The _____ and _____ increase the efficiency of sound transfer between the transducers PZT and the skin.

The _____ and _____ increase the efficiency of sound transfer between the transducers PZT and the skin.

• A. Matching Layer; Gel
• B. Gel; Skin
• C. PZT; Skin
• D. Backing Material; PZT

Answer: (A)

Efficient sound transfer from the transducer into tissue depends on reducing reflections at the boundary and ensuring tight acoustic contact. The matching layer sits between the PZT and the skin system and is designed to have an acoustic impedance between that of the PZT and the tissue. This bridges the impedance gap and minimizes reflections at the interface, so more of the emitted energy actually enters the tissue. The gel fills microscopic air gaps and provides a consistent, moisture-rich path for the ultrasound, eliminating air pockets that would otherwise reflect energy away. Put together, the matching layer and the gel optimize the boundary where the transducer meets the skin, boosting transmission into the tissue. The other options don’t provide both aspects—impedance bridging and gapless coupling—in the same effective combination.

Efficient sound transfer from the transducer into tissue depends on reducing reflections at the boundary and ensuring tight acoustic contact. The matching layer sits between the PZT and the skin system and is designed to have an acoustic impedance between that of the PZT and the tissue. This bridges the impedance gap and minimizes reflections at the interface, so more of the emitted energy actually enters the tissue. The gel fills microscopic air gaps and provides a consistent, moisture-rich path for the ultrasound, eliminating air pockets that would otherwise reflect energy away. Put together, the matching layer and the gel optimize the boundary where the transducer meets the skin, boosting transmission into the tissue. The other options don’t provide both aspects—impedance bridging and gapless coupling—in the same effective combination.