The LARP screen differs only in a few details from the screen structure for the Durchführung des Kopf-Impulstest lateral:

Head position target
The additional triangle shows the position in which the head is positioned in relation to the Head zero position is to be turned in order to Linken-Anteriors / Rreal-Posterior LARP archway.
LARP copy orientation area
The LARP head orientation area is highlighted in green when the subject's head is in the correct position for performing a head impulse in the LARP plane: rotated 45° to the right relative to the Head zero position.

Pulse direction diagram LARP

Technical information on naming and assigning the head axes can be found at Head motion axis assignment.

With the body and head in a straight position, please set the zero point of the head orientation by clicking / tapping on the head.

The LA & RP arcs tested on the LARP vKIT are rotated 90° and 45° around the z-axis (yaw) in relation to each other. The subject's head is therefore rotated 45° to the right so that the LA and RP semicircular canals lie in one axis through the zero position.

LARP head impulses are short (~10°) jerky turns of the head forwards and backwards.

Execution: Turn your head to the right until the avatar's nose points to the triangular mark.

The subject's eye should remain focused on the gaze target, i.e. it turns to the left in the video to counteract the turn of the head.

Performing the lateral head impulse test

Preparation

Head orientation

Please like top the subject's head position as described above.

Gaze fixation target

To carry out the LARP vKIT, the test person needs a gaze fixation target that is centrally located in their field of vision at a distance of 1m. Please position the gaze fixation target in such a way that it can be held firmly in place even if the subject turns their head up or down by 10-15°.

The fixation target is still located straight before the patient. Only a forward gaze ensures that the eye moves up and down and thus in the direction of the head impulse.

Pupil centering

Please ensure that the pupil is centered in the video image in the current orientation of the patient's head. Repeat the pupil centering if necessary.

Implementation

During the test, please ensure that the pupil can be easily recognized. If necessary, regularly ask the test person to open their eyes wide.

The test can only be performed if the pupil can be easily recognized by the system!

Good pupil recognition is characterized by the fact that the cross drawn in the pupil is stable.

Subject familiarization

I will now turn your head 45° to the right. Please continue to fix your gaze on the target in front of you. I will then make jerky and very small turns of your head forwards and backwards. Please bite your teeth so that you don't accidentally bite your tongue. Make sure that you keep your eyes wide open during the entire examination and look firmly at the target. Keep your head relaxed and do not tense your neck. The movements are very small and not uncomfortable. Please do not try to help me - I guide your head.

The system automatically recognizes head impulses forwards and backwards in the set LARP level.
Gently rock the patient's head back and forth to loosen it.
Keep an eye on the patient's eye on the screen and instruct the patient to open the eye if their eyelashes or eyelid begin to cover the pupil.
Perform a head impulse when the pupil is not covered. To do this, make a short (~10°) jerky turn of the head forwards or backwards. Important: After the impulse has been carried out, the head remains in the end position and is then slowly turned back to the starting position.
Please refer to the information area after performing the head impulse. This first displays the data recording:
The data analysis is then displayed immediately:
Once the data has been analyzed, the success or failure of the head impulse is displayed in the info area: Furthermore: the head pulse counter increases the time course of the head and eye velocity is displayed the gain value is updated.
Repeat further head impulses each time after the data analysis of the previous pulse is completed.