摘要 |
A high-frequency oscillator (HFO) ventilator has a gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and outlet disposed to define therebetween a bias gas flow-path within the conduit. An oscillator is operable to induce pressure oscillations in gas within the conduit to move a volume of gas ("tidal volume") along a respiration flow-path, intersecting the bias gas flow-path, alternately in to and out of the opening at a predetermined high-frequency to provide, respectively, an inspiration phase and an expiration phase of a breathing cycle. The HFO ventilator further has an extraction device operable during the breathing cycle, and preferably in timed relation with the operation of the oscillator, to withdraw an additional amount of gas from the respiration flow-path. |