The displacement cardiograph.
D000818:Animals; D004285:Dogs; D004582:Electronics, Medical / Q000295:instrumentation*; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D005082:Physical Exertion; D011859:Radiography; D013903:Thoracic Surgery; D013909:Thorax / Q000601:surgery