Design and validation of the RiceWrist-S exoskeleton for robotic rehabilitation after incomplete spinal cord injury

Abstract

SUMMARYRobotic devices are well-suited to provide high intensity upper limb therapy in order to induce plasticity and facilitate recovery from brain and spinal cord injury. In order to realise gains in functional independence, devices that target the distal joints of the arm are necessary. Further, the robotic device must exhibit key dynamic properties that enable both high dynamic transparency for assessment, and implementation of novel interaction control modes that significantly engage the participant. In this paper, we present the kinematic design, dynamical characterization, and clinical validation of the RiceWrist-S, a serial robotic mechanism that facilitates rehabilitation of the forearm in pronation-supination, and of the wrist in flexion-extension and radial-ulnar deviation. The RiceWrist-Grip, a grip force sensing handle, is shown to provide grip force measurements that correlate well with those acquired from a hand dynamometer. Clinical validation via a single case study of incomplete spinal cord injury rehabilitation for an individual with injury at the C3-5 level showed moderate gains in clinical outcome measures. Robotic measures of movement smoothness also captured gains, supporting our hypothesis that intensive upper limb rehabilitation with the RiceWrist-S would show beneficial outcomes.

Estimating anatomical wrist joint motion with a robotic exoskeleton

“…1, is unpowered, backdriven, and measurements are taken from the 500 count Avago HEDL-5540 quadrature encoders at each robotic joint. The sensor resolution of this device is on the order of hundredths of a degree, similar to previously presented devices [4]. Encoder velocity is obtained with a Q8-USB DAQ from Quanser.…”

“…Rehabilitation robots for the wrist have been proposed, such as Pehlivan, et. al [4] and Masia, et. al [5].…”

“…Devices rely on a variety of features, from passive degrees of freedom [4] to anatomically designed wrist mechanisms [14], to align exoskeleton joints to the complex rotations in the wrist. However, preventing kinematic overconstraint is not enough to ensure that robotic joint measurements are accurate reflections of human joint measurements, in particular when unmeasured movement is part of the design.…”

Editorial: Foreword for special issue on rehabilitation robotics and human–robot interaction – ROBOTICA

“…On the other hand, the control of the physical interaction of the therapeutic device with the subject to effectively accelerate recovery is of paramount importance. This special issue focuses on the current state of knowledge about sensorimotor control and brain plasticity, models of sensorimotor functional recovery, and use of intelligent robot controllers to provide robotic-assisted therapy for motor rehabilitation.This special issue includes studies that describe the development, optimization and testing of robotic devices and exoskeletons used for both upper 1,2,9,10,11,12,14,15 and lower limbs. 4,6,8 Methods for quantifying and improving sensorimotor control are also discussed.…”

“…This special issue includes studies that describe the development, optimization and testing of robotic devices and exoskeletons used for both upper 1,2,9,10,11,12,14,15 and lower limbs. 4,6,8 Methods for quantifying and improving sensorimotor control are also discussed.…”