CPC A61B 5/082 (2013.01) [A61B 5/087 (2013.01); A61B 5/0836 (2013.01); A61B 5/097 (2013.01); A61B 5/7246 (2013.01); G01N 33/497 (2013.01); A61B 5/091 (2013.01); A61M 16/085 (2014.02); A61M 16/0833 (2014.02); A61M 2230/432 (2013.01); G01N 1/2247 (2013.01); G01N 2001/2297 (2013.01); G01N 2033/4975 (2013.01)] | 19 Claims |
1. A method for determining a volume of exhaled CO2 as a function of time using side-stream capnography, the method comprising:
obtaining, by a processing unit, flow dynamics measurements of a subject from a flow sensor;
obtaining, by the processing unit, CO2 concentration measurements of the subject from a side-stream CO2 monitor;
determining, by the processing unit, a duration of time (ΔTs1) for a sample of gas to flow from a side-stream reference point to the side-stream CO2 monitor, wherein determining the ΔTs1 is performed based on a time from on-start of inhalation (Ti) until a notch in the CO2 concentration measurement, the notch resulting from a bolus of clean air or a bolus of air having a known CO2 concentration introduced between the side-stream reference point and the side-stream CO2 monitor at Ti;
synchronizing, by the processing unit, in time the CO2 concentration measurement with the flow dynamics measurement, based on the determined ΔTs1; and
determining, by the processing unit, a volume of CO2 exhaled as a function of time, based on the flow dynamics measurement and the synchronized CO2 concentration measurement.
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