Principles of Operation of the Diagnostic Ultrasound System
Medical ultrasound images are created when the computer's digital memory converts the highfrequency wave signals that are transmitted and received by the probe. As ultrasound waves propagate through the human body, they generate reflected signals whenever they encounter a change in density. For example, reflected signals are generated when signals pass from fatty tissues to muscle tissues. Reflected signals return to the probe where they are converted into electronic signals. The reflected signals are amplified and processed by analog and digital circuits that have filters for various frequencies and response time options. Then they are again converted into high-frequency electronic signals, and saved as a series of digital image signals. The monitor displays the image signals stored on the storage device in real time. The entire process of transmitting, receiving, and processing signals is controlled by the computer