Journal of Ultrasound in Medicine, Vol 9, Issue 8 429-436, Copyright © 1990 by American Institute of Ultrasound in Medicine
Testing ultrasonic pulsed Doppler instruments with a physiologic string phantom
D. J. Phillips, J. Hossack, K. W. Beach and D. E. Strandness Jr
Department of Surgery, School of Medicine, University of Washington, Seattle 98195.
The spatial, temporal, and frequency resolution of conventional ultrasonic
Doppler instruments and the time/space distortions in two-dimensional color
Doppler imaging systems can be measured using a pulsatile moving string
target. The diameter of the string is small compared with the Doppler
sample volume, the velocity (speed and direction), acceleration and timing
of the string motions are precisely known with reference to the R wave
timing mark, and the spatial location of the string is known. A loop of
surgical thread or monofilament fishline running between pulleys is driven
by a motor that provides constant string speeds from 0.05 to 150 cm/s and
variable string speeds programmed to mimic arterial velocity waveforms from
the carotid, aortic, and femoral arteries. Constant string speeds are used
to evaluate the Doppler sensitivity, frequency processing, and sample
volume size; pulsatile movement of the string provides a physiologic model
to evaluate the temporal performance of conventional Doppler systems and
the temporal and spatial performance of two-dimensional color Doppler
imaging scanners.
