According to an estimate released by World Health Organization, WHO, about 7 – 10% of the global population has some kind of disability. They further state that 80 % of these people with disabilities, especially children, live in third world or developing countries. According to The United Nations Statistical Office there are about 20 million people in the world who need a wheelchair, but cannot afford to buy one. (Oderud n. d. ) Whirlwind wheelchair International & DISCARE
Whirlwind wheelchair international, WWI, a program of the Center for Civic and Community Engagement at San Francisco State University (SFSU), is into designing wheelchairs for Third World Countries from locally available materials. WWI was founded in 1989 as the Wheeled Mobility Center by SFSU Engineering professor Peter Pfaelzer and paraplegic engineer and wheelchair designer Ralf Hotchkiss. The wheelchairs designed by WWI, use thin-walled steel tubing which is readily available almost everywhere. These wheelchairs can be built by disabled craftsperson as a village industry.
For building these wheelchairs effectively only a short training is required – usually welding skills and simple math. The cost of materials is usually US $ 100. (Baumrind n. d. ) DISCARE is located in one of the world’s poorest countries – Zambia. From its modest two-man repairing team in 1991, DISACARE has now grown to an organization with 23 employees, many of whom are disabled. To be at the breakeven point DISACARE must sell between 15-20 wheelchairs a month, which it finds very difficult to do, because of the inability of poor people of Zambia to buy these wheelchairs (Kornbluth & Osafo-Kwaako n. d. ) Wheel-Chair and foot rest design
The most important design consideration while designing a wheel chair is that it should fit the needs of the rider. A customer’s height, width, level of disability, and even the terrain where the wheelchair is used will affect the design of the chair. The main focus is the comfort of the person using the wheelchair, who has mobility limitations due to problem with either posture or motion. The first design of a wheelchair based on comfort was in the eighteenth century – a convertible wheelchair with reclining back and adjustable footrest, having three wheels, two large wheels in front and one smaller one in the back (Hotchkiss 1985).
The focus of wheelchair design in developing countries is building good quality, low-cost wheelchairs in developing countries from locally available materials. In general, wheelchairs with fixed foot rests are less expensive to produce and tend to be stronger. The design in this project focuses on adjustable footrest, as this is the major inefficiency of an otherwise standardized wheelchair design. Here the leg rests are attached to the two front sides of the wheelchair frame, so that they move with it, maintaining the desired angle.
Here the footrest pivots from the leg rest, and is like a complete solid piece which allows the footrest to remain with the leg rest. The footrests are like a simple bar across the front with a platform for feet and are a part of the frame structure. They are flip-up in nature and at a standard angle. The footrests can be extended or retracted based on requirement and are controlled by a bracket on the wheel. Materials for the footplate Following are the main materials used for the manufacture of frames: 1. Steel – It is the strongest material and also the cheapest for manufacturing.
The frame made is also easier to repair. However, it is heavier than other materials and may corrode if there is damage to the finish. 2. Aluminum Magnesium alloy – This material is lighter than the previous material and is not very expensive. To prevent the corrosion and scratching, an anodized finish is done on the frame. 3. Titanium and Carbon fiber – This material is very strong, light and does not corrode. On the other hand it is expensive and may be difficult to repair. (http://www. dlf. org. uk/factsheets/pdf/Choosing_an_Active_User_Wheelchair_sponsored. pdf)
Sometimes in villages, wood chairs are also built. These wheelchairs, in addition to being cheap also require fewer skills to build – mainly carpentry. The footrest is also made up of thin wood or plywood with padded sides and bottom. In any case foot should be observed daily for any sign of sores. However, a plywood frame while is a lower-cost alternative to metal, when it is not made well, or if it is left out in the rain, the chair may weaken and the plywood can split. (Werner 1999) Another variation is to weave back, seat, and footrest with ribbon, local wicker, cane, rattan or polyethylene plastic.
In another similar variation thin, lightly stretched strips of car inner tube or canvas webbing can also be used. In this case, the slide out part of the leg rest is made of casters. Using re-bar and woven plastic fairly cheaper wheelchairs could be made but the chair is heavy and also when it is used by a heavyset person or used roughly, it may bend out of shape. In contrast when PVC pipes are used the wheelchair is lighter, but is costly and still may bend out of shape. In this case it might become necessary to fiberglass the frame-which adds to cost, work, and weight. . (Werner 1999) Cost factor
The cost of a wheelchair in Mexico • Using wood frames is about US $ 40. 00. • Using re-bar (metal reinforcing rod used to strengthen cement) and woven plastic is about US $ 40. 00. • Using steel tubes is about US $ 40. 00. • Using PVC plastic pipes is costlier than the others, about US $ 100. 00. (Werner 1999) In china and Taiwan, the basic wheelchair cost is about US $ 50 – 75. The cost of a steel wheel chair made by DISCARE in Zambia is about US $ 220 – 280, which while is cheaper than the wheelchairs made in US and Europe, about US $ 500 – 1000, is still not preferable to be sold to the poor countries.
References
Baumrind S, “Engineering a better world for people with disabilities”, http://www. whirlwindwheelchair. org/articles/archive/EngineeringaBetterWorld. pdf “Choosing an Active User Wheelchair”, Disabled Living Foundation, 2003, http://www. dlf. org. uk/factsheets/pdf/Choosing_an_Active_User_Wheelchair_sponsored. pdf Hotchkiss R, “Independence through Mobility”, 1985, Appropriate Tech. International, http://www. ideanet. org/content. cfm? id=595871&CFID=1183177&CFTOKEN=78115328 Kornbluth K, Osafo-Kwaako P, “Wheelchairs in Zambia”, http://web. mit. edu/d-lab/Readings/disacare. pdf