Abstract: In a pulmonary ventilation system, a filter arrangement useful as an input filter arrangement and an output filter arrangement is constructed to allow for changing or cleaning of the filter without interrupting or impacting the ventilation therapy and to limit the release of pathogens to the surrounding area or atmosphere. A preferred exhaust filter is constructed to function as a water trap and filter. Methods of operating the pulmonary ventilation system are also disclosed along with kits containing materials to construct an input or an output filtration structure.

Abstract: A ventilation system supplies a gas mixture that is humidified and heated through a proportional valve which is a fail closed and normally closed servo control valve positioned proximate a patient. The proportional valve is operated by a controller that regulates the pressure and the mode (e.g., high frequency, normal respiration, combinations) gas is delivered to the patient through a nozzle connected to the endotracheal tube. The nozzle has an exhaust connected to it and a pressure sensor through a pressure sensing port. The exhaust is a capped corrugated tube that is heated and perforated to allow air to escape, to muffle gas and respiration noises, and to trap moisture.