User guide

70 Exam-based calculations
To perform a Transcranial Doppler or
Orbital calculation
1 Select the correct exam type:
• Orbital (Orb) to measure Opthalmic
Artery and Siphon
• Transcranial (TCD) for other
measurements
See “To change the exam type” on page 33.
2 On a frozen Doppler spectral trace, press the
CALCS key.
3 From the calculations menu, select Left or
Right.
4 Do the following for each measurement you
want to take:
a From the calculations menu, select the
measurement. (You may need to select
Next or Prev to locate the measurement.)
b Do one of the following:
• For a manual trace measurement, use
the touchpad to position the caliper.
Press the
SELECT key. Use the touchpad
to trace the waveform.
If you need to make a correction, select
Undo on-screen or press the
BACKSPACE
key.
• For an auto trace measurement, select
Auto on-screen, and use the touchpad
to position the first caliper at the
beginning of the waveform. Press the
SELECT key, and position the second
caliper at the end of the waveform.
Confirm that the system-generated
boundary is correct. If you are not satisfied
with the trace, obtain a higher quality
Doppler spectral trace image, or trace
manually.
c Press the
SET key.
d Save the calculation. (See “To save a
calculation” on page 47.)
AL ECVA TAP
PSV
EDV
PI
RI
S/D
Gate Size
*Available but not required
WARNING:
To avoid injury to the patient, use
only an Orbital (Orb) or
Ophthalmic (Oph) exam type
when performing imaging
through the eye. The FDA has
established lower acoustic energy
limits for opthalmic use. The
system will not exceed these
limits only if the Orbital or
Ophthalmic exam type is
selected.