Apparatus for determining whether respiratory gas is present in a gaseous sample
DCFirst Claim
1. Apparatus for determining whether a gaseous sample contains a predetermined concentration of carbon dioxide, comprising:
- means for introducing the gaseous sample into an enclosure;
dry reagent detector means within the enclosure for producing a response to the presence of said predetermined concentration of carbon dioxide in the sample, said detector means comprising a carrier having a aqueous indicating composition applied thereto, said indicating composition providing an indication of the presence of said predetermined concentration of carbon dioxide in the sample within a diagnostically effective period of time when the carbon dioxide concentration in the sample is at least about 2% and providing said indication after about ten minutes when the carbon dioxide concentration in the sample is about 0.03%.
2 Assignments
Litigations
0 Petitions
Accused Products
Abstract
A method and apparatus are is disclosed for determining whether respiratory gas is present in a gaseous sample. The sample is brought into contact with an indicator which yields an indication within a diagnostically effective period of time of the presence in the sample of carbon dioxide in concentration of at least 2% while an indication of the presence of carbon dioxide or other trace acidic gas in a sample of ambient air is delayed beyond a predetermined period of time. The method and apparatus of the present invention have particular utility in determining the correct placement of an endotracheal catheter in a patient or in the direction of apnea.
-
Citations
25 Claims
-
1. Apparatus for determining whether a gaseous sample contains a predetermined concentration of carbon dioxide, comprising:
-
means for introducing the gaseous sample into an enclosure; dry reagent detector means within the enclosure for producing a response to the presence of said predetermined concentration of carbon dioxide in the sample, said detector means comprising a carrier having a aqueous indicating composition applied thereto, said indicating composition providing an indication of the presence of said predetermined concentration of carbon dioxide in the sample within a diagnostically effective period of time when the carbon dioxide concentration in the sample is at least about 2% and providing said indication after about ten minutes when the carbon dioxide concentration in the sample is about 0.03%. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. An element for use in detecting the presence of respiratory concentrations of carbon dioxide in a gaseous sample, comprising:
-
a substrate; and a dried non-volatile chemical composition carried by said substrate, said composition providing an indication within a predetermined period of time of the presence of a respiratory concentration of carbon dioxide in the sample and providing said indication after about ten minutes when the concentration of carbon dioxide in the sample is substantially less than said respiratory concentration.
-
-
23. A device for detecting the presence of a predetermined concentration of carbon dioxide in a gaseous sample comprising a non-liquid detector element having a non-volatile chemical composition the pH of which changes in the presence of said predetermined concentration and means responsive to said change in pH for providing an indication within a predetermined period of time of the presence of said predetermined concentration of carbon dioxide in the sample and providing said indication after about ten minutes when the concentration of carbon dioxide in the sample is substantially less than said respiratory concentration.
-
24. Apparatus for determining whether a gaseous sample contains a predetermined concentration of carbon dioxide, comprising:
-
means for introducing the gaseous sample into an enclosure; detector means within the enclosure for responding to the presence of the predetermined concentration of carbon dioxide, said detector means comprising a carrier to which a non-volatile indicating composition has been applied, said indicating composition providing a first response within a diagnostically effective period of time when the carbon dioxide concentration in the sample is at least about 2% but not providing said first response for more than about ten minutes when the carbon dioxide concentration in the sample is about 0.03%, and providing a second response within said diagnostically effective period of time when the sample is replaced with ambient air. - View Dependent Claims (25)
-
Specification