Diagnostic ultrasound equipment is equipment that applies ultrasonic waves to an object and maps its internal shape based on the rebounding waves. In the medical field, it is used in examining internal organs, fetuses and other parts of the human body.
The technology, which had been used for equipment to detect submarines and schools of fish since the 1910s, was first applied to the medical field in the 1940s. Initially, ultrasonic waves could only be transmitted in a single direction, allowing only two-dimensional, still images to be produced. In the 1970s, it became possible to send ultrasonic waves in the form of a fan, enabling real-time imaging of the movements of internal organs or fetuses. More recently, with progress in image processing technologies, more vivid and clear three-dimensional images can be produced.
As diagnostic ultrasound equipment uses sound waves instead of radiation, it poses no threat of radiation exposure to the patients. In addition, requiring no elaborate preparations, it possesses advantages such as easier, less painful testing of patients. On the other hand, since ultrasonic waves do not propagate through bones or air, the equipment is not suitable for observing lungs, stomachs and intestines, which all contain air.