Artificial pancreas under stable pulsatile MPC: Improving the closed-loop performance

Closed-loop MPC-based artificial pancreas: Handling circadian variability of insulin sensitivity

“…al. [12], the temporal evolution of IOB results is consistent with the fact that these two state component (associated to the meal ingestion) are uncontrollable.…”

“…Following the parameter estimation algorithm presented in Abuin et.al. [12], the model parameters for 2 insulin sensitivity labels (S j I and αS j I ) were determined. For the first one, the scenario was configured by setting the UVA/Padova simulator insulin sensitivity in its original time-invariant value and the parameter estimation algorithm initialized according to the nominal values of selected patient.…”

“…al. [12] is extended to the time-varying case (pZMPC-LTV). As in the previous work, the glucose (and state) predictions are based on a discrete-time pulsatile representation of system (1), being the control objective to drive (and maintain) the blood glucose to a safety zone given by Y T ar , while fulfilling the input and state constraints in the path.…”

“…, with p > 0, and dist A (a) representing the distance from the point a to the set A, is a stationary cost devoted to steer y a to the target equilibrium Y T ar Note that,r is the estimated meal ingest rate (or carb counting per sampling time) andx =x(k|k) is the estimated state the current time (k) by an output disturbance observer (ODO) [12]. Therefore, the optimization problem to be solved by the MPC is given by…”

“…Even though many control algorithm have been formulated for AP system, a few of them have considered explicitly diurnal variations of insulin sensitivity [7]- [9], being restricted to intra and inter-day adaptive formulations such as generalized predictive control [10] and run-to-run strategies [11]. Furthermore, in the light of authors knowledge, neither proposals have considered pulsatile insulin administration [12], which has several physiological benefits (in fact, the healthy pancreas segregates insulin in such a way), being limited to zero-order hold (ZOH) constant infusion between samples.…”