Name in decreasing order of impedance PZT to Skin.

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Sharpen your skills for the Davies Publishing SPI Test with targeted flashcards and multiple-choice questions, complete with hints and clarifications. Prepare thoroughly for success!

Multiple Choice

Name in decreasing order of impedance PZT to Skin.

Explanation:
The main idea is acoustic impedance and how layers are arranged to transfer ultrasound energy with minimal reflections. The PZT element has a very high acoustic impedance compared with body tissues. To push most of the acoustic energy into the body, you insert a matching layer right next to the PZT that has an impedance between the PZT and the tissue. The gel, which fills the gap to the skin, has an impedance closer to that of tissue and helps bridge the boundary to skin. The skin itself presents the lowest impedance in this stack, so the sequence from highest to lowest impedance goes PZT → matching layer → gel → skin. If any step went the other way (an interface with higher impedance after a lower one, or placing skin ahead of gel), the reflections at that interface would increase and energy transfer would be less efficient.

The main idea is acoustic impedance and how layers are arranged to transfer ultrasound energy with minimal reflections. The PZT element has a very high acoustic impedance compared with body tissues. To push most of the acoustic energy into the body, you insert a matching layer right next to the PZT that has an impedance between the PZT and the tissue. The gel, which fills the gap to the skin, has an impedance closer to that of tissue and helps bridge the boundary to skin. The skin itself presents the lowest impedance in this stack, so the sequence from highest to lowest impedance goes PZT → matching layer → gel → skin. If any step went the other way (an interface with higher impedance after a lower one, or placing skin ahead of gel), the reflections at that interface would increase and energy transfer would be less efficient.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy