Abstract:John Thomas Watson is a mechanical engineer, physiologist, and administrator whose career has centered on the research, development, and validation of biomedical technologies for assisting the ailing heart. His papers focus on the activities of the National Heart, Lung, and Blood Institute (NHLBI)'s Devices and Technology Branch -- originally known as the Artificial Heart Program -- and Watson's professional career as administrator of that branch. Reports, administrative records, requests for proposals, contract applications and reviews, conference files, videos, manuscript drafts, reprints, and three-dimensional medical devices document the mechanical cardiac assist device research conducted under the auspices of the NHLBI from 1964 to 2003.