Heated respiratory therapy humidifier

Claim 1

A humidifier assembly for humidifying a breathable gas, said humidifier assembly comprising a housing; heater means mounted on said housing, said heater means having a generally horizontally disposed heater surface and being adapted to receive liquid water in a direct heat transfer relationship with said heater surface; liquid water supply means communicating with the heater means; a hollow shell on the housing, defining a humidification chamber and having an inlet for a breathable gas and an outlet for humidified breathable gas; and hydrophobic filter means in the humidification chamber positioned in juxtaposition with said heater surface for passing water vapor into the breathable gas; said hydrophobic filter means being situated adjacent said heater surface, said liquid water supply means communicating with the heater means to supply liquid water to the heater surface from below the filter means so that only water vapor passes upwardly through the filter means into the humidification chamber and further including a liquid water passageway through the heater means, and said heater means being provided with a valve means within the liquid water passageway for closing the passageway when the filter means is not in place.