Patient Warming Device for Casualty Care

Abstract : We have shown that convective air warming device (e.g., "Bair Hugger') is feasible for cold weather conditions and aeromedical evacuation. The goal of the project was to develop such a device that can keep patients warm in 0 deg C conditions and can run for 2 hours using battery power. Our testing showed that with appropriate insulation and recirculation of warm air from within the device, as little as 250W was needed for adequate function. Using this information, we built prototype heating units and coverlets that made efficient use of available battery power. The warming coverlet was designed as disposable sleeping bag that fully encloses the patient but still allows easy access for medical treatment. The heating unit attaches under a standard litter and readily adapts to available power sources(110 VAC, 24 VDC, and battery). Testing with volunteers verified that the system was well able to meet requirements. Therefore it could follow a patient from forward medical facilities, through ground and helicopter transport, post-surgical waiting, and finally through evacuation on military aircraft. It is also compatible with existing Bair Hugger surgical blankets. Civilian uses for the same technology are planned, specifically medical transport and outdoor rescue.