What settings should be used for low frequency filter (LFF) during an EOG?

The low frequency filter (LFF) setting for electrooculography (EOG) is typically set at 0.3 Hz. This setting is effective in filtering out unwanted slow-wave fluctuations while still capturing the relevant eye movement signals that are of interest during polysomnography. A 0.3 Hz filter allows for the detection of eye movements while reducing the impact of slow artifact, which may be caused by various physiological factors or movement.

The choice of 0.3 Hz as the LFF setting helps ensure that the EOG signal is both clear and clinically useful. It strikes a balance between minimizing low-frequency noise and preserving the integrity of the eye movement data. Using higher LFF settings—such as 0.5 Hz or 1.0 Hz—might inadvertently filter out important low-frequency components of the EOG signal, potentially obscuring valuable diagnostic information. Similarly, a lower setting like 0.1 Hz may introduce too much low-frequency noise into the EOG signal, making it less reliable for clinical interpretation. Therefore, 0.3 Hz is regarded as the optimal setting for capturing accurate EOG data in polysomnographic studies.