1983 Volume 3 Issue 3 Pages 350-354
We studied coaxial dual flow ventilation circuit which was combined with the humidifier controlling inspired gas temperature automatically.
The variation of inspired gas temperature was controlled within ±0.3°C when tidal volume and respiratory rate were changed. Inspired gas temperature indicated stably within ±0.2°C under the change of specified temperature of inspired gas and ventilation. In addition, inspired gas temperature was little influenced by the change of room temperature.
Rainout in the circuit slightly increased with decreasing of respiratory rate, however, its value was lower than that of conventional circuit, as this circuit is dual flow system warming an inspired limb with heat of expired gas.
From the above results, we conclude that this system can control inspired gas temperature accurately and simply, and there is less rainout in the circuit.
