Additive Manufacturing Solutions to Improve and Customise Joystick Knob of Motorised Wheelchair

Problem Statement

Motorised wheelchair users with hand mobility conditions such as weak grip or missing hand parts from a congenital or acquired disability, often face difficulties in controlling the original joystick that comes with motorised wheelchairs. Long hours of use can also cause strain and soreness in their hands. Preliminary observations suggested that their ability to control the joystick can be enhanced by modifying the design of the joystick knob. There is a need to assess the handgrip of these individuals and design customised joysticks for them.

Objective

This project aims to design and 3D print customised joystick knobs of motorised wheelchairs for persons with disabilities who have hand mobility conditions, in order to reduce the effort required to control the joystick and enable the person with disability to control the joystick with ease without straining their hands.

This collaboration was led and managed by SG Enable and the provision of user information and user testing was facilitated by AWWA. Meanwhile, Republic Polytechnic (RP) provided research, design and development expertise, with 3 iterations of joystick designs undergoing prototyping and reliability testing at RP’s 3D printing facilities. Therapists from AWWA also provided information on the most common gripping needs of persons with disabilities, and how their clients’ behaviour and conditions may affect their use of the joystick.

A motorised test jig was built to simulate the ‘hand manoeuvre motion’ for stress testing of the 3D printed joysticks.
A motorised test jig was built to simulate the ‘hand manoeuvre motion’ for stress testing of the 3D printed joysticks.

Key Benefits/Outcomes

  • With feedback gathered from user testing facilitated by AWWA therapists, Republic Polytechnic continuously optimised and improved the design of the joystick knobs and has successfully fabricated 2 designs that received positive feedback from pilot participants. Each design includes 2 sizes to cater to users with different hand sizes.
  • Clients feel more comfortable and empowered in manoeuvring their motorised wheelchairs using the customised joysticks, as compared to the original joystick.
  • Optimal printing methods and skin-safe materials have been studied and selected for scaling up production in the future.
  • As part of the scaling up plan, Republic Polytechnic and SG Enable are in discussion with a service bureau to explore printing the joysticks for clients from AWWA and other social service agencies.

Collaborator

Contacts

Mr. Marc Lee marc.lee@ntuitive.sg

Damian Wong (RP) damian_wong@rp.edu.sg