A Wearable Gaze-Driven Augmentative and Alternative Communication Prototype: Design and Preliminary Evaluation of a Near-Eye Radial Interface
Abstract
Augmentative and alternative communication (AAC) can support people who communicate in ways other than speech, including people with cerebral palsy (CP) who may have limited hand control for conventional input devices. However, many high-technology AAC systems depend on a screen, a mount, or a separate computer, and may be difficult to use independently in everyday settings. We present a wearable AAC proof-of-concept that combines a near-eye display, a radial text-entry interface, camera-based gaze input, text-to-speech output, and head-gesture controls in a single prototype. The system uses a Raspberry Pi Zero 2 W to process camera input and an Android application on Google Glass Enterprise Edition 2 to render the interface and produce speech output. A two-step radial interaction technique groups letters before selection to reduce the effect of small gaze-estimation errors. The prototype also includes an inertial measurement unit (IMU) for two head-tilt commands and an LED feedback signal to make active communication visible to other people. We report a preliminary engineering evaluation based on the original project tests. In 414 gaze-region trials collected from one tester across seven days, mean region-classification accuracy was 78.2%. In a separate IMU test, five users each completed 30 repetitions and achieved a mean activation success rate of 91.8%. During a three-minute run, measured Raspberry Pi surface temperatures were below 30 C\(^\circ \), while the exterior case was 34.2 C\(^\circ \). A general-audience survey of 30 respondents provided preliminary feedback on the interface, but was not conducted with people with CP and is not treated as user validation. These results demonstrate an integrated and wearable interaction prototype while identifying the need for representative-user evaluation, improved comfort, and more robust gaze selection before any real-world deployment.