Integral Backstepping and Synergetic Control for Tracking of Infected Cells During Early Antiretroviral Therapy

Human Acquired Immune Deficiency Syndrome or Human Immunodeficiency Virus (HIV) Infection is a disease caused by a lentivirus known as the HIV virus. It alters the human immune system making him/her vulnerable to diseases and infections. The susceptibility worsens if the syndrome is not controlled through proper drug injection. In the literature, the researchers have proposed different control methodologies of drug injection so that the infected cells may reach the desired reference value. In this paper, nonlinear control algorithms based on the integral backstepping approach and synergetic control have been proposed to reduce steady-state error for robust tracking of infected helper T-cells to a set reference level for a deterministic model of HIV virus. The model is based on the mass balance of helper T-cells and viral load. System stability analysis has been proved with the help of a suitable Lyapunov-based theory. The viral load has been suppressed to zero. Both the numerical analysis and the simulations have been performed to validate the performance of proposed controllers. The proposed controllers have been compared with each other, with generic backstepping and backstepping embedded with sliding mode control techniques. They have been used to check the effect of efficiency of the drug on the control input. The simulations have been performed on MATLAB/Simulink.