Correction of Human Forehead Temperature Variations Measured by Non-Contact Infrared Thermometer

Elevated body temperature (fever) can be a common symptom of a medical condition, such as a viral or bacterial infection, including SARS-CoV-2 or influenza. Non-contact infrared thermometers are able to measure forehead temperature in a timely manner and were used to perform a fast fever screening in a population. However, forehead temperature measurements differ greatly from basal body temperatures, and are the target of massive perturbations from the environment. Here we gathered a dataset of N=18024 measurements using the same precision infrared sensor in different locations while tracking both outside temperature, room temperature, time of measurement, and identity. Herein, we propose a method able to extract and remove the influence of external perturbations, and set the threshold for fever detection to 37.38 degrees C, after calibration and temperature correction. This method can help manufacturers and decision-makers to build and use more accurate tools so as to maximize both sensitivity and specificity of the screening protocol.

Automated summary

Fever is a common medical symptom, and non-contact infrared thermometers are used for fast fever screening by measuring forehead temperature. However, forehead temperature measurements are easily influenced by the environment, and we propose a method to eliminate external perturbations and improve temperature accuracy.