Infrared Thermography with High Accuracy in a Neonatal Incubator

Keisuke Hamada,Yasuhiro Nagata,Hayato Hayashi,Eiji Hirakawa,Hidetsugu Asano,Takashi Mine,Tatsuki Ichikawa

doi:10.1007/s10439-022-02937-w

Abstract

As the accuracy of body temperature measurement is especially critical in premature infants on admission to the neonatal intensive care unit (NICU), noninvasive measurement using infrared thermography (IRT) has not been widely adopted in the NICU due to a lack of evidence regarding its accuracy. We have established a new calibration method for IRT in an incubator, and evaluated its accuracy and reliability at different incubator settings using a variable-temperature blackbody furnace. This method improved the accuracy and reliability of IRT with an increase in percentage of data with mean absolute error (MAE) < 0.3 °C to 93.1% compared to 4.2% using the standard method. Two of three IRTs had MAE < 0.1 °C under all conditions examined. This method provided high accuracy not only for measurements at specific times but also for continuous monitoring. It will also contribute to avoiding the risk of neonates' skin trouble caused by attaching a thermistor. This study will facilitate the development of novel means of administering neonatal body temperature.

Highlights

Body temperature is an important health indicator in the formulation of a clinical management plan, and appropriate management of body temperature is required for maintenance of normal physiological functions and to facilitate prompt recovery after illness.[28, 38] Especially stringent body temperature management is required for premature infants, and it has been known since the 1960s that reducing heat loss in the first few days of life can improve the survival rate0090-6964/22/0500-0529/0 Ó 2022 The Author(s) of premature infants.[36]
The mean absolute error (MAE) of Infrared thermography (IRT)-2 and IRT-3 were high with the conventional equation (3)
Using Eq (3), the MAE of IRT-3 exceeded 3 °C in some cases, and the MAE values were different for IRT-1 and IRT-2 even with the same specifications

Summary

Introduction

Body temperature is an important health indicator in the formulation of a clinical management plan, and appropriate management of body temperature is required for maintenance of normal physiological functions and to facilitate prompt recovery after illness.[28, 38] Especially stringent body temperature management is required for premature infants, and it has been known since the 1960s that reducing heat loss in the first few days of life can improve the survival rate0090-6964/22/0500-0529/0 Ó 2022 The Author(s) of premature infants.[36]. Stringent body temperature management is required for premature infants, and it has been known since the 1960s that reducing heat loss in the first few days of life can improve the survival rate. Newborn infants lose heat at a rate two to three times higher than adults, and without treatment, neonatal body temperature usually decreases by 0.1–0.3°C per minute.[4, 41]. The importance of controlling body temperature in clinical practice has been widely acknowledged since the mercury thermometer was first used for medical purposes in the late 18th century.[42]. Since the 1980s, predictive thermometers have commonly been used to measure temperature in newborn infants. The infrared thermometer is already used as a noninvasive means of measuring body temperature, in daily clinical practice and for non-medical purposes at home.[30]. As IRT has a wide field of view (FOV), it can simultaneously measure multiple objects, and is useful for screening at airports.[9, 13] For example, IRT has been used for fever screening in the coronavirus disease 2019 (COVID-19) pandemic.[5, 8] IRT must be used in combination with a Food and Drug Administration (FDA)-approved thermometer due to its low level of accuracy.[11]

Methods

Results

Conclusion