Method and system for closed-loop control of an artificial pancreas

A method to control an infusion pump responsive to a controller that receives data from a glucose sensor, the method comprising:

• measuring a glucose level of a physiological fluid from a user with the glucose sensor;
• and
• automatically performing the following steps using the controller:
• receiving from the glucose sensor respective glucose level measurements for each time interval of a series of discrete time intervals;
• receiving a temporary insulin delivery profile extending over a selected time range of the time intervals;
• calculating a candidate insulin delivery amount for a selected one of the time intervals based on a model predictive controller that:
• if the selected time interval is outside the selected range,
• predicts an excursion of the glucose level from a selected target glucose range using at least some of the glucose measurements;
• computes an estimated insulin delivery amount;
• and
• adjusts the estimated insulin delivery amount to provide the candidate insulin delivery amount, the adjustment performed in accordance with the predicted excursion and a base insulin delivery profile;
• and
• if the selected time interval is in the selected range, retrieves the candidate insulin delivery amount for the selected time interval from the temporary insulin delivery profile;
• determining an approved insulin delivery amount from the candidate insulin delivery amount;
• and
• commanding the infusion pump to deliver the approved insulin delivery amount.

Apparatus for the delivery of insulin, the apparatus comprising:

• a) a glucose monitor adapted to measure respective glucose levels of a subject at discrete time intervals and provide respective glucose measurement data indicating each measured glucose level;
• b) an insulin infusion pump configured to deliver insulin in response to a delivery control signal;
• c) a memory configured to store a base insulin delivery profile;
• d) an interface adapted to selectively receive a temporary insulin delivery profile extending over a selected time range of the time intervals and to provide a first signal indicating whether the temporary insulin delivery profile was received;
• and
• e) a controller adapted to, for each of a plurality of the discrete time intervals:
• i) receive the glucose measurement data for that time interval from the glucose monitor;
• ii) determine an insulin delivery amount for that time interval using model predictive control based on a selected target glucose concentration range, the received glucose measurement data, the stored base insulin delivery profile, or, in response to the first signal and if that time interval is in the selected time range, the received temporary insulin delivery profile;
• and
• iii) provide to the insulin infusion pump a delivery control signal corresponding to the determined insulin delivery amount, whereby a corresponding amount of insulin is delivered.

Apparatus for the delivery of insulin, the apparatus comprising:

• a) a glucose monitor adapted to measure respective glucose levels of a subject at discrete time intervals and provide respective glucose measurement data indicating each measured glucose level;
• b) an insulin infusion pump configured to deliver insulin in response to a delivery control signal;
• c) a memory configured to store a base insulin delivery profile;
• d) an interface adapted to receive a temporary insulin delivery profile extending over a selected time range of the time intervals;
• and
• a controller adapted to, for each of a plurality of the discrete time intervals:
• i) receive the glucose measurement data for that time interval from the glucose monitor;
• ii) if that time interval is in the selected time range, retrieve a corresponding insulin delivery amount from the temporary insulin delivery profile, or else determine an insulin delivery amount for that time interval using model predictive control based on a selected target glucose concentration range, the received glucose measurement data, and the base insulin delivery profile;
• and
• iii) provide to the insulin infusion pump a delivery control signal corresponding to the insulin delivery amount, whereby a corresponding amount of insulin is delivered.