Eyelid Drive System: An Assistive Technology Employing Inductive Sensing of Eyelid Movement

This paper presents the design, development, and validation of the eyelid drive system (EDS), an assistive technology comprising a specialized pair of glasses and millimeter-sized passive resonators, attached to the user's eyelids, that transduce eyelid movement (blinking and winking) through inductive sensing. The theory of operation and design optimization with simulations are presented. A proof-of-concept prototype EDS was constructed using a pair of nonprescription glasses and commercial-off-the-shelf components. In benchtop tests with model eyelids, the EDS demonstrated basic functionality. Initial trials were performed involving six human subjects interacting with custom designed graphical user interfaces on a computer. A group mean accuracy of 96.3% was achieved using a set of four different commands at a response rate of 3 s. A mean information transfer rate (ITR) of 56.1 b/min over all subjects was achieved with a set of six different commands at a response rate of 1.5 s. This proof-of-concept device consumes 51.6 mW of power. The EDS compares favorably with related eye-interfacing assistive technologies and provides a unique combination of advantages, including high accuracy and ITR, wearability, insensitivity to lighting and noise conditions, obviation of facial electrodes, and the use of nonexaggerated gestures.