Air temperature recordings in infant incubators

Abstract

Air temperatures were continuously recorded inside 4 incubators with proportional heating control and 6 incubators with on/off heating cycles, during routine use. The air temperatures in the former were constant throughout, with a gradient between the roof and above mattress air temperature not exceeding 1°C. In contrast, the recordings from the latter models showed a regular cyclical oscillation, the duration of the cycle varying from 14 to 44 min. Each incubator had a characteristic profile. The roof air temperature could vary by as much as 7.1°C and the above mattress air temperature by as much as 2.6°C during the cycle. The oscillation persisted in the air temperatures recorded inside an open ended hemicylindrical heat shield when used inside these incubators, but was markedly reduced inside a closed ended heat shield. Carbon dioxide concentration did not increase significantly inside the latter.