Figure 1.

ASPIDS system. The Servo Ventilator 900C complemented by a system for Circuit Flushing (in red) and a system for aspiration of gas from the tip of the tracheal tube (in blue). During Circuit Flushing only the red valve is opening during the last third of the expiration period. During ASPIDS both red and blue valves are opening. A development suggested in the Discussion is to program the regular inspiratory flow regulating valve (Ins.) to perform Circuit Flushing without any extra tube or other hardware.