Figure 1.

A simulation of typical solutions of the non-sliding piecewise system (5) for Case 1 with C_T = 400. The initial conditions and parameter values are given in Table 1 with η_RT = η_{P I} = 0.6. (A) Total CD4⁺ T cell population; (B) Expanded view of late stage of (A); (C) Durations of drug-on (square) and drug-off (circle) for each drug-on/off switch; (D) Phase plane plot of healthy CD4⁺ T cell and infected CD4⁺ T cell populations.