A calibration system of O2 consumption and CO2 production for premature infants

An apparatus to calibrate the system of measuring O₂ consumption and CO₂ production has been developed for premature infants. This system is based on the alcohol combustion principal. The alcohol combustion is used to test the indirect calorimetric system due to its simplicity and reliability. In the previous studies, the O₂ consumption rate of alcoholic combustion is too large to simulate the breath of premature infants. A new design is proposed to burn alcohol continuously at a rate as low as 0.004 ml min^-1, equivalent to an O₂ consumption rate of only 3.9 ml min^-1, a level in the breath range of preterms of about 660 g based on the measurement 5.9 ml kg^-1 min^-1. The alcohol combusts with various steady-state rates to imitate the breath of premature infants, and it is useful for a canopy open-circuit system. The calibration tool proposed here would be helpful in the clinical study of energy expenditure for preterms.