One-dimensional input device of electric wheelchair for persons with severe Duchenne Muscular Dystrophy

Abstract

Persons with Duchenne Muscular Dystrophy (DMD) usually have difficult in operating electric wheelchairs (EWs) using standard input device due to the lack of muscular power and the deformation of their hands. To solve this problem, various kinds of input devices are developed considering their physical limits. However, as the disease progresses, persons with severe DMD will gradually lose the ability to operate the developed input devices. In this study, we first made an investigation of physical functions for persons with severe DMD and found that functions of upper limb, especially functions of the fingers, tended to remain better in at least one-dimensional direction. A novel one-dimensional input device (1DID) was developed for persons with severe DMD based on a quantitative evaluation of the hand functions. Thus, this device can be operated using slight force and one-dimensional movement of a finger. Therefore, persons with severe DMD can adjust the straight and turning motion of an EW using two 1DIDs with the cooperative operation by two fingers. The validity of this device was demonstrated by evaluation experiments of 10 persons with severe DMD including those who do not have a proper input device. The evaluation results also show that the developed 1DID has the possibility to be widely used as a generic input device with computers for persons with severe disabilities.