Transducer Components

Question 1

electrical shield

Answer 1

thin, metallic barrier lining inside of case

prevents spurious electrical signals in the air, unrelated to diagnostic info, from entering the transducer

helps prevent electrical noise from contaminating the clinically important electric signals used to create diagnostic images

Question 2

acoustic insulator

Answer 2

thin barrie of cork or rubber that isolates or “uncouples” the internal components of the transducer from the case

prevents vibrations in the case from inducing an electrical voltage on the PZT

Question 3

PZT

Answer 3

the piezoelectric crystal

characteristics of the sound beam emitted by the transducer are related to the dimensions of the active element

the PZT is one-half wavelength thick

Question 4

wire

Answer 4

provides an electrical connection between the PZT and the ultrasound system

the voltage from the system causes the crystal to vibrate and produce an ultrasonic wave

during reception, the crystal’s vibration produces a voltage that returns to the system to be processed into an image

Question 5

matching layer

Answer 5

lies in front of the PZT at the face of the transducer, increases the efficiency of sound energy transfer between the active elements and the body, also protects the active element

matching layer is one-quarter wavelength thick

Question 6

case

Answer 6

tube, made of metal or plastic

protects internal components of the transducer from damage

also insulates patient from electrical shock

Question 7

backing material(damping element)

Answer 7

bonded to the back of the active element, reduces the “ringing” of PZT

material causes the PZT crystal to produce short pulses, rather than one long one, which enhances axial resolution