Microclimate cooling (MCC) technologies have been successful in alleviating heat strain in Soldiers confined to vehicles, but cooling limitations and power and weight restrictions make MCC impractical when mobilized on foot.
A solution was needed that increased the efficiency of heat transfer from the human body to the microclimate cooling system. Traditional MCC approaches involve constant skin cooling with liquids at low temperatures and high flow rates. As a result, MCC power, size, and weight requirements are large.
Scientists at the U.S. Army Research Institute of Environmental Medicine, with the help of engineers at the U.S. Army Natick Soldier Research, Development, and Engineering Center, discovered that over-cooling the skin can slow heat loss, while under-cooling the skin results in greater strain on the heart. Both problems were minimized by allowing skin temperature to fluctuate narrowly using skin temperature itself to automate cooling.
A patent for body temperature regulation using skin temperature feedback was funded by the U.S. Army Medical Research and Materiel Command (MRMC) and awarded Nov. 23, 2010 (U.S. Patent No. 7,837,723). The new body temperature regulation approach is an MCC methodology for maximizing heat flux, minimizing physiological strain, and conserving battery power. Sensors within an MCC garment signal the need to provide or withdraw cooling based on an optimal skin temperature range determined empirically from laboratory experiments. A series of studies demonstrated that with this approach, heat extraction is optimized (similar to constant cooling), and power consumption is reduced by 40 to 50 percent.
The application and integration of this MCC method will decrease the size and weight of future MCC systems and make possible effective MCC for Soldiers mobilized on foot.
- Article courtesy of MRMC
