A dual-hormone multicontroller for artificial pancreas systems

FUSHIMI, EMILIA; DE BATTISTA, HERNÁN; GARELLI, FABRICIO

IEEE journal of biomedical and health informaticsl

IEEE

Año: 2022

Artificial pancreas (AP) algorithms can be divided into single-hormone and dual-hormone (DH). Single-hormone algorithms regulate glycemia using insulin as their control input. On the other hand, dual-hormone algorithms also use glucagon to counteract insulin. While single-hormone AP systems are already commercially available, dual-hormone AP systems are still in an earlier research phase. DH-AP systems have been questioned since the added complexity of glucagon infusion does not always guarantee hypoglycemia prevention and might significantly raise insulin delivery. In this work, a dual-hormone multicontroller is proposed based on a single-hormone LQG algorithm with an additional LQG controller to deliver glucagon. This strategy has a switched structure that allows activating one of the following three controllers when necessary: a conservative insulin LQG controller to modulate basal delivery ($K_1$), an aggressive insulin LQG controller to counteract meals ($K_2$), or a glucagon LQG controller to avoid imminent hypoglycemia ($K_3$). Here, an extit{in silico} study of the benefits of incorporating controller $K_3$ and the conditions under which it should be active is carried out. Intra-patient variability and mixed meals are considered. Results indicate that the proposed switched, dual-hormone strategy yields to a reduction in hypoglycemia without increasing hyperglycemia, with no significant raise insulin delivery.