Mechanical wheelchair propulsion system for patients with arthrogryposis
Arthrogryposis is a congenital disorder characterized by extreme joint stiffness that inhibits strength and flexibility in upper and lower extremities. Cases vary in sever-ity, but this research focuses on those in which patients require a wheelchair for mobility. Currently, two conventional designs exist: mechanical and electric wheelchairs. For most arthrogryposis patients, existing mechanical wheelchairs are insufficient for independent propulsion as their joints are severely impaired, prohibiting them from reaching the outer handrails on the wheels and expending enough force to propel and steer. Existing devices that improve the mechanical advantage of wheelchairs are insufficient for the needs of these patients who have very limited and specific ranges of motions, which are not compatible with the required force inputs. Though electric wheelchairs allow independent mobility, they are expensive to maintain and not easily portable, limiting their use by socioeconomically disadvantaged patients. Arthrogryposis patients require a lightweight, portable and durable mechanical wheelchair that takes advantage of the user's specific strengths, and is easily maneuvered in all directions without assistance. A design is presented for a socioeconomically disadvantaged teenage client with arthrogryposis. After taking data regarding the ranges of motion and strength of the client, a new propulsion system was designed and retrofitted to a conventional wheelchair. Prototye I has been tested and a second-generation design which fits the needs of a wider audience suffering from arthrogryposis is presented. Copyright © 2012 by ASME.
