Caterina Procopio

Arm rehabilitation with a robotic exoskeleleton in Virtual Reality

Several studies demonstrate the importance of an early, constant and intensive rehabilitation following cerebral accidents. This kind of therapy is an expensive procedure in terms of human resources and time, and the increase of both life expectance of world population and incidence of stroke is making the administration of such therapies more and more important. The development of new robotic devices for rehabilitation can help to reduce this cost and lead to new effective therapeutic procedures. In this paper we present an exoskeleton for the robotic-assisted rehabilitation of the upper limb. This article describes the main issues in the design of an exoskeletal robot with high performance, in terms of backdrivability, low inertia, large workspace isomorphic to the human arm and high payload to weight ratio. The implementation of three different robotic schemes of therapy in virtual reality with this exoskeleton, based on an impedance control architecture, are presented and discussed in detail. Finally the experimental results of a preliminary evaluation of functionality of the system carried out on one patient are presented, and compared with the performance in the execution of the exercise obtained with healthy volunteers. Moreover, other preliminary results from an extended pilot clinical study with the L-Exos are reported and discussed.

Positive effects of robotic exoskeleton training of upper limb reaching movements after stroke

This study, conducted in a group of nine chronic patients with right-side hemiparesis after stroke, investigated the effects of a robotic-assisted rehabilitation training with an upper limb robotic exoskeleton for the restoration of motor function in spatial reaching movements. The robotic assisted rehabilitation training was administered for a period of 6 weeks including reaching and spatial antigravity movements. To assess the carry-over of the observed improvements in movement during training into improved function, a kinesiologic assessment of the effects of the training was performed by means of motion and dynamic electromyographic analysis of reaching movements performed before and after training. The same kinesiologic measurements were performed in a healthy control group of seven volunteers, to determine a benchmark for the experimental observations in the patients’ group. Moreover degree of functional impairment at the enrolment and discharge was measured by clinical evaluation with upper limb Fugl-Meyer Assessment scale (FMA, 0–66 points), Modified Ashworth scale (MA, 0–60 pts) and active ranges of motion. The robot aided training induced, independently by time of stroke, statistical significant improvements of kinesiologic (movement time, smoothness of motion) and clinical (4.6 ± 4.2 increase in FMA, 3.2 ± 2.1 decrease in MA) parameters, as a result of the increased active ranges of motion and improved co-contraction index for shoulder extension/flexion. Kinesiologic parameters correlated significantly with clinical assessment values, and their changes after the training were affected by the direction of motion (inward vs. outward movement) and position of target to be reached (ipsilateral, central and contralateral peripersonal space). These changes can be explained as a result of the motor recovery induced by the robotic training, in terms of regained ability to execute single joint movements and of improved interjoint coordination of elbow and shoulder joints.

An EMG-Controlled Robotic Hand Exoskeleton for Bilateral Rehabilitation

This paper presents a novel electromyography (EMG)-driven hand exoskeleton for bilateral rehabilitation of grasping in stroke. The developed hand exoskeleton was designed with two distinctive features: (a) kinematics with intrinsic adaptability to patients hand size, and (b) free-palm and free-fingertip design, preserving the residual sensory perceptual capability of touch during assistance in grasping of real objects. In the envisaged bilateral training strategy, the patients non paretic hand acted as guidance for the paretic hand in grasping tasks. Grasping force exerted by the non paretic hand was estimated in real-time from EMG signals, and then replicated as robotic assistance for the paretic hand by means of the hand-exoskeleton. Estimation of the grasping force through EMG allowed to perform rehabilitation exercises with any, non sensorized, graspable objects. This paper presents the system design, development, and experimental evaluation. Experiments were performed within a group of six healthy subjects and two chronic stroke patients, executing robotic-assisted grasping tasks. Results related to performance in estimation and modulation of the robotic assistance, and to the outcomes of the pilot rehabilitation sessions with stroke patients, positively support validity of the proposed approach for application in stroke rehabilitation.

A pilot clinical study on robotic assisted rehabilitation in VR with an arm exoskeleton device

The development of new robotic devices for rehabilitation can lead to new and more efficient therapeutic procedures. Moreover, the use of VR-based scenarios in which patients perform rehabilitation exercises dramatically increases the patients¿ motivation and thus the final therapy outcome. In this paper preliminary results of a pilot study carried out with an exoskeleton for the robotic assisted rehabilitation of the upper limb are presented. The paper briefly describes the main kinematic and mechanical features of the exoskeleton system, showing its peculiar characteristics which make it useful for rehabilitation purposes. The implementation of three different robotic schemes of therapy in virtual reality with this exoskeleton, based on an impedance control architecture, are presented and discussed in detail. Finally, qualitative and quantitative results obtained in a 6 week pilot study with three chronic stroke patients are reported.

Robot-mediated arm rehabilitation in Virtual Environments for chronic stroke patients: A clinical study

This paper presents the results of a clinical trial employing the PERCRO L-Exos (Light-Exoskeleton) system, which is a 5-DoF force-feedback exoskeleton for the right arm, for robotic-assisted rehabilitation. The device has demonstrated itself suitable for robotic arm rehabilitation therapy when integrated with a Virtual Reality (VR) system. Three different schemes of therapy in VR have been tested in the clinical evaluation trial, which was conducted at the Santa Chiara Hospital in Pisa with nine chronic stroke patients. The results of this clinical trial, both in terms of patients performance improvements in the proposed exercises and in terms of improvements in the standard clinical scales which have been used to monitor patients progresses will be reported and discussed throughout the paper. It is to be noted that statistically significant improvements have been demonstrated in terms of Fugl-Meyer scores, Ashworth scale and increments of active and passive ROMs on shoulder, elbow and wrist joints of the impaired limb.

A full upper limb robotic exoskeleton for reaching and grasping rehabilitation triggered by MI-BCI

In this paper we propose a full upper limb exoskeleton for motor rehabilitation of reaching, grasping and releasing in post-stroke patients. The presented system takes into account the hand pre-shaping for object affordability and it is driven by patients intentional control through a self-paced asynchronous Motor Imagery based Brain Computer Interface (MI-BCI). The developed antropomorphic eight DoFs exoskeleton (two DoFs for the hand, two for the wrist and four for the arm) allows full support of the manipulation activity at the level of single upper limb joint. In this study, we show the feasibility of the proposed system through experimental rehabilitation sessions conducted with three chronic post-stroke patients. Results show the potential of the proposed system for being introduced in a rehabilitation protocol.

Rehabilitation training and evaluation with the L-EXOS in chronic stroke

This paper presents the results of the evaluation training performed in a group of chronic stroke patients using a robotic exoskeleton device. The effects of training were assessed both by means of clinical evaluation in terms of Fugl-Meyer and Modified Ashworth assessment scales and of functional evaluation, by means of Bimanual Activity Scale. Interestingly we found a significant improvement of both clinical and functional evaluation.

Serious Game and Wearable Haptic Devices for Neuro Motor Rehabilitation of Children with Cerebral Palsy

Cerebral palsy (CP) is a group of disorders that affect the development of movement and posture, resulting in limited activities. To optimize pediatric neuro-rehabilitation and to complement conventional occupational therapies, serious game based therapies for upper limb (UL) rehabilitation have been developed or adapted for the pediatric field during recent years. In this work, we present the design and development of UL rehabilitation scenario for CP patients, based on Serious Games (SG) and enhanced by immersive virtual reality (VR) with haptic feedback to increase engagement and provide rich, congruent multi-sensory feedback during virtual interaction.

A Novel Approach for Upper Limb Robotic Rehabilitation for Stroke Patients

This paper presents a novel neuro-rehabilitation system for recovery of arm and hand motor functions involved in reaching and grasping. The system provides arm weight support and robotic assistance of the hand closing/opening within specific exercises in virtual reality. A user interface allows the clinicians to perform an easy parametrization of the virtual scenario, customizing the exercises and the robotic assistance to the needs of the patient and encouraging training of the hand with proper recruitment of the residual motor functions. Feasibility of the proposed rehabilitation system was evaluated through an experimental rehabilitation session, conducted by clinicians with 4 healthy participants and 2 stroke patients. All subjects were able to perform the proposed exercises with parameters adapted to their specific motor capabilities. All patients were able to use the proposed system and to accomplishing the rehabilitation tasks following the suggestion of the clinicians. The effectiveness of the proposed neuro-rehabilitation will be evaluated in an imminent prolonged clinical study involving more stroke patients.

Rationale of an Integrated Robotic Approach for Upper Limb Functional Rehabilitation

Upper limb motor impairment often causes long-term disability in stroke patients and implies limitations in activities of daily living. Several studies tested robotic devices for proximal or distal upper limb rehabilitation and reported results principally focused on specific treated district without significant global effects. We propose a novel approach that integrates a hand distal effector in task-oriented arm training for upper limb functional rehabilitation. Four chronic stroke patients underwent to an intensive rehabilitative treatment using a robotic device that provides arm weight support and assistance of the hand closing/opening within specific setting in virtual reality. After treatment improvements in upper limb functional scales and in kinematic and pressure assessments were observed, highlighting effects on global upper limb motor performance and distal motor control. Furthermore a decrease in resting motor threshold and a reduction in silent period recorded from unaffected hemisphere were evident, suggesting a potential cortical reorganization.