Abstract: An anesthetic delivery system has a delivery unit containing a carbon dioxide retaining element and a reversible action anesthetic absorber/desorber for releasably retaining therein at least a portion of a charge of anesthetic agent. An externally accessible first internal flow section in the delivery unit directs gas through the delivery unit first through the anesthetic absorber/desorber and then through the carbon dioxide retaining element, sequentially. An externally accessible second internal flow section directs gas through the delivery unit via the anesthetic absorber/desorber and bypassing the carbon dioxide retaining element.

Abstract: A high-frequency oscillator ventilator has a first gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and a bias flow outlet disposed to define therebetween a flow path for a bias gas within the first conduit. An oscillator operable to alternately introduce a volume of additional gas from a source into, and to withdraw at least the same volume of gas from, the first gas conduit, thereby inducing pressure oscillations in gas within the first conduit to move gas along a path intersecting the flow path for a bias gas alternately into and out of the opening at a predetermined high-frequency dependent on the output of a control signal generator.