Focusing with a curved active element is an example of which focusing type?

Focusing with a curved active element is an example of which focusing type?

• A. Phased array focusing
• B. External focusing
• C. Internal focusing
• D. Dynamic focusing

Answer: (C)

Focusing is determined by where the beam’s convergence is created. When the active element itself is curved, it acts as its own lens, bending the emitted wave so it converges to a focal point inside the tissue. This built‑in shaping of the beam by the element’s curvature is called internal focusing. No external lens is needed, and the focus is set by the curvature of the crystal. External focusing would use a separate lens outside the element to bend the beam. Phased‑array focusing relies on electronic delays across multiple elements to steer and focus, rather than the curvature of a single element. Dynamic focusing involves adjusting timing delays to change the focal depth during transmission or reception, typically within an array setup. So, the curved active element directly creates the focus within the transducer itself—internal focusing.

Focusing is determined by where the beam’s convergence is created. When the active element itself is curved, it acts as its own lens, bending the emitted wave so it converges to a focal point inside the tissue. This built‑in shaping of the beam by the element’s curvature is called internal focusing. No external lens is needed, and the focus is set by the curvature of the crystal.

External focusing would use a separate lens outside the element to bend the beam. Phased‑array focusing relies on electronic delays across multiple elements to steer and focus, rather than the curvature of a single element. Dynamic focusing involves adjusting timing delays to change the focal depth during transmission or reception, typically within an array setup.

So, the curved active element directly creates the focus within the transducer itself—internal focusing.