Upper-limb Rehabilitation Robot Research Articles

EEG predicts upper limb motor improvement after robotic rehabilitation in chronic stroke patients

Robotic rehabilitation is known to be at least as effective as conventional training for upper limb motor recovery after stroke; nevertheless, which patients could benefit from this treatment is unknown and finding markers that could predict rehabilitation outcome is a challenge. We aimed at understanding the neural mechanisms of motor function recovery after upper limb robotic rehabilitation in chronic stroke patients using neurophysiological markers obtained by electroencephalography recording (EEG). Fourteen chronic stroke patients (M/F: 11/3; 59.5 ± 13 yrs) with mild to moderate upper limb paresis were subjected to 10 sessions of upper limb rehabilitation with a planar mobile robotic device (MOTORE, Humanware). Fugl–Meyer Assessment Scale (FMAS) and Wolf Motor Function Test (WMFT) were administered before (t0), at the end (t1) and at 1 month follow-up (t2); at the same timing 64-channals EEG was recorded. We analyzed power spectrum density in different frequency bands of the affected and unaffected hemispheres with 64-ch EEG and their correlation with motor impairment as measured by clinical scales. Correlation analyses were performed to identify the indicators of good rehabilitative outcome. Clinical assessment indicated a significant functional improvement in upper limb motor function at the end of rehabilitation as assessed with FMAS and WMFT score that is maintained at follow-up. We found a positive correlation between global Alpha activity at t0 and WMFT score variation (t0–t1) and between global Beta activity at t0 and WMFT time variation (t0–t1) and a positive correlation between Beta activity at t0 in the unaffected hemisphere and FMAS variation (t0–t1 and t0–t2). Robotic rehabilitation improves upper limb motor performance in stroke patients even in the chronic phase. The amount of Alpha and Beta band power at t0 is suggestive of rehabilitation-related motor outcome. Our results suggest that EEG recording preliminarily to robotic rehabilitation could help identifying good responders to treatment thus optimizing results.

Towards Robot-Based Cognitive and Motor Assessment Across the HIV-Stroke Spectrum.

There is an increasing population of people living with both HIV and stroke around the world with no effective neurorehabilitation strategies to deal with the combination of physical, cognitive, and social impairment that result from both diseases. This gap is caused by a lack of tools that are able to assess the various impairments across the HIV-stroke spectrum. Rehabilitation robotics provide a potential approach to address this problem. In this study, we implement a motor and cognitive task on the Haptic TheraDrive, a single degree-of-freedom upper limb rehabilitation robot. We collect data on healthy and HIV-stroke subjects from both upper limbs. Our preliminary data show that mean performance error on a trajectory tracking task and total score and reaction time on the n-back task are metrics that show differences between HIV-stroke patients and a healthy population.

Clinical and kinematic evaluation of the H-Man arm robot for post-stroke upper limb rehabilitation: Preliminary findings of a randomised controlled trial

The H-Man robot, a table-top, portable, 2D planar, end-effector with virtual reality feedback was designed to deliver self-paced, repetitive reaching arm movements. Preliminary results of a randomized clinical trial of 26/44 strokes with hemiparetic arm weakness are presented. Inclusion criteria included first-stroke, > 4 months duration with Fugl Meyer Assessment Scale (FMA) 20–50/66) without contraindications to robot-aided therapy. Following informed consent, subjects were randomized into 2 groups: H-Man-conventional (HCT) group received 18 sessions over 6 weeks of 60 minutes of H-man training then 30 minutes of conventional therapy (CT), while control group (CG) received a similar intensity of 90 minutes of CT. Blinded outcome assessments at weeks 0 (baseline), 3, 6 (end-training), 12 and 24 (follow-up). The primary outcome measure was FMA change at week 6. Parametric analysis was used and level of significance was P < 0.05. Altogether, data from 26 out of 44 subjects were analyzed. (13 HCT, 13 CG). Mean age was 54.0 years (SD 10.9), 14/26 were male, 15/26 had hemorrhagic strokes, mean stroke duration 227.2 days (SD 207.2), and mean baseline FMA 38.6 (SD 11.1). The HCT group achieved significantly better FMA gains compared to CG (4.15 HCT vs. 1.69 CG, P = 0.03) at week 6 (post-training), and at week 24 (5.77 HCT vs 2.61 CG, P = 0.03). There were no adverse side effects or drop outs. Robotic kinematic measures of line and circle temporal tracing correlated with FMA scores at Week 0. Combinatory arm rehabilitation with H-Man robot was superior to CT and well tolerated.

Drafting methodology of clinical care pathways: Practical application to the care pathway for the “prevention, diagnosis and treatment of motor disability in people after stroke”

Clinical Care Pathways (CCP) optimize quality of care and resource allocation in health systems. They translate guidelines or evidence into local practice. This work aims to provide a methodological approach for drafting a CCP, referring to a model for the prevention, diagnosis and treatment of post-stroke disability. The research method is based on a six-stages process: identification of health needs to priorities in the local care system; establish a multidisciplinary working group; selection of guidelines and evaluation of quality with the Grilli criteria, the AGREE and GRADE methodology; integration of gaps/updates among guidelines; adaptation to the local context; regular updating. The output is an integrated flow-chart. Indicators are identified for auditing. Three international guidelines were selected (NICE 2013, Canadian 2015, AHA/ASA 2016). The US one was excluded because of non-comparable health services in the two countries. Evidence for upper limb robotic rehabilitation was obtained with a narrative review by the authors. Outpatient rehabilitation is the most appropriate context for management of post-stroke disability. Access to outpatients is regulated by the rehabilitation physician, the GP or other specialists involved in stroke care. A clinical and instrumental assessment will provide indication to physical, medical and/or surgical treatments. Cognitive deficits will be already been identified and treated from the Stroke Unit. Follow-up entails clinical and/or instrumental re-evaluations, treatment modifications, or exit from the pathway. The “process” indicators include: number of first accesses; number of visits/year; time to access to service from prescription; number of control visits and retreatment. Among “outcome” indicators there are: complications; number of resolved cases; access within 6 months of the acute event. This CCP was designed according to international standards for CCPs. Adaptation to the local context led to the development of a codified and univocal pathway with a specialized and personalized care for patients with post-stroke disability.

Study on the center-driven multiple degrees of freedom upper limb rehabilitation training robot

With the aging of the society, the number of stroke patients has been increasing year by year. Compared with the traditional rehabilitation therapy, the application of upper limb rehabilitation robot has higher efficiency and better rehabilitation effect, and has become an important development direction in the field of rehabilitation. In view of the current development status and the deficiency of upper limb rehabilitation robot system, combined with the development trend of all kinds of products of the upper limb rehabilitation robot, this paper designed a center-driven upper limb rehabilitation training robot for cable transmission which can help the patients complete 6 degrees of freedom (3 are driven, 3 are underactuated) training. Combined the structure of robot with more joints rehabilitation training, the paper choosed a cubic polynomial trajectory planning method in the joint space planning to design two trajectories of eating and lifting arm. According to the trajectory equation, the movement trajectory of each joint of the robot was drawn in MATLAB. It laid a foundation for scientific and effective rehabilitation training. Finally, the experimental prototype is built, and the mechanical structure and design trajectories are verified.

ORTE: Robot for Upper Limb Rehabilitation. Biomechanical Analysis of Human Movements

This work presents ORTE, an upper limb rehabilitation system that includes: 1) a three-dimensional musculoskeletal model of the upper limb in order to study normal and pathological movements and to simulate a particular shoulder injury and its effect in muscular force, ranges of movement and muscle length changes; and 2) a 5 degrees-of-freedom upper limb robotic exoskeleton that can serves as a tool for the treatment of different injuries in the human arm. We performed the simulation of several upper arm movements of a healthy subject and one with upper brachial plexus injury in a postoperative state to compare and study the differences between them. The development of the musculoskeletal model and the results obtained by the simulations was used to design an adaptable exoskeleton prototype. Tests with different subjects was carry out and the functionality of the rehabilitation system can be demonstrated to assist in the diagnosis and treatment of upper limb injuries.

Double Iterative Compensation Learning Control for Active Training of Upper Limb Rehabilitation Robot

In this paper, the problem of non parametric uncertainty in the active training stage of stroke patients is discussed. On the basis of the nonlinear iterative learning theory, a double iterative compensation learning control is proposed. This method adopts the strategy of double loop iteration which can adjust controller parameters in real time to satisfy the patients’ condition. First, a class of saturated nonlinear functions is introduced to satisfy the requirement of position constraints. Then, reference trajectory self-modified strategy is designed for the initial positioning error. Meanwhile, the iterative compensation controller is designed according to the active torque of the patient, which can provide appropriate power compensation to the affected limb and update the parameters of the iterative learning controller continuously. At last, the convergence condition and its proof are given. The simulation results show the effectiveness and practicability of the proposed double iterative compensation optimal control strategy.

Modulation of shoulder muscle and joint function using a powered upper-limb exoskeleton

Robotic-assistive exoskeletons can enable frequent repetitive movements without the presence of a full-time therapist; however, human-machine interaction and the capacity of powered exoskeletons to attenuate shoulder muscle and joint loading is poorly understood. This study aimed to quantify shoulder muscle and joint force during assisted activities of daily living using a powered robotic upper limb exoskeleton (ArmeoPower, Hocoma). Six healthy male subjects performed abduction, flexion, horizontal flexion, reaching and nose touching activities. These tasks were repeated under two conditions: (i) the exoskeleton compensating only for its own weight, and (ii) the exoskeleton providing full upper limb gravity compensation (i.e., weightlessness). Muscle EMG, joint kinematics and joint torques were simultaneously recorded, and shoulder muscle and joint forces calculated using personalized musculoskeletal models of each subject’s upper limb. The exoskeleton reduced peak joint torques, muscle forces and joint loading by up to 74.8% (0.113 Nm/kg), 88.8% (5.8%BW) and 68.4% (75.6%BW), respectively, with the degree of load attenuation strongly task dependent. The peak compressive, anterior and superior glenohumeral joint force during assisted nose touching was 36.4% (24.6%BW), 72.4% (13.1%BW) and 85.0% (17.2%BW) lower than that during unassisted nose touching, respectively. The present study showed that upper limb weight compensation using an assistive exoskeleton may increase glenohumeral joint stability, since deltoid muscle force, which is the primary contributor to superior glenohumeral joint shear, is attenuated; however, prominent exoskeleton interaction moments are required to position and control the upper limb in space, even under full gravity compensation conditions. The modeling framework and results may be useful in planning targeted upper limb robotic rehabilitation tasks.

Active Control Strategy for Upper Limb Rehabilitation Robot Based on Velocity Field

Active Control Strategy for Upper Limb Rehabilitation Robot Based on Velocity Field

Comparison of proximal versus distal upper-limb robotic rehabilitation on motor performance after stroke: a cluster controlled trial

This study examined the treatment efficacy of proximal-emphasized robotic rehabilitation by using the InMotion ARM (P-IMT) versus distal-emphasized robotic rehabilitation by using the InMotion WRIST (D-IMT) in patients with stroke. A total of 40 patients with stroke completed the study. They received P-IMT, D-IMT, or control treatment (CT) for 20 training sessions. Primary outcomes were the Fugl-Meyer Assessment (FMA) and Medical Research Council (MRC) scale. Secondary outcomes were the Motor Activity Log (MAL) and wrist-worn accelerometers. The differences on the distal FMA, total MRC, distal MRC, and MAL quality of movement scores among the 3 groups were statistically significant (P = 0.02 to 0.05). Post hoc comparisons revealed that the D-IMT group significantly improved more than the P-IMT group on the total MRC and distal MRC. Furthermore, the distal FMA and distal MRC improved more in the D-IMT group than in the CT group. Our findings suggest that distal upper-limb robotic rehabilitation using the InMotion WRIST system had superior effects on distal muscle strength. Further research based on a larger sample is needed to confirm long-term treatment effects of proximal versus distal upper-limb robotic rehabilitation.

Innovative development of a spherical parallel robot for upper limb rehabilitation

Innovative development of a spherical parallel robot for upper limb rehabilitation

Innovative development of a spherical parallel robot for upper limb rehabilitation

Post-stroke robotic rehabilitation is an ever increasing field of research that aims to offer custom care with maximised effectiveness. This paper presents the necessity of pursuing further improvements in said field as well as the factors that contributed towards the development of an innovative yet simple spherical-parallel robotic device targeting the rehabilitation of the upper human limb. A conceptual device entitled ASPIRE is proposed. The robotic system kinematics and singularities are derived to assert the robot functionality for the rehabilitation exercises. Moreover, two design structures are presented for the ASPIRE system, and motion simulations are performed.

Smallest real differences for robotic measures of upper extremity function after stroke: Implications for tracking recovery.

IntroductionMeasurements from upper limb rehabilitation robots could guide therapy progression, if a robotic assessment’s measurement error was small enough to detect changes occurring on a time scale of a few days. To guide this determination, this study evaluated the smallest real differences of robotic measures, and of clinical outcome assessments predicted from these measures.MethodsA total of nine older chronic stroke survivors took part in 12-week study with an upper-limb end-effector robot. Fourteen robotic measures were extracted, and used to predict Fugl-Meyer Assessment-Upper Extremity (FMA-UE) and Action Research Arm Test (ARAT) scores using multilinear regression. Smallest real differences and intraclass correlation coefficients were computed for the robotic measures and predicted clinical outcomes, using data from seven baseline sessions.ResultsSmallest real differences of robotic measures ranged from 8.8% to 26.9% of the available range. Smallest real differences of predicted clinical assessments varied widely depending on the regression model (1.3 to 36.2 for FMA-UE, 1.8 to 59.7 for ARAT), and were not strongly related to a model’s predictive performance or to the smallest real differences of the model inputs. Models with acceptable predictive performance as well as low smallest real differences were identified.ConclusionsSmallest real difference evaluations suggest that using robotic assessments to guide therapy progression is feasible.

Dynamic Modeling and Interactive Performance of PARM: A Parallel Upper-Limb Rehabilitation Robot Using Impedance Control for Patients after Stroke.

The robot-assisted therapy has been demonstrated to be effective in the improvements of limb function and even activities of daily living for patients after stroke. This paper presents an interactive upper-limb rehabilitation robot with a parallel mechanism and an isometric screen embedded in the platform to display trajectories. In the dynamic modeling for impedance control, the effects of friction and inertia are reduced by introducing the principle of virtual work and derivative of Jacobian matrix. To achieve the assist-as-needed impedance control for arbitrary trajectories, the strategy based on orthogonal deviations is proposed. Simulations and experiments were performed to validate the dynamic modeling and impedance control. Besides, to investigate the influence of the impedance in practice, a subject participated in experiments and performed two types of movements with the robot, that is, rectilinear and circular movements, under four conditions, that is, with/without resistance or impedance, respectively. The results showed that the impedance and resistance affected both mean absolute error and standard deviation of movements and also demonstrated the significant differences between movements with/without impedance and resistance (p < 0.001). Furthermore, the error patterns were discussed, which suggested that the impedance environment was capable of alleviating movement deviations by compensating the synergetic inadequacy between the shoulder and elbow joints.

A Review of Intent Detection, Arbitration, and Communication Aspects of Shared Control for Physical Human–Robot Interaction

As robotic devices are applied to problems beyond traditional manufacturing and industrial settings, we find that interaction between robots and humans, especially physical interaction, has become a fast developing field. Consider the application of robotics in healthcare, where we find telerobotic devices in the operating room facilitating dexterous surgical procedures, exoskeletons in the rehabilitation domain as walking aids and upper-limb movement assist devices, and even robotic limbs that are physically integrated with amputees who seek to restore their independence and mobility. In each of these scenarios, the physical coupling between human and robot, often termed physical human robot interaction (pHRI), facilitates new human performance capabilities and creates an opportunity to explore the sharing of task execution and control between humans and robots. In this review, we provide a unifying view of human and robot sharing task execution in scenarios where collaboration and cooperation between the two entities are necessary, and where the physical coupling of human and robot is a vital aspect. We define three key themes that emerge in these shared control scenarios, namely, intent detection, arbitration, and feedback. First, we explore methods for how the coupled pHRI system can detect what the human is trying to do, and how the physical coupling itself can be leveraged to detect intent. Second, once the human intent is known, we explore techniques for sharing and modulating control of the coupled system between robot and human operator. Finally, we survey methods for informing the human operator of the state of the coupled system, or the characteristics of the environment with which the pHRI system is interacting. At the conclusion of the survey, we present two case studies that exemplify shared control in pHRI systems, and specifically highlight the approaches used for the three key themes of intent detection, arbitration, and feedback for applications of upper limb robotic rehabilitation and haptic feedback from a robotic prosthesis for the upper limb.

Upper limb robotic rehabilitation for chronic stroke survivors: a single-group preliminary study.

[Purpose] This study aimed to assess whether robotic rehabilitation can improve upper limb function, activities of daily living performance, and kinematic performance of chronic stroke survivors. [Subjects and Methods] Participants were 21 chronic stroke survivors (19 men; 60.8 years; Mini-Mental State Examination score: 28; onset duration: 10.2 years). Training exercises were performed with a Whole Arm Manipulator and a 120-inch projective display to provide visual and auditory feedback. Once the training began, red and grey balls appeared on the projective display, and participants performed reaching movements, in the assist-as-needed mode, toward 6 directional targets in a 3-dimensional space. All participants received training for 40 minutes per day, thrice per week, for 6 weeks. Main outcome measures were upper limb function (Fugl-Meyer Assessment, Action Research Arm Test, and Box and Blocks Test scores), activities of daily living performance (Modified Barthel Index), and kinematic performance (movement velocity) in 6 directions. [Results] After 6 weeks, significant improvement was observed in upper limb function, activities of daily living performance, and kinematic performance. [Conclusion] This study demonstrated the positive effects of robotic rehabilitation on upper limb function, activities of daily living performance, and kinematic performance in chronic stroke survivors.

Hybrid impedance control of a robot manipulator for wrist and forearm rehabilitation: Performance analysis and clinical results

Therapeutic exercises play an important role in the physical therapy and the rehabilitation. The exercises that can be assisted by a physiotherapist are increasingly being performed by the rehabilitation robots partially or fully due to their various merits. This study aims to develop a complete rehabilitation system, which consists of a rehabilitation robot, an HMI and a hybrid impedance controller that can model all the therapeutic exercises for an upper limb rehabilitation. The 3-DOF upper limb rehabilitation robot is able to perform the movements of flexion–extension and ulnar–radial deviation for the wrist, and the movement of pronation–supination for the forearm. The experimental studies were conducted with healthy subjects and patients. First, the experiments were done with the healthy subjects to prove the control performance of the robotic system. The results showed that the hybrid impedance controlled robot can perform the therapeutic exercises very successfully. Then, the experimental studies were carried out with the real patients in a clinical environment. At the end of the treatment process, remarkable improvements were observed in terms of the limb force in all of the patients.

Sliding Mode Tracking Control of a Wire-Driven Upper-Limb Rehabilitation Robot with Nonlinear Disturbance Observer.

Robot-aided rehabilitation has become an important technology to restore and reinforce motor functions of patients with extremity impairment, whereas it can be extremely challenging to achieve satisfactory tracking performance due to uncertainties and disturbances during rehabilitation training. In this paper, a wire-driven rehabilitation robot that can work over a three-dimensional space is designed for upper-limb rehabilitation, and sliding mode control with nonlinear disturbance observer is designed for the robot to deal with the problem of unpredictable disturbances during robot-assisted training. Then, simulation and experiments of trajectory tracking are carried out to evaluate the performance of the system, the position errors, and the output forces of the designed control scheme are compared with those of the traditional sliding mode control (SMC) scheme. The results show that the designed control scheme can effectively reduce the tracking errors and chattering of the output forces as compared with the traditional SMC scheme, which indicates that the nonlinear disturbance observer can reduce the effect of unpredictable disturbances. The designed control scheme for the wire-driven rehabilitation robot has potential to assist patients with stroke in performing repetitive rehabilitation training.

A motion intention-based upper limb rehabilitation training system to stimulate motor nerve through virtual reality

Motor rehabilitation strategies for treating motor deficits after stroke are based on the understanding of the neural plasticity. In recent years, various upper limb rehabilitation robots have been proposed for the stroke survivors to provide relearning of motor skills by stimulating the motor nerve. However, several aspects including costing, human–robot interaction, and effective stimulation of motor nerve still remain as major issues. In this article, a new upper limb rehabilitation training system named as motion intention-based virtual reality training system is developed to close the aforementioned issues. The system identifies the user’s motion intention via force sensors mounted on the rehabilitation robot to conduct therapeutic exercises and stimulates the user’s motor nerve by introducing the illusion of immersion in virtual reality environment. The illusion of immersion is developed by creating Virtual Exoskeleton Robot model which is driven by user’s motion intention and reflecting the motion states in real time. The users can be present to the training exercises by themselves and fully engage in the virtual reality environment, so that they can relax, move, and recreate motor neuro-pathways. As preliminary phase, six healthy subjects were invited to participate in experiments. The experimental results showed that the motion intention-based virtual reality training system is effective for the upper limb rehabilitation exoskeleton and the evaluations of the developed system showed a significant reduction of the performance error in the training task.

Assistive-as-Needed Strategy for Upper-Limb Robotic Systems: An Initial Survey

Stroke is amongst the leading causes of deprivation of one’s ability in carrying out activities of daily living. It has been reported from literature that, the functional recovery of stroke patients are rather poor, unless frequent rehabilitative therapy is assumed on the affected limb. Recent trends of rehabilitation therapy have also shifted towards allowing more participation of the patient in the therapy session rather than simple passive treatments as it has been demonstrated to be non-trivial in promoting neural plasticity to expedite motor recovery process. Therefore, the employment of rehabilitation robotics is seen as a means of mitigating the limitations of conventional rehabilitation therapy. It enables unique methods for promoting patient engagement by providing patients assistance only as needed basis. This paper attempts on reviewing assist-as-needed control strategy applied on upper-limb robotic rehabilitation devices.