Chapter 6: The Doppler Effect

frequency, wavelength, reflector

the Doppler effect is a change in _______ or ________, caused by the motion of a wave source, receiver, or ______.

doppler effect

the apparent change in frequency

compression

when the train is stationary, the outer line is

rarefaction

when the train is stationary, the space between the lines is

higher

in the direction the train is moving the _____ the pitch is

lower

the opposite direction of the train the ______ the pitch is

doppler effect

no motion = no ______ ______

compressed

the faster the movement, the more _______ it is

true

true or false: the velocity of the moving object affects doppler frequency

positive, red

when the source is towards the transducer it is a ______ Doppler shift. And it shows up as the color ____

negative, blue

when the source is away from the transducer it is a ______ Doppler shift. And it shows up as the color ____

speed of motion, angle, frequency

frequency shifts depend on ____ ____ ____ of the reflector, the ______ between the wave’s propagation direction and the direction of motion, and the _______ emitted by the source

fdop=frecieved-foriginal

what is the general Doppler shift equation?

2foV/c

what is the equation in order to find fdop when parallel to the blood

2foVcos0/c

what is the equation in order to find fdop at an angle?

100 Hz-11,000 Hz

what is the typical Doppler shift range?

inverse, non-linear

what is the relationship between Doppler angle and Doppler frequency

0 degrees parallel facing direction of flow

what is the angle for the maximum positive Doppler shift?

180 degrees parallel facing opposite the direction of flow

what is angle for the maximum negative Doppler shift?

0-30

the critical angle is between what range on the positive side of 90 degrees?

150-180

the critical angle is between what range on the negative side of 90 degrees?

true

true or false: where a person is standing will determine what they will hear

(1-cosvalue)x100

what is the equation for percent underestimation?

original velocity x cosvalue

what is the equation for calculated velocity?

calculated velocity+((1-cos)xactual velocity)

what is the equation for compensated velocity?

blood flow

compensated Velocity=actual _____ ______ velocity

calculated velocity/cosvalue

actual velocity=

false

true or false: if you forget to put angle correct on, machine will not underestimate velocity

vessel, angle

uncompensated velocity=scanning a ____ without _____ correction

above

is the Doppler above the line or below the line when it is towards the transducer?

below

is the Doppler above the line or below the line when it is away from the transducer?

use the highest frequency transducer and use as small a Doppler angle as possible

to obtain the best Doppler shift you must….

up to 100 cm/s

what is the typical range from flow speed?

30-60, 0 when possible

what is the typical range for doppler angle?

2-15 MHz

what is the typical range for operating frequency?

100 Hz-11,000 Hz

what is the typical range for Doppler shifts?

presence, absence, character, velocity, amplitude

doppler tells us _____ or _____ of flow, direction of flow, _______ (turbulent or laminar), v______of flow, and a________ of Doppler signal

fDc/2focos0

what is the veocity equation? (how fast the blood is moving)

cw, pw, color

what are the Doppler modalities?

spontaneous contrast

what is another term for smokey blood?

rouleau formation

what is the term for when blood slows and starts stacking?

0 degree insonification

what is it called when the direction are pointing towards each other and is a positive Doppler?

180 degree insonification

what is it called when the arrows are pointing in the same direction from each other and is a negative Doppler?

0

when you say “flow towards” you can assume the angle is ___ when there is no angle specified?

180

when you say “flow away” you can assume the angle is ___ when there is no angle specified?

1,540

when there is no propagation speed given, you can assume that it is ____ m/s