Initial analysis and design of an assistive rehabilitation hand device with free loading and fingers motion visible to subjects

The objective of this work is first to present a study and analysis of fundamental issues that constitute the development of a hand rehabilitation system by making use of mechanisms for objective and quantitative assessment for patients with motor weakness, such as spinal cord injury (SCI) and post-stroke. The proposed rehabilitation system aims to improve the functional ability of impaired hand on the identified functional activities of daily living (ADL) and rehabilitation exercises. The system, through an interactive control, assists the subject to undergo activities of daily living (ADL) task relevant training on the impaired hand. The work also contributes in closing the knowledge gap of clinical and engineering groups. A kinematics modeling for the human hand-finger model is derived. The joint model has then been linked to rehabilitation functional activities of daily living (ADL). According to the kinematics studied and the joint ranges identified, a single five-bar mechanism assisting the finger motion is proposed. The kinematics of the five-bar mechanism is derived and the inverse solutions are obtained. An 11-DOF load-free hand prototype formed and assembled by a set of the five-bar mechanisms is described with four associated modules. Finally, the preliminary works and future research are concluded in this paper.