Identification of Need
Independence of users of wheelchairs has been a quality of life aspect that has been improved through the emergence of modern technologies. Independence is a common struggle, especially for young users of wheelchairs that want to become less dependent on help workers and more so on themselves (Lumsdaine & Thurston, 2016). The purpose of this design is to increase the independence of paraplegic swimmers by making a self-driven method to get in and out of swimming pools that is convenient and does not require external help. This system must be consistently reliable and safe, and not require users to have to perform any difficult corrections like resetting a fallen wheelchair. Users must also be free of the risk of tipping while lifting themselves back into the wheelchair, as this is one of the biggest safety concerns for disabled people when they are alone (Kirby & Lugar, 1999). Due to reduced mobility, most of the methods of entering and exiting pools for users of wheelchairs use either pulley systems or physical support from others (USA Patent No. US06031858, 1980). These systems are not only expensive and inconvenient but can be humiliating for people whose only choice is to use them. New technologies should take note of this and simplify the process to make a subtler entrance into the pool for swimmers that do not want to draw attention to themselves. An important aspect of wheelchair safety is the anti-tipping/falling technologies that are implemented in wheelchairs. Like pool accessibility, anti-tipping innovations have greatly increased the independence of users of wheelchairs, and therefore have has positive impacts on their quality of life. Despite being a niche demographic to design an engineering solution for, the implications that the option for complete independence in certain situations can have great benefits on the quality of life of disabled swimmers, especially if this freedom is supported by convenience, confidence, and safety.
Assessment of Current Technology
Anti-tipping technologies in wheelchairs are those that have simple and complicated applications. However, simple is relative term in the domain of wheelchair safety. For instance, in Ronald Lee Kirby’s “Anti-tip devices for wheeled conveyances including wheelchairs and method related thereto” (USA Patent No. US6530598 B1, 1999), what looks like a simple wheelchair extension (refer to Appendix 2) that is not specifically innovative, really has had a considerable amount of thought and function put into it, as evident in the patent’s background.
“…it alone can support the loads being imposed during the tilting motion and the load when the device and rear wheels are supporting the weight of the user and wheelchair.” (Kirby & Lugar, 1999)
This is one example of the features implemented into a standard anti-tipping that likely required extensive testing or sound load distribution calculations. There are many existing devices that serve similar purposes to that that was previously mentioned. These devices vary in terms of the use of wheels or rubber stoppers, as well as in the load distributions that they are positioned to protect against. In addition to these forward tipping prevention devices, research and development has gone into the less common forms of tipping, sideways tipping. Where extremities outside the side of a standard wheelchair are not as feasible as those on the front and back due to size constraints, there are other methods that can be used, as well as other research that has been done into elimination or reduction of risk and impact of less common falling situations. For example, it has been found that removing constraints on users of wheelchairs greatly reduces impact when falling due to wheels being on uneven planes (Erikson, et al., 2016).
Last, when sideways tipping is not a common occurrence in every day wheelchair use, it is very common in wheelchair sports such as wheelchair rugby or basketball. Wheelchair specifically designed for these sports have been develop and tested to find the optimal measurements of attributes like wheel tilt, castor wheel distance, and backrest angle (Mason, Porcellato, van der Woude, & Goosey-Tolfrey, 2010). All these attributes help to prevent wheelchair tipping in their own way, through counteracting loads, distributing loads differently, or by other means.
Assessment of Emerging Technologies
Traditionally, wheelchairs have been manually powered designs that are compact and simple. As technology progresses, modern innovations will change course, meaning that new technologies in the domain of wheelchairs will be geared more towards automatic wheelchairs, as opposed to traditional ones. Considering the capabilities of modern mechanical and software engineering, the room for innovation in this field is larger than it has ever been. In fact, electric wheelchair technologies began advancing faster than any other type of wheelchair many years ago, as noted by Rory A. Cooper (Cooper, 1999). These electric powered wheelchairs have faced mobility and stability problems, especially since users sacrifice some control for convenience and efficiency. To accommodate for this decreased control, engineers have used technological engineers have taken strides to increase tipping prevention, including posture sensors, magnetic break bars, and altered control boards (Takei, et al., 2010). Devices like this are optimized by considering physical loading factors like chair mass, tipping angle, and the integrity of materials that the wheelchair is composed of (Winter & Hotchkiss, 2010). Measurements like this are integral to the success of anti-tipping technology, as they allow engineers to find where loads can be placed, and how much force each location on the chair can withstand. An example of a device in which these factors are taken into consideration is in Daniel P. H. Wu’s “Wheel bracket mechanism for an electric wheelchair equipped with auxiliary wheels” (USA Patent No. US7175193B2, 2003). Wu invented a bracket mechanism that a wheelchair is to be mounted onto that uses adjustable wheel heights to smooth rides over uneven surfaces, as well distribute the load in the chair evenly when being used in such situation (Appendix 3 and 4). These modern innovations show how current technological engineers have a large room for progression in the field of assistive technology, a field in which the possibility for further innovation will always be present.