The Oxylog oxygen consumption meter: a portable device for measurement of energy expenditure.

The Oxylog (PK Morgan, Kent, UK) is a recently developed portable device for measurement of oxygen consumption and energy expenditure in man. It incorporates a turbine flowmeter and two polarographic oxygen sensors and is powered by rechargeable batteries. Two instruments were modified for operation at low ventilation rates and used in simultaneous Oxylog and Douglas Bag measurements of resting metabolic rate (RMR) in nine healthy subjects. The coefficients of correlation between RMR measured by the two methods were +0.904 (p less than 0.02) and +0.934 (p less than 0.01) and the standard errors of the mean percent error in energy expenditure were +/- 2.0% and +/- 2.7% for the two instruments respectively. This suggests that the Oxylogs are sufficiently accurate for many field studies of energy expenditure.