Body temperature in premature infants during the first week of life: Exploration using infrared thermal imaging

Abstract

Background Hypothermia is a problem for very premature infants after birth and leads to increased morbidity and mortality. Previously we found very premature infants exhibit abnormal thermal patterns, keeping foot temperatures warmer than abdominal temperatures for their first 12 hours of life. Purpose We explored the utility of infrared thermography as a non-invasive method for measuring body temperature in premature infants in an attempt to regionally examine differential temperatures. Results Our use of infrared imaging to measure abdominal and foot temperature for extremely premature infants in heated, humid incubators was successful and in close agreement using Bland and Altman technique with temperatures measured by skin thermistors. Conclusions Our study methods demonstrated that it was feasible to capture full body temperatures of extremely premature infants while they were resting in a heated, humid incubator using a Flir SC640 infrared camera. This technology offers researchers and clinicians a method to examine acute changes in perfusion differentials in premature infants which may lead to morbidity.

Thermal imaging applications in neonatal care: a scoping review

“…(23–29 gestational weeks; examined during the first month of life)FLIR SC640 cameraHerry et al [25]2011Case seriesCanadaTo compare thermograms of the abdomen of healthy newborns and newborns with NEC, to distinguish differences and to investigate if TI is suitable for diagnosing NEC in infants.59 newborns (48 were had a gestational age of 28.3 ± 2.4 weeks; 11 were of 26.7 ± 1.8 weeks)No brand name (Infrared camera, uncooled microbolometer focal plane array, 320 × 420 pixels, thermal and spatial sensitivity of 0.05° at 30 °C and 1.3 mrad)Abbas et al [34]2011Case seriesGermanyTo use TI to monitor thermal distributions of neonates within the neonatal intensive care unit.7 preterm newborns (gestational age was a mean of 29 weeks, included in the study directly after birth)VarioCAM hr. head camera (InfraTech GmbH)Knobel et al [8]2011Case seriesUSATo measure body temperature in infants and examine the relationship between body temperature and symptoms of NEC in infants with low birth weights.10 low birth newborns (gestational age less than 29 weeks, examined during the first 5 days of life)FLIR SC640 uncooled infrared cameraKnobel et al [35]2013Case seriesUSATo test instrumentation and develop analytic models to use in a larger study to examine developmental trajectories of body temperature and peripheral perfusion from birth in extremely low birth weight (EBLW) infants.4 newborns, 4 h of birth (< 29 weeks gestational age)Not mentionedHeimann et al [36]2013Case seriesGermanyTo evaluate skin temperature by using different positions with TI in multiple body areas of preterm infants for detailed information about temperature regulation and distribution.10 preterm infants (12–62 days old)VarioCam hr-Head (InfraTec GmbH, Germany)Kurath-Koller et al [37]2015Case seriesAustriaTo evaluate the safety of laser acupuncture in newborn infants by using a thermal camera to analyse changes in thermal distributions.20 newborns (23 days old)FLIR i5 cameraKnobel-Dail et al [38]2017Case seriesUSATo explore the utility of TI as a non-invasive method for measuring body temperature in premature infants in an attempt to regionally examine differential temperatures.Data was collected from 31 infants originally; only 22 had valid thermograms and the first two were used for training (23 to 28 gestational weeks; first 5 days of life)FLIR SC640 uncooled microbolometerBarcat et al [39]2017Case seriesFranceTo investigate whet...…”

“…Other early studies (1977) used the Spectrotherm 2000 by General Electric, which was equipped with a single element liquid nitrogen cooled Mercury Cadmium Telluride (HgCdTe) detector, with a resolution of 256 × 256 points, and the need for conversion and use of a Polaroid film [15]. The latest studies used the much more sophisticated high resolution radiometric thermal imagers, such as the FLIR SC640 uncooled camera (1.8 kg) with thermal sensitivity of <30mK, resolution of 640X480, FOV ranging from 12°× 9° to 45°× 34° and radiometric video recording with real-time analysis (2017) [38].…”

“…Some years later, Knobel-Dail et al (2017) [38] investigated the accuracy of TI in comparison to using a probe to measure body temperature, and the possibility of using TI to detect early perfusion injury signs, such as NEC in premature neonates. Temperatures of the abdomen and foot were measured using probes, while a thermal camera was used to take images of the neonates within their first five days of life.…”

“…In this study, valid and reliable measures were obtained, so the authors concluded that a well-structured methodology with an appropriate camera for this specific environment could provide beneficial research opportunities related to body temperature and peripheral perfusion from birth in extremely low birth weight infants [35]. Other reported difficulties included water droplets on the polyurethane sheet, the type of camera, which was not cordless and had to be connected to a laptop, the limited lens depth and the small port-hole of the incubator [8, 35, 38]. In addition, although an ideal condition is a newborn that is perpendicular to the line-of-sight, achieving this is not always possible.…”

Negative Temperature Differential in Preterm Infants Less Than 29 Weeks Gestational Age

“…(A pilot study of five infants was completed to evaluate methods prior to initiating enrollment in the larger study [Knobel, Levy, Katz, Guenther, & Holditch-Davis, 2013]. ) The three-year parent study assessed body temperature using measured thermistor skin temperatures, infrared thermal imaging (Knobel-Dail, Holditch-Davis, Sloane, Guenther, Katz, 2017), and compared foot temperature to perfusion index in the foot (Knobel-Dail, Tanaka, Holditch-Davis, & White, 2016). Perfusion index analysis confirmed that foot temperature is elevated due to increased perfusion in the foot, which rules out this abnormal temperature pattern as being due to external factors, such as high incubator heat.…”