Abstract: An MIE apparatus has a blower, a direction valve, an oscillator, and a mask hose connector. The blower is connected to the direction valve, which is connected to the oscillator, which is connected to the hose connector. During insufflation, a direction valve connects exhaust of a blower to an oscillator, causing positive pressure at the hose connector. During exsufflation, the direction valve connects the blower intake to the oscillator, causing negative pressure at the hose connector. The oscillator is a butterfly valve with a 360° rotating disc. During insufflation, the disc is fixed to steadily modulate the airflow. During exsufflation, the oscillator is inactive or in flutter mode. When inactive, the disc is fixed to allow maximum air flow. In flutter mode, the disc continuously rotates so that the air flow rapidly alternates between maximum and minimum.