Term
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Definition
Any device that converts one form of energy into another |
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Term
Define:
Piezoelectric Effect |
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Definition
A property of certain materials to create a voltage when pressure is applied or when the material is mechanically deformed |
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Term
What are some common piezoelectric materials and what is another name for it? |
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Definition
AKA ferroelectric material
Natural: quartz, Rochelle salts, tourmaline
Man-made: barium titanate, lead metaniobate, leat titanate, lead zironate titanate (PZT) |
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Term
How is the Piezoelectric Material polarized? |
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Definition
The material is exposed to a strong electrical field while being heated to a substantial temperature. |
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Term
The temperature at which PZT is polarized is? |
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Definition
The Curie Temperature or Point
~360°C or 680°F |
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Term
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Definition
The complete destruction of all living microorganisms by means of exposure to heat, chemical agents, or radiation. |
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Term
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Definition
Refers to the application of a chemical agent to reduce or eliminate infectious organisms on an object. |
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Term
Should an object be sterilized or disinfected when it is designed to penetrate skin or mucous membranes? |
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Definition
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Term
Should an object be sterilized or disinfected when it is designed to come into contact with mucous membranes? |
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Definition
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Term
What is an approved method to disinfect an ultrasound transducer? |
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Definition
Cidex or other cold gemicides such as gluteradehyde |
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Term
What are the basic components of an ultrasound transducer? |
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Definition
case
electrical shield
acoustic insulator
PZT, active element
wire
matching layer
backing material/damping element |
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Term
Which component of the transducer is being described?
The cylindrical tube, constructed of metal or plastic, that protects the internal components of the transducer from damage. This component also insulates the patient from electrical shock. |
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Definition
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Term
Which component of the transducer is being described?
A thin metallic barrier lining the inside of the case. This component also prevents spurious electrical signals in the air, unrelated to diagnostic information, from entering the transducer. Thus, this component helps prevent electrical noise from contaminating the clinically important electrical signals used to create diagnostic images. |
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Definition
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Term
Which component of the transducer is being described?
A thin barrier of cork or rubber that isolates or "uncouples" the internal components of the transducer from the case. This component prevents vibrations in the case from inducing an electrical voltage in the PZT of the transducer. |
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Definition
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Term
Which component of the transducer is being described?
This component is shaped like a coin. The characteristics of the sound beam emitted by the transducer are related to the dimensions of this component. This component is constructed to be 1/2 wavelength thick. |
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Definition
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Term
Which component of the transducer is being described?
Provides an electrical connection between the PZT and the ultrasound system. The active element requires electrical contact so that during transmission, the voltage from the ultrasound system can cause the crystal to vibrate and produce an ultrasonic wave. Similarly, during reception, the crystal's vibration produces a voltage that must return to the system for processing into an image. |
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Definition
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Term
Which component of the transducer is being described?
Positioned in front of the PZT at the face of the transducer. This component is designed to increase the efficiency of the sound energy transfer between the active element and the body, and to protect the active element. This component is 1/4 wavelength thick. |
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Definition
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Term
Which component of the transducer is being described?
Bonded to the back of the active element, it reduces the "ringing" of the PZT. This component is commonly made of epoxy resin impregnated with tungsten filaments. When an electrical spike excites the PZT, this component restricts the extent of PZT deformation. The emitted sound pulse is dampened; this, it is short in duration and length. |
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Definition
backing material aka damping element |
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Term
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Definition
Range of frequencies (or difference) between the highest and the lowest frequency emitted from a transducer. |
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Term
Define:
Quality Factor
What is the equation? |
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Definition
A unitless number representing the extent of damping.
QF = main frequency/bandwidth |
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