Methods, devices, systems, and compositions for detecting gases

Abstract

A method of monitoring a respiratory stream can be provided by monitoring color change of a color change material to determine a CO2 level of the respiratory stream in contact with the color change material by emitting visible light onto the color change material. Related devices, systems, and compositions are also disclosed.

1 - 10 . (canceled) 
     
     
         11 . An apparatus to monitor a respiratory stream comprising:
 a breathing circuit adapter configured for coupling to a breathing circuit to provide the respiratory stream; and   a color change material comprising a reactive portion and an unreactive portion, the color change material at least partially inside the breathing circuit adapter positioned for contact with the respiratory stream.   
     
     
         12 . The apparatus of  claim 11 , wherein the reactive and unreactive portions are separated from one another, the reactive portion is configured to provide a first color responsive to a CO 2  level in the respiratory stream and the unreactive portion is configured to a second color, different from the first color, that is irrespective of the CO 2  level in the respiratory stream. 
     
     
         13 . The apparatus of  claim 12 , wherein the color change material is removably attached to the apparatus. 
     
     
         14 . The apparatus of  claim 11 , wherein the breathing circuit adapter further comprises an enclosure positioned inside the breathing circuit adapter proximate to the respiratory stream and configured to isolate the unreactive portion from the respiratory stream. 
     
     
         15 . The apparatus of  claim 11 , wherein the breathing circuit adapter further comprises an opening to the respiratory stream and configured to provide positioning of the unreactive portion outside the respiratory stream and to provide positioning of the reactive portion inside the breathing circuit adapter proximate to the respiratory stream. 
     
     
         16 . The apparatus of  claim 11 , wherein the color change material comprises a composition, wherein an alkaline material is present in an amount of about 0.1% to about 10% by weight of the composition. 
     
     
         17 . The apparatus of  claim 12 , wherein the unreactive portion comprises a quenched reactive portion. 
     
     
         18 . The apparatus of  claim 12 , wherein the unreactive portion comprises an external reactive portion that is outside the respiratory stream. 
     
     
         19 . The apparatus of  claim 12 , wherein the reactive portion comprises a catalyst and the unreactive portion is substantially free of the catalyst. 
     
     
         20 . The apparatus of  claim 12 , wherein the breathing circuit adapter includes at least one retaining feature configured to hold the unreactive portion outside the respiratory stream. 
     
     
         21 . An apparatus for use in monitoring a respiratory stream comprising:
 a color change material having a reactive portion thereon, wherein the reactive portion is configured to provide a first color based on exposure to a first CO 2  level and is configured to change from the first color through a first range of colors to a second color based on exposure to a second CO 2  level that is greater than the first CO 2  level; and   an unreactive portion, spaced apart from the reactive portion on the color change material, wherein the unreactive portion is configured to provide a first color based on exposure to the first CO 2  level and is configured to change from the first color through a second range of colors that is smaller than the first range of colors to a third color based on exposure to the second CO 2  level.   
     
     
         22 . The apparatus of  claim 21 , wherein the color change material comprises a composition, wherein an alkaline material is present in an amount of about 0.1% to about 10% by weight of the composition. 
     
     
         23 . The apparatus of  claim 21 , wherein the reactive portion includes a color change indicator and the unreactive portion is free of the color change indicator. 
     
     
         24 . The apparatus of  claim 21 , wherein the reactive portion and unreactive portion each comprise a color change indicator comprising an alkaline material, wherein the amount of the alkaline material in the unreactive portion is configured to provide the unreactive portion with a greater pH than the reactive portion. 
     
     
         25 . A carbon dioxide indicator comprising:
 a color change material, wherein the color change material is responsive to carbon dioxide; and   a control material, wherein the control material is substantially non-responsive to carbon dioxide.   
     
     
         26 . The carbon dioxide indicator of  claim 25 , wherein the color change material comprises a composition, wherein an alkaline material is present in an amount of about 0.1% to about 10% by weight of the composition. 
     
     
         27 . The carbon dioxide indicator of  claim 25 , wherein the color change material and the control material are configured to be exposed to substantially the same conditions. 
     
     
         28 . The carbon dioxide indicator of  claim 25 , wherein the color change material is configured to change from a first color to a second color and return to the first color in response to contact with at least one carbon dioxide concentration. 
     
     
         29 . The carbon dioxide indicator of  claim 25 , wherein the color change material is configured to change from a first color to a second color and return to the first color about 1 to about 60 times per minute in response to contact with at least two consecutive carbon dioxide concentrations. 
     
     
         30 . The carbon dioxide indicator of  claim 25 , wherein in operation, the color change material and the control material are substantially the same color at a first CO 2  concentration prior to contact with a second CO 2  concentration having a greater CO 2  concentration.