FIGURE 5.
a) Experimental system to carry out a bench test of noninvasive ventilators. V′: flow into the lung chamber; V′c: flow delivered by the ventilator; Paw: airway pressure. Reproduced from [36] with permission from the publisher. b) Commercially available lung simulators to test mechanical ventilators (www.ersbuyersguide.org/features/category/lung-simulation). Some patient simulators for ventilation are passive (resistance–compliance systems) and some of them are computerised patient models allowing to easily simulate lung resistance and compliance and to activate inspiratory pressures simulating the patient's muscles activity.