of claim 14, wherein said at least one bolus of insulin is delivered using a relatively discrete mechanism during said transitional phase, and said insulin is provided using a relatively continual mechanism during said continual phase in accordance with a control algorithm.

16. The method of claim 1, wherein said controlling comprises:

delaying initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin; and

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after a measured blood glucose concentration of the patient is less than a target blood glucose concentration for the patient.

17. The method of claim 16, wherein said controlling further comprises:

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after said detected rate of change of blood glucose concentration of the patient becomes less than a predetermined rate of blood glucose change.

18. The method of claim 17, wherein said controlling further comprises:

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after said detected rate of change of blood glucose concentration of the patient becomes negative.

19. The method of claim 1, wherein said controlling comprises:

delivering at least one of glucose or glucagon to the patient if a measured blood glucose concentration of the patient is less than a threshold glucose concentration level.

20. An apparatus comprising:

a controller to receive one or more signals based on glucose sensor measurements, said controller comprising one or more processors to;

detect a request for entry of an automatic mode of operation of a glucose monitoring and insulin delivery system for a patient; and

control said entry of said automatic mode of operation based, at least in part, on a detected rate of change of blood glucose concentration of the patient.

21. The apparatus of claim 20, further comprising:

one or more glucose sensors adapted to be coupled to a patient to obtain glucose sensor measurements and adapted to provide said one or more signals based on said glucose sensor measurements,

wherein said detected rate of change of blood glucose concentration is based, at least in part, on measurements obtained from said one or more glucose sensors.

22. The apparatus of claim 20, wherein said controller is capable of controlling said entry by delaying initiation of a continual phase of said automatic mode of operation at least until said detected rate of change of blood glucose concentration of the patient is less than a predetermined rate of blood glucose change.

23. The apparatus of claim 22, wherein said controller is capable of controlling said entry by delaying initiation of said continual phase of said automatic mode of operation at least until said detected rate of change of blood glucose concentration of the patient indicates that the blood glucose concentration of the patient is not increasing.

24. The apparatus of claim 20, wherein said controller is capable of controlling said entry by delaying initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin.

25. The apparatus of claim 20, wherein said controller is capable of controlling said entry by initiating a continual phase of said automatic mode of operation if a measured blood glucose concentration of the patient does not exceed a target blood glucose concentration for the patient.

26. The apparatus of claim 20, wherein said controller is capable of controlling said entry by:

calculating a correction bolus of insulin based, at least in part, on an insulin-on-board value and a target blood glucose concentration for the patient; and

delivering said correction bolus of insulin to the patient if an amount of said correction bolus of insulin exceeds a predetermined minimum bolus amount.

27. The apparatus of claim 26, wherein said controller is capable of calculating said correction bolus of insulin by calculating said correction bolus of insulin based, at least in part, on said detected rate of change of blood glucose concentration of the patient.

28. The apparatus of claim 20, wherein said controller is capable of controlling said entry by initiating a continual phase of said automatic mode of operation if said detected rate of change of blood glucose concentration of the patient does not exceed a first predetermined rate of blood glucose change.

29. The apparatus of claim 28, wherein said controller is further capable of controlling said entry by:

waiting a predetermined period of time if said detected rate of change of blood glucose concentration of the patient exceeds said first predetermined rate of blood glucose change; and

after expiration of said predetermined period of time, determining if a correction bolus of insulin is to be delivered based, at least in part, on an insulin-on-board value.

30. The apparatus of claim 28, wherein said controller is further capable of controlling said entry by:

comparing said detected rate of change of blood glucose concentration of the patient to a second predetermined rate of blood glucose change if said detected rate of change of blood glucose concentration of the patient exceeds said first predetermined rate of blood glucose change;

if said detected rate of change of blood glucose concentration of the patient exceeds said second predetermined rate of blood glucose change, waiting a first predetermined period of time;

if said detected rate of change of blood glucose concentration of the patient does not exceed said second predetermined rate of blood glucose change, waiting a second predetermined period of time; and

after expiration of said first or second predetermined period of time, determining if a measured blood glucose concentration of the patient exceeds a target blood glucose concentration for the patient.

31. The apparatus of claim 20, wherein said controller is capable of controlling said entry by:

establishing a reference trajectory for a set point of said automatic mode of operation;

initiating a continual phase of said automatic mode of operation; and

attempting to cause a measured blood glucose concentration of the patient to track said reference trajectory.

32. The apparatus of claim 20, wherein said controller is capable of controlling said entry by determining a time at which to exit a transitional phase of said automatic mode of operation and enter a continual phase of said automatic mode of operation.

33. The apparatus of claim 32, wherein said one or more processors of said controller are further to:

provide insulin in accordance with a basal rate and deliver at least one bolus of insulin in accordance with measured blood glucose concentration of the patient during said transitional phase of said automatic mode of operation; and

provide insulin in accordance with said current measured blood glucose concentration of the patient during said continual phase of said automatic mode of operation.

34. The apparatus of claim 33, wherein said at least one bolus of insulin is delivered using a relatively discrete mechanism during said transitional phase, and said insulin is provided using a relatively continual mechanism during said continual phase in accordance with a control algorithm.

35. The apparatus of claim 20, wherein said controller is capable of controlling said entry by:

delaying initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin; and

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after a measured blood glucose concentration of the patient is less than a target blood glucose concentration for the patient.

36. The apparatus of claim 35, wherein said controller is capable of controlling said entry by:

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after said detected rate of change of blood glucose concentration of the patient becomes less than a predetermined rate of blood glucose change.

37. The apparatus of claim 36, wherein said controller is capable of controlling said entry by:

after at least said predetermined length of time has elapsed, initiating said continual phase of said automatic mode of operation after said detected rate of change of blood glucose concentration of the patient becomes negative.

38. The apparatus of claim 20, wherein said one or more processors of said controller are further to:

selectively delay initiation of a continual phase of said automatic mode of operation based on a length of time that has elapsed since a most-recent manual delivery of a bolus of insulin; and

selectively delay initiation of said continual phase of said automatic mode of operation while a measured blood glucose concentration of the patient is increasing as determined from said detected rate of change of blood glucose concentration of the patient.

39. The apparatus of claim 20, wherein said controller is capable of controlling said entry by delivering at least one of glucose or glucagon to the patient if a measured blood glucose concentration of the patient is less than a threshold glucose concentration level.

40. An apparatus comprising:

means for detecting at a controller a request for entry of an automatic mode of operation of a glucose monitoring and insulin delivery system for a patient; and

means for controlling said entry of said automatic mode of operation based, at least in part, on a detected rate of change of blood glucose concentration of the patient.

41. The apparatus of claim 40, wherein said means for controlling comprises:

means for delaying initiation of a continual phase of said automatic mode of operation at least until said detected rate of change of blood glucose concentration of the patient is less than a predetermined rate of blood glucose change.

42. The apparatus of claim 40, wherein said means for controlling comprises:

means for delaying initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin.

43. The apparatus of claim 40, wherein said means for controlling comprises:

means for initiating a continual phase of said automatic mode of operation if a measured blood glucose concentration of the patient does not exceed a target blood glucose concentration for the patient.

44. The apparatus of claim 40, wherein said means for controlling comprises:

means for initiating a continual phase of said automatic mode of operation if said detected rate of change of blood glucose concentration of the patient does not exceed a first predetermined rate of blood glucose change.

45. The apparatus of claim 40, wherein said means for controlling comprises:

means for establishing a reference trajectory for a set point of said automatic mode of operation;

means for initiating a continual phase of said automatic mode of operation; and

means for attempting to cause a measured blood glucose concentration of the patient to track said reference trajectory.

46. An article comprising:

at least one storage medium having stored thereon instructions executable by one or more processors to;

detect at a controller a request for entry of an automatic mode of operation of a glucose monitoring and insulin delivery system for a patient; and

control said entry of said automatic mode of operation based, at least in part, on a detected rate of change of blood glucose concentration of the patient.

47. The article of claim 46, wherein to control said entry of said automatic mode of operation said at least one storage medium has stored thereon further instructions executable by one or more processors to:

determine a time at which to exit a transitional phase of said automatic mode of operation and enter a continual phase of said automatic mode of operation.

48. The article of claim 47, wherein said at least one storage medium has stored thereon further instructions executable by one or more processors to:

provide insulin in accordance with a basal rate and deliver at least one bolus of insulin in accordance with measured blood glucose concentration of the patient during said transitional phase of said automatic mode of operation; and

provide insulin in accordance with said current measured blood glucose concentration of the patient during said continual phase of said automatic mode of operation.

49. The article of claim 48, wherein said at least one bolus of insulin is delivered using a relatively discrete mechanism during said transitional phase, and said insulin is provided using a relatively continual mechanism during said continual phase in accordance with a control algorithm.

50. The article of claim 46, wherein to control said entry of said automatic mode of operation said at least one storage medium has stored thereon further instructions executable by one or more processors to:

delay initiation of a continual phase of said automatic mode of operation until at least a predetermined length of time has elapsed since a most-recent manual delivery of a bolus of insulin; and

after at least said predetermined length of time has elapsed, initiate said continual phase of said automatic mode of operation after a measured blood glucose concentration of the patient is less than a target blood glucose concentration for the patient.

51. The article of claim 50, wherein to control said entry of said automatic mode of operation said at least one storage medium has stored thereon further instructions executable by one or more processors to:

after at least said predetermined length of time has elapsed, initiate said continual phase of said automatic mode of operation after said detected rate of change of blood glucose concentration of the patient becomes less than a predetermined rate of blood glucose change.