How is the transmitted sound beam steered in phased array transducers?

In phased array transducers, the steering of the transmitted sound beam is achieved by varying the timing of the electrical pulses sent to the individual piezoelectric elements. This method allows for precise control over the direction of the ultrasound beam.

When each element in a phased array transducer is excited with a slightly different time delay, the resulting sound waves from these elements constructively and destructively interfere, which effectively formats the beam to point in a specific direction. By manipulating these timing differences, sonographers can steer the beam to various angles without physically moving the transducer, enabling dynamic scanning of structures.

This capability is essential for imaging various anatomical planes and adjusting the focal point of the ultrasound, improving both the quality and versatility of the images obtained. The other methods listed, such as varying the frequency, adjusting the shape of the transducer, or changing the distance between elements, do not contribute to the steering of the sound beam in a phased array system.