In 1816, Laennec examined a young woman for heart disease. At that time, the doctor would put his ear close to the patient's chest to listen for heart sounds. But in the conservative thinking of the time, he felt that this was not correct, especially since the female patient was overweight. So he rolled a piece of paper into a tube and pressed it against the patient's chest to listen for a heartbeat. Some believe it was inspired by his playing the flute. Laennec later built a prototype of a hollow wooden stethoscope based on his experiments with paper tube auscultation, with a microphone at one end and a receiver at the other, and named it the stethoscope. The name comes from the Greek words for "chest" and "examination." This instrument instantly crossed Europe, was introduced to the United States, and became popular all over the world. Thanks to the invention of the stethoscope, Laennec was able to diagnose many different chest diseases, and he is also regarded as the "father of thoracic medicine".