Oxygen Uptake Determination During Severe Exercise in a Hyperbaric Environment

Abstract

A method is described which enables accurate measurement of oxygen uptake (VO₂) in exercising subjects breathing 95% oxygen by open circuit respirometry. A mixture of 5% helium in oxygen is inspired until steady-state equilibrium has occurred (60 min.). During subsequent work tasks the helium concentrations of the inspired and expired gas mixture are measured on a helium analyser and substituted for F_IN₂ and F_EN₂ in the appropriate gas exchange equations. Contamination of the collected respired gas samples with atmospheric nitrogen is thus measurable and appropriate corrections can be made.