PURPOSE: To assure a sufficient capacity, i.e., the large work done to the respiration systems without being restricted by the inertia arising from forward and backward movements by using a pressure generating machine operated by revolution of a blower and a selector valve as a pressure generating source, thereby stabilizing the positive pressure on a blower discharge side and the suction pressure on a blower suction port side.
CONSTITUTION: A high-frequency respirator oscillation generator B has the blower 11 as the pressure generating source and the selector valve 12 of a rotary type. The positive pressure generated by the discharge port 11a of the blower 11 and the negative pressure generated by the suction port 11b are alternately applied to an oscillation circuit 13 by the selector valve 12. A positive pressure port P1 is communicated with an atm. releasing port P4 when a pressure applying port P3 is closed by a valve disk part 25c and is conversely communicated with the pressure applying port P3 when the atm. releasing port P4 is closed by the valve disk part 25c. The pressure applying port P3 is eventually communicated alternately to the positive pressure port P1 and the negative port P2 by the phase difference between the two valve disk parts 25b and 25c.