Closed-loop method for controlling insulin infusion

• US 7,402,153 B2
• Filed: 03/31/2004
• Issued: 07/22/2008
• Est. Priority Date: 06/09/1997
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Rebrin, Kerstin, Steil, Garry M.
• Primary Examiner(s): Sirmons; Kevin C.
• Assistant Examiner(s): WITCZAK, CATHERINE
• Application Number:
  US10/816,021
• Publication Number:
  US 20040193025A1
• Time in Patent Office: 1,574 Days
• Field of Search: 604/131, 604/66, 604/890.1, 604/504, 604 65- 67, 604/891.1, 700 41- 43
• US Class Current: 604/131
• CPC Class Codes: A61B 2017/3492 against the outside of the body
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61M 2005/1581 Right-angle needle-type devices
• CPC Class Codes: A61M 2005/1587 suitable for being connected to an infusion line after insertion into a patient
• CPC Class Codes: A61M 25/0612 Devices for protecting the needle; Devices to help insertion of the needle, e.g. wings or holders
• CPC Class Codes: Y10S 439/909 Medical use or attached to human body

Abstract

A closed loop infusion system controls the rate that fluid is infused into the body of a user. The closed loop infusion system includes a sensor system, a controller, and a delivery system. The sensor system includes a sensor for monitoring a condition of the user. The sensor produces a sensor signal, which is representative of the condition of the user. The sensor signal is used to generate a controller input. The controller uses the controller input to generate commands to operate the delivery system. The delivery system infuses a liquid into the user at a rate dictated by the commands from the controller. Preferably, the sensor system monitors the glucose concentration in the body of the user, and the liquid infused by the delivery system into the body of the user includes insulin.

Claims

1. A method of infusing a fluid into a body of a user, the method comprising:

obtaining a current blood glucose concentration of the user;

generating a controller input based on the current blood glucose concentration;

generating commands by a proportional plus, integral plus, derivative (PID) controller from the controller input using at least one preset controller gain, wherein a proportional component and a derivative component of the PID controller are combined to represent a first phase insulin response, as measured from a normal glucose tolerant individual, and an integral component of the PID controller represents a second phase insulin response, as represented by the steady increase in insulin release under hyperglycemic clamp; and

infusing the fluid based on the commands from the PID controller;

wherein the PID controller accurately estimates a hypoglycemic glucose excursion.

2. The method of infusing a fluid into a body of a user in accordance with claim 1, wherein the PID controller is a bilinear PID controller.

3. A system for infusing a fluid into a body of a user, the system comprising:

means for obtaining a current blood glucose concentration of the user;

means for generating a controller input based on the current blood glucose concentration;

means for generating commands by a proportional plus, integral plus, derivative (PID) controller from the controller input using at least one preset controller gain, wherein a proportional component and a derivative component of the PID controller are combined to represent a first phase insulin response, as measured from a normal glucose tolerant individual, and an integral component of the PID controller represents a second phase insulin response, as represented by the steady increase in insulin release under hyperglycemic clamp; and

means for infusing the fluid based on the commands from the PID controller;

wherein the PID controller accurately estimates a hypoglycemic glucose excursion.

4. The system for infusing a fluid into a body of a user in accordance with claim 3, wherein the PID controller is a bilinear PID controller.