e-Pupil: IoT-based Augmentative and Alternative Communication device exploiting the pupillary near-reflex

So far, very little attention has been paid to the role of the autonomic nervous system in augmentative alternative communication solutions. In this regard, the pupil near reflex, one component of the triadic accommodative response to a visual plane shift in-depth, may play a key role. Such reflex does not necessitate any requirement of skeletal muscles, and thus may be preserved in diseases affecting somatic motoneurons, such as the amyotrophic lateral sclerosis. On this basis, the pupillary accommodative response, i.e. the pupil constriction in response to a far-to-near visual shift in depth, can constitute an effective communication tool, bypassing the well-known limitations of canonical eye-trackers, which require recruitment of skeletal muscles. This paper introduces e-Pupil: a low-cost, stand-alone, portable and smart device exploiting the pupillary accommodative response as a communication tool. The Internet of Things plays a crucial role in our device, guaranteeing portability, accessibility and usability, as well as several remote functionalities. We propose two different routes to communicate with the external world, both built upon the identification of the pupil constriction event in response to a voluntary far-to-near visual shift. The experimental validation proves the reliability of the system as well as its intrinsic simplicity of use.