RIU 320 Chapter Notes - Chapter 4: Pulse Repetition Frequency, Acoustic Impedance, Lead Zirconate Titanate

• School: GVSU
• Department: Radiation and Imaging - Ultrasound
• Course: RIU 320
• Professor: Angela Malone

Document Summary

What determines the natural resonance frequency of a piezoelectric crystal: thickness of the matching layer, thickness of the crystal, diameter of the crystal, diameter of the backing material. What is the design goal of the matching layer: reduce acoustic impedance mismatch between crystal and patient, reduce the transmitted bandwidth. The acoustic impedance of the matching layer is less than pzt but more than tissue. What is the purpose of the matching layer: reduce spatial pulse length, reduce the transmitted bandwidth. The acoustic impedance of the matching layer is intermediate between pzt and tissue to enhance transmission of ultrasound into patient. What is the purpose of the backing material: reduce spatial pulse length, reduce the transmitted bandwidth. The backing layer enhances transmission of ultrasound into the patient and reduces ringing. Where is the matching layer: next to the backing layer, contiguous with the rf shield, next to the crystal, at the cable connection to the transducer.