oscilloscope (osc) /osil″əskōp/ [L, oscillare, to swing; Gk, skopein, to look] , an instrument that displays a visual representation of electric variations on the fluorescent screen of a cathode ray tube. The graphic representation is produced by a beam of electrons on the screen. The beam is focused or directed by a magnetic field that is influenced in turn by a source such as an amplified current produced by heart contractions. As used in cardiology, the oscilloscope can function as a continuous electrocardiogram.
