Fig. 2

Description of the experimental bench model. The figure presents the bench set-up used to evaluate the different CPAP devices in terms of FiO₂ and oxygen consumption. All devices were connected to a manikin head with realistic upper airways structures. The manikin’s trachea was connected to the ASL 5000 test lung to simulate spontaneous breathing. A pressure transducer and an oxygen sensor were used to measure the airway pressure and the inspired fraction of oxygen, respectively, and were placed in the trachea of the manikin. All signals were recorded using an analog/numeric data-acquisition system (Biopac systems)