The system AUPREM is a new measurement device, which allows continuous measurement of the mechanical properties of the lung and bronchial system. Pulmonary elastance and airway resistance can be measured continuously even in extremly debilitated or unconscious patients. Transpulmonary pressure change, airflow and tidal volume are used as input. From these values airway resistance and pulmonary elastance are calculated. Comparative measurements in a group of healthy subjects and in a group of patients with pathological resistance and elastance values revealed that there was no significant correlation between the system AUPREM and the commonly used methods bodyplethysmography and elastance measurement by oesophageal balloon. However, the differences are in a low order of magnitude.