Karl von Vierordt
Born 1 Jul 1818; Died 22 Nov 1884 at age 64.
A German doctor who invented the heart rate monitor, the first tool to realize human pulse monitoring from blood pressure measurement by non-invasive method. His method of using weights and mechanical scales was rudimentary, but established the principle that blood pressure could be measured by finding the back pressure needed to equalize the pulse of the arteries. Vierordt also invented the sphygmomanometer to monitor the rate of blood flow. He performed spectroscopic analyzes of solutions of hemoglobin, bile and urine, and also studied respiration and sound conduction.