Alexander Filippovich Samoylov (7 April 1867 – 22 July 1930) was a Russian physiologist and pioneer of electrophysiology and electrocardiography who applied techniques of using the ECG for diagnostic purposes.
Samoylov was born in Odessa and after losing his father at an early age, he began to work to earn for the family.
He obtained a doctorate from St. Petersburg for a thesis on the fate of iron in the animal organism and joined research under Ivan Pavlov on digestion.
This led him to examine similar processes using a capillary electrometer, designing a drum recorder capturing what he called electrograms.
In 1904 he met Willem Einthoven at the International Physiological Congress in Brussels and then began to make use of a string galvanometer.