Existence and global attractivity of a positive periodic solution of a delayed periodic respiration model

In this paper, we consider the following delayed periodic differential equation, which describes a ‘dynamic disease’ involving respiratory disorders. Using the method of coincidence degree, we first show the existence of a positive periodic solution. This result greatly extends the existing ones. Then, several sufficient conditions for the global attractivity of this periodic solution are established. These results are independent of each other and, in general, are much better than the existing ones