In ancient Greece, doctors put their ears close to the patient's chest to listen to his heart. But this skill was forgotten, and it was not until the Renaissance that it became a routine inspection method again.

Later, one day on 18 16, a young woman came to the clinic in Lei Naike because of heart discomfort. Lei Naike is too shy to put her ear near the plump breasts of female patients. He remembers seeing a child tapping at one end of the wood and another child listening at the other end. Laennec grabbed a stack of paper and rolled it into a tube. Then, he put the paper tube on the chest of the female patient and listened at the other end. To his surprise, he heard a clear heartbeat that he had never heard before.

Lei Naike made a permanent stethoscope with a length of about 23cm and a thickness of 4cm from wood. He described all the sounds he heard in the patient's chest and associated many sounds with various diseases.

The wooden stethoscope was not replaced by a stethoscope made of rubber tube until 1850. 1852 an American doctor named George Kaman added two headphones to the stethoscope. At 1878, someone invented a microphone, which was connected to the chest of a stethoscope to amplify the sound.

Modern stethoscope is mainly composed of copper, rubber tube, spring leaf and listening head.

The listening head is formed by die hot forging, with high tissue density, no Chacon and clearer sound transmission.

At present, there are three types of stethoscopes: single stethoscope, double stethoscope, vertical stethoscope with three stethoscopes and multi-purpose stethoscope. There are many colors.

Generally, it is divided into many types according to different combinations of listening heads.

Flat auscultation head is often used to auscultate high-pitched murmurs.

The large and small dual-function flat-panel listening head is used to detect low-frequency heart sounds, dilated sounds, third sounds, and the first and second heart sounds, and children's heart sounds can already be heard.

Bell-shaped auscultation head is often used to auscultate low-pitched murmurs, which can hear the heartbeat of the baby's abdomen.

Watch stethoscope, often used to auscultate the pulse sound of wrist.

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