Sliding mode control in a mathematical model to chemoimmunotherapy: The occurrence of typical singularities

The application of sliding mode control and piecewise smooth vector fields in cancer is an incipient research area. Here we propose a piecewise dynamics to explore chemoimmunotherapeutic strategies. We investigate the dynamic behavior of the discontinuous mathematical model and we observe the occurrence of typical singularities. The on-off treatment strategies are defined in terms of a time-dependent variable such as the number of cancer or immune cells. (C) 2019 Elsevier Inc. All rights reserved.