| 摘要 |
A high frequency oscillator (HFO) ventilator (2) comprises a gas conduit (26,6) having an opening (30) for gas connection with a patient's airways and a bias gas flow inlet (34) and outlet (10) disposed to define therebetween a bias gas flow-path within the conduit (26,6). An oscillator (16) is operable to induce pressure oscillations in gas within the conduit (26,6) 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 (30) at a predetermined high frequency to provide respectively an inspiration phase and an expiration phase of a breathing cycle. The HFO ventilator (2) further comprises an extraction device (38,44) operable during the breathing cycle, and preferably in timed relation with the operation of the oscillator (16), to withdraw an additional amount of gas from the respiration flow-path. <IMAGE> |
