Photograph – Page 18 – PFT History Tissot spirometer used for BMR measurements From Can Med Assoc J 1918 June; 8 (6): 491–509 The determination of basal metabolism by the “Respiratory-valve and spirometer method” of indirect calorimetry, with an observation on a case of polycythemia with splenomegaly Maude E Abbott Tissot 1920s, Photograph, Spirometer