Optimal scheduling of drug treatment for HIV infection: continuous dose control and receding horizon control

Abstract: It is known that HIV (Human Immunodeficiency Virus) infection, which causes AIDS after some latent period, is a dynamic process that can be modeled mathematically. Effects of available anti-viral drugs, which prevent HIV from infecting healthy cells, can also be included in the model. In this paper we illustrate control theory can be applied to a model of HIV infec-tion. In particular, the drug dose is regarded as control input and the goal is to excite an immune response so that the symptom of infected patient should not be developed into AIDS. Finite hori-zon optimal control is employed to obtain the optimal schedule of drug dose since the model is highly nonlinear and we want maximum performance for enhancing the immune response. From the simulation studies, we found that gradual reduction of drug dose is important for the optimal-ity. We also demonstrate the obtained open-loop optimal control is vulnerable to parameter varia-tion of the model and measurement noise. To overcome this difficulty, we finally present nonlin-ear receding horizon control to incorporate feedback in the drug treatment