In external focusing, what is placed in front of the piezoelectric material?

In external focusing, what is placed in front of the piezoelectric material?

• A. Lens
• B. Mirror
• C. Filter
• D. Crystal

Answer: (A)

External focusing relies on shaping the emitted ultrasound waves with a lens placed right in front of the piezoelectric element. The piezoelectric material acts as the sound source, converting electrical energy into mechanical vibrations. By placing an acoustic lens in front of it, the wavefronts are refracted so they converge at a chosen focal point. This concentrates energy at a specific depth, improving lateral resolution and signal intensity where you want it. A mirror would reflect rather than focus the beam, a filter would alter frequency content rather than focus, and a crystal is the piezoelectric material itself, not the focusing component.

External focusing relies on shaping the emitted ultrasound waves with a lens placed right in front of the piezoelectric element. The piezoelectric material acts as the sound source, converting electrical energy into mechanical vibrations. By placing an acoustic lens in front of it, the wavefronts are refracted so they converge at a chosen focal point. This concentrates energy at a specific depth, improving lateral resolution and signal intensity where you want it. A mirror would reflect rather than focus the beam, a filter would alter frequency content rather than focus, and a crystal is the piezoelectric material itself, not the focusing component.