Basic Instrumentation Flashcards
the US system converts _____ sound waves from the patient and converts them into _______ information
mechanical
electrical
basic instrumentation box graph
Tx <–> beam former –> signal processer –> image processor –> display
pulser (beam former) (does what/determines)
sends the voltage pulse to the probe determining the intensity, the operating frequency, and the PRF
in doppler ____ determines PRF
in 2D ____ determines PRF
scale
depth
pulse delays (beam former)
applies the delays necessary to accomplish focusing, beam steering, and aperture size (also apodization)
T/R (beam former)
transmit/receive switch
directs the pulse in the correct direction to protect sensitive components from large voltage pulses
amplifiers (beam former)
the pulses that return from the patient are weak and need this to make the trip through the circuitry of the machine
ADCs (beam former)
analog to digital conversion
the pulses pass through this and become digitized. this is necessary for storage in memory and for manipulation of the image later on
analog = ____ and shows ___
digitial = ____ and shows ____
ramp
every change of motion (ex. 9:19:08, (9:19:09)
stairs
not every change (9:19, 9:20)
echo delays (beam former)
remember that the echo pulses were delayed and must be reset to properly construct an image
sum (beam former)
adds together the pulses from each element in the segment to form the resulting scan line
what happens if you add together before delaying
waves not in phase with each other = destructive interferance
digitization of the voltage is crucial to maintain the ___ of the data through the system
integrity
digitization is a process that involves converting the _____ into a ______ which is more ____
voltage
binary number
stable
when can digitization occur
before or after echo delay but preference is to stabilize it early on
