Design and testing of a novel power-assisted wheelchair system

A power-assisted wheelchair is a hybrid between a manual and power wheelchair that consists of an electric-assist system that can be easily mounted on a manual wheelchair. These devices have a demonstrated benefit on the health and mobility of wheelchair users. However, current power-assisted wheelchairs are not addressing all user needs, and as a result there is room for improvement. In this thesis, a novel power-assisted wheelchair system was developed using Stanford Design Thinking. Design requirements were developed using ISO 13485. Concept designs were iterated and a prototype was fabricated. The result is the NeuwDrive, a lightweight power-assist system. The NeuwDrive demonstrates novelty through the use of a right-angled geared motor and a hub design that maintains the overall wheelchair width and allows for easy removal of the drive system. The functionality of the NeuwDrive was verified in two ways. First, the performance was tested using an absorption dynamometer to measure torque and speed. The test results were within the specifications of class-leading devices on the market. The weight of the NeuwDrive is 10.2 kg, below any currently available hub-motor products. Second, a focus group with power-assist wheelchair users was conducted to collected end-user feedback. The results were favourable, with participants favouring the low device weight, removable batteries and narrow width of the NeuwDrive. The results of the testing indicate that the NeuwDrive is a novel power-assist system with potential for future development.