Abstract

A respiratory gas humidifier comprises a closed water reservoir having a water level therein which is maintained so that it does not vary beyond a great change in the height level. A guide nipple is mounted on the bottom of the reservoir and extends upwardly in the water and an inlet conduit extends into the top of the reservoir and overlies the guide nipple, but is spaced therefrom. A float is provided with a sleeve or hub portion which is guided on the guide nipple and the inlet conduit and includes a float portion which maintains the lower end of the hub portion below the level of the water in the reservoir. Respiratory gases are guided through the inlet conduit and to a space between the hub portion of the float and the guide nipple so that it always exits into the water at the same level and bubbles upwardly through the water and out through an outlet for use by a patient. In accordance with the method of the invention, respiratory gases are directed into a liquid reservoir containing water which is heated to a controlled temperature and it is permitted to bubble upwardly through the liquid at substantially the same height of upward bubbling travel and, wherein the height is controlled by a float so that the gas is always delivered at the same level below the surface of the water for upward bubbling therethrough.