Pulsed Echo Instrumentation Flashcards
Ultra sound systems contain these six major components
Transducer, pulser and beam former receiver, display, storage, master synchronizer
During transmission this transforms electrical energy into acoustic energy. During reception this converts the returning acoustic energy into electrical energy.
Transducer
Creates and controls The electrical signals sent to the transducer that generate sound pulses.
Pulser and beam former 
Transforms electrical signals from the transducer produced by the reflected sound into a form suitable for display
Receiver
Presents processed data
Display
Archives the ultrasound studies
Storage
Maintains and organizes the proper timing and interaction of the systems components
Master synchronizer
When signal to noise ratio is high the signal is much ___ then the noise
Higher
Increasing output power also increases
Signal to noise ratio
The most common way to improve the signal to noise ratio
Increase output power
The order of receiver operations
Amplification, compensation, compression demodulation, reject

Amplification is also called
Receiver gain
The process of improving the quality of a signal before it is amplified. Occurs within the transducer itself

Pre-amplification 
What creates an image that is uniformly bright from top to bottom
Compensation
Echoes arising from greater depths are what because sound beams attenuate the farther they travel
Weaker
Compensation is also known as
Time gain compensation, depth gain compensation, and swept gain
Within the five receiver functions what is not adjustable
Demodulation
What changes the gray scale characteristics of the image
Compression
Humans can distinguish approximately how many shades of Gray
20
Other names for compression
Log compression or dynamic range
Changes the form of the electrical signal so that it is appropriate for the systems display
 Demodulation
2 parts in demodulation
Rectification and smoothing
Converts all negative voltages into positive voltages
Rectification
Controls whether low level gray scale info within the data will appear in the displayed image
Reject
Synonyms for reject
Threshold or suppression
If image is too bright adjust the
Output power
If image is too dark adjust the
receiver gain
The depth of the tgc in which it begins is known as
Delay
At the depth of this in tgc, reflections are maximally compensated by the us system
Knee
At superficial depths, reflection undergo a smal constant amount of compensation called
Near gain
Maximum amount of compensation that the receiver can provide
Far gain
Compression synonyms
Log compression and dynamic range
Reject synonyms
Threshold and suppression
