Real Time Thermoregulatory Model for Extreme Cold Stress: Applicable to Objective Force Warrior (OFW)
Abstract
A mathematical model for predicting shivering and thermoregulatory responses during long term cold exposure has been developed and validated. The basis for this model is a six-cylinder mathematical model of human temperature regulation which was well validated (Xu and Werner, App!. Human Sci. 16:61-75, 1997) for dynamic conditions: incorporating heat, cold (less than 2 hours), clothing systems, and exercise. To what extent shivering is maintained over a long duration is not clearly known and a modeling technique has been sought to predict such responses. A new conceptual model for control of shivering intensity that takes into account the shivering endurance, inhibition due to a low core temperature and maximal shivering capacity was proposed. This conceptual model was further incorporated into the six-cylinder model to extend its capacity to long term cold exposure. The individual characteristics were defined as height, weight, fat percentage, age and V02 max in the new model. The new model was validated against three test cases: 10 individual subjects who were immersed in 8-10 degrees Celsius water for 2 to 6.5 hours, a group of 9 subjects who were exposed in 5 degrees Celsius air for 3 hours, and 6 people who were involved in a shipboard accident and immersed in 16.7 degrees Celsius water for 7 to 38 hours. The comparison has shown that the mode predictions of the core temperature, mean skin temperature and shivering response to water immersion results were reliable within root mean square deviations of plus/minus 0.8 degrees Celsius, plus/minus 1.9 degrees Celsius, and plus/minus 47.2 W, respectively. This model is applicable for cold stress predictions including Objective Force Warrior scenarios in its present form.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2003
- Accession Number
- ADA516060
Entities
People
- Gordon Giesbrecht
- Richard Gonzalez
- Xiaojiang Xu
Organizations
- United States Army Research Institute of Environmental Medicine