Nội soi là một ống được trang bị ánh sáng có thể đi vào cơ thể qua một lỗ thông tự nhiên trong cơ thể hoặc qua một vết rạch nhỏ do phẫu thuật tạo ra.
The original endoscopes were made of rigid tubes and were invented more than 100 years ago. Although they have gradually improved, they are still not widely used. Later, in the 1950s, endoscopes were made of flexible tubes that could bend easily around the corners of the body. In 1965, Harold Hopkins installed a lenticular lens on an endoscope to make the field of view clearer. Today's endoscopes usually have two fiberglass tubes through which light enters the body. Doctors Observation is done through another tube or through a camera, and some endoscopes even have tiny integrated circuit sensors that feed back what is observed to a computer.
