Design and Development of a Hand Exoskeleton for Assessing Hand Spasticity

Numerous hand exoskeletons have been developed in the past decades, but very few have the function of spasticity assessment. This paper presents a novel hand exoskeleton (CureHand) whose mechanical structure and sensing system are designed for quantitative assessment of hand spasticity. By analysing the symptoms of hand spasticity and the anatomy of hands, we identified design criteria for a hand exoskeleton to assess spasticity. The exoskeleton features adaptive cablelinkage transmission mechanisms with a bi-directional force sensor setup. It can flexibly exert controllable extension and flexion on separate finger joints while concurrently registering joint torque and position. A kinematic model of the transmission system was derived and used to govern the control
of joint positions via servos. Furthermore, the functionality tests validated that the current prototype effectively mimics the clinical scale for spasticity assessment and quantitatively evaluates spasticity characteristics, including range of motion and catch angle.