Final answer:
TOFD probes are used in a variation of the pulse-echo ultrasonic technique, which is applied in medical imaging to construct detailed images of internal structures.
Step-by-step explanation:
TOFD probes are used in a variation of the pulse-echo ultrasonic technique. In medical diagnostics, ultrasound technology is widely used to create images and detect motion. For instance, the common method involves sweeping a directional beam across the area of interest with multiple ultrasound sources phased to interact constructively. This process, which involves the measurement of echoes by depth and position, allows for the construction an image that reveals the internal structures' shape and density. Another technique, the Doppler-shifted ultrasound, is used to detect motion and determine velocity, as seen when monitoring the fetal heartbeat, measuring blood velocity, or detecting blood vessel occlusions by the Doppler shift of an echo.