Von Ziemssen’s Handbook of general therapeutics, Volume 3, Translated by Elder Smith, 1885, page 389.
Based on the principles of Waldenburg’s Pneumotherapy, this system consisted of large gasometers to provide both positive and negative pressure.
From: Die Geschwindigkeith des Athemstromes und das Athemvolum des Menschen, by H. Zwaardemaker and C.D. Ouwehand, Archiv für Anatomie und Physiologie, Volume 28, Published by Physiologische Gesellschaft zu Berlin, 1904, page 243.
An early flow measuring device. When a subject blew through the central tube (a), positive and negative pressure in the opposed pitot tubes (b) caused thin plastic domes (f) to rise or fall. Their movement was transferred to a long, counter-balanced pen which traced a curve on a smoked drum.
From: Die Geschwindigkeith des Athemstromes und das Athemvolum des Menschen, by H. Zwaardemaker and C.D. Ouwehand, Archiv für Anatomie und Physiologie, Volume 28, Published by Physiologische Gesellschaft zu Berlin, 1904, page 243.
An early flow measuring device. When a subject blew through the central tube (a-a’), positive and negative pressure in the opposed pitot tubes (b-b) caused thin plastic domes (f-f) to rise or fall. Their movement was transferred to a long, counter-balanced pen which traced a curve on a smoked drum.