In 1816, a French physician named René Laennec found himself in a delicate situation. He needed to listen to the heart of a young female patient but didn’t have an ideal way to do so based on the standard practices of the time. Doctors in the early 19th century relied primarily on touch to assess the heart, pressing their hands to gauge its strength and rhythm. This method often wasn’t reliable, especially, as was the case in Laennec’s situation, if the patient was of a heavier weight....
