Establishing user needs for a stability assessment tool to guide wheelchair prescription.

PURPOSE: The WheelSense project aims to develop a system for assessing the stability and performance of wheelchairs through a user-centred design process. This study sought to capture user needs and define the specification for the system. METHOD: A mixed methods approach was adopted. An online survey was completed by 98 participants working in wheelchair provision. The results were built upon through 10 semi-structured interviews and one focus group (n = 5) with professionals working in wheelchair provision in three NHS Trusts in the UK. RESULTS: The results provided a picture of the current UK practice in stability testing. Issues with the reliability and usefulness of the existing methods used to assess the stability and performance of wheelchairs were highlighted. Requirements for a new system were ascertained. These included improved accuracy of tipping angles, features to support record keeping, improved client/carer education support and ability to model or predict client-wheelchair system performance in different configurations. CONCLUSIONS: The paper concludes that there is a need for improved tools to determine the stability of the client-wheelchair system and support the prescription process, to ensure client safety and optimum equipment performance. A list of requirements has been produced to guide the future development of WheelSense. Implications for Rehabilitation The results of this survey and interview-based study present a picture of wheelchair stability testing practices in the UK, and highlight the need for new, more informative methods for guiding wheelchair prescription. The requirements for the design of a new system, or further development of existing tools to support the stability testing and prescription of wheelchairs have been established.

The development and testing of a system for wheelchair stability measurement.

Wheelchair stability has an impact on safety as well as wheelchair performance, propulsion and manoeuvrability. Wheelchair stability is affected by the addition of life-supporting heavy equipment, e.g. ventilators and oxygen cylinders, as well as the characteristics of the user e.g. limb amputations, obesity. The aim of the research described here was to develop and test a stability assessment system that would guide and support the adjustment of wheelchairs to individual needs, characteristics and lifestyles. The resulting system provides assessment of centre of gravity and wheelchair stability and calculates the wheelchair tipping angles. The system consists of a force platform that senses the weight distribution of the wheelchair and calculates the centres of the contact points of the wheels and the distances between them. The measurement data are transferred via a WiFi connection to a portable tablet computer where wheelchair stability parameters are calculated. A touchscreen GUI provides visualization of the stability results and navigation through the measurement modes. The developed new concept has been evaluated through technical laboratory-based testing to determine the validity of the data collected. Initial testing has been undertaken within the clinical setting in 3 large hospitals in the UK. Initial results suggest that Wheelsense® provides a valuable tool to support clinical judgement.

Improving wheelchair prescription: an analysis of user needs and existing tools.

Wheelchair users experience many situations that affect the stability and associated performance of their wheelchair. Stability is affected by user characteristics and abilities, environmental features and conditions, and wheelchair modification and accessories. Wheelchair prescribers need effective tools and methods to provide quantitative evaluation and prediction of the behavior of the user-wheelchair system in a variety of static and dynamic situations. Such information is very important to guide efficient management of associated risks and adjust chairs accordingly. This project involves a user-centered approach for design and evaluation of a load cell based wheelchair stability assessment system (Wheel-SAS). Here, the current methods for assessing stability are described, and their shortcomings explained. The user-centered design approach being applied to the development of the associated Wheel-SAS hardware and software is described. Future work including semi-structured interviews and an online survey with wheelchair prescribers and associated healthcare professionals for deriving user requirements and a design specification for a load cell system for measuring dynamic wheelchair stability are detailed.