Safety Goggle Compliance Monitoring Using Hall Effect Sensors

This article presents the design, fabrication, testing, and evaluation of a Hall effect based sensor system that detects whether or not safety glasses are worn in proper position on the eyes (i.e., compliance). The system detects the motion of the goggle or eyeglass temple relative to the top (helix) of the ear. The sensor/magnet pair is designed to transmit or store signals that allow identification of eyeglass position and movement relevant to compliance versus noncompliance. A prototype of this system was tested on four individuals (two males, two females). Detecting compliance using only the static position of the safety goggles had limited success. However, when transient (movement) data were considered using a matched filter approach, the system was able to successfully distinguish among movements from the proper position (on the bridge of the nose) to the four other positions in 79.5% of cases (85%, 78%, 80%, and 75% for the four subjects individually). Based on these prototype results, the Hall-effect approach shows promise for monitoring eyewear compliance for safety goggles, as well as other wearable systems where compliance is critical.