A Thermal Monitor of Metabolism in the Neonate

A conventional Ohmeda Intensive Care Incubator was instrumented with an ambient and five wall temperature probes and an ambient humidi ty meter. The infant being monitored was f i t ted with heel and abdominal skin temperature probes and an esophageal probe. An Apple lie microcomputer sampled analog output voltages from these sensors, and components of the metabolic energy balance were calculated at half-minute intervals as follows: insensible heat loss across the skin was the product of a-water transfer coefficient and the skin-to-ambient vapor pressure difference; sensible heat loss from the skin was the product of a total heat t r ans fe r c o e f f i c i e n t and the mean skin-to-environmental temperature difference; and respiratory heat loss was inferred from energy and water balances around the lungs.