Abstract: Anesthesia or respirator apparatus is disclosed for supplying a gas stream to a patient, including a ventilator for delivering the gas stream, including an inhalation conduit and a compressible bag or bellows, with the gas stream being in contact with the inner surface of the compressible bag and with its outer surface being in contact with a propellant gas stream so that an increase in pressure in the gas stream within the compressible bag can be created by application of the propellant gas against the outer surface of the bag, and including a manual pump associated with the propellant gas stream so that increased pressure can be created in the propellant gas stream, thus resulting in application of the propellant gas stream against the outer surface of the bag, by actuation of the manual pump, and a resultant increase in the pressure in the gas stream within the bag, in turn resulting in an increased flow of the gas stream through the inhalation conduit to the patient.

Abstract: For the purpose of carrying out an MMV-treatment (Mandatory Minute Volume) by means of a lung ventilator which includes a breathing-gas source from which a patient connected to the ventilator is able to breath spontaneously through an inspiratory line, and a ventilator unit which can be activated by means of a control signal so as to deliver to the patient through the inspiratory line a mandatory breath of determinable tidal volume from the breathing-gas source, the flow of breathing gas through the inspiratory line is continuously sensed by means of a flow meter. In a control unit there is generated a signal which is representative of the continuous integral of the difference between a reference signal and the flow signal from the flow meter. The value of the integrated difference signal is compared with a given limit value. Each time the value of the integrated difference signal reaches the limit value, the ventilator unit is activated to deliver to the patient a mandatory breath of given tidal volume.