What are the two function that an ultrasound transducer performs?
transmitting and receiving
What describes the property of certain materials to create a voltage when they are mechanically deformed?
Piezoelectric materials change shape when a voltage is applied to them, is a process called what?
reverse piezoelectric effect
What is another word for peizoelectric?
What is the cylindrical tube, constructed of metal or plastic, that protects the internal components of a transducer from damage?
What is the thin metallic barrier which lines the inside of the case and prevents spurious electrical signals in the air from entering the transducer?
What is the thin barrier of cork or rubber that isolates the internal components of the transducer from the case?
What is the piezoelectric element in a transducer?
crystal, PZT, etc (active element)
What provides an electrical connection between the PZT and the ultrasound system?
What increases the efficienty of sound energy transfer between the active element and the body and protect the active element?
Bonded to the back of the active element, this is needed to reduce the ringing of the pulse in the transducer.
backing material (damping)
What increases the efficiency of sound between the transducer's element and the skin?
matching layer and gel
The range between the highest and lowest frequencies in the pulse is the what?
The main frequency divided by the bandwidth is what?
Q-factor (quality factor)
What are low Q-factors a result of?
Exposure of a material to a strong electrical field while being heated to the Currie point results in what?
If a polarized element is heated to the Curie point, what happens to its piezoelectric properties?
they are destroyed
The destruction of all microorganisms by exposre to extreme heat, chemical agents, or radiation is what?
The application of a chemical agent to reduce or eliminate infectious organisms on an object is what?
The frequency of sound emitted by a CW probe is equal to the frequency of what?
The frequency of sound created by the active element of a pulsed ultrasound transducer depends upon the characteristics of what?
Which characteristics of the active element determine the frequency of sound created by a pulsed wave transducer?
speed of sound in the PZT, thickness of the PZT
In a pulsed wave transducer, how are the speed of sound in PZT and the frequency of sound related?
The speed of sound in most piezoelectric materials ranges from what?
For pulsed wave transducers, thinner active elements create what?