Nonlinear Controller Design for the Chemotherapy Treatment of Brain Tumor

Abstract

There are various methods for the treatment of Brain Tumor few of these are Surgery, Chemotherapy, Radiation Therapy etc. Treatment methods of Brain Tumors not only depend on the type of tumor but also on other factors like age of patient, duration of tumor, size of tumor etc. For less severe tumors i.e. Benign, sometimes applying surgery is suitable because these tumors are small in size and have definite edges. While in case of a severe tumors i.e. Malignant suggesting surgery won’t be a good option as these tumors don’t have definite boundaries and are attached very closely with other sensitive tissues of brain. Also, when the patient is a child it is suggested to go with an option other than surgery. In this research Non Linear Techniques have been applied by using Chemotherapy Treatment method on a Brain Tumor model. The main objective of the thesis is to design a controller for the therapeutic agent in order to minimize the tumor cells, maintain a safe amount of healthy cells and ensure suitable amount of drug during the therapy process. Three nonlinear controllers have been designed for this purpose; 1) Synergetic Controller 2) Backstepping Controller 3) Lyapunov Redesign. The nonlinear controllers use Lyapunov based stability theory to analyze the system’s asymptotic stability and convergence of the tumor cells to their desired reference. The simulations have been performed in Matlab / Simulink and the results show that this therapy is effective enough to reduce the tumor cells to zero while a safe amount of healthy cells has been retained using minimum amount of therapeutic agent.