Born May 21, 1860, in Samarang, Java; died Sept. 29, 1927, in Leiden, The Netherlands. Dutch physiologist.

Einthoven, upon graduating from the University of Utrecht in 1885, became a professor of physiology at the University of Leiden. His works dealt mainly with electrophysiology. By analyzing electrocardiograms mathematically, Einthoven interpreted the electrical reactions of the heart with unprecedented accuracy. He made a fundamental contribution to clinical electrocardiography in 1903 by devising a string galvanometer.

Einthoven conceived the idea of recording heart currents from three leads, and suggested the use of a triangle to illustrate change in the height of electrocardiographic waves and their interaction in relation to the recording method; he provided a physiological explanation for every wave and interval on the EKG. Einthoven also invented vectorcardiography in 1913. He was one of the first to do research in neuroelectrophysiology. He detected impulses in the depressor nerve and recorded impulses in the pathways of the sympathetic nerves.

Einthoven was awarded a Nobel Prize in 1924.