Walter Rudolf Hess (17 March 1881 – 12 August 1973)[1] was a Swiss physiologist who won the Nobel Prize in Physiology or Medicine in 1949 for mapping the areas of the brain involved in the control of internal organs.

He received his medical degree from the University of Zurich in 1906 and trained as surgeon in Münsterlingen (in the same canton as his birthplace Frauenfeld) under Conrad Brunner (1859–1927).

He developed a viscosimeter to measure blood viscosity and published his dissertation in 1906 titled Zum Thema Viskosität des Blutes und Herzarbeit.

[3] In 1907, he went to the University of Zurich to study under Otto Haab to be trained as an ophthalmologist and opened his own private practice in Rapperswil SG.

He developed a special technique he called "interrupted direct-current (DC) stimulation" which used stimuli of long duration (typically 12.5 or 25 ms) with ramp-like upward and downward slopes.

When stimulating the anterior part, he could induce fall of blood pressure, slowing of respiration and responses such as hunger, thirst, micturition (urination) and defecation.