AUTOMATIC CLOSED-LOOP CONTROL ADJUSTMENTS AND INFUSION SYSTEMS INCORPORATING SAME

• US 20150217052A1
• Filed: 02/06/2014
• Published: 08/06/2015
• Est. Priority Date: 02/06/2014
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Keenan, Desmond Barry, Mastrototaro, John J., Grosman, Benyamin, Roy, Anirban
• Granted Patent: US 9,399,096 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3365 Rotational speed
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2205/70 with testing or calibration facilities
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• 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: G16H 20/17 delivered via infusion or injection

Abstract

Infusion systems, infusion devices, and related operating methods are provided. An exemplary method of operating an infusion device capable of delivering fluid to a user involves identifying a condition of the user that is likely to influence a response to the fluid in the body of the user and classifying the condition as a first type of a plurality of types of conditions. After classifying the condition as the first type, the method continues by adjusting control information for operating the infusion device based on the first type and operating the infusion device to deliver the fluid to the user in accordance with the adjusted control information.

Claims

1. A method of operating an infusion device capable of delivering fluid to a user, the method comprising:

identifying a condition of the user that is likely to influence a response to the fluid in a body of the user;

classifying the condition as a first type of a plurality of types of conditions; and

after classifying the condition as the first type;

adjusting control information for operating the infusion device based on the first type, resulting in adjusted control information; and

operating the infusion device to deliver the fluid to the user in accordance with the adjusted control information.

2. The method of claim 1, further comprising obtaining a heart rate measurement associated with the user, wherein identifying the condition comprises detecting the condition when the heart rate measurement is greater than a first threshold value and a variability metric associated with the heart rate measurement is less than a second threshold value.

3. The method of claim 2, further comprising obtaining an activity metric associated with the user, wherein classifying the condition comprises:

classifying the condition as exercise when the activity metric is greater than an exercise threshold value; and

classifying the condition as stress when the activity metric is less than the exercise threshold value.

4. The method of claim 3, wherein:

adjusting the control information comprises decreasing a gain coefficient in response to classifying the condition as exercise; and

operating the infusion device comprises;

determining a delivery command using the adjusted gain coefficient; and

operating the infusion device in accordance with the delivery command.

5. The method of claim 4, wherein:

adjusting the control information comprises increasing a delivery limit in response to classifying the condition as exercise; and

determining the delivery command comprises determining the delivery command using the adjusted gain coefficient in accordance with the adjusted delivery limit.

6. The method of claim 3, wherein:

adjusting the control information comprises increasing a gain coefficient in response to classifying the condition as stress; and

operating the infusion device comprises;

determining a delivery command using the adjusted gain coefficient; and

operating the infusion device in accordance with the delivery command.

7. The method of claim 6, wherein:

adjusting the control information comprises decreasing a delivery limit in response to classifying the condition as stress; and

determining the delivery command comprises determining the delivery command using the adjusted gain coefficient in accordance with the adjusted delivery limit.

8. The method of claim 1, wherein:

adjusting the control information comprises determining an adjusted value for a gain coefficient based on the first type; and

operating the infusion device comprises;

determining a delivery command using the adjusted value for the gain coefficient; and

operating the infusion device in accordance with the delivery command.

9. The method of claim 8, wherein in response to classifying the condition as exercise:

determining the adjusted value comprises;

estimating an amount of energy expenditure during the exercise;

calculating a change in glycemic level for the user based on the amount of energy expenditure;

determining an equivalent insulin amount based on the change in glycemic level; and

determining an adjusted proportional gain coefficient based on a first difference between a daily insulin requirement for the user and the equivalent insulin amount; and

determining the delivery command comprises applying the adjusted proportional gain coefficient to a second difference between a measured blood glucose and a target blood glucose.

10. The method of claim 8, wherein in response to classifying the condition as stress:

determining the adjusted value comprises;

estimating a change in glycemic level for the user based at least in part on an intensity of the stress;

determining an equivalent insulin amount based on the change in glycemic level; and

determining an adjusted proportional gain coefficient based on a first difference between a daily insulin requirement for the user and the equivalent insulin amount; and

determining the delivery command comprises applying the adjusted proportional gain coefficient to a second difference between a measured blood glucose and a target blood glucose.

11. The method of claim 1, wherein operating the infusion device comprises:

determining a difference between a measured value and a target value for a second condition of the user to be regulated;

applying the adjusted control information to the difference to produce a delivery command; and

operating a motor of the infusion device in accordance with the delivery command to deliver the fluid to the user.

12. An infusion system comprising:

a motor operable to deliver fluid to a user, delivery of the fluid influencing a first condition of the user;

a sensing arrangement to obtain a measured value indicative of the first condition of the user; and

a control system coupled to the motor and the sensing arrangement to;

identify a second condition of the user that is likely to influence a response to the fluid in a body of the user;

classify the second condition as a first type of a plurality of types of conditions; and

after classifying the second condition as the first type;

adjust control information for operating the motor based on the first type, resulting in adjusted control information; and

operate the motor to deliver the fluid to the user based at least in part on the adjusted control information and a difference between a target value for the first condition of the user and the measured value.

13. The infusion system of claim 12, further comprising a heart rate sensing arrangement to obtain heart rate measurement data for the user, wherein the control system is coupled to the heart rate sensing arrangement to detect the second condition based on the heart rate measurement data when a measured heart rate for the user is greater than a first threshold value and a heart rate variability metric for the user is less than a second threshold value.

14. The infusion system of claim 13, further comprising an acceleration sensing arrangement to obtain acceleration measurement data for the user, wherein the control system is coupled to the acceleration sensing arrangement to:

determine an activity metric for the user based on the acceleration measurement data;

classify the second condition as exercise when the activity metric is greater than an exercise threshold value; and

classify the second condition as stress when the activity metric is less than the exercise threshold value.

15. The infusion system of claim 14, wherein in response to classifying the second condition as exercise, the control system is configured to:

adjust the control information by decreasing a gain coefficient value; and

operate the motor by;

applying the gain coefficient value to the difference between the target value and the measured value to obtain a delivery command; and

operating the motor in accordance with the delivery command.

16. The infusion system of claim 14, wherein in response to classifying the second condition as stress, the control system is configured to:

adjust the control information by increasing a gain coefficient value; and

operate the motor by;

applying the gain coefficient value to the difference between the target value and the measured value to obtain a delivery command; and

operating the motor in accordance with the delivery command.

17. A method of operating an infusion device capable of delivering insulin to a user, the method comprising:

obtaining heart rate measurement data for the user;

identifying an insulin sensitivity condition based on the heart rate measurement data;

obtaining an activity metric for the user;

classifying the insulin sensitivity condition as a first type of a plurality of types of insulin sensitivity conditions based on the activity metric; and

after classifying the insulin sensitivity condition as the first type;

automatically adjusting control information for operating the infusion device based on the first type, resulting in adjusted control information;

determining one or more delivery commands for operating a motor of the infusion device in accordance with the adjusted control information; and

operating the motor to deliver the insulin to the user in accordance with the one or more delivery commands.

18. The method of claim 17, wherein identifying the insulin sensitivity condition based on the heart rate measurement data comprises identifying the insulin sensitivity condition when a heart rate associated with the user is greater than a first threshold and a heart rate variability associated with the user is less than a second threshold value.

19. The method of claim 18, wherein classifying the insulin sensitivity condition as the first type of the plurality of types of insulin sensitivity conditions comprises identifying the insulin sensitivity condition as exercise when the activity metric is greater than a third threshold value.

20. The method of claim 19, wherein classifying the insulin sensitivity condition as the first type of the plurality of types of insulin sensitivity conditions comprises identifying the insulin sensitivity condition as stress when the activity metric is less than the third threshold value.