A novel eyelid motion monitor.

BACKGROUND: Eyelid motion analysis can provide important information about ophthalmic, neurologic, and systemic diseases. Routine assessment of eyelid function is currently based mainly on clinical examination estimating Levator Function and static palpebral fissure measurements. Most clinical tools developed to date are cumbersome expensive and difficult to operate. Currently there is no widely available, affordable device providing user friendly precision based evaluation of eyelid kinematics. Our goal is to develop a novel device for evaluation of eyelid kinematics providing rapid defined diagnosis of diseases involving eyelid movement.

METHODS: A real-time prototype eyelid motion monitoring system was designed based on magnetic field sensors detecting movement of a tiny magnet located on the upper eyelid. Motion is recorded and analyzed using specially developed hardware and software, respectively, enabling both real-time and off-line data presentation. The Eyelid Motion Monitor correlates between blinking characteristics of eyelid movement and the output voltages produced by the system. Blink detection is defined as peak in voltage, caused by eyelid closure or opening. The device was tested on 20 healthy volunteers with normal clinical blinking patterns.

RESULTS: The Eyelid Motion Monitor succeeded in detecting full blink motion. The system easily extracts different parameters of eyelid kinetics.

CONCLUSIONS: An inexpensive prototype novel device was developed for monitoring and analyzing eyelid motion characteristics, including the inter-blink interval, eye closing/opening duration and entire blink duration. The device should allow early objective non- invasive diagnosis and follow-up of disease progression. It could be of great potential value in many ophthalmic, neurologic, and systemic diseases.