Rea Sensory Shield: A Real-Time Web-Based Sensory Environment Monitoring Tool for Individuals with Autism Spectrum Disorder

Rea Sensory Shield is an open-source, browser-based assistive technology tool designed to monitor environmental sensory stimuli in real time for individuals on the Autism Spectrum Disorder (ASD). The system integrates six independent sensor modules — acoustic level measurement, AI-based person and animal detection, colour salience analysis, frame-difference motion quantification, and ambient light sensing — into a unified composite Sensory Stress Index (SSI) ranging from 0% to 100%. Implemented entirely in client-side HTML5/JavaScript using TensorFlow.js (COCO-SSD Lite), the Web Audio API, the Canvas 2D API, and the AmbientLightSensor API, the tool requires no server-side infrastructure and runs on any modern HTTPS-capable device. Three weighted alert thresholds (noise > 75 dB, crowd > 5 persons, motion > 15%) produce real-time colour-coded feedback for caregivers and educators. The application is multilingual (Italian, English, Spanish) and has been deployed at Centro Educativo Pugliautismo in Bari, Italy, as a complementary observational instrument within the REA System framework. This paper describes the system architecture, sensor fusion algorithm, implementation details, pedagogical rationale, and preliminary field observations.