Abstract: A humidifier for respirators includes a vessel having a tubular passage therethrough which is connected at one end to the inhalation line and the opposite end to the line leading to the patient. Water is circulated from a storage tank to a water chamber defined around the tubular member and the tubular member is made of a material which defines an evaporation surface which is impervious to water but pervious to water vapor so that the inhalation air becomes moistened when it is passed through the tubular member. The water which is circulated is circulated from a storage tank which is maintained at a predetermined level by the gravity of feed of water from a closed container which is mounted above the storage tank. The water in the storage tank is advantageously heated before it is circulated.

Abstract: A humidity exchanger in an apparatus for respiration and anasthesia comprises an inhalation air conduit which is juxtaposed to an exhalation air conduit and separated therefrom by a diffusion foil which permits the passage of a vapor therethrough but not a liquid. Both the inhalation and exhalation conduits are connected at their one ends to the respirator and at their opposite ends they are connected together and to a mouthpiece for use by the patient. The temperatures in both conduits adjacent the mouthpiece are maintained at temperatures so that there is a temperature difference between the inhalation air and the exhalation air in the respective conduits to thus provide a condensation zone. Another zone is provided toward the opposite end of the two conduits in which the temperatures between the air and the two conduits is maintained substantially the same so as to define a diffusion zone. The foil advantageously comprises a fluorinated hydrocarbon polymer which is hygroscopic.

Abstract: A method for the control of the proportion of two gases which are delivered to a mixed gas line for use for example in a respiratory breathing apparatus in which the gases are delivered to a mixed gas line from a pressure control vessel, comprises continuously monitoring the pressure in the control vessel and when the pressure therein is at an initial predetermined pressure admitting a first gas into the pressure control vessel until the pressure therein increases to a predetermined higher pressure and then stopping the admission of the first gas and initiating the admitting of a second gas into the pressure control vessel, continuing to admit the second gas until a predetermined additional higher pressure is achieved in the pressure control vessel, discontinuing the admission of the second gas when the predetermined additional higher pressure is reached and initiating the withdrawal of the mixed gas through the mixed gas line, continuing to withdraw the mixed gas through the mixed gas line until an initial p

Abstract: A breathing air humidifier for respirator devices comprising an inspiration conduit which is connected to the mouth of the user of the respirator and which has a section or portion with a foil surface of a material which is impervious to water but pervious to water vapor. A water chamber surrounds the foil surface and water which is warmed is delivered to the water chamber from a supply tank located above the chamber which carries a heater for warming the water to a preselected temperature.