Abstract
In recent years the nursing auxiliary equipment is has been gradually emphasized by people In advanced countries, fewer babies and old age society are serious matters .We should spend more and more time taking care on people with disabilities .If nursing auxiliary equipment is more convenient means of taking care that can be easier Pressure sores is a most commonly seen people who were deep coma or on their bed for a long time .The causes of pressure sores is patient's skin in pressure for long time. For pressure sores, prevention is more important than treatment. The simplest way to prevention is turn-over patient's body frequently. In this thesis, we try to use simple linkage to achieve a mechanism that can assist user overturn . To build a computer program according to different turning angle and installation space produces solution for linkage length ratio. We can design a turn-over assistance bed mechanism design.