Doppler waveform analysis capabilities include
indicating the severity of the occlusive process can be used in combination with segmental pressures
Limitations to doppler waveform analysis include____
*patients with casts or bandages
*waveform affected by temp
*CHF may result in dampened waveform
unable to discriminate STENOSIS from OCCLUSION; technically dependent test.
___ is a type of velocimetry that employs a zero-crossing frequency meter to display the signals graphically on a strip chart recorder
____ estimates frequencies present in the reflected signal and displays them. The circuitry counts ea time the input signal crosses through the baseline within a time span.
zero crossing detector
with zero-crossing detection ___ frequency waves have many oscillations and ___ frequency waves have few.
___ is a type of velocimetry that uses individual frequencies displayed by the FFT method
an upper extremity arterial doppler velocity wave form exam includes ____ arteries
subclavian, axillary, brachial at elbow antecubital fossa, radial thumb side at wrist, ulnar at wrist
a lower extremity arterial doppler velocity wave form exam includes ___ arteries
CFA, SFA popliteal, PTA medial malleolus, DPA top of foot, and peroneal if necessary at lateral malleolus
A qualitatively normal wave form is __ while abnormal wave forms may be __ or __
triphasic, biphasic, monophasic
a ____ signal is often obtained proximal to an obstruction, with no diastolic flow.
when there is vasodilation of distal vessels assoc with a proximal obstruction __ occurs
reduction in the pulsatility causing the signals to have lower resistant (steady) flow quality
Normal Doppler waveform Post exercise will have what type of appearance
pre exercise wave form qualities are maintained and/or augmented
*no reverse component
Remember that, usually just segmental pressures obtained post exercise describes
Abnormal Doppler waveform Post exercise will have what type of appearance
*slow upstroke with more rounded peak
no reverse component
absent doppler signals that may suggest occlusion or pre-occlusive vessel is known as___.
___ helps to differentiate inflow (aorto-iliac) disease from outflow (S femoral) disease
___ is based on the principle that proximal arterial obstruction results in a slowing of the time interval between the onset of systole to the point of maximum peak.
what are some of the drawbacks of using Analog vs Spectral analysis for obtaining doppler waveform analysis
noise high velocities underestimated
less sensitivity low velocities overestimated
spectral analysis free of many of the analog recording drawbacks
how do you obtain the calibration of doppler waveform on the analog system
most equipment does a self calibration when the system is activated
The circuitry in analog _____
zero crossing frequency meter
how many times the input signal crosses through zero (the baseline) w/n a time span