Quantification of eyelid closure and facial movements during electrically elicited eye-blinking

Electrical stimulation (ES) has demonstrated potential for reanimating eye-blink following facial paralysis caused by damage to the seventh cranial nerve. However, the effective restoration of a natural-like eyeblinking and the possible alteration of facial mimic motion associated with ES has been scarcely investigated and quantified in humans. An objective quantification of eyelid motion and overall facial movements could help to identify the stimulation pattern which may provide the most natural eyelid closure without exciting adjacent facial musculature. We developed and experimentally evaluated a new method based on image analysis aimed at quantifying the eyelid closure and any possible facial movements induced by eye-blink stimulation.