In modern linear sequential array transducers focusing is achieved _________.

In modern linear sequential array transducers focusing is achieved _________.

• A. Electronically
• B. Mechanically
• C. Optically
• D. Acoustically

Answer: (A)

Focusing in modern linear sequential array transducers is achieved electronically by applying precise time delays to the drive signals (and to the received signals) of the individual elements. These delays shape a converging wavefront so the beam focuses at a chosen depth, and they can be adjusted for dynamic focusing as depth changes. Mechanical focusing would require lenses or curved crystals, which aren’t used for these arrays, and optical focusing isn’t involved in ultrasound beam formation. Acoustics describes how the sound interacts with tissue, not how the beam is steered or focused by the transducer electronics.

Focusing in modern linear sequential array transducers is achieved electronically by applying precise time delays to the drive signals (and to the received signals) of the individual elements. These delays shape a converging wavefront so the beam focuses at a chosen depth, and they can be adjusted for dynamic focusing as depth changes. Mechanical focusing would require lenses or curved crystals, which aren’t used for these arrays, and optical focusing isn’t involved in ultrasound beam formation. Acoustics describes how the sound interacts with tissue, not how the beam is steered or focused by the transducer electronics.