The comparison of two supine manikins and the use of a shock and vibration isolation system for litter patients in air medical transpor

Studies show that repeated shock and vibration during aero medical and ground transport are causing patient pain and may be adversely affecting patients' medical outcome. Patients with spine and head injuries and other severe neurological injuries are the most vulnerable to repeated shock and vibration exposure caused by the vehicle. It is crucial to minimize the effects of these forces on patients during air and ground medical transport. The development of new medical evacuation platforms creates a need to better understand the effects of human exposure to shock and vibration. The use of human subjects to measure whole body vibration for the evaluation of patient transport systems generates a challenge for designers of and evaluators of enroute care systems. Therefore two different supine manikins were created for this project, manikin 1 and manikin 2. Manikin 2 was a modification of manikin 1 so that it would have a closer biodynamic response to that of humans when subjected to repeated shock and vibration. The main objective of this project was to test the two manikins under various conditions and compare the results. The manikins' design was based on the standards of a 95th percentile male. Another objective was to analyze the utilization of a litter air bladder to lower the consequences of human exposure to repeated shock and vibration due to aero medical transport.;The vibration signals used to perform the test were derived from research performed at the United States Army Aeromedical Research Laboratory at Fort Rucker Alabama. The vibration signals were captured from field tests conducted on a medevac litter mounted in a HH-60M Black Hawk helicopter in different modes of flight. After processing the recorded data, laboratory vibration tests were conducted on the manikins placed in the supine position to obtain the acceleration and transmissibility magnitudes at different locations on the manikins and the stirrup of the litter. The square root of the sum of the squares (RSS) acceleration in the real time was calculated to examine various strap restraint and stirrup clearance configurations and the effects of the use of the air bladder.;The results exposed the differences between manikin 1 and manikin 2. The resonant frequency of the manikins plus litter was approximately 4 Hz. In addition, the accelerations increased as the straps restraint was increased, which was expected as the manikins were less likely to move. For some conditions, the increase of stirrup clearance caused the acceleration values increase. Test results indicated the use of the air bladder between the manikins and litter resulted in an increase in acceleration values.