This invention relates to a patient heat-moisture exchanger attached to a nebulizer circuit. More particularly, it refers to a heat-moisture exchanger attached to a patient ventilator circuit, which includes a metered dose inhaler, the exchanger permitting medicament to pass through the heat moisture exchanger without passing through internally mounted filters and without disconnection from the ventilator circuit.
A heat-moisture exchanger attached to a nebulization device is described in U.S. Pat. No. 6,550,476. This device has a rotatable second housing connected to a first housing. The first housing has at least two chambers enclosing an absorbent material and providing a passageway for an aerosol. The second housing encloses the nebulizer. Valves control the primary gas flow through a passageway to bypass the absorbent material. This device maintains the continuity of a closed ventilator circuit when administering an aerosolized medication to prevent interruption of ventilation to a patient. However, the device is complex and expensive to produce. A simpler device is needed to maintain the continuity of a closed ventilator circuit when administering an aerosolized medication to a patient connected to a ventilation system.
The present invention is directed towards a simplified way of maintaining the continuity of a closed ventilator circuit when administering an aerosolized medication to a patient. The inventive device has two annular housings rotatable with respect to each other. Each housing has a heat-moisture exchange material attached along an interior surface edge. Each heat moisture exchanger material (HMEM) has an annular opening axially aligned with an annular opening in the housing to which it is attached. A threaded tube is slidable through the openings in the two housings and the HMEM when the two housings are turned to a proper position, thereby allowing passage of an aerosol medication through the circuit. When the openings in the two housings and the HMEM are not aligned then the patient ventilator circuit is set for use as a conduit of air to and from the patient.