The transient absorption characteristics of the two-phase blood/gas system: a comparison to the Danckwerts model

The transient gas absorption characteristics of a motionless two-phase system consisting of blood and air were investigated. The data were compared to the general liquid/gas system model developed by Danckwerts (1970). The results have shown that the amount of change in concentration of the gases in the gas phase of the system is linearly proportional to the square root of the time the two phases are in contact with each other. This relationship is consistent with the Danckwerts model. The results have revealed the potential of the transient two-phase absorption phenomenon for measuring blood gas tensions clinically. Empirical equations were derived from the data which yielded blood gas concentration estimates for nitrous oxide and oxygen from absorption time and the concentration of the gas phase of the system.