Non-linear controller design for controlling HIV/AIDS and improving patient’s immune system

Abstract

Human Immunodeficiency Virus (HIV) is an extremely dangerous and can lead to Acquired Immune Deficiency Syndrome, if not treated timely and effectively. It reduces the CD4 + T cells (type of white blood cells), decreasing the ability of the body to fight against viral infections. As a result, the body becomes susceptible to opportunistic infections with weaken immune system, which in severe case may leads to death of a patient. Different mathematical models have been presented in the literature to study the dynamics of HIV/AIDS. In this thesis, an updated five state model of HIV/AIDS has been considered and three non-linear controllers: Synergetic, Lyapunov Redesign and Double Integral Sliding Mode controllers have been proposed. Patient’s immune system will be improved by eliminating infected CD4+T cells, free HIV and increasing count of healthy CD4+T cells by injecting lesser amount of anti-retroviral therapy drugs governed by the proposed controllers. Healthy CD4+T cells have been tracked to reference/desired values and infected CD4+T cells & viral load has been suppressed to zero. Stability of these controllers has been ensured by using Lyapunov theory. The simulation results have been presented using Matlab/simulink environment.