Setup 1 Spirometer set up to just measure breaths and volume Cylinder, hoses and mouthpiece form a closed system Air is sucked out of cylinder through one hose and pushed into the cylinder with the other hose (valves in mouthpiece move air in one direction) Pen moves up and down - volume changes are scribed on drum paper Drum turns at calibrated speed (mm/sec) for time calibration When a person puts mouth over mouthpiece now the persons trachea and lungs are connected to this closed system

Machine Ventilation - Use mechanical device to move measured amount of air in and out - Measure frequency and volume Raw Data from Machine Breathing

Human Ventilation -Fill with 100% Oxygen -Breath in and out repeatedly -Oxygen will be removed and Carbon Dioxide will be added to volume in closed system -Note any changes in overall volume as person continues to breath *If there is uneven exchange of O2 and CO2 then the volume will change Change in volume represents disproportion between O2 in vs. CO2 out In this case there is 100ml less air after 1 minute If O2 consuption = 500 ml/min and CO2 production = 400 ml/min then discrepancy = 100 ml/min Raw Data from Human Breathing

Setup 2 Measure Oxygen Consumption by absorbing all Carbon Dioxide that is exhaled -Insert CO2 absorber on return hose to remove all CO2 that is exhaled -Now change in volume will represent change in amount of oxygen

Overall volume will change more rapidly now that we are removing the CO2 that is exhaled 1 breath in 100% oxygen from spirometer 2 breath out 97% oxygen 3% CO2 3 absorb all CO2 as air moves back to spirometer 4 note drop in volume over time rate is oxygen consumption ml O2 / minute (Slope = oxygen consumption) 300 ml O2/min 600 ml O2/min