Bilateral assessment of body core temperature through axillar, tympanic and inner canthi thermometers in a young population

Abstract

There are several sites in which the human body core temperature can be estimated and used to identify febrile states in a threat of pandemic situations at high-populational-traffic places (e.g. airports, ports, universities, schools, public buildings). In these locations, a fast method is required for temperature screening of masses. The most common methods are axillar and tympanic thermometers. However, in addition, measurement of the inner canthi (IC) of the eye with infrared thermal (IRT) imaging has been suggested as a fast mass measurement screening tool. Objective: It is the aim of this research to identify the bilateral difference of the available body temperature screening methods with potential use for large-scale fever screening and to verify if such a difference is acceptable. Approach: A total of 206 young participants (104 females and 102 males) were recruited, having their temperatures taken with the different methods bilaterally under neutral environmental conditions. The obtained results were statistically processed. Main results: Results established absent reference data for site and method in west European populations. The bilateral differences were minor using the IC of the eye monitored with infrared imaging, which was also proved with the Bland-Altmann limits of agreement. Significance: Based on the findings of this research, despite all methods being able to estimate body core temperature, it is suggested to use IRT images of the IC of the eye, due to its fast, reliable and reproducible procedure for mass screening. Further research is required to understand the higher bilateral variability in using the traditional thermometer axilla and tympanic membrane assessments, since these are the methods currently used within a clinical setup. The same procedure must be applied to fever cases to establish a decision threshold per method.

An Overview of Thermal Infrared Imaging-Based Screenings during Pandemic Emergencies

“…To minimize the measurement error, distances between 80 and 120 cm and angles as close as possible to 90 • should be used when the inner-canthi of the eye temperature is recorded with conventional lenses and standard image analysis software for fever screening [43]. Vardasca et al [44] also demonstrated, employing the Bland-Altmann limits of agreement, that the bilateral difference of the inner canthus of the eyes is negligible.…”

Fundamental Concepts of Human Thermoregulation and Adaptation to Heat: A Review in the Context of Global Warming

“…The temperature of venous blood and afferent signals from thermo-sensitive nerves on the body surface are used by the brain as reference temperatures for regulating autonomic and behavioral responses around a Tb set-point [8]. As the measurement of venous blood temperature is invasive and impractical to perform in research and clinical settings, the most common sites for indirect measurement of Tc are the rectum, esophagus, and gastrointestinal tract [68][69][70][71] for research, and the axillar, sub-lingual, ear canal, and forehead for diagnosis of fever [7]. In this review, and unless specified, Tc is used generically to encompass temperatures measured in the sites used for research [1,7,72,73].…”

Análise Situacional Da Covid-19 No Brasil E Nos Três Maiores Alcances Do Mundo

“…A base da comparação foi avaliar as diferenças de temperatura bilateral, uma vez que os humanos são simétricos termicamente. Com base nos achados desta pesquisa, apesar de todos os métodos terem sido capazes de estimar a temperatura central do corpo, sugere-se o uso de imagens de termografia no canto medial do olho, uma vez que é um procedimento rápido, confiável e reproduzível para triagem em massa [27].…”

“…A termografia oferece um excelente meio para determinar qualitativamente a temperatura do BTT, mas há muitas dificuldades em obter uma medição absoluta, como: exigir um ambiente controlado, limitar a interferência do infravermelho, posicionamento e inicialização da câmera térmica, falta de treinamento dos operadores, presença de artefatos (como máscaras, óculos, chapéus, cachecóis), presença de uma referência de temperatura, diferentes formatos de arquivos pelos fabricantes e total desconhecimento dos padrões existentes nos locais de triagem. Tudo isso pode ser tratado, mas exige tempo, conscientização e treinamento [27]. Desde a pandemia da SARS em 2003, quando se iniciou o emprego da técnica no rastreamento de pessoas, cientistas e entidades de metrologia elaboraram diretrizes de padronização para garantir o melhor desempenho para esta finalidade.…”