Ole Storstein is first author of a 1959 experimental study separating airway resistance from lung compliance. The investigators recorded mouth-to-esophageal pressure differences, breathing volume and airflow to analyze the mechanical behavior of respiration.[ref]
Airway Resistance and Lung Compliance by Ole Storstein and others. Primary byline; Methods, simultaneous pressure, volume and airflow recordings
The apparatus used an intra-esophageal balloon, a differential pressure transducer and a pneumotachograph with volume integration. The paper selected corresponding points of no mouth airflow for its compliance calculation and used paired observations during inflation and deflation to estimate resistance.[ref]
Airway Resistance and Lung Compliance by Ole Storstein and others. Methods, Sanborn recording apparatus and definitions of compliance and resistance
Simultaneous signals matter because a pressure observed during flow includes a different mechanical contribution from pressure observed after that flow term vanishes.For an original one-compartment model with a chosen zero-volume baseline, writewhere is lung compliance and is airway resistance. This neglects inertial and regional effects. At stipulated , L, and L/s, the elastic contribution is 4 and the resistive contribution is 1 cm of water. Total modeled pressure is 5 cm of water.
Dividing volume by that total would give , below the chosen compliance. At the same modeled volume and zero flow, pressure becomes 4 cm of water and the ratio recovers 0.10. A time point and the definition of the pressure difference are therefore part of the observable, rather than optional details.
The primary paper explicitly notes the limitation of treating a nonuniform mechanical system as uniform.[ref]
Airway Resistance and Lung Compliance by Ole Storstein and others. Discussion, interpretation of the simplified mechanical analysis
Zero net airflow at the mouth need not establish that every region has identical local behavior. Storstein's documented contribution combines apparatus, simultaneous observations and a stated mechanical interpretation, rather than equating one pressure/volume ratio with every aspect of lung function. New to topics? Read the docs here!