Safeguarding techniques for a closed-loop insulin infusion system
First Claim
1. A processor-implemented method of controlling an insulin infusion device having an insulin reservoir for insulin to be delivered from the insulin infusion device to a body of a user, the method comprising:
- operating a processor architecture comprising at least one processor device to obtain sensor calibration data for a continuous glucose sensor that generates a sensor variable indicative of blood glucose of the user;
identifying a most recent calibration factor from the sensor calibration data, the most recent calibration factor representing a first conversion value applicable to convert a first value of the sensor variable to a first blood glucose value;
identifying a prior calibration factor from the sensor calibration data, the prior calibration factor representing a second conversion value applicable to convert a second value of the sensor variable to a second blood glucose value, and the prior calibration factor corresponding to an earlier time relative to the most recent calibration factor;
regulating entry into a closed-loop operating mode of the insulin infusion device, based on the most recent calibration factor and the prior calibration factor; and
operating the insulin infusion device in a closed-loop mode to continuously deliver insulin from the insulin reservoir to the body of the user in accordance with the most recent calibration factor and the prior calibration factor, wherein;
regulating entry into the closed-loop operating mode comprises permitting entry into the closed-loop operating mode only when t−
tRecent≦
tR≦
t;
t is a time when attempting to enter the closed-loop operating mode;
tRecent is a predetermined time period; and
tR is a time when the most recent calibration factor was obtained.
1 Assignment
0 Petitions
Accused Products
Abstract
Processor-implemented methods of controlling an insulin infusion device for a user are provided here. A first method obtains and analyzes calibration factors (and corresponding timestamp data) for a continuous glucose sensor, and regulates entry into a closed-loop operating mode of the infusion device based on the calibration factors and timestamp data. A second method obtains a most recent sensor glucose value and a target glucose setpoint value for the user at the outset of the closed-loop mode. The second method adjusts the closed-loop insulin infusion rate over time, in response to the sensor glucose value and the setpoint value. A third method calculates an upper insulin limit that applies to the insulin infusion rate during the closed-loop mode. The insulin limit is calculated based on a fasting blood glucose value of the user, a total daily insulin value of the user, and fasting insulin delivery data for the user.
264 Citations
24 Claims
-
1. A processor-implemented method of controlling an insulin infusion device having an insulin reservoir for insulin to be delivered from the insulin infusion device to a body of a user, the method comprising:
-
operating a processor architecture comprising at least one processor device to obtain sensor calibration data for a continuous glucose sensor that generates a sensor variable indicative of blood glucose of the user; identifying a most recent calibration factor from the sensor calibration data, the most recent calibration factor representing a first conversion value applicable to convert a first value of the sensor variable to a first blood glucose value; identifying a prior calibration factor from the sensor calibration data, the prior calibration factor representing a second conversion value applicable to convert a second value of the sensor variable to a second blood glucose value, and the prior calibration factor corresponding to an earlier time relative to the most recent calibration factor; regulating entry into a closed-loop operating mode of the insulin infusion device, based on the most recent calibration factor and the prior calibration factor; and operating the insulin infusion device in a closed-loop mode to continuously deliver insulin from the insulin reservoir to the body of the user in accordance with the most recent calibration factor and the prior calibration factor, wherein; regulating entry into the closed-loop operating mode comprises permitting entry into the closed-loop operating mode only when t−
tRecent≦
tR≦
t;t is a time when attempting to enter the closed-loop operating mode; tRecent is a predetermined time period; and tR is a time when the most recent calibration factor was obtained. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A processor-implemented method of controlling an insulin infusion device having an insulin reservoir for insulin to be delivered from the insulin infusion device to a body of a user, the method comprising:
-
operating a processor architecture comprising at least one processor device to obtain sensor calibration data for a continuous glucose sensor that generates a sensor variable indicative of blood glucose of the user; identifying a most recent calibration factor from the sensor calibration data, the most recent calibration factor representing a first conversion value applicable to convert a first value of the sensor variable to a first blood glucose value; identifying a prior calibration factor from the sensor calibration data, the prior calibration factor representing a second conversion value applicable to convert a second value of the sensor variable to a second blood glucose value, and the prior calibration factor corresponding to an earlier time relative to the most recent calibration factor; regulating entry into a closed-loop operating mode of the insulin infusion device, based on the most recent calibration factor and the prior calibration factor; and operating the insulin infusion device in a closed-loop mode to continuously deliver insulin from the insulin reservoir to the body of the user in accordance with the most recent calibration factor and the prior calibration factor, wherein; regulating entry into the closed-loop operating mode comprises permitting entry into the closed-loop operating mode only when;
t−
tRecent≦
tR≦
t;
CFmin≦
CFR≦
CFmax;
CFmin≦
CFP≦
CFmax;
tR−
tDiffmax≦
tP≦
tR−
tDiffmin; anda difference between CFR and CFP is less than or equal to a threshold value; CFR is the most recent calibration factor; CFP is the prior calibration factor; CFmin is a minimum acceptable calibration factor value; CFmax is a maximum acceptable calibration factor value; t is a time when attempting to enter the closed-loop operating mode; tRecent is a predetermined time period; tR is a time when CFR was obtained; tP is a time when CFP was obtained; tDiffmax is a maximum allowable time difference; and tDiffmin is a minimum allowable time difference. - View Dependent Claims (12)
-
-
13. A processor-implemented method of controlling closed-loop delivery of insulin from an insulin reservoir of an insulin infusion device to the body of a user, the method comprising:
-
operating a processor architecture comprising at least one processor device to calculate a maximum insulin infusion rate for the user based on a fasting blood glucose value associated with the user, a total daily insulin value associated with the user, and fasting insulin delivery data that is indicative of insulin delivered to the user during a fasting period, wherein the maximum insulin infusion rate is applicable during a period of closed-loop operation of the insulin infusion device; obtaining a first closed-loop insulin infusion rate for the user, wherein the first closed-loop insulin infusion rate is obtained for a current sampling point during the period of closed-loop operation; providing a second closed-loop insulin infusion rate for the user when the obtained first closed-loop insulin infusion rate is greater than the calculated maximum insulin infusion rate, wherein the second closed-loop insulin infusion rate is less than the first closed-loop insulin infusion rate; and operating the insulin infusion device in a closed-loop mode to continuously deliver insulin from the insulin reservoir to the body of the user in accordance with either the first closed-loop insulin infusion rate or the second closed-loop insulin infusion rate. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
Specification