Fever screening of seasonal influenza patients using a cost-effective thermopile array with small pixels for close-range thermometry

OBJECTIVE: Infrared thermography systems have been used for fever screening at many airports since the outbreak of severe acute respiratory syndrome (SARS) in 2003. However, many of these systems are expensive and non-portable. Therefore, we developed a cost-effective and compact (2.9 × 5.8 × 2.0 cm) thermopile array for fever screening of patients with infectious diseases in the clinical setting. METHODS: The array was created with small pixels (48 × 47 = 2256 pixels) fabricated on a silicon wafer using microelectromechanical systems technology. We tested this array on 155 febrile and afebrile patients (35.4 °C ≤ axillary temperature ≤ 39.3 °C) with seasonal influenza at the Japan Self-Defense Forces Central Hospital. RESULTS: The maximum facial temperature, measured by the array at 0.3 m from the subject, exhibited a positive correlation with axillary temperature measured using a contact-type thermometer (r = 0.71, p < 0.01). The sensitivity and specificity of the thermopile array in identifying the febrile subjects were 80.5% and 93.3%, respectively, setting the threshold cut-off of maximum facial temperature at an appropriate value. CONCLUSIONS: Our cost-effective thermopile array appears promising for future close-range fever screening of patients with infectious diseases at primary care doctor clinics, health care centers, and quarantine stations in developing and developed countries.