The doctor wants to know about the working of lungs and the heart before treating a patient. He or she can do it easily with the help of a simple instrument called the stethoscope. It was invented by Rene Laennec.
Once Dr. Rene Laennec saw two children playing with a hollow log. One was whispering to the other through this log. Rene picked the idea from this whispering game. He rolled a newspaper like a hollow tube and placed it on the chest of one of his patients. He was thrilled to hear the heartbeats clearly. He also tried to listen to the in and out movement of air from the lungs. This was the first stethoscope. Today we have far more sensitive and powerful stethoscopes. The keen observation of Rene Laennec led to the invention of the stethoscope, which is now used by every doctor throughout the world.