René Laennec

Raised by his physician uncle in Nantes during the Terror, Laennec studied medicine under Corvisart in Paris. In 1816, consulted by a young woman with heart disease whose symptoms were obscured by obesity and modesty, he rolled a sheet of paper into a tight cylinder and placed it over her chest, discovering that heartbeats were heard with startling acoustic clarity.

Laennec crafted wooden hollow monaural cylinders, naming his instrument the 'stethoscope' (from Greek 'to view the chest'). In his 1819 treatise De l'auscultation médiate, he coined medical terms still used worldwide, including rales, rhonchi, bronchophony, and melanoma, as well as cirrhosis ('Laennec's cirrhosis').