Term
Go-Return-Time
(Time-of-Flight) |
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Definition
| The elapsed time from pulse creation to pulse reception. |
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Term
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Definition
| For every 13us of go-return-time, the object creating the reflection is 1cm deeper in the body. |
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Term
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Definition
| The go-return-time of a sound pulse between the transducer and the bottom image. |
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Term
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Definition
| Any device that converts one form of energy into another. |
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Term
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Definition
| When electrical energy from the system is converted into sound. |
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Term
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Definition
| When the reflected sound pulse is converted into sound. |
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Term
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Definition
A pressure-electric effect. The ability of a material (PZT) to create a voltage when mechanically deformed.
(Received)
(1/2 λ thick) |
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Term
| Reverse Piezoelectric Effect |
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Definition
The changing of the element's shape as a voltage is applied.
(Transmit) |
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Term
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Definition
Increases the efficiency of sound entering the body.
(1/4 λ thick) |
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Term
Backing Material
(Damping Material) |
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Definition
| A high degree of sound absorption that shortens the ringing of the element and the length of the pulse. |
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Term
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Definition
| The range of frequencies from the lowest to the highest in the pulse. |
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Term
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Definition
| A unitless number used to describe the sensitivity of a transducer. |
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Term
Curie Temperature
(Curie Point) |
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Definition
The temperature at which PZT is polarized.
(400o C) |
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Term
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Definition
| The loss of piezoelectric properties. |
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Term
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Definition
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Term
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Definition
| The location where the beam is the narrowest. |
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Term
Near Zone
(Near Field, Fresnel Zone) |
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Definition
| The region of the sound beam from the transducer to the focus. |
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Term
Focal Length
(Focal Depth, Near Zone Length) |
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Definition
| The distance from the transducer to the focus. |
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Term
Far Zone
(Far Field, Fraunhofer Zone) |
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Definition
| The region of the beam that starts at the focus and extends deeper into the body. |
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Term
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Definition
| The region around the focus where the beam is narrowed. |
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Term
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Definition
| Adjustable focus systems. |
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Term
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Definition
| The gradual spread of the ultrasound beam in the far field. |
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Term
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Definition
| Numerous constructive and destructive interferences that make an hourglass shaped beam. |
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Term
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Definition
| The ability to create accurate images. |
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Term
Axial Resolution
(Longitudinal, Range, Radial, Depth Resolution) |
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Definition
| The ability to see 2 very close structures as 2 seperate structures when they are parallel to the beam's main axis. |
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Term
Lateral Resolution
(Angular, Transverse, Azimuthal) |
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Definition
| The ability to see 2 very close structures as 2 seperate structures when they are perpendicular to the beam's main axis. |
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Term
Fixed Focusing
(Mechanical, Conventional) |
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Definition
| Focus from a single element transducer that cannot be changed. |
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