NTU builds a better wheelchair

Singapore’s Nanyang Technological University (NTU) has developed an innovative ‘gap clearing’ mechanism that could bring about long term convenience and benefits to physically disabled people in wheelchairs. This invention, called the Wheelchair Gap Enabler, allows wheelchair users to board a bus faster and easier and also clear low steps, such as roadside curbs, with ease and efficiency.

Wheelchair users find it difficult to board buses because of the gap between the roadside curb and the bus door. The gap could be reduced if a bus is fitted with a low ramp but it is expensive and the wheelchair loading time is long.

These difficulties prompted Assistant Professor John Heng of NTU’s School of Mechanical and Aerospace Engineering (MAE) at NTU to develop a ‘gap crossing’ mechanism that can be fitted to existing wheelchairs.

The NTU invention is unobtrusive. It does not limit the functions of the wheelchair – the wheelchair chair is still collapsible and there is still free space under the wheelchair for better manoeuvrability.

The invention is less costly compared to commercially available wheelchairs that can 'cross gaps' but are bulkier and difficult to use. The NTU mechanism lifts the wheelchair user into a ‘wheelie’ position, balancing on the two large back wheels only, centring the user’s weight onto the large wheels. The ‘roller skis’ on the invention then help support the user who can then roll the wheelchair easily over a gap.

Wheelchair users can now easily clear low steps, like roadside curbs, with the NTU invention. Previously, only skilled wheelchair users with sufficient strength could do the ‘wheelie’ to overcome such obstacles.

Asst Prof Heng, who completed the project in just a month, says: “We are very happy to have come up with a low-cost and efficient solution for wheelchair users to board buses and clear low roadside curbs more easily. We feel very excited that our research work which resulted in this invention can bring about useful benefits to society and long term convenience to physically disabled people in wheelchairs. This is yet another example of how research at NTU meets real world needs.”

Asst Prof Heng will continue to improve and enhance the design based on user feedback. Suitable for low cost mass production and easily retrofitted to existing wheelchair designs, the NTU invention could result in cost savings for both the wheelchair users and charity organisations such as Society for the Physically Disabled (SPD). The NTU invention was showcased at the launch of SPD’s ‘Wheelchair Enabler Competition’ on 31 May 2006.