Figure legends
Figure 1 Experimental apparatus of the connection test lung model
The designed spontaneous breathing lung model essentially contains two TTL, an airway management trainer and a ventilator. The driving bellows (A) with a lifting bar (coupling clip) in the site is connected to a LTV1200. The ventilation bellow (B) is connected to the tracheal of an airway management trainer through a set of a Y piece (Y1) adaptor and V1 and V2, which bring together through Y2). The expiratory gas modification bellow(C) is connected to the bellow B through a rigid metal strip and is connected to Y1 through V3 and V4. The open end of the main bronchus, which the carina position was to join together through the Y piece (Y3), and oxygen analyzer is connected between the Y1 and Y3. When the driving ventilator enlarges the bellow A of the TTL, which results in negative pressure within the bellow B and bellow C, and inspiration flow into the bellow B and C through the V1 and V4, respectively, and airway trainer, just like spontaneous breathing. During the expiration phase, the bellows B and bellow C passively deflates the gas outside through V2 and V3, respectively. The gas from bellow C through V3 was used to wash out the previous gas in the anatomic dead space in the airway trainer. An oxygen analyzer is position near the carina to monitor the FO2 insp. and FO2 pre-insp. of gas during the inspiratory and expiratory phases, respectively. The airway trainer is equipped with nasal cannula.
Figure 2 Simulated spontaneous breathing lung model and nasal cannula setting. VT: tidal volume, f: respiratory rate, TI: inspiratory time.
Figure 3 The friction of oxygen waveform during respiratory cycle. FO2 insp.: peak inspired oxygen concentration, FO2 pre-insp.: end-expired oxygen concentration.
Figure 4 Effect of VT on muscle pressure
Figure 5 Effect of VT on FO2insp. during the same f
Figure 6 Effect of tidal volume on FO2pre-insp. during the same f