(v l´ m nt´h v n) (KEY) , 1860–1927, Dutch physiologist, b. Java, M.D. Univ. of Utrecht, 1885. He was professor at the Univ. of Leiden from 1886. To measure the electric currents developed by the heart, he invented a string galvanometer and with its aid produced the electrocardiogram (EKG), a graphic record of the action of the heart. For this he received the 1924 Nobel Prize in Physiology or Medicine.