Santorio Santorio, Latin Sanctorius or Santorius, (born March 29, 1561, Capodistria [now Koper, Slvn.]—died Feb. 22, 1636, Venice [Italy]), Italian physician who was the first to employ instruments of precision in the practice of medicine and whose studies of basal metabolism introduced quantitative experimental procedure into medical research. Santorio was a graduate of the University of Padua (M.D., 1582), where he later became professor of medical theory (1611–24). About 1587 he was apparently summoned to attend as physician on a Croatian nobleman. From 1587 to 1599 Santorio seems to have spent much time among the southern Slavs, though he maintained a frequent correspondence with his Paduan colleagues, the astronomer Galileo Galilei and the anatomist Hieronymus Fabricius ab Aquapendente. Santorio was an early exponent of the iatrophysical school of medicine, which attempted to explain the workings of the animal body on purely mechanical grounds, and he adapted several of Galileo’s inventions to medical practice, resulting in his development of a clinical thermometer (1612) and a pulse clock (1602). https://www.britannica.com/biography/Santorio-Santorio https://en.wikipedia.org/wiki/Santorio_Santorio