System and method for providing closed loop infusion formulation delivery

• US 10,549,036 B2
• Filed: 09/30/2016
• Issued: 02/04/2020
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Starkweather, Timothy J., Lebel, Ronald J., Shah, Rajiv, Miller, Michael E.
• Primary Examiner(s): Gilbert, Andrew M
• Application Number:
  US15/282,731
• Publication Number:
  US 20170021100A1
• Time in Patent Office: 1,222 Days
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• 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
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A system and method for providing closed loop infusion formulation delivery which accurately calculates a delivery amount based on a sensed biological state by adjusting an algorithm'"'"'s programmable control parameters. The algorithm calculates a delivery amount having proportional, derivative, and basal rate components. The control parameters may be adjusted in real time to compensate for changes in a sensed biological state that may result from daily events. Safety limits on the delivery amount may be included in the algorithm. The algorithm may be executed by a computing element within a process controller for controlling closed loop infusion formulation delivery. The biological state is sensed by a sensing device which provides a signal to the controller. The controller calculates an infusion formulation delivery amount based on the signal and sends commands to an infusion formulation delivery device which delivers an amount of infusion formulation determined by the commands.

Claims

1. An insulin formulation delivery system, comprising:

an infusion device that delivers an amount of insulin formulation; and

a controller that receives a sensor signal representative of a sensed blood glucose level from a sensor at predefined timed intervals, determines a rate of change in the sensed blood glucose level that includes a trend term over time, and generates commands that are communicated to the infusion device including a command to enable delivery of the amount of insulin formulation in response to determining that the trend term is changing over time to reduce a risk of hypoglycemia,

wherein the controller further adjusts control parameters to compensate for changes in the sensed blood glucose level, and generates a command to enable delivery of the amount of insulin formulation based on the adjusted control parameters, wherein adjusting the control parameters further comprises adjusting a trend up gain and a trend down gain, wherein the trend down gain is adjusted such that the trend term results in a negative value high enough to substantially cut off further delivery of insulin formulation in response to determining that the trend term is falling over time.

2. The system of claim 1, wherein the controller compares the sensed blood glucose level in the sensor signal to a predefined blood glucose level set point and generates a command to enable delivery of the amount of insulin formulation in response to determining that the sensed blood glucose level is below the predefined blood glucose level set point and the trend term is not falling over time.

3. The system of claim 1, wherein the controller compares the sensed blood glucose level in the sensor signal to a predefined blood glucose level set point and generates a command to enable delivery of the amount of insulin formulation in response to determining that the sensed blood glucose level is above the predefined blood glucose level set point and the trend term is not falling over time.

4. The system of claim 1, wherein delivery of insulin formulation to a user is substantially cut off even though the sensed blood glucose level is above a predefined glucose level set point of the user.

5. The system of claim 1, wherein the control parameters further comprise at least one of a glucose set point, a basal rate, the trend term, the trend up gain or the trend down gain.

6. The system of claim 1, wherein the trend term is multiplied by one of the trend up gain or the trend down gain.

7. The system of claim 1, wherein the control parameters are programmable.

8. The system of claim 7, wherein the control parameters are programmable in real time.

9. The system of claim 1, wherein adjusting the control parameters further comprises adjusting a basal rate including selecting a basal rate value from a programmable table of basal rate values.

10. The system of claim 9, wherein the basal rate value is selected from the programmable table at timed intervals.

11. The system of claim 9, wherein the basal rate value is selected based on a user'"'"'s historical physiological data.

12. The system of claim 9, wherein the controller selects the basal rate value from the programmable table of basal rate values to calculate the amount of insulin formulation for a particular event.

13. The system of claim 12, wherein the particular event comprises a particular time of day.

14. The system of claim 12, wherein the basal rate values are based on daily events including at least one of a meal, sleep, exercise, stress inducing events, or ingested medications.

15. The system of claim 1, wherein the controller calculates an amount by which the sensed blood glucose level exceeds a predefined blood glucose level set point, determines a rate at which the sensed blood glucose level is changing, and delivers the amount of insulin formulation based on the amount which the sensed blood glucose level exceeds the predefined blood glucose level set point and the rate at which the sensed blood glucose level is changing.

16. The system of claim 15, wherein the controller causes an adjustment to be introduced into the amount of insulin formulation delivered not related to the amount which the sensed blood glucose level exceeds the predefined blood glucose level set point or the rate at which the sensed blood glucose level is changing.

17. An insulin formulation delivery system, comprising:

an infusion device that delivers an amount of insulin formulation;

a sensor that generates a sensor signal representative of a sensed blood glucose level at predefined timed intervals; and

a controller that receives a sensor signal representative of a sensed blood glucose level from a sensor at predefined timed intervals, determines a rate of change in the sensed blood glucose level that includes a trend term over time, and generates commands that are communicated to the infusion device including a command to enable delivery of the amount of insulin formulation in response to determining that the trend term is changing over time to reduce a risk of hypoglycemia,

wherein the controller further adjusts control parameters to compensate for changes in the sensed blood glucose level, and generates a command to enable delivery of the amount of insulin formulation based on the adjusted control parameters, wherein adjusting the control parameters further comprises adjusting a trend up gain and a trend down gain, wherein the trend down gain is adjusted such that the trend term results in a negative value high enough to substantially cut off further delivery of insulin formulation in response to determining that the trend term is falling over time.