otometrics ICS Impulse USB User Manual page 12

User Guide
6.5.2 LARP or RALP test
This procedure assumes that the test is performed after the Lateral test.
1. Choose the
head trace) should be bold in the Real Time Trace. It also determines the shape of the training curves.
2. For patients with spontaneous nystagmus or gaze-evoked nystagmus (evoked by gaze position during head impulse),
select the check box
tagmus or gaze-evoked nystagmus, it prevents good impulses from being rejected inappropriately.
Note
• Clicking
The button is disabled if the setting for
dow. Please refer to the Reference Manual.
3. Ensure that the patient's head is not moving and that it is perfectly centered. Click
4. Move the head to the right (LARP test) or to the left (RALP test) until the head and canals turn green on the head pos-
ition feedback graphic.
5. Position the ROI (Region of Interest) around the pupil:
– click on the green box and drag to center it on the pupil, or
– click on the pupil to center the pupil inside the green box.
6. Ask the patient to stare at the fixation dot. Assess pupil tracking by observing the cross-hair: If the cross-hair fails to
track the pupil (jumps around and does not stay centered on the pupil), move the threshold slider to adjust.
7. Select OK
Note Calibration values calculated for the Lateral test remain valid for the LARP/RALP tests.
•
8. If a Lateral test was performed prior to starting this test, continue to (
12
Impulse Type LARP RALP
: or
Spontaneous Nystagmus
Center
sets the reference point used to provide feedback for head position during LARP/RALP testing.
Head Position Feedback During LARP/RALP
to accept the ROI position.
. Choosing the impulse type determines which plane of the gyroscopes (i.e.,
. By selecting this check box for a patient who has spontaneous nys-
Collecting Head Impulse data ► 17
Options
is disabled in the win-
Center .
).
Otometrics - ICS Impulse USB