A ventilator circuit comprising an inspiratory line and an expiratory line converging at a junction. The junction has a Y piece having a first end, a second end, and a stem. The first end is attached to the inspiratory line. The second end is attached to the expiratory line. The stem is attached to, and is in fluid communication with, (i) an endotracheal tube and (ii) a liquid aerosol nebulizer. The nebulizer is not positioned in the inspiratory line or the expiratory line, but is positioned on the stem such that it directs an aerosol comprising liquid droplets into the endotracheal tube. The nebulizer comprises an aerosol delivery end comprising an aerosol generator, the generator comprising a dome-shaped aperture plate capable of generating an aerosol when said plate vibrates.
