Humidification arrangement for a respiratory apparatus

Abstract

An air delivery tube for a CPAP system includes a first end configured to connect to a flow generator of the CPAP system and a second end configured to connect to a patient interface of the CPAP system. The air delivery tube also includes a central lumen that is formed by an inner wall of the air delivery tube and is configured to convey pressurized breathable gas from the first end to the second end. In addition, a circumferential chamber surrounds the central lumen and is configured to retain a supply of water. A wick is located within the central lumen and is connected to the inner wall.

1 . A gas conduit for respiratory apparatus, including a lumen for passage of a breathable gas to a patient and a flexible conduit wall surrounding the lumen, the flexible conduit wall having a humidification apparatus for delivering water vapour into the gas passing through the lumen. 
     
     
         2 . A gas conduit according to  claim 1 , wherein said humidification apparatus comprises one or more liquid water delivery passages extending along the conduit wall and means for vaporising said liquid water to produce said water vapour. 
     
     
         3 . A gas conduit according to  claim 2 , wherein said one or more water delivery passages extend helically along said conduit wall. 
     
     
         4 . A gas conduit according to  claim 2 , wherein said one or more water delivery passages extend longitudinally along said conduit wall. 
     
     
         5 . A gas conduit according to  claim 1 , wherein the humidification apparatus includes a heater for heating the water to form water vapour. 
     
     
         6 . A gas conduit according to  claim 5  where the heater is in thermal contact with the humidification apparatus such that the heater heats the water within the humidification apparatus. 
     
     
         7 . A gas conduit according to  claim 6  wherein said heater is in thermal contact with the gas passing through lumen. 
     
     
         8 . A gas conduit according to  claim 7 , comprising a plurality of humidification apparatus and/or a plurality of heaters adapted for independent actuation. 
     
     
         9 . A gas conduit according to  claim 1 , wherein the humidification apparatus includes one or more semi-permeable membrane portions allowing water vapour to pass therethrough into the lumen. 
     
     
         10 . A gas conduit according to  claim 9 , wherein the one or more semi-permeable membrane portions form portions of the inner surface of the conduit wall. 
     
     
         11 . A gas conduit according to  claim 10 , wherein said semi-permeable membrane portions comprise finely perforated material. 
     
     
         12 . A gas conduit according to  claim 9 , wherein said semi-permeable membrane portions comprise hydrophobic material. 
     
     
         13 . A gas conduit according to  claim 12 , wherein the semi-permeable membrane portions comprises a plurality of water tubes forming one or more portions of an inner wall of the flexible gas conduit. 
     
     
         14 . A gas conduit according to  claim 1 , wherein the humidification apparatus comprises at least one wick and/or capillary action device associated with one or more portions of the inner wall for transporting water into said lumen. 
     
     
         15 . A gas conduit according to  claim 14 , wherein the wick device comprises hydrophilic material. 
     
     
         16 . A gas conduit according to  claim 15  wherein the wick device is located in the one or more water delivery passages. 
     
     
         17 . A gas conduit according to  claim 16  where the inner surface of the conduit wall forms at least a portion of the one or more water delivery passages and
 said portion having a plurality of through holes to the lumen. 
 
     
     
         18 . A gas conduit according to  claim 17  where each hole has a width in the range of 0.2 micrometres to 1 millimetre 
     
     
         19 . A gas conduit according to  claim 16  where the inner surface of the conduit wall forms at least a portion of the one more water delivery passages and
 said portion is a semi-permeable membrane allowing water vapour to pass therethrough into the lumen. 
 
     
     
         20 . A gas conduit according to  claim 19 , wherein said semi-permeable membrane comprises finely perforated material.