Performance of a linear controller in the nonlinear model of drug and virus delivery in cancer chemovirotherapy: A comparison between continuous and discrete approaches

Best cancer treatment is the one which reduces the tumor’s density in minimum time with less side effects, considering the input limitations. In this paper, a tracking controller was designed to achieve the mentioned objectives, simultaneously. An ordinary differential equations (ODEs)-based mathematical model of a human’s body under chemovirotherapy was selected, which includes the uninfected and infected tumor cells, free viruses, immune cells, and a chemotherapeutic drug. Stability analysis was used to determine the sensible equilibrium points. For tracking purposes, a servo controller based on the entire eigenstructure assignment (EESA) approach was applied to the model, continuously and discretely. By regulating the command input properties, optimal treatment duration with limited drug dosage and virus dosage was determined. The results indicate that the discrete controller performs smoother than the continuous controller. In the discrete controller, optimum time interval for the injection of drugs and viruses was determined to propose an optimal treatment schedule.