Control of infection dynamics, with applications to the HIV disease
Author(s)
Chang, Hyeygjeon
Type
Thesis
Abstract
The human immunodeficiency virus (HIV) infection, that causes acquired immune
deficiency syndrome (AIDS), is a dynamic process that can be modeled via differential
equations. The primary goal of this thesis is to show how to drive any initial state
into an equilibrium, called the long-term nonprogressor, in which the infected patient
does not develop symptoms of AIDS. We first propose three control methods for HIV
treatment. These methods are designed for antiretroviral drug therapy and are based on
the understanding of the system dynamics. We apply these control strategies to several
HIV dynamic models as well as a general disease dynamic model. Then we derive a
new output feedback control scheme from one of the proposed methods. To show the
feasibility of the output feedback control, the HIV model is studied analytically. This
control method guarantees that the immune state is enhanced to a certain level, which
is enough for a typical patient to be driven into the long-term nonprogressor. We also
investigate methods to estimate approximately the state of the immune system based on
the available outputs of the HIV model. The feasibility and effectiveness of the control
strategies and estimation ideas are demonstrated by computer simulations.
Key Words. HIV dynamic model, AIDS, output feedback control, drug scheduling,
biological system analysis.
deficiency syndrome (AIDS), is a dynamic process that can be modeled via differential
equations. The primary goal of this thesis is to show how to drive any initial state
into an equilibrium, called the long-term nonprogressor, in which the infected patient
does not develop symptoms of AIDS. We first propose three control methods for HIV
treatment. These methods are designed for antiretroviral drug therapy and are based on
the understanding of the system dynamics. We apply these control strategies to several
HIV dynamic models as well as a general disease dynamic model. Then we derive a
new output feedback control scheme from one of the proposed methods. To show the
feasibility of the output feedback control, the HIV model is studied analytically. This
control method guarantees that the immune state is enhanced to a certain level, which
is enough for a typical patient to be driven into the long-term nonprogressor. We also
investigate methods to estimate approximately the state of the immune system based on
the available outputs of the HIV model. The feasibility and effectiveness of the control
strategies and estimation ideas are demonstrated by computer simulations.
Key Words. HIV dynamic model, AIDS, output feedback control, drug scheduling,
biological system analysis.
Date Issued
2009-06
Date Awarded
2009-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Astolfi, Alessandro
Creator
Chang, Hyeygjeon
Publisher Department
Electrical and Electronic Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)