A ventilation interface and system is described which can be adapted to be connected to a source of ventilation. The ventilation interface and system may include variable exhaust ports. The ventilation interface system may optionally include feed tubes, y-connector, tube holder, and headgear....http://www.google.co.uk/patents/US7191781?utm_source=gb-gplus-sharePatent US7191781 - Nasal ventilation interface and system
