ABSTRACT
The use of ultrasound (sound with frequencies ranging roughly from 30 kHz to more than 30 MHz) in medical diagnosis is best associated with its ability to image internal structures of the body. However, ultrasound, by virtue of its short wavelengths in the body, is also well suited to nonimaging “A-mode” applications where the phase and frequency of the reflected sound is used to measure the distance to and velocity of the reflector or reflecting objects.
