An Anthropomorphic Passive Instrumented Hand for Validating Wearable Robotic Systems

Robotic exoskeletons for the hand have the potential to enhance physical rehabilitation and augment functional recovery following neurological injury. However, before such devices can be deployed to the home and clinic, robust experimental validation of performance capabilities is required. Currently, researchers rely on human subjects for these validations, but this method makes the separation of device and active wearer contributions difficult to determine. To address the need for a robust mechanical analog of the human hand in exoskeleton validation, we have produced a low-cost, open-source, instrumented hand. This design features variable stiffness joints with position sensing, anthropomorphic palm and finger phalanges with human-like joint couplings, thumb origin location, and kinematic structure. Importantly, the novel joint design enables human-like double exponential finger joint stiffness. It improves on the state of the art, which comprises linear joint stiffness profiles, non-anthropomorphic size and shape, and inaccurate thumb kinematics. In this paper, we detail the design of this device and validate its performance for use in the design and validation of wearable systems.