Shock and vibration isolation system for ambulatory and litter patients in ground and air medical transport

This project explored the effectiveness of seat and litter air bladder technologies in reducing patient exposure to whole body shock and vibration during ground borne and airborne medical transport. Several seat and litter air bladder configurations were examined during field tests in a U.S. Army RG-33 MRAP ambulance and a U.S. Army HH-60M Black Hawk helicopter. The MRAP field tests were conducted at Ft. Detrick, Maryland. The Black Hawk field tests were conducted at Ft. Rucker, Alabama.;During the field tests, tri-axial vibration signals were recorded on a 16-channel CoCo90 Data Logger/Frequency Analyzer and then post processed in the laboratory to obtain three-axis 1/3 octave vibration spectra and vibration transmissibility values and low-pass, band-pass and ISO overall vibration values. Vibration reductions through the seat air bladder of up to 47 percent in the vertical direction were achieved. The vibration reducing characteristics of the litter air bladder were significantly affected by the flexibility of the litter webbing and were more difficult to evaluate. More testing is necessary on the litter air bladder to more accurately determine its effectiveness in reducing patient exposure to shock and vibration during medical transport.