Critical care simulator is an application developed in Matlab / Simulink R2014b to evaluate the ventilatory response of respiratory patients under mechanical ventilation. He is a coach of mechanical ventilation including the complex interaction between the respiratory system and a mechanical ventilator last generation. This software tool, based on physiological models to simulate the effect of different ventilation modes applied by a mechanical ventilator patients with various diseases and clinical situations, for which it has three interconnected independent models and referenced in a model of higher rank called MV-Trainer: patient, ventilator and monitor. To do this, the user has a graphical interface to intuitively: a) set the parameters associated with the patient to simulate, b) configure the control parameters selected ventilation mode c) display the simulation results. This interface facilitates the use of the simulator by the clinical staff and training, as it avoids direct user interaction with complex mathematical models underlying the tool.