A-Scan Biometry: Ultrasound Principles, Ultrasound Biometry Instrumentation, Accuracy and Standard D
Sound is defined as a vibratory disturbance within a solid or liquid that travels in a wave pattern. When the sound frequency is between 20 hertz (Hz) and 20,000 Hz, the sound is audible to the human ear. To be considered ultrasound, sound waves must have...