1. An instrument that uses both a photoelectric recording system and a fluoroscope to make a record of the movements of a shadow within the fluoroscopic field: "Electrokymographs were once commonly used to study the movements of the heart."
2. A device that provides a continuous recording of the movements of an internal body organ; such as, the heart, generally by recording the movements or the changes in density of the shadow of the organ as presented on a fluoroscope.
3. An appliance which combines a photoelectric recording system with a fluoroscope in order to make it possible for the continuous recording of the movements of a shadow within the fluoroscopic field or of changes in density in that shadow.