The Ambulance Stretcher - Lie A Simulation Study Of Human Body System Vibration

Ambulance was used to transport critical patient and urgently relief them on the way, equipped with emergency equipment, drugs, stretcher and other equipment. With the development of science and technology and the continuous improvement of the health system, the requirement of the ambulance performance was getting higher and higher.At present most of ambulance were modified by light truck chassis or off-road vehicle chassis and stretcher was composed of elastic components and shock absorber, both of them cannot satisfy the safety and comfort requirement of patients. In order to safely transport patient and decrease patient pains on the way, patients vibration must be strictly controlled. In the paper two measures were proposed as follow:first, active ambulance stretcher was proposed and the secondary vibration absorption was realized effectively. Active vibration absorption can control system vibration according to the state of the vibration system and current response. second, improve ambulance suspension system. Semi-active suspension was used in ambulance, vibration because of the road roughness was decreased through the improvement of vehicle smooth.The objective of this study was to simulate the vibration of ambulance stretcher-supine body system. Ambulance driving dynamic model was built by using the vehicle dynamics theory, was numerically simulated in MATLAB/Simulink. Using the vertical acceleration and pitch angular acceleration of ambulance stretcher-supine body system, dynamic response of them in time domain and frequency domain were obtained.It was shown that the proposed two measures were more effective in reduction of vertical and pitch vibration of ambulance stretcher-supine body system in contrast to the conventional passive one, decreased the vibration of specific bands of frequencies. This study provided new conceptions and methods to improve the ride comfort of ambulance supine body.