spi·ro·graph
(spī′rə-grăf′)n. An instrument for registering the depth and rapidity of respiratory movements.
spi′ro·graph′ic adj.
spi′ro·graph′i·cal·ly adv.
spi·rog′ra·phy (spī-rŏg′rə-fē) n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
spirography
(spaɪˈrɒɡrəfɪ) n (Medicine) med the study of breathing using a spirograph
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014