ABSTRACT
Transferring of patients through direct contact lifting method whereby a patient is carried or transferred from a wheelchair to a stretcher and to a bed by an attendant, by hand without any instrumental aid and the manual unfolding of a manual foldable wheelchair is an unhealthy and more laborious way of transferring a patient from the wheelchair to the stretcher or from one location to another. This method of transfer can result to increase in pain and injury on that patient. The objective of this study is to reduce the difficulties and exertions in transferring of patients. This problem was perceived in the University of Benin Teaching Hospital which resulted to the aim of the project focused on designing and fabricating of a spring release foldable wheelchair cum stretcher for patients in hospitals and disabled people to allow for their easy movement. The design is projected at lifting a maximum weight of 100kg.
To achieve this, several concepts were considered and a most suitable one was chosen. These concepts involved the use of hydraulic jaw, screw jaw, chains and motors but the selected concept involved the use of inverted slider crank mechanism and extension spring. This concept was reviewed in literature, detailed design, and detailed drawing using Solidworks CAD, stress simulation using Solidworks CAD and necessary calculations were done.
After fabrication, the extension spring effect, the weight balancing and weight load were evaluated by testing of the machine. During tilting the applied variable input angle on the connecting rod resulted to a corresponding variable output angle at the backrest and leg rest. The machine withstood 100kg load, and the extension spring effect and unfolding of the device was within 3 seconds.
This project work gives room for possible improvements which could be considered such as making the device electrically powered, addition of sensors and hydraulic lifts.Importantly, this work creates a foundation for developing a wheelchair cum stretcher for comfortable transportation of patients in hospitals and disabled persons.
