US Patent 8020551 Breathable gas apparatus with humidifier

A respiratory treatment device comprising a flow generator and a humidifier adapted to receive a supply of air at positive pressure from the flow generator and deliver it to an air delivery tube, wherein the humidifier includes a base, a humidifier lid, and a water tank, and the water tank includes a water tank lid, the water tank is removably receivable in the base to define a first air flow path from the flow generator to an interior of the water tank, and the humidifier lid is connectable to the air delivery tube, and is adapted to form a seal with the water tank lid to define a second air flow path from the interior of the water tank to the air delivery tube.