Standardization of Doppler Echocardiographic Signals
J. C. Conti, Ph.D., E. R. Strope, Ph.D., D. J. Rohde,
C. L. Hanawalt,* R.D.M.S., K. Scott,* R.D.M.S.
Sage Ewing, Galena, MO, *St. John's Hospital, Springfield, MO
A flow standard or phantom has been developed that allows
the cardiologist to assure reliable flow velocity values.
Proven technologies have been utilized to fabricate a device
that generates highly reproducible and reliable pulsatile
flow velocities up to 6 meters per second. Internationally
recognized experts in the area of cardiovascular flow
dynamics have contributed to this project.
After initial fabrication, the flow field of the flow phantom
was mapped using laser Doppler anemometry. All regions
within the flow field were accurate to approximately 2%
with a pulse-to-pulse reproducibility of 2%. The flow
phantom was then used to evaluate several clinical
ultrasound machines at four medical centers. Results
were mixed but indicated that nearly 30% of all the devices
evaluated were irreproducible or displayed Doppler
velocity signals as much as 25% in error.
Details of the design, calibration and clinical use of this
device will be presented.