Ambulance Stretcher Suspensions

Existing methods for vibration isolation of patients transported by ambulance are discussed. Some alternative suspensions are outlined and a relatively simple mechanism analysed. This can give virtually constant vertical natural frequency over a wide range of patient load. Variation in pitch natural frequency can also be minimized at the expense of some variation in vertical natural frequency. The elements used are a coil spring, load arm and an electric actuator. Initial testing of the mechanism has been made to confirm the feasibility of the concept.