The stethoscope began as a rolled-up sheet of paper

In 1816, at the Necker Hospital in Paris, René Laennec needed to examine a young woman with signs of heart disease. Placing an ear directly on the chest was standard practice, but it seemed inappropriate here, and percussion told him little.

He rolled a sheet of paper into a tight cylinder, put one end over her heart and the other to his ear, and heard the heartbeat more clearly than he ever had. He spent the next three years refining the idea into a wooden tube about 25 cm long, comparing what he heard with autopsy findings.

His 1819 treatise on mediate auscultation founded modern chest examination. Laennec died of tuberculosis in 1826, at 45, leaving his stethoscope to his nephew as "the best part of my legacy."