Model-Based Therapeutic Correction of Hypothalamic-Pituitary-Adrenal Axis Dysfunction
Figure 3
Idealized corrective control action.
Concentrations of CRH (x1), ACTH (x2), GR (x3) and cortisol (x4) as a function of time in response to an ideal externally applied perturbation in cortisol u(t). The negative supplement in cortisol signifies a pharmaceutical removal or inactivation of circulating cortisol. ACTH concentration serves to monitor the progress of the treatment which is discontinued when ACTH increases by ∼30% over baseline.