Wrist rehabilitation in chronic stroke patients by means of adaptive, progressive robot-aided therapy

Abstract

Despite distal arm impairment after brain injury is an extremely disabling consequence of neurological damage, most studies on robotic therapy are mainly focused on recovery of proximal upper limb motor functions, routing the major efforts in rehabilitation to shoulder and elbow joints. In the present study we developed a novel therapeutic protocol aimed at restoring wrist functionality in chronic stroke patients. A haptic three DoFs (degrees of freedom) robot has been used to quantify motor impairment and assist wrist and forearm articular movements: flexion/extension (FE), abduction/adduction (AA), pronation/supination (PS). This preliminary study involved nine stroke patients, from a mild to severe level of impairment. Therapy consisted in ten 1-hour sessions over a period of five weeks. The novelty of the approach was the adaptive control scheme which trained wrist movements with slow oscillatory patterns of small amplitude and progressively increasing bias, in order to maximize the recovery of the active range of motion. The primary outcome was a change in the active RoM (range of motion) for each DoF and a change of motor function, as measured by the Fugl-Meyer assessment of arm physical performance after stroke (FMA). The secondary outcome was the score on the Wolf Motor Function Test (WOLF). The FMA score reported a significant improvement (average of 9.33±1.89 points), revealing a reduction of the upper extremity motor impairment over the sessions; moreover, a detailed component analysis of the score hinted at some degree of motor recovery transfer from the distal, trained parts of the arm to the proximal untrained parts. WOLF showed an improvement of 8.31±2.77 points, highlighting an increase in functional capability for the whole arm. The active RoM displayed a remarkable improvement. Moreover, a three-months follow up assessment reported long lasting benefits in both distal and proximal arm functionalities. The experimental results of th- s preliminary clinical study provide enough empirical evidence for introducing the novel progressive, adaptive, gentle robotic assistance of wrist movements in the clinical practice, consolidating the evaluation of its efficacy by means of a controlled clinical trial.

A Subject-Adaptive Controller for Wrist Robotic Rehabilitation

“…The fact that the desired trajectory is only defined in the task space makes this controller independent of time, thus allowing movement velocity to be completely defined by the subject. Applying the AAN approach to a wrist rehabilitation robot, the algorithm proposed in [13] adapts the desired range of motion according to the performance of the subject, and introduces nonlinear feedback control action to minimize assistance force/torques when the error is small.…”

Desarrollo de un Robot de Rehabilitación pasiva para la articulación de la muñeca mediante la implementación de un microcontrolador Arduino UNO

“…Adicionalmente se caracteriza por poseer un controlador de movimiento activado por un actuador lineal acoplado sobre una rótula esférica [3]. Entre otro de los dispositivos destacados en rehabilitación de muñeca y antebrazo, es el desarrollado por el Instituto Italiano di Tecnología [4]. Este robot posee tres grados de libertad controlados por tres motores rotatorios DC acoplados con un sistema de transmisión de engranaje cónico, el cual cuenta con un protocolo terapéutico que permite la restauración de la funcionalidad de la muñeca en pacientes con accidente cerebrovascular crónico.…”

Improving Challenge/Skill Ratio in a Multimodal Interface by Simultaneously Adapting Game Difficulty and Haptic Assistance through Psychophysiological and Performance Feedback

“…The main idea behind these systems is to assist the subject in completing a given task (e.g., reaching or grasping), typically by using a haptic controlled robotic device to deliver the forces needed for the correct completion of the objective (Liu et al, 2006; Nef et al, 2009; Song et al, 2013; Squeri et al, 2014; Pignolo et al, 2016). The intended output of these therapeutic robots is to promote engagement, human effort, and intention of movement and, therefore, to accelerate motor learning and induce neural plasticity (Reinkensmeyer et al, 2004; Edgerton et al, 2008; Huang and Krakauer, 2009; Pennycott et al, 2012).…”