spirometer?

Question

my question is if a gas inside spirometer is
a) atmospheric air with CO2 exhaled into it
b) atmospheric air with CO2 not exhaled into the spirometer
c)100% O2 with CO2 exhaled into it
d)100% O2 with CO2 not exhaled into it

then in which case would ventilation rate be at highest and lowest and why??

Answer 1

Depends what kind of spirometer. I suppose you are talking about connecting a lung simulator to a spirometer and checking how are the measured parameters influenced by the gas composition. Well, they shouldn't be! Only the temperature and saturation should matter and for these we have the BTPS correction.

There are spirometers based on turbine, on pneumotach (Fleisch or Lilly principle), and other kinds. Some of them are could be more influenced by the gas composition than others, because the principle of measuring is different.
But if the device is calibrated before the measurement using the calibration pump (syringe) then the gas compostion shouldn't really matter.

Answer 2

I don't quite understand the question, but ventilation rate will be highest when the person is hypoxic (low O2) and hypercapnic (high CO2). And ventilation rate will be lowest when the O2 saturation is 100% and the person is in alkalosis (low pH) or hypocapnic (low CO2).

Answer 3

atmospheric

Answer 4

c