A Proof‐of‐Concept Assessment of a Novel Wearable Eyelid Muscle Device: A Pre‐Clinical Animal Cadaver Study for Eyelid Closure Restoration

Spontaneous blinking (SB) is a critical function required to maintain eye health. The act of SB lubricates the cornea with precorneal tear film and removes foreign particles to prevent damage. People who suffer from various forms of facial nerve palsy (FNP) regularly demonstrate a deterioration of their SB mechanism performance. Often, their eyelid are unable to achieve adequate closure, or they are unable to blink frequently enough. Absence of this mechanism can result in severe consequences such as permanent eye damage, blindness, and social isolation. This article introduces a soft wearable eyelid sling device incorporating a hydraulic soft artificial muscle (SAM) for achieving complete closure of an eyelid. The SAM is driven by a cam mechanism that provides a displacement profile closely matched with those of a healthy eyelid. A prototype concept has been produced and tested on the head of a sheep cadaver. A series of twelve sequential blinks was induced through the activation of the novel wearable eyelid muscle device across ten separate trials on a single specimen. Experiments reveal that the proposed concept can achieve complete average eyelid closure across all 12 blinks for each trial at a frequency of 15 blinks per minute, successfully replicating the SB mechanism. The outcome provides confidence that the device has the potential to undergo more extensive pre‐clinical and clinical testing to become an effective solution for blinking rehabilitation of patients suffering from FNP.