Executive Summary : | Road accidents in India continue to be a significant issue, causing fatalities, hospitalizations, and disabilities. In 2019, 449,002 accidents occurred, with 1.5 lakh fatalities and 4.5 lakh injuries. Although the injury rate has decreased over the last decade, the number of fatalities has increased from 1.38 to 1.51 lakhs. Road ambulance service is crucial for increasing survival rates within the "golden hour." Patients on stretchers and those in a supine position are exposed to longitudinal and pitching vibration during ambulance operations. This vibration is mainly due to frequent braking and acceleration, as well as lateral and roll acceleration. The combined impact affects the cardiovascular system, bones, central nervous system, and respiratory-system functions, further worsening the patient's condition. Isolation of stretcher vibration is essential for patient transportation. Researchers have suggested actively controlled beds, magneto-rheological controlled beds, and semi-active solutions based on 4-PUU mechanisms. However, these solutions have not been manufactured for practical applications due to energy consumption and additional space requirements. This research aims to reduce the vibration of stretchers in accordance with standards by providing a force between the ambulance floor and stretcher using the novel Semi-active Interconnected Suspension (SIS). This force can be achieved by utilizing pressure magnified in actuator chambers, transferred to low pressure chambers via 4/3 directional control valves (DCV) and interconnected pipes. The proposed stretcher can be easily implemented in trolley-cum foldable ambulance stretchers without impairing its primary functions. |