An analog approach to measuring O2 uptake on-line

Abstract

An analog circuit has been designed to provide a solution to the Haldane transformation that yields true O2 fraction. Incoming signals proportional to fractional concentration of CO2 and O2 in mixed expired gas are utilized in the circuit and the results are multiplied by a value proportional to ventilation. The final products are analog signals proportional to O2 uptake and CO2 output. The system is applicable to the anesthetized and paralyzed animal kept at a known constant ventilation. The final products are analog signals proportional to O2 uptake and CO2 output. The system is applicable to the anesthetized and paralyzed animal kept at a known constant ventilation. Diagrams of the circuit and expired gas collection and analysis arrangements are provided.