or

or

taken

why

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size     Small Size show me how

# PhysicsModule5

### Questions from Module 5 of the Physics component

Describe the Doppler Effect. Waves transmitted from a moving object have a freq dependent upon relative velocity between transmitter and observer.
Explain the Doppler shift phenomenon under the following conditions:Stationary source and stationary receiver. Frequency is unchanged, because neither of the objects are moving.
Explain the Doppler shift phenomenon under the following conditions:Stationary source and moving receiver. If receiver is moving TOWARDS the Tx- frequency increasesIf receiver is moving AWAY from the Tx- frequency decreases
Discusss the relationship between Doppler (frequency)shift, Doppler source/target speed, and Doppler source/target direction. Doppler shift is the absolute difference between the frequency of the source and the target's echoes. Higher velocities produce higher frequency shifts.
What kind of information is presented in a CW Doppler display? There is no range resolution,it samples all flow along the path, there is fill-in of the window, and displays high velocity without aliasing
What kind of information is presented in a PW Doppler display? It's range specific, subject to aliasing, affected by sample box size, and Max velocity indirectly prop to US freq
Describe triphasic flow. Bidirectional flow (dips below the baseline) that feeds high resistance beds, examples: Ao, femoral arteries, ECA
Describe biphasic flow. Unidirectional flow that feeds low resistance beds, examples: ICA, RA
Describe monophasic flow Unidirectional flow that feeds very low resistance beds, examples, L/R hepatic, arcuate artery
Describe laminar flow indicated by an “open” window on spectral analysis **center of vessel has highest flow freq. / Majority of vessels in body have laminar flow
Describe turbulent flow. blood no longer flows in one direction along the vessel's length but occurs crosswise; indicated by a filled-in window on spectral analysis
Describe plug flow. blood is going at same velocity in the vessel; large diameter aa (Ao and common iliac)/triphasic (bidirectional)
Describe parabolic flow. same as laminar flow
Give examples of quantitative data. Numeric data: peak/mean velocity, pulsatility/resistive index, area under curve, slope
Give examples of qualitative data. descriptive data: characteristics of wave form, presence or absence of flow, patancy of flow, direction of flow, laminar vs turbulent, phasic vs continuous, spectral broadening
Created by: sbeard1