Global analysis and optimal therapy in immunogenic tumors: a nonlinear state-dependent hybrid model with a dynamic threshold policy
摘要
This paper proposes a nonlinear state-dependent hybrid model with a dynamic threshold strategy. We first introduce the concepts of impulse and phase sets, and define the Poincaré map to analyze its properties. Next, we investigate the existence and stability of boundary periodic solution and positive order-k periodic solutions. The existence of boundary periodic solutions suggests that comprehensive treatment can be administered at fixed intervals, thereby reducing the need for frequent monitoring of tumor size. Subsequently, we theoretically prove the existence and types of bifurcations, and derive the formula for calculating the maximum Lyapunov exponent to verify the presence of chaos. Finally, we perform numerical simulations to analyze the types of bifurcations using