Heat and Mass Transfer of Preterm Neonates Nursed inside Incubators - A Review
Résumé
Neonates, especially preterm and sick infants, face difficulty controlling their body temperature. Thus, they are nursed inside incubators in order to improve their hygrothermal condition and monitor their body temperature as well as other vital signs. The complex processes of heat and mass transfer between the neonates and the surrounding air and surfaces are the key concerns essential to their growth and survival. Several methods are used in order to better understand the physical phenomena of dry and latent heat losses from neonates and the body-environment interaction occurring during transient clinical processes and in thermoneutrality, which is the optimum thermal environment for neonates nursed inside incubators. These methods can be classified into three main categories: bioheat modeling, computational fluid dynamics and experimental studies. The objective of these methods is to analyze the effect of different ambient conditions, such as air temperature and humidity, incubator wall temperatures and air flow, on the dry heat losses by convection, conduction and radiation and on latent heat losses due to skin evaporation and respiratory process. The main indicators are the metabolic heat generation, skin and core body temperatures. Moreover, based on these methods, different techniques are proposed to enhance the incubator hygrothermal conditions. All these issues are reviewed in this paper and some future recommendations are drawn.