[Semi-quantitative diagnosis of the degree of emphysema from CO2 expirograms]

Previous studies have shown that the part of mixed air (phase II) of CO2-expirograms is very sensitive and specific for diagnosing pulmonary emphysema. Model calculations show that the course of phase II can be understood by serial inhomogeneities in the lung trumpet only, without assuming parallel inhomogeneities. Vice versa a single number can be derived by model calculations to characterize the grade of pulmonary emphysema.