myograph
/ˈmʌɪə(ʊ)ɡrɑːf/ /ˈmʌɪə(ʊ)ɡraf/Medicine
noun
An instrument for displaying or recording muscular contractions and relaxations; (now) especially an electromyograph.
Origin
Mid 19th century; earliest use found in Journal of Anatomy. From myo- + -graph, after French myographe (1824 in sense ‘someone who describes muscles’, 1866 or earlier denoting E. J. Marey's device; compare E. J. Marey 1866, in Jrnl. de l'Anat. 415).