Stochastic-Deterministic Electromagnetic Modeling of Human Head Exposure to Microsoft HoloLens

In this paper, the electromagnetic (EM) simulation of the exposure of a spherical model of the human head to the HoloLens, a mixed reality device developed and manufactured by Microsoft, is performed at 10 GHz in addition to IEEE 802.11ac Wi-Fi frequencies of 2.4 and 5 GHz. The compliance assessment with current guidelines and standards for limiting human exposure to EM fields up to 300 GHz by means of incident power density (IPD) is provided at separation distances between the model and antenna ranging from 2.5 to 150 mm. The effect of the curvature of the average adult and child head on the IPD is investigated on a control surface of 4 cm2. Results stemming from stochastic analysis indicate marginal difference between the spatially averaged IPD on the two distinct head models. On the other hand, comparative analysis of the spatially averaged IPD on the least and most curved body parts points to relative differences of up to 20% in certain exposure scenarios. Overall, spherical head models yield significantly higher values of the spatially averaged IPD (up to 25%) compared to standard planar models. It is therefore important to consider the inherent curvature of the nonplanar exposed body parts (e.g., head) to accurately assess targeted exposure quantities.