Blood glucose validation for a closed-loop operating mode of an insulin infusion system

Patent metadata

Field	Value
Publication number	US-2016162662-A1
Application number	US-201514731356-A
Country	US
Kind code	A1
Filing date	Jun 4, 2015
Priority date	Aug 30, 2012
Publication date	Jun 9, 2016
Grant date	—

Abstract

A method of controlling an insulin infusion device is presented here. The method can be implemented in a suitably configured electronic device, on an electronic storage medium, or the like. In accordance with certain embodiments, the method evaluates the operational integrity of a glucose sensor that measures sensor glucose values for a user of the insulin infusion device, and calculates a sensor integrity metric based on the evaluation. The calculated sensor integrity metric is used to adjust the aggressiveness of a closed-loop therapy algorithm that is used to control a closed-loop operating mode of the insulin infusion device. The insulin infusion device is operated in the closed-loop operating mode in accordance with the adjusted therapy setting.

First claim

What is claimed is:

1 . A method of controlling an insulin infusion device, the method comprising:
evaluating operational integrity of a glucose sensor that measures sensor glucose values for a user of the insulin infusion device; calculating a sensor integrity metric based on the evaluating; adjusting, in response to the calculated sensor integrity metric, aggressiveness of a closed-loop therapy algorithm used for controlling a closed-loop operating mode of the insulin infusion device, resulting in an adjusted therapy setting; and operating the insulin infusion device in the closed-loop operating mode in accordance with the adjusted therapy setting.

2 . The method of claim 1 , wherein evaluating operational integrity of the glucose sensor comprises:
obtaining a meter blood glucose value from a blood glucose meter, the meter blood glucose value having a measurement time associated therewith; obtaining a sensor glucose value from the glucose sensor, the sensor glucose value having the measurement time associated therewith; and comparing the obtained meter blood glucose value to the obtained sensor glucose value, wherein the sensor integrity metric is calculated based on a result of the comparing.

3 . The method of claim 1 , wherein:
evaluating operational integrity of the glucose sensor comprises obtaining electrical measurements corresponding to one or more operating parameters of the glucose sensor; and the sensor integrity metric is calculated based on the obtained electrical measurements.

4 . The method of claim 1 , wherein the adjusting adjusts the aggressiveness of the closed-loop therapy algorithm as a function of the calculated sensor integrity metric.

5 . The method of claim 4 , wherein the adjusting adjusts the aggressiveness of the closed-loop therapy algorithm such that the aggressiveness is proportional to the calculated sensor integrity metric.

6 . The method of claim 1 , wherein:
the closed-loop therapy algorithm utilizes a maximum insulin infusion rate variable (Umax) expressed in Units/hour; and the adjusting adjusts Umax as a function of the calculated sensor integrity metric.

7 . The method of claim 1 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having a proportional component, an integral component, and a derivative component; the integral component has a maximum value (Imax) expressed in Units/hour; and the adjusting adjusts Imax as a function of the calculated sensor integrity metric.

8 . The method of claim 1 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having an error gain variable; and the adjusting adjusts the error gain variable as a function of the calculated sensor integrity metric.

9 . The method of claim 1 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having a derivative gain variable; and the adjusting adjusts the derivative gain variable as a function of the calculated sensor integrity metric.

10 . The method of claim 1 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having an integral gain variable; and the adjusting adjusts the integral gain variable as a function of the calculated sensor integrity metric.

11 . The method of claim 1 , further comprising:
maintaining, at the insulin infusion device, a plurality of different user-specific closed-loop insulin delivery profiles for the user; and selecting one of the plurality of different user-specific closed-loop insulin delivery profiles to obtain a selected profile, wherein the selecting is based on the calculated sensor integrity metric; wherein the adjusting adjusts the aggressiveness of the closed-loop therapy algorithm in accordance with the selected profile.

12 . An electronic device comprising:
a processor architecture comprising at least one processor device; and at least one memory element associated with the processor architecture, the at least one memory element storing processor-executable instructions that, when executed by the processor architecture, perform a method of controlling an insulin infusion device for a user, the method comprising:
evaluating operational integrity of a glucose sensor that measures sensor glucose values for the user;
calculating a sensor integrity metric based on the evaluating;
adjusting, in response to the calculated sensor integrity metric, aggressiveness of a closed-loop therapy algorithm used for controlling a closed-loop operating mode of the insulin infusion device, resulting in an adjusted therapy setting; and
operating the insulin infusion device in the closed-loop operating mode in accordance with the adjusted therapy setting.

13 . The electronic device of claim 12 , wherein:
the electronic device comprises a monitor device for the insulin infusion device; and the monitor device and the insulin infusion device are physically distinct hardware devices.

14 . The electronic device of claim 12 , wherein the electronic device comprises the insulin infusion device.

15 . The electronic device of claim 12 , wherein the adjusting adjusts the aggressiveness of the closed-loop therapy algorithm as a function of the calculated sensor integrity metric, and such that the aggressiveness is proportional to the calculated sensor integrity metric.

16 . The electronic device of claim 12 , wherein:
the closed-loop therapy algorithm utilizes a maximum insulin infusion rate variable (Umax) expressed in Units/hour; and the adjusting adjusts Umax as a function of the calculated sensor integrity metric.

17 . The electronic device of claim 12 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having a proportional component, an integral component, and a derivative component; the integral component has a maximum value (Imax) expressed in Units/hour; and the adjusting adjusts Imax as a function of the calculated sensor integrity metric.

18 . The electronic device of claim 12 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having an error gain variable; and the adjusting adjusts the error gain variable as a function of the calculated sensor integrity metric.

19 . The electronic device of claim 12 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having a derivative gain variable; and the adjusting adjusts the derivative gain variable as a function of the calculated sensor integrity metric.

20 . The electronic device of claim 12 , wherein:
the closed-loop therapy algorithm utilizes a proportional-integral-derivative insulin feedback (PID-IFB) control algorithm having an integral gain variable; and the adjusting adjusts the integral gain variable as a function of the calculated sensor integrity metric.

21 . A tangible and non-transitory electronic storage medium having processor-executable instructions that, when executed by a processor architecture comprising at least one processor device, perform a method of controlling an insulin infusion device for a user, the method comprising:
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Assignees

• Medtronic Minimed Inc

Inventors

• Monirabbasi Salman
• Grosman Benyamin

Classifications

• A61M2205/50

  with microprocessors or computers · CPC title

• A61M2230/005

  Parameter used as control input for the apparatus · CPC title

• G16H40/40

  for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades · CPC title

• G16H20/17

  delivered via infusion or injection · CPC title

• A61B5/4839

  combined with drug delivery · CPC title