calculation for oxygen uptake

[biology_06er]

Hi there..

How do I measure oxygen uptake---i have a formula minute volume*(fraction of oxygen inspired-fraction of O2 expired)=O2 uptake..

and my info. i have is as follows--fractional conc. of O2=19%, fraction conc. of CO2=2.2%, volume of expired air=59.5L/min...

also how do i calculate minute volume (is this just the volume of expired air)?? because if so I have another formula of minute volume of ventilation which includes stuff like room temp. and barometric pressure...


cheers,
biology_06er