Dual band ultrasonic systems

摘要

A dual-frequency band ultrasonic apparatus provides a first ultrasound signal to a region at a first frequency band and a second ultrasound signal at a second frequency band for monitoring the region. A processor controls the first and second ultrasound signals such that a predetermined phase relationship is achieved between the first frequency band signal and the second frequency band signal. The apparatus can employ a single transducer operable at both frequency bands or separate transducers for the first and second frequency bands.