Carleton University School of Industrial Design
The CrossTrainer Wheelchair is designed to introduce disabled youth to adaptive sports. Its' innovative design qualifies it for government funding grants for daily use wheelchairs, but packs all the features of a sports wheelchair. The unique camber adjustment allows changes to the angle and position of the wheels, exponentially increasing functionality. A range of sports can be played with interchangeable front ends. Sound mass production principles lower the cost of the chair versus existing wheelchairs. These factors combine to create a wheelchair that greatly increases the accessibility of disabled sport to youth.2. The Brief: Summarize the problem you set out to solve. What was the context for the project, and what was the challenge posed to you?
This thesis project started out with a general question: "How can design be used to increase accessibility to adaptive sports for those living with disabilities?". As research into adaptive sports progressed, a theme emerged. The specialty wheelchairs used many adaptive sports all share the same core design with relatively minor variations to tailor the chair to a particular sport. Furthermore, almost all of these wheelchairs are constructed of bent metal tube frame, and welded by hand with the use of jigs. The craft production nature makes these chairs prohibitively expensive. Disabled children can greatly benefit from the rehabilitation offered by adaptive sports. The high costs of equipment and available funding for only daily use wheelchairs prevent parents from purchasing several sports wheelchairs for their children. A “cross-trainer” chair that could be adapted to several sports would help increase participation of children in adaptive sports. The challenge would be to design a wheelchair that could function as a daily use wheelchair, but also had the ability to be used for sports purposes. The chair needed to qualify for government funding, but also have a lower cost than existing wheelchairs. Finally, the chair needed to be able to grow with a child, so it could be sold as a single solution.3. The Intent: What point of view did you bring to the project, and were there additional criteria that you added to the brief?
From the project outset, the personal objective was to leverage mass production principles in the design of the wheelchair so that a tangible working prototype could be made. The hope was that the project would serve as a hallmark to my design education. While this freed the design process from being anchored in existing wheelchair designs, I began to realize that the process could have greater social implications than simply having a neat looking thesis project. The joy that access to sport could provide children was a driving force in the project. While the physical outcome of the project was a fully working Crosstrainer wheelchair, the project provided me with insight into the world of disabled living, and helped shape my progress as a designer. My goal is to continue to refine the project, apply for patent protection and begin actual development of the wheelchair.4. The Process: Describe the rigor that informed your project. (Research, ethnography, subject matter experts, materials exploration, technology, iteration, testing, etc., as applicable.) What stakeholder interests did you consider? (Audience, business, organization, labor, manufacturing, distribution, etc., as applicable)
The project started with extensive research into adaptive sports. Numerous amateur level games were attended to understand the sports and the participant's attitude towards them and their equipment. This research led to the theme of the project: that many sports wheelchairs shared numerous design features, each tailored to a particular sport. It was also noticed that the high end solutions available to professional athletes were far over built/designed for the amateur athlete. The project next progressed to quick sketch concepts illustrating various ways that a wheelchair might convert or adjust from one sport to another. While some ideas were starting to take form, the project still had no clear direction. An expert at a leading wheelchair distributor and former paralympian was consulted to help define the design task. In discussions with him, the idea for a wheelchair that could be used daily but also be used for occasional sports took hold. Further refinement and advice narrowed this idea to a wheelchair for children that would give them access to sports they might otherwise not have. At this point, Rhino3D was used to quickly flesh out ideas for mechanisms, and the required dimensions of the chair in different configurations. A plywood mockup was built to gain insight into the proper location of the chairs centre of gravity and the range of adjustment required. This lead to a clear understanding of the human factors involved in design a successful convertible wheelchair. Investigations into alternate production methods revealed die casting as suitable alternative to the traditional bent and welded tube construction of existing wheelchairs. This would also allow for a simple adjustment mechanism to be designed into the chair. With a production process in mind, the chair was styled and worked modeled in SolidWorks. This allowed for draft analysis of the components, ensuring their suitability for die casting. SolidWorks was also employed to perform rudimentary FEA analysis of the design. A robust CAD model also allowed for virtual testing of wheel angles, required clearances and a complete bill of materials for the first prototype. The SolidWorks data was used to CNC cut the frame members out of styrene foam. The styrene parts acted as sacrificial cores in sand casting aluminium. Once the parts were cast, they were finished with hand and machine tools and assembled into a working prototype. While this did not mimic the die casting process, it allowed for a fully functional prototype within the university setting. Throughout the process, numerous stakeholders were considered. First and foremost, the child who had to use a chair on a daily basis. Also critical were parents and support personal who would have a role in purchasing the chair and changing its use. The production methods were also pivotal in shaping the design while still being manufacturable . Finally, government requirements for wheelchair funding had to be considered.5. The Value: How does your project earn its keep in the world? What is its value? What is its impact? (Social, educational, economic, paradigm-shifting, sustainable, environmental, cultural, gladdening, etc.)
While one third of the Canadian able body population participates in sport, only three percent of people with disabilities partake in sport. Sport offers a number of benefits both physically and socially including rehabilitation, healthy living, and confidence building. The benefits of recreational sport can be instrumental in a child coming to terms and accepting their disability. Sport provides exercise, social bonding and a sense of empowerment over ones disability. A 1998 study by Emory University and the University of Georgia showed that children who participate in sports improve in strength, coordination and flexibility. In addition, parents and teachers report the children are less likely to be depressed and often show improvement in behavior, academics and social interaction. The Crosstrainer wheelchair bridges the gap between daily use wheelchairs and the specialized equipment used to play adaptive sports. By being designed primarily as a daily use wheelchair, it qualifies for government funding. The built in sports functionality comes as an added bonus to the child using the chair. This allows a child an introduction to adaptive sports they otherwise might not have had. The ability of the chair to easily expand also increases its usefulness; the chair can grow with a child instead of being replaced at a high cost to a parent or government agency. The change in manufacturing method from what is essentially a craft method to mass production could also act as a precursor to new, innovative and low cost wheelchair designs for the developing world.