D-0134090-A – 2022/11
VisualEyes™ - Instructions for Use - EN
Page
86
3.9.2.3 Dix Hallpike Advanced
The Dix Hallpike Advanced is performed similarly to the Dix Hallpike test described in section 3.9.1.3.
However, the Dix Hallpike Advanced also enables torsional eye movement recordings, and uses the 3D
head model to get feedback on the patient’s head position. The spatial position of the head will be presented
with a black bar on the two position sliders. The shaded areas on the position sliders present the desired
position of the head. When the head is positioned in the desired angle, the shaded area will turn green
instead of orange.
3.9.2.4 Gaze Stabilization
The Gaze Stabilization Test (GST) requires the VORTEQ
TM
IMU to be attached to the headband. This test
does not require any goggle or rotary chair. The patient needs to be in the sitting position in front of the
testing screen and if you use a rotary chair, ensure that it is locked.
Note:
The distance between the patient and the test screen should be optimized based on the screen size.
The software shows a warning message if the patient is seated too far away.
Before starting the test, the patient will establish his/her static acuity by correctly defining the optotype
character
without shaking the head. In the GST test, the optotype size remains the same but the head
velocity changes. The head velocity is measured in degrees per second. The results are plotted as a bar
graph. Please refer to the
Additional Information
for a detailed description.
3.9.3 VORTEQ™ diagnostic
VORTEQ™ Diagnostic can be added to
VisualEyes™ 525
, and includes
Active Head Rotation and vHIT
VORTEQ
™. The tests require the use of the VORTEQ™ IMU.
3.9.3.1 Active Head Rotation
Ensure the chair is in the sitting position and locked. If applicable, leave the hook and loop straps (Orion and
System 2000) from the head support detached from the goggles. Attach the VORTEQ
TM
IMU to the binocular
goggles. The start of the test will have the patient shake his/her head to the sound of a metronome at a low
frequency for ten seconds as practice before the test begins. Have the patient smoothly shake his/her head
side to side for horizontal testing or up and down for vertical testing. If the test is performed with a wrong
orientation, the operator gets a warning message from the software.
3.9.3.2 vHIT VORTEQ
TM
Ensure that the patient is seated in an upright position and the head rest of the rotational chair is taken off.
Ensure the calibration is done before starting the test. Side mounted/top mounted goggles with camera can
be used for this test. Make sure the IMU is connected and switched on before starting the test.
