Exam 2 Review

14 cards·by Rachel Valley

What is a transducer?

ANY DEVICE THAT IS CAPABLE OF CHANGING ONE FORM OF ENERGY INTO ANOTHER

What is it called when certain materials are mechanically deformed, and they produce a voltage?

Piezoelectric effect

What is the indirect piezoelectric effect?

Electrical Voltages converted into acoustic energy

What is the direct piezoelectric effect?

Acoustic energy converted into electrical voltages

List the natural piezoelectric materials

AMBER

List the man made piezoelectric materials

LEAD ZIRCONATE TITANATE 5 (PZT)

What is the most common element used in ultrasound?

LEAD ZIRCONATE TITANATE 5 (PZT)

What is the purpose of the matching layer?

PROVIDES AN INTERMEDIATE IMPEDANCE IN RELATION TO CRYSTAL AND TISSUE

What number would be the best choice for the matching layer if the skins impedance is 800 rayls and the piezoelectric element is 1200 rayls?

1000 Rayls - an intermediate number between the skin and element

In regards to element thickness, the higher the frequency the ______ the element.

Thinner

Would the element be thicker with a 2MHz probe or an 8 MHz probe?

2 MHz

What is the ideal thickness of the matching layer?

1/4 the wavelength

What component of the transducer limits the ringing of the pulse and reduces pulse duration?

Damping layer

What does the damping material do?

Reduces number of cycles in pulse, Reduces pulse duration, Reduces spatial pulse length, Increases frequencies present, Improves spatial (l