Closed-Loop Method for Controlling Insulin Infusion

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.

Description

RELATED APPLICATIONS[0001]This application is continuation-in-part of U.S. application Ser. No. 09 / 586,175 filed Jun. 1, 2000, entitled “Closed Loop System For Controlling Insulin Infusion,” which claims priority on U.S. Provisional Application Ser. No. 60 / 137,601 filed Jun. 3, 1999, entitled “Closed Loop Algorithms For Continuous Monitoring And Insulin Infusion,” and U.S. Provisional Application Ser. No. 60 / 162,255 filed Oct. 29, 1999 and entitled “Closed Loop Algorithms For Continuous Monitoring And Insulin Infusion,” all of which are specifically incorporated by reference herein.FIELD OF THE INVENTION[0002]This invention relates to closed loop drug delivery systems and more specifically to systems for controlling the infusion rate of insulin based on continuously monitored body glucose levels.BACKGROUND OF THE INVENTION[0003]The pancreas of a normal healthy person produces and releases insulin into the blood stream in response to elevated blood plasma glucose levels. Beta cells (...

AI Technical Summary

Benefits of technology

The patent describes a closed loop infusion system and method for controlling blood glucose concentration in a user. The system includes a sensor system that monitors the user's condition and generates commands based on the sensor signal. The system infuses a liquid into the user's body in response to the commands. The controller uses a proportional plus integral plus derivative (PID) controller to regulate the glucose concentration. The system can be predominately external or internal to the user's body. The controller uses one or more controller gains that match the insulin response of an individual with a healthy pancreas. The system can also compensate for insulin delivery delay using a post-controller lead / lag compensator or integrator clip. The system can be influenced by other measured body characteristics such as amino acid concentrations or gastrointestinal hormone concentrations. The technical effect of the invention is to provide a closed loop infusion system and method for controlling blood glucose concentration in a user with high accuracy and efficiency.

Problems solved by technology

Although offering control, pump therapy can suffer from several complications that make use of traditional external infusion pumps less desirable for the user.

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