Transducer Components Flashcards
electrical shield
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
acoustic insulator
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
PZT
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
wire
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
matching layer
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
case
tube, made of metal or plastic
protects internal components of the transducer from damage
also insulates patient from electrical shock
backing material(damping element)
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