Pulsed Echo Instrumentation Flashcards

Flashcards related to Pulsed Echo Instrumentation

Pulsed Echo Instrumentation

Ultrasound systems create sound pulses, retrieve reflections, and present audio and visual information for our interpretation.

Transducer

Turns electric energy to acoustic energy during transmission and acoustic energy back into electrical energy during reception

Pulser and Beam Former

Creates and controls the electrical signals sent to the transducer that generate sound pulses.

Pulser

Determines amplitude, PRP, and PRF

Beam Former

Determines the firing delay patterns for phased array systems

Receiver

Transforms the electrical signals from the transducer into a form suitable for display

Display

Presents processed data.

Storage

Archives the ultrasound studies.

Master Synchronizer

Maintains and organizes the proper timing and interaction of the systems components.

Pulser

Creates electrical signals that excite the transducer’s PZT crystals and create sound beams.

Transducer Output

The sonographer can adjust the magnitude of the pulser’s electrical voltage spike.

Noise

A random and persistent disturbance that obscures or reduces a signal’s clarity

Signal-to-noise ratio

A comparison of the meaningful information in an image (signal), compared to the amount of contamination (noise).

High signal-to-noise ratio

The signal is much stronger than the noise and the image is of high quality

Low signal-to-noise ratio

The strength of the signal is closer to the strength of the noise and the image contains a larger amount of visible contamination and has less diagnostic value

Beam Former

Part of the transmitter, and functions with array transducers during transmission and reception

Digital Beam Former

Device that modern beam formers use to produce signals in digital format

Transmit-Receive Switch

Protects the sensitive electrical components in the receiver from the high voltages created during transmission and directs the electrical signals from the transducer to the appropriate electronic and processing components within the US system

Channel

A single PZT element, electronics in the beam former/pulser and a wire that connects them

Amplification/Receiver Gain

Each signal returning to the machine from the transducer is made larger and each signal undergoes an equal amount of amplification.

Preamplification

The process of improving the quality of a signal before it is amplified.

Compensation

Creates an image that is uniformly bright from top to bottom.

Compression

Keeps the electrical signal levels within the accuracy range of the system’s electronics and keeps an image’s gray scale content within the range of detection by the human eye.

Demodulation

Two-part process that changes the electrical signals within the receiver into a form more suitable for display on a monitor

Rectification

Converts all negative voltages into positive voltages

Smoothing or Enveloping

Places a smooth line around the “bumps” and evens them out

Reject

Allows us to control whether low-level gray scale information within the data will be displayed on the image.

Dynamic Frequency Tuning

Systems with dynamic frequency tuning use only the high frequency part of the reflected pulses bandwidth to create the superficial portion of the image & Lower frequency portion of the bandwidth is used to create deeper portions of the image

Output Power

Affects image brightness by altering the strength of the sound pulse that the transducer sends to the body

Receiver Gain (Amplification)

Alters the strength of the voltages in the receiver that the transducer created during reception.

ALARA

As Low As Reasonably Achievable