Design and experimental validation of a new wheelchair seat stabilization system.

Purpose: Seat tilting wheelchair features can increase the comfort and safety of the user. Although many power wheelchairs have tilting mechanisms, they are often designed with a specific wheelchair model in mind. In this study, a design process for seat tilting mechanisms that can be applied to most rear-wheel drive wheelchair models is developed.

Methodology: Equations were developed to describe the geometrical and load constraints that were used to size the electric actuator that powers the system and define its position. Finally, the equations were used to create the seat tilting mechanism of a prototype wheelchair, which was then tested.

Results: The equations yielded coherent results which showed that advantageous actuator positions from a load minimization perspective usually require dimensions that cannot be found in commercial actuators. Also, there are positions in which the load increases exponentially, which should be avoided. The tests showed that the system was able to function properly on the prototype wheelchair and that the actuator position affected the time taken for the actuator to execute different parts of the tilting movement.

Conclusions: The design process presented here was successful and modelled by general equations that can be applied to most front-wheel drive wheelchairs. It presents a low-cost option for the design of seat tilting systems, which can increase their accessibility.