A json formatted message is sent on this topic, when a head impulse test is detected and when it’s processing is completed

The completed-Message updates state and timestamp. The other fields are retained from the previous detected-Message.

State

Possible values:

• idle
  Not yet used. Status will be set to idle,

  • at start of device

  • when https://zeisberg.atlassian.net/wiki/spaces/DPET/pages/2156593292 is called

  • whenever DEV mode is terminated

  • whenever testaxis is different from lateral, LARP, RALP

• detected
  Is set, whenever the head velocity in the current testaxis (lateral, LARP, RALP) is exceeding the specified threshold for head impulse detection.

• completed
  Is set, when the pupil analysis is completed for the full video recorded

• failed
  Is set 1 second after detected event, if no completed event occured.

Plane

Plane is set acc. to the currently selected examination plane:

• lateral

• larp

• ralp

Timestamp

Timestamp in UnixMicros() at the time of creating the mqtt message.

Speed

Head velocity in the current test axis when recording the impulse was triggered.
Note: the actual start of the recording will be be before this trigger point. The system buffers both head-positions and video stream to allow presenting the head- and eye-velocity traces incl. the time before the head impulse was initiated.

Threshold

This is the specified threshold value that triggers a head impulse in the selected test plane.