[Non-invasive measurement of venous circulatory resistance in man].

Plethysmography using the mercury gauge was applied to measure the changes of volume in the calf caused by venous congestion at varying pressures, achieved using an inflated pneumatic band round the thigh. By analysing the deposit graphs, it is possible to calculate a value for the circulatory resistance of the venous system. The significance of this parameter, notably for the diagnosis of venous thrombosis, is explained.