When a frame does not contain normal data, it is called an error frame. The type of error frame is displayed in the Error Information bar at the bottom of the main form.
In most cases, it should display "TrackingErr."
In the case of tracking errors, there are broadly two reasons.
The first is an error due to fixational microsaccade detection. Frames in which fixational microsaccades occur move faster than the camera's shutter speed. Therefore, if such frames are included in the analysis, incorrect values may be produced. This function was introduced from Ver. 3. However, this detection function is not extremely accurate. In rare cases where errors appear at the rising phase of the heartbeat, it is highly likely that the detection is erroneous. If you wish to adjust this detection function, please edit the contents of "Sys.ini." This file should be located in the "C:\Program Files\Softcare.,Ltd\LSFG Analyzer" directory. Open the file and increase the value of "KOSHIBIDO_SHIKIICHI." This will make the detection function less sensitive. The value can be increased up to a maximum of 1. Setting the value to 1 disables this function.
The second reason is an error caused by exceeding the tracking movement limit.
This applies to cases where, for example, the optic disc was at the center of the screen at the start of measurement, but fixation could not be maintained afterward and the disc position shifted significantly to the right. The current tracking distance limit is 100 pixels relative to the reference frame. This is because tracking beyond that distance would likely result in areas with insufficient sample counts when creating HeartBeat or Composite maps.