What knowledge does stethoscope have?

At present, stethoscopes include single stethoscope, double stethoscope, triple stethoscope, vertical stethoscope, multi-purpose stethoscope and the latest electronic stethoscope. There are many colors. Generally, it is divided into many types according to different combinations of listening heads. A flat stethoscope is usually used to auscultate high-pitched noises. The 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 auscultation head is often used to auscultate the pulse sound of wrist.