Comparison of Robust mu-Controllers for Type I Diabetes Mellitus

The paper extends on previous authors’ results related to designing robust mu-controllers for Type I Diabetes (T1D) subjects. The aim is to compare the stability and performance of a full mu controller with free structure and PD (proportional-differential)-mu controller. Both controllers are designed over the same modification of the classical Hovorka model with addition of a multiplicative uncertain element to account for unmodelled dynamics and inter-subject variability of model parameters. Comparison is presented for a 7-day simulation with UVa/Padova simulator, which is officially recognized by the Food and Drug Administration (FDA) as a benchmark for T1D artificial insulin delivery (AID) system evaluation. Additional details are presented explaining the glucose dynamics with respect to insulin injections to explain the observed frequency response of the mu-controllers. The result from the comparison clearly shows that while the full mu controller performs better, the PD-mu is also efficient with just its second order structure.