[The flow-volume-diagram (author's transl)].

The analysis of forced expiratory maneuvers by flow-volume-diagrams increasingly succeeds in practical lung function diagnosis. Models for pressure-flow-volume relations during forced expiration basing these diagrams are presented. Indicators resulting by evaluation of the flow-volume-diagram are discussed in reference to their clinical relevance and to the parameters of the conventionally written volume-time-relation of the Tiffeneau-test.