Infra-red radiant intensity exposure safety study for the Eye Tracker.

With any device that is used to record or evaluate biosignals, it is in the inventor's interest to determine how that device withstands a rigorous examination in regards to its inherent safety during use. For this, a Risk Management (Hazard) Analysis is a useful exercise. With this in mind, the most probable hazard concerning the Eye Tracker System (a device used to measure saccadic eye movements utilizing Reflective Differencing of Infra-Red light) is the exposure effect to the human eye caused by the Radiant Intensity of the IR emitters mounted on the Head Mounted Transducer. Presented in this article are the results of a study used to determine the Radiant Intensity exposure of the Eye Tracker as designed. Comparing these results with accepted norms for Radiant Intensity exposure, a redesign of the Head Mounted Transducer is detailed with results given showing that this new transducer fits safely into the accepted norms of Radiant Intensity exposure. Presented are the mathematical calculations used for the initial study and the redesign.