Robotic Hand Exoskeletons for Rehabilitation and Assistance: A State-of-the-Art

The number of patients with hand dysfunction is increasing worldwide, and their activities of daily living (ADLs) are seriously affected. Robotic medical devices such as robotic hand exoskeletons have been investigated to help restore and improve the hand functions of these patients. In comparison with the traditional therapies, robotic hand exoskeletons have the advantages of providing a controllable assistive force/torque, recording the wearer's motion data, and improving the wearer's voluntary participation and motivation in the rehabilitation, which can improve the hand rehabilitation efficiency. Currently, there is a lack of systematic reviews of robotic hand exoskeletons. This paper presents a systematic review of robotic hand exoskeletons. Six electronic databases are searched using the same keywords, and a total of 86 papers that meet the inclusion criteria are selected for this review. The biomechanics of a human hand is introduced. The design concepts of robotic hand exoskeletons are also proposed, which include the actuator design and configuration, human-machine kinematic compatibility, and design of degrees-of-freedom (DOFs). Additionally, the control strategies of robotic hand exoskeletons are described. Finally, the limitations of the currently available robotic hand exoskeletons and their possible future research and development directions are discussed. The significance of this review is to provide useful information for the engineers and researchers to develop robotic hand exoskeletons with practical and plausible applications.