Method and/or system for closed-loop control of glucose to a treatment range

• US 10,561,785 B2
• Filed: 06/22/2010
• Issued: 02/18/2020
• Est. Priority Date: 06/22/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Roy, Anirban, Palerm, Cesar C.
• Primary Examiner(s): Price, Nathan R
• Assistant Examiner(s): Lee, Weng
• Application Number:
  US12/820,944
• Publication Number:
  US 20110313390A1
• Time in Patent Office: 3,528 Days
• Field of Search: 604504, 3405731, 703 2, 706 52
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2205/6018 providing set-up signals for the apparatus configuration
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/158 Needles for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

Subject matter disclosed herein relates to monitoring and/or controlling blood glucose levels in patients. In particular, one or more substances may be delivered to a patient at a particular infusion rate while the patient'"'"'s estimated glucose level is within a predetermined range. A different insulin infusion rate may then be applied if the patient'"'"'s estimated blood glucose level deviates outside of the predetermined range.

Claims

1. A method comprising:

establishing a blood glucose set-point for a patient;

establishing a range about the blood glucose set-point, the range being defined, at least in part, by a first bound greater than the blood glucose set-point and a second bound less than the blood glucose set-point;

delivering insulin to the patient using an infusion device at a first insulin delivery rate while a first estimated blood glucose level of the patient at a first point in time is within the range;

determining by one or more processors that a second estimated blood glucose level of the patient at a second point in time is greater than the first bound or less than the second bound;

applying by the one or more processors a second insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the one or more processors that the second estimated blood glucose level of the patient at the second point in time is greater than the first bound or less than the second bound, the second insulin delivery rate being different from the first insulin delivery rate and the second insulin delivery rate being applied by the one or more processors based, at least in part, on the blood glucose set-point;

determining by the one or more processors that a third estimated blood glucose level of the patient at a third point in time is decreasing at a rate exceeding a threshold and that the third estimated blood glucose level is less than the first bound and greater than a third bound that is between the blood glucose set-point and the second bound; and

applying by the one or more processors a third insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the one or more processors that the third estimated blood glucose level of the patient at the third point in time is decreasing at the rate exceeding the threshold and that the third estimated blood glucose level is less than the first bound and greater than the third bound, the third insulin delivery rate being different from the first and second insulin delivery rates, and the third insulin delivery rate being applied by the one or more processors based, at least in part, on the blood glucose set-point,

wherein the first, second and third estimated blood glucose levels of the patient are based, at least in part, upon signals of a blood glucose sensor in contact with the patient.

2. The method of claim 1, wherein the range is determined based, at least in part, on a predetermined daily insulin requirement established for the patient.

3. The method of claim 1, and further comprising applying the second insulin delivery rate in response to a prediction that a fourth estimated blood glucose level of the patient at a fourth point in time is to be outside of the range.

4. The method of claim 1, wherein the second insulin delivery rate is less than the first insulin delivery rate if the second estimated blood glucose level is below the range.

5. The method of claim 4, wherein the second insulin delivery rate comprises a zero insulin infusion rate.

6. The method of claim 1, wherein the second and third insulin delivery rates are based, at least in part, on a PID algorithm.

7. The method of claim 1, and further comprising:

applying the first insulin delivery rate while a fourth estimated blood glucose level of the patient at a fourth point in time is above the range if insulin delivered to the patient over a sliding window exceeds a threshold amount.

8. The method of claim 1, wherein the blood glucose set-point is determined based, at least in part, on a reference trajectory.

9. The method of claim 1, and further comprising receiving commands from the patient to determine the first insulin delivery rate, and wherein the applying the second insulin delivery rate to the patient further comprises applying the second insulin delivery rate in an absence of at least one command received from the patient after receiving the commands to determine the first insulin delivery rate.

10. The method of claim 1, and further comprising delivering glucose to the patient while a fourth estimated blood glucose level of the patient at a fourth point in time is less than the second bound.

11. The method of claim 1, and further comprising delivering glucagon to the patient while a fourth estimated blood glucose level of the patient at a fourth point in time is less than the second bound.

12. An article for use with an infusion device containing insulin and attached to a patient, and for use with a blood glucose sensor in contact with the patient and configured to generate signals, the article comprising:

a storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to;

initiate application by the infusion device of the insulin to the patient at a first insulin delivery rate while a first estimated blood glucose level of the patient at a first point in time is within a range about a blood glucose set-point for the patient, wherein the range is defined, at least in part, by a first bound greater than the blood glucose set-point and a second bound less than the blood glucose set-point;

determine that a second estimated blood glucose level of the patient at a second point in time is greater than the first bound or less than the second bound;

initiate application of a second insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the special purpose computing apparatus that the second estimated blood glucose level of the patient at the second point in time is greater than the first bound or less than the second bound, the second insulin delivery rate being different from the first insulin delivery rate and applied by the special purpose computing apparatus based, at least in part, on the blood glucose set-point;

determine that a third estimated blood glucose level of the patient at a third point in time is decreasing at a rate exceeding a threshold and that the third estimated blood glucose level is less than the first bound and greater than a third bound that is between the blood glucose set-point and the second bound; and

initiate application of a third insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the special purpose computing apparatus that the third estimated blood glucose level of the patient at the third point in time is decreasing at the rate exceeding the threshold and that the third estimated blood glucose level is less than the first bound and greater that the third bound, wherein the third insulin delivery rate is different from the first and second insulin delivery rates and is applied by the special purpose computing apparatus based, at least in part, on the blood glucose set-point, and

wherein the first, second and third estimated blood glucose levels of the patient are based, at least in part, upon the signals of the blood glucose sensor in contact with the patient.

13. The article of claim 12, wherein the second and third insulin delivery rates are based, at least in part, on a PID algorithm.

14. The article of claim 12, wherein the instructions are further executable by the special purpose computing apparatus to initiate application by the infusion device of the second insulin delivery rate in response to a prediction that a fourth estimated blood glucose level of the patient at a fourth point in time is to be outside of the range.

15. The article of claim 12, wherein the instructions are further executable by the special purpose computing apparatus to initiate application by the infusion device of the first insulin delivery rate while a fourth estimated blood glucose level of the patient at a fourth point in time is above the range if insulin delivered to the patient over a sliding window exceeds a threshold amount.

16. An apparatus for use with an infusion device containing insulin and attached to a patient, the apparatus comprising:

a blood-glucose sensor configured to generate a sensor signal representative of a blood glucose level in the patient; and

a controller adapted to;

initiate application by the infusion device of the insulin to the patient at a first insulin delivery rate while an estimate of a first blood glucose level of the patient at a first point in time is within a range about a blood glucose set-point for the patient, the estimate of the first blood glucose level being based, at least in part, on the sensor signal, and wherein the range is defined, at least in part, by a first bound greater than the blood glucose set-point and a second bound less than the blood glucose set-point;

determine that a second estimated blood glucose level of the patient at a second point in time is greater than the first bound or less than the second bound;

initiate application of a second insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the controller that the second estimated blood glucose level of the patient at the second point in time is greater than the first bound or less than the second bound, the second insulin delivery rate being applied by the controller based, at least in part, on the blood glucose set-point, wherein the second insulin delivery rate is different from the first insulin delivery rate;

determine that a third estimated blood glucose level of the patient at a third point in time is decreasing at a rate exceeding a threshold and that the third estimated blood glucose level is less than the first bound and greater than a third bound that is between the blood glucose set-point and the second bound; and

initiate application of a third insulin delivery rate at which to deliver insulin to the patient using the infusion device in response to the determination by the controller that the third estimated blood glucose level of the patient at the third point in time is decreasing at the rate exceeding the threshold and that the third estimated blood glucose level is less than the first bound and greater that the third bound, wherein the third insulin delivery rate is different from the first and second insulin delivery rates and is applied by the controller based, at least in part, on the blood glucose set-point.

17. The apparatus of claim 16, wherein the controller is further adapted to receive commands from the patient to determine insulin delivery, and initiate application of the second insulin delivery rate to the patient in an absence of receipt of a command at the controller.