Model of human thermoregulation for intermittent regional cooling.
BACKGROUND
A prospective approach to save energy expenditure for a liquid cooling garment (LCG) system is to provide intermittent regional cooling (IRC) to the human body instead of continuous cooling. In order to gain insight into IRC mechanisms, a mathematical model was developed to simulate thermal interaction between the human and IRC.


METHODS
Human thermoregulatory responses were simulated by a previously validated six-cylinder mathematical model. Two equations were derived from the energy balance principle to estimate LCG heat removal during ON (coolant circulation) and OFF (no coolant circulation) periods. The heat removal equations were incorporated into the boundary equations of the human model. The augmented model was used to predict human thermal responses under different IRC conditions.


CONCLUSIONS
The model was evaluated against experimental results with IRC in warm environments. The comparison demonstrated that the model predictions of the core temperature and mean skin temperature were reliable within root mean square deviations of +/- 0.10 degrees C and 0.44 degrees C, respectively. Simulation analysis showed that IRC has the potential to reduce power requirements. Modeling is an effective alternative to predict efficacy when actual responses cannot be attempted. A systematic approach, consisting of manikin measurements, physiological experiments, and mathematical modeling can expedite the research and development of LCG systems.
Xu
Xiaojiang
X
U.S. Army Research Institute of Environmental Medicine, Biophysics and Biomedical Modeling Division, Natick, MA 01760, USA. xiaojiang.xu@us.army.mil
Berglund
Larry G
LG
Cheuvront
Samuel N
SN
Endrusick
Thomas L
TL
Kolka
Margaret A
MA
D001833:Body Temperature Regulation / Q000502:physiology*; D003080:Cold Temperature; D004734:Energy Metabolism / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D008834:Microclimate; D008962:Models, Theoretical; D011446:Prospective Studies