| 摘要 |
<p>Ventilator apparatus for treating a patient has a ventilator enclosure to which oscillating air flow is controlled via a valve connected to the enclosure and to sources of positive and negative pressure. The valve (A) comprises a main chamber (812) separated via a valve seat and a shutter member (810) from subsidiary chambers (816, 817) which are isolated from one another. Rotation of the shutter member by a stepper motor (B) connects each subsidiary chamber to the main chamber in turn to produce oscillating gas flow through a main port (812a) connected to the enclosure.</p> |
