Patent ID: 11864881
Assignee: COVIDIEN LP
Field: Measurement (Instruments)
Classification: CPC A  G | IPC A  G

Claim 9:
10. A device for determining a volume of exhaled CO2 as a function of time, the device comprising:
a side-stream CO2 monitor configured to measure CO2 concentration over time; and
a processor configured to:
obtain flow dynamics measurements,
obtain the CO2 concentration measurements from the side-stream CO2 monitor,
determine 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 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 on-start of inhalation (Ti),
synchronize in time the CO2 concentration measurement with the flow dynamics measurement based on the determined ΔTs1, and
determine a volume of CO2 exhaled as a function of time based on the flow dynamics measurement and the synchronized CO2 concentration measurement.