
Operation Manual
5-8
Doppler Mode
These are measurement results taken with the RMI 1425A Phantom.
Measurement Type Range Accuracy Notes
Velocity PW: 0.1cm/s - 8.8m/s
<
± 1 % or 1/2 pixel Acquisition
Frequency PW: 6Hz - 22.727kHz
<
± 1 % or 1/2 pixel Acquisition
Time dierence 10ms - 9.44s
<
± 1 % or 1 column Acquisition
Velocity dierence PW: 0.2cm/s - 8.8m/s
<
± 2 % or 1 pixel Acquisition
Frequency dierence PW: 12Hz - 22.727kHz
<
± 2 % or 1 pixel Acquisition
Slope (in Velocity) PW: 0.1cm/s
2
- 880m/s
2
<
± 1 % or 1 pixel /1 column Acquisition
Slope (in Frequency) PW: 1Hz/s - 2272.7kHz/s
<
± 1 % or 1 pixel /1 column Acquisition
NOTE: Accuracy in the table is determined by the cursor position in Doppler Mode and the cursor
position during measurement. The velocity tests can therefore be used to check these values since
these are not indicators of the underlying absolute velocity assurance. Accuracy tests for absolute
velocity are performed with Phantom measurements.
* Absolute Doppler Velocity Accuracy
Accuracy is dened as the dierence between a calibrated phantom velocity and that annotated as the
time-averaged mean by the system. The time-averaged mean velocity is calculated as the average over
a determined period of time of the intensity-weighted mean of the spectrum.
All probes have been tested to ensure that the time-averaged mean velocity falls within +/- 15% of that
annotated on the phantom. Due to Doppler phantom constraints, these tests have been conducted in
the range 15 cm/sec to 110 cm/sec.
Comentarios a estos manuales