Impact of wear position on dosimeter performance: a hybrid measurement-simulation approach to quantify in-situ factors

Quantifications of personal light exposure (PLE) are important for research on human health and well-being. To capture real-world PLE, dosimeters (light sensors) are often worn on the body, rather than at the eye. Currently, it is largely unknown how such placement influences the dosimeter's performance for measuring actual eye-level light exposure. To overcome limitations of real-world studies, we introduce a novel hybrid measurement-simulation approach to quantify three factors affecting dosimeter performance: the translational and rotational dosimeter displacement and body self occlusion. Using 3D body scans of twelve subjects, we illustrate how an individual's body morphology influences the magnitude and distribution of these factors and identify the dosimeter positions where these factors are minimized. Additionally, we defined illustrative limits to identify regions of the chest suitable for dosimeter placement. Depending on the subject's posture, between 0 and 46.4% of the chest area exhibits sufficiently small magnitudes of these factors to be considered suitable. To ensure valid PLE data in light-dosimetry field studies, it is essential to select a dosimeter position that minimizes each of these three factors for typical subject postures.