For centuries, temperature measurement deficiencies attributable to
biological barriers and low thermo-conductivity (k) have
precluded accurate surface-based fever assessment. At this stage of the
pandemic, infection detection in children (who due to immature immune
system may not effectively respond to vaccines) is critical because
children can be readily infected and also become a large mutation
reservoir. We reveal hitherto-unrecognized worldwide body temperature
measurements (T°), in children and adults, over tissue typified by
low-k similar to wood that may reach 6.8°C in thermal
variability, hampering thereby COVID-19 control. Brain-eyelid thermal
tunnels’ (BTT) integration of low-k and high-k regions
creating a thermal pathway for undisturbed heat transmission from
hypothalamus to high-k skin eliminates current shortcomings and
makes the brain indispensable for defeating COVID-19 given that brain
thermoregulatory signals are not limited by mutations.
Anatomo-histologic, emissive, physiologic, and thermometric
bench-to-bedside studies characterized and overcome biophysical
limitations of thermometry through high-k eyelid-enabled brain
temperature measurements in children and adults. BTT eyelid features
fat-free skin (~900 µm) and unique light emission
through a blood/fat configuration in the underlying tunnel. Contrarily,
forehead features variable and thick dermis (2000–2500 µm) and variable
fat layers (1100–2800 µm) resulting in variable low-k as well as
temperatures 1.97 °C lower than BTT temperature (BTT°). Highest emission
present in only ~3.1% of forehead averaged 1.08±0.49 °C
(mean±SD) less than BTT° (p=0.008). Environmental and biological
impacts during fanning revealed thermal imaging limitations for COVID-19
screening. Comparison of paired measurements for 100 pediatric patients
showed that in the children subgroup above 37°C, BTT° exceeded body core
temperature (Core°) in 60/72 patients; the average difference in the 72
patients was 0.62±0.7°C (p<0.001 by unpaired t-test); and in
the subgroup beyond 37.5°C, BTT° exceeded Core° in 30/32 patients.
Delineating hypothalamic activity in children facilitates early
infection detection, which is essential because children’s
immunogenicity prevents effective vaccination and causes accelerated
viral evolution. Capturing hypothalamic thermal signals from BTT was
further supported by brain thermal kinetics via BTT using wearables
during anesthesia, sedation, sleep, brain injury, exercise, and
asymptomatic infection, which revealed brain/core discordance and
enabled automated noninvasive afebrile infection detection for
interrupting asymptomatic human-to-human transmission. BTT-based
spot-check thermometry can be harmlessly implemented for children
worldwide without undue burden and costs; meanwhile, continuous
brain-eyelid T° in concert with biological and physical principles
affords a new dimension for combating pandemics. The
“detection–vaccination” pair solution presented is required to
mitigate COVID-19 from spreading indefinitely through mutations and
vaccine evasion while opening a viable path for eradicating COVID-19.
Brain thermal kinetics at brain-eyelid thermal tunnels overcoming COVID-19 thermometry limitations for automated asymptomatic infection detection in concert with physical and biological principles
