The aim of this project is to address two fundamental problems with conventional wheelchairs. The first problem that we aim to address is the manual effort required to propel the wheelchair. In a manual wheelchair, the user gets the benefit of physical activity, but has difficulty climbing inclines or traveling over rough terrain. In contrast, the electric wheelchairs facilitate locomotion under demanding conditions, but do not allow the user to receive the benefits of physical activity while using the device. In order to give the user the benefits of electrical and manual wheelchairs, our project proposes a hybrid design which uses both electrical assistance and manual power
The second issue that we are targeting is the biomechanics of propelling the wheelchair. Studies have shown that the traditional handrim of a wheelchair causes an elevated load in the upper extremities and produces a sub-optimal power output. One solution to this problem is a lever/ratchet mechanism. This has been implemented is some existing wheelchairs, but has not been coupled with an assistive power source.