Adaptive hybrid robotic system for rehabilitation of reaching movement after a brain injury: a usability study

Abstract

BackgroundBrain injury survivors often present upper-limb motor impairment affecting the execution of functional activities such as reaching. A currently active research line seeking to maximize upper-limb motor recovery after a brain injury, deals with the combined use of functional electrical stimulation (FES) and mechanical supporting devices, in what has been previously termed hybrid robotic systems. This study evaluates from the technical and clinical perspectives the usability of an integrated hybrid robotic system for the rehabilitation of upper-limb reaching movements after a brain lesion affecting the motor function.MethodsThe presented system is comprised of four main components. The hybrid assistance is given by a passive exoskeleton to support the arm weight against gravity and a functional electrical stimulation device to assist the execution of the reaching task. The feedback error learning (FEL) controller was implemented to adjust the intensity of the electrical stimuli delivered on target muscles according to the performance of the users. This control strategy is based on a proportional-integral-derivative feedback controller and an artificial neural network as the feedforward controller. Two experiments were carried out in this evaluation. First, the technical viability and the performance of the implemented FEL controller was evaluated in healthy subjects (N = 12). Second, a small cohort of patients with a brain injury (N = 4) participated in two experimental session to evaluate the system performance. Also, the overall satisfaction and emotional response of the users after they used the system was assessed.ResultsIn the experiment with healthy subjects, a significant reduction of the tracking error was found during the execution of reaching movements. In the experiment with patients, a decreasing trend of the error trajectory was found together with an increasing trend in the task performance as the movement was repeated. Brain injury patients expressed a great acceptance in using the system as a rehabilitation tool.ConclusionsThe study demonstrates the technical feasibility of using the hybrid robotic system for reaching rehabilitation. Patients’ reports on the received intervention reveal a great satisfaction and acceptance of the hybrid robotic system.Trial registrationRetrospective trial registration in ISRCTN Register with study ID ISRCTN12843006.

Feedback Error Learning with Sliding Mode Control for Functional Electrical Stimulation: Elbow Joint Simulation

“…From the results, it is clear that the FEL scheme is able to adapt to fatigue with accuracy and speed. This result is in line with previous results reported in [29], [30], [31], which show the capability of adaptation of the FEL scheme to the highly non-linearity and time-varying response of the musculoskeletal system to the FES. In this study, the results also point out the superior performance to the FEL scheme compared to purely feedback controllers.…”

“…These experimental results show that the network satisfactorily learned within a few iterations. Although no other network topologies were evaluated in this work, the configuration used in this study was chosen based on previous results presented in the literature [31], [30]. Although the analysis of stability and robustness of the controllers was not presented in this works, instability was never observed in all the experiments carried out in this study.…”

“…These features make this strategy an interesting approach for clinical settings. The FEL algorithm has been used to control the wrist [29], [30], ankle and more recently the shoulder and elbow simultaneously in a hybrid configuration (FES + robotics support system), [31]. In these studies, PD and PID feedback controllers were implemented.…”

Treatments and rehabilitation in the acute and chronic state of traumatic brain injury

“…There is growing interest in technology in rehabilitation, either as an aid to more traditional rehabilitation promoting gain in function, particularly exoskeletons for motor function , or as a potentially powerful form of compensatory aid. The research base is however still in its infancy: while motor deficits can have a major impact on function for some individuals surviving severe TBI, these patients are relatively few in number.…”

Mobile Mechatronic/Robotic Orthotic Devices to Assist–Rehabilitate Neuromotor Impairments in the Upper Limb: A Systematic and Synthetic Review

“…Specifically, “soft body robots” (Nycz et al, 2015 ; Polygerinos et al, 2015 ) are bionic/biomimetic inspired, possibly actuated by “variable length tendons in the form of tension cables or shaped-memory alloy actuators” (as already afore exposed) or based on the expansion properties of elastomer structures, that can be powered either pneumatically or hydraulically (Dowling et al, 2014 ; Rus and Tolley, 2015 ; Polygerinos et al, 2015 ). Briefly resumed here, there are other two very important and useful features of such devices following the general trend of being more and more wearable and effective: anatomical/functional and or technical/structural modularity (Ding et al, 2008 ; Lo et al, 2010 ; Schill et al, 2011 ; Pearce et al, 2012 ; Noveanu et al, 2013 ; Lee, 2014 ; Xiao et al, 2014 ; Nycz et al, 2016 ) and complexity of “all-in-one”/hybrid kind (Giberti et al, 2014 ; Looned et al, 2014 ; Gandolla et al, 2017 ; Resquin et al, 2017 ; Tu et al, 2017a , b ).…”