A 3-DoF Robotic Platform for the Rehabilitation and Assessment of Reaction Time and Balance Skills of MS Patients

The central nervous system (CNS) exploits anticipatory (APAs) and compensatory (CPAs) postural adjustments to maintain the balance.The postural adjustments comprising stability of the center of mass (CoM) and the pressure distribution of the body influence each other if there is a lack of performance in either of them.Any predictable or sudden perturbation may pave the way for the divergence of CoM from equilibrium and in homogeneous pressure distribution of the body.Such a situation is often observed in daily livings of Multiple Sclerosis (MS) patients owing to their poor APAs and CPAs, and induces their falls.The way of minimizing risk of falls in neurological patients is utilizing perturbation-based rehabilitation, as it is efficient in the recovery of the balance disorder.In the light of the findings, we present the design, implementation, and experimental evaluation of a novel 3 DoF parallel manipulator to treat the balance disorder of MS.The robotic platform allows angular motion of the ankle based on its anthropomorphic freedom.The end-effector endowed with upper and lower platforms is designed to evaluate both the pressure distribution of each foot and the CoM of the body, respectively.Data gathered from the platforms are utilized to both evaluate performance of the patients and used in high-level control of the robotic platform to regulate the difficulty level of tasks.In this study, kinematic and dynamic analyses of the robot are derived and validated in the simulation environment. Low-level control of the prototype is also successfully implemented through PID controller.The capacity of each platform is evaluated with a set of experiments considering assessment of pressure distribution and CoM of the foot-like-objects on the end-effector. Experimental results indicate that such a system well-address the need for balance skill training and assessment through the APAs and CPAs.