Ambulance stretcher with active control isolator system

Abstract

This paper considers the theoretical design of support systems for a stretcher, whilst being transported in an ambulance, in order to reduce vibration-induced discomfort. However, travelling on normal roads at high speeds results in an ambulance and its occupants being subjected to vibration. To avoid this problem ambulances often travel at very low speeds causing traffic congestion and delaying the patient's arrival at hospital. Ambulance suspension systems often give poor ride comfort, which may result in deterioration in the condition of injured patients. Suspension of the ambulance stretcher itself is a lower cost option than a purpose built ambulance suspension system and may offer superior isolation of the patient from road surface disturbances. This paper describes the development of a hydro-pneumatic stretcher suspension system, in order to reduce vibration-induced discomfort. Rubber, hydro-pneumatic, slow-active and active isolators systems are presented to support the stretcher/patient, allowing motion relative to the vehicle chassis. Also, theoretical models of these systems are compared to improve the patient's ride comfort.