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 should reduce the density of tumor in a minimum time with few 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 body under chemovirotherapy was selected, which included the uninfected and infected tumor cells, free viruses, immune cells, and a chemotherapeutic drug. Stability analysis was employed 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, an optimal treatment duration with limited drug dosage and virus dosage was determined. The results indicated that the discrete controller performed smoother than the continuous controller. Thus, an optimal discrete treatment schedule with optimum duration of drug and virus delivery was proposed.