| 摘要 |
A device for administering to a patient a mixture of a first gas and at least one second gas in a desired, predetermined ratio between 0 and 100%, includes a self-expanding, lung-venting bladder having an inlet through which the gases are introduced into the bladder and an outlet through which the gases are administered to a patient, and a check valve controlling the bladder inlet for preventing the gases from escaping from the bladder through the bladder inlet. The first gas is supplied to the device by a non-pressurized system, while the second gas is supplied under pressure. The bladder is adapted to expand for drawing the gases thereinto through the bladder inlet and to be compressed for discharging the gases therefrom through the bladder outlet. The device further includes a suction valve which has a housing defining a chamber; a valve outlet disposed centrally with respect to the chamber and connected to the bladder inlet for maintaining communication between the chamber and the bladder inlet. The suction valve also has a suctional intake opening positioned radially outwardly of the valve outlet and continuously communicating with the non-pressurized system; and at least one inlet nozzle supported adjacent the suctional intake opening and oriented tangentially with respect to the chamber for injecting the second gas tangentially into the chamber. The inlet nozzle is arranged for controlling, by means of the second gas, the intake of the first gas by changing the pressure drop between the suctional intake opening and the valve outlet. |
