Quantitative methanol-burning lung model for validating gas-exchange measurements over wide ranges of FIO2.

The methanol-burning lung model has been used as a technique for generating a predictable ratio of carbon dioxide production (VCO2) to oxygen consumption (VO2) or respiratory quotient (RQ). Although an accurate RQ can be generated, quantitatively predictable and adjustable VO2 and VCO2 cannot be generated. We describe a new burner device in which the combustion rate of methanol is always equal to the infusion rate of fuel over an extended range of O2 concentrations. This permits the assembly of a methanol-burning lung model that is usable with O2 concentrations up to 100% and provides continuously adjustable and quantitative VO2 (69-1,525 ml/min) and VCO2 (46-1,016 ml/min) at a RQ of 0.667.