APPARATUS FOR VENTILATING A PATIENT

摘要

Oxygen and pressurized air are fed to the adjustable mixing valve device (5), which allows for setting the desired oxygen content in the supply duct (6). The volume flow in the supply duct (6) is controlled using an adjustable valve device (8). The binary gatekeeper valve (10a) is controlled for intermittent supply of pressurized gas to the main inlet (12) of the venturi (11). In order to achieve decelerating flow profiles, a proportional valve (10b) is used. From the outlet (14) of the venturi (11), the inspiration gas is fed to the patient port (16). An injection duct (19) bypassing the venturi (11) is provided for intermittent injection of oxygen from the cylinder (1) to the patient port (16). The injection valve (20) allows controlled injection of oxygen during an initial phase of the inspiration phase. Through the recirculation duct (22) exhaled gas is fed to the side inlet (13) of the venturi (11) for recirculating. An absober unit (23) reduces the concentration of carbon-dioxide in the recirculated exhalation gas.