SBIR-STTR Award

A power propulsion attachment design concept for manual wheelchairs has been developed that can successfully bridge the gap between manual and power wheelchairs for the majority of users. Manual wheelchair users benefit from the simplicity, reliability, and transportability inherent to these designs. But for all users there are situations where the strength and endurance required is unacceptable and detrimental to their health. At some point this occurs frequently enough that the user is forced to transition to a power wheelchair. While power wheelchairs can liberate the user from their physical limitations there are the disadvantages of high cost, reduced transportability, and the total loss of therapeutic physical exertion. The success of pushrim-controlled power assist devices, the latest entry into this market, have been limited by their high cost, high weight, and difficulty in installing or returning to the original manual configuration. The proposed design replaces one of the front castor assembles and with an efficient and lightweight single motor drive system steered with a manual joystick. The user can easily switch between manual and power wheelchair functionality without having the major disadvantages of either. In Phase I an existing motor, controller, and battery system will be adapted to the prototype steering system. Fundamental stability and maneuverability criteria will be evaluated. In Phase II a custom drive system will be developed and steering refined. Complete functional and user testing will then take place at an established wheelchair test facility. The proposed simple and innovative attachment allows the wheelchair user to switch easily between power and manual propulsion on any manual wheelchair. This inexpensive design allows the user themselves to choose which is appropriate for their current condition and situation they face

A lightweight power propulsion attachment for manual wheelchairs will be developed to bridge the gap between manual and power wheelchairs for the majority the 2,500,000 users in the United States who depend entirely on wheelchairs for their mobility and quality of life. All manual wheelchair users encounter real-world situations that require strength and endurance that exceed their capabilities and are potentially detrimental to their health. When this occurs too frequently, users are forced to transition to power wheelchairs. While liberated from their physical limitations, power wheelchair users face significant disadvantages including high cost, total loss of therapeutic physical exertion and dramatically reduced transportability. Studies have found that maintaining mobility is essential for quality of life and reduces overall health care costs. Society as a whole also gains from users' full participation. It is therefore important to enable the user to extend as long as possible, without risking injury, the transition from manual to power wheelchairs. The proposed design replaces one front castor with a new castor coupled to an efficient and lightweight drive system steered with a manual joystick. The user can easily detach the entire drive unit and revert to the original manual wheelchair configuration. The lightweight power attachment unit can then be folded and stowed. The Phase II objectives are to complete the product development by adding the remaining required features, and optimizing the drive system, user interface, and structure. The specific aims are to meet weight, range, speed, traction, stability, reliability, cost, and ease of attaching/detaching requirements. These requirements were developed from user input, product analysis, and previous user, industry, and market studies. Phase II will begin with a detailed requirements analysis and design investigation. The design work will begin with the motor, gearbox, and brake systems. This will be followed by the design of the wheel coupling, the battery and power electronics, and the user interface. Complete industry standard tests will be performed at an established wheelchair test facility. User testing will verify functionality in real-world conditions. The combination of the simple, innovative design with the use of existing components, materials, and fabrication techniques results in a product with revolutionary features at a lower cost than existing products, creating an entirely new product category. With a superior market position, the power attachment is poised to capture a significant market share of the $800 million dollar power mobility industry. A successful introduction of this innovative product will stimulate further technical innovation in an industry constrained by antiquated structural and technological paradigms. A cost effective, exceptionally lightweight power propulsion attachment for manual wheelchairs will be developed that can be easily attached/detached by the user. This product will allow users to exercise their individual physical abilities without risking the injuries due to overexertion. The product seamlessly combines the transportability of manual wheelchairs with the functionality of power wheelchairs, increasing the overall mobility of the user. Studies have found that as mobility increases, quality of life is improved and health care costs are reduced.

Thesaurus Terms:
Assistive Device /Technology, Biomedical Equipment Development, Biomedical Equipment Safety, Portable Biomedical Equipment, Technology /Technique Development Cost Effectiveness, Evaluation /Testing, Functional Ability, Person With Disability, Quality Of Life Bioengineering /Biomedical Engineering, Clinical Research, Human Subject, Interview, Medical Rehabilitation Related Tag