Trends in rehabilitation robotics

Virtual reality-induced motor function of the upper extremity and brain activation in stroke: study protocol for a randomized controlled trial

Background

The benefits of virtual reality (VR)-based rehabilitation were reported in patients after stroke, but there is insufficient evidence about how VR promotes brain activation in the central nervous system. Hence, we designed this study to explore the effects of VR-based intervention on upper extremity motor function and associated brain activation in stroke patients.

Methods/design

In this single-center, randomized, parallel-group clinical trial with a blinded assessment of outcomes, a total of 78 stroke patients will be assigned randomly to either the VR group or the control group. All stroke patients who have upper extremity motor deficits will be tested with functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and clinical evaluation. Clinical assessment and fMRI will be performed three times on each subject. The primary outcome is the change in performance on the Fugl-Meyer Assessment Upper Extremity Scale (FMA-UE). Secondary outcomes are functional independence measure (FIM), Barthel Index (BI), grip strength, and changes in the blood oxygenation level-dependent (BOLD) effect in the ipsilesional and contralesional primary motor cortex (M1) on the left and right hemispheres assessed with resting-state fMRI (rs-fMRI), task-state fMRI (ts-fMRI), and changes in EEG at the baseline and weeks 4 and 8.

Discussion

This study aims to provide high-quality evidence for the relationship between upper extremity motor function and brain activation in stroke. In addition, this is the first multimodal neuroimaging study that explores the evidence for neuroplasticity and associated upper motor function recovery after VR in stroke patients.

Clinical trial registration

Chinese Clinical Trial Registry, identifier: ChiCTR2200063425.

Efficacy of Virtual Reality Combined With Real Instrument Training for Patients With Stroke: A Randomized Controlled Trial

OBJECTIVE

To investigate the efficacy of real instrument training in virtual reality (VR) environment for improving upper-extremity and cognitive function after stroke.

DESIGN

Single-blind, randomized trial.

SETTING

Medical center.

PARTICIPANTS

Enrolled subjects (N=31) were first-episode stroke, assessed for a period of 6 months after stroke onset; age between 20 and 85 years; patients with unilateral paralysis and a Fugl-Meyer assessment upper-extremity scale score >18.

INTERVENTIONS

Both groups were trained 30 minutes per day, 3 days a week, for 6 weeks, with the experimental group performing the VR combined real instrument training and the control group performing conventional occupational therapy.

MAIN OUTCOME MEASURES

Manual Muscle Test, modified Ashworth scale, Fugl-Meyer upper motor scale, hand grip, Box and Block, 9-Hole Peg Test (9-HPT), Korean Mini-Mental State Examination, and Korean-Montreal Cognitive Assessment.

RESULTS

The experimental group showed greater therapeutic effects in a time-dependent manner than the control group, especially on the motor power of wrist extension, spasticity of elbow flexion and wrist extension, and Box and Block Tests. Patients in the experimental group, but not the control group, also showed significant improvements on the lateral, palmar, and tip pinch power, Box and Block, and 9-HPTs from before to immediately after training. Significantly greater improvements in the tip pinch power immediately after training and spasticity of elbow flexion 4 weeks after training completion were noted in the experimental group.

CONCLUSIONS

VR combined real instrument training was effective at promoting recovery of patients' upper-extremity and cognitive function, and thus may be an innovative translational neurorehabilitation strategy after stroke.

Motion Tracking for Quantitative and Qualitative Assessment of Upper Limb Movements Following Acromioclavicular Joint Ligament Reconstruction: A Pilot Study

Background:

Technological tools as robotic devices and wearable sensors can provide accurate and repeatable measurements of physical variables (e.g., position, velocities, forces) which can be used for quantitative and qualitative assessment of movement analysis and upper limb motor performance.

Objective:

The study aims to propose a quantitative and qualitative assessment of upper limb motor performance by means of seven kinematic parameters recorded by a passive mechatronic device in patients who underwent a surgical procedure for ligament reconstruction following acromioclavicular joint dislocation.

Method:

Five patients (mean age: 40 ± 12 years) with acromioclavicular joint dislocation were enrolled.

A passive end-effector mechatronic device characterized by 7 degrees of freedom and designed for the assessment of upper limb motor performance - especially for measuring the hand position in three-dimensional space - was used.

The Constant-Murley score and seven kinematic parameters were used as clinical outcome measure and quantitative and qualitative assessment, respectively.

Results:

The preliminary results of this study show no significant differences between the impaired arm and unimpaired arm: the end-effector passive mechatronic device used in this study is able to provide an overall assessment of the upper limb motor performance following shoulder impairment.

Conclusion:

The motion tracker can be easily used as effective tool for quantitative and qualitative assessment of upper limb motor performance, even several years after the surgical operation.

A Comparative Analysis of 2D and 3D Tasks for Virtual Reality Therapies Based on Robotic-Assisted Neurorehabilitation for Post-stroke Patients

Post-stroke neurorehabilitation based on virtual therapies are performed completing repetitive exercises shown in visual electronic devices, whose content represents imaginary or daily life tasks. Currently, there are two ways of visualization of these task. 3D virtual environments are used to get a three dimensional space that represents the real world with a high level of detail, whose realism is determinated by the resolucion and fidelity of the objects of the task. Furthermore, 2D virtual environments are used to represent the tasks with a low degree of realism using techniques of bidimensional graphics. However, the type of visualization can influence the quality of perception of the task, affecting the patient's sensorimotor performance. The purpose of this paper was to evaluate if there were differences in patterns of kinematic movements when post-stroke patients performed a reach task viewing a virtual therapeutic game with two different type of visualization of virtual environment: 2D and 3D. Nine post-stroke patients have participated in the study receiving a virtual therapy assisted by PUPArm rehabilitation robot. Horizontal movements of the upper limb were performed to complete the aim of the tasks, which consist in reaching peripheral or perspective targets depending on the virtual environment shown. Various parameter types such as the maximum speed, reaction time, path length, or initial movement are analyzed from the data acquired objectively by the robotic device to evaluate the influence of the task visualization. At the end of the study, a usability survey was provided to each patient to analysis his/her satisfaction level. For all patients, the movement trajectories were enhanced when they completed the therapy. This fact suggests that patient's motor recovery was increased. Despite of the similarity in majority of the kinematic parameters, differences in reaction time and path length were higher using the 3D task. Regarding the success rates were very similar. In conclusion, the using of 2D environments in virtual therapy may be a more appropriate and comfortable way to perform tasks for upper limb rehabilitation of post-stroke patients, in terms of accuracy in order to effectuate optimal kinematic trajectories.

Implementation and Validation of Engagement Monitoring in an Engagement Enhancing Rehabilitation System

Enhancing engagement of patients during stroke rehabilitation exercises are in the focus of current research. Various methods and computer supported tools have been developed for this purpose, which try to avoid mundane exercising that is prone to become a routine or even boring for the patients and leads to ineffective training. This paper introduces an engagement enhancing cyber-physical stroke rehabilitation system (CP-SRS) aiming at enhancing the patient's engagement during rehabilitation training exercises. This paper focuses on introducing the implementation and validation of the engagement monitoring subsystem (EMS) in the CP-SRS. The EMS is expected to evaluate the patient's actual engagement levels in motor, perceptive, cognitive and emotional aspects. Experiments in these four aspects were conducted separately, in order to characterize the range and accuracy of the engagement indicators by influencing the subjects into different engaged states. During the experiments, different setups were created to mimic the situations in which the subject was engaged or not engaged. The subjects involved in the experiments were healthy subjects. Results showed that the measurement in motor, perceptive, cognitive, and emotional aspects can represent the corresponding engagement level. More experiments will be conducted in the future to validate the efficiency of the CP-SRS in enhancing the engagement with stroke patients.

Texture- and deformability-based surface recognition by tactile image analysis

Deformability and texture are two unique object characteristics which are essential for appropriate surface recognition by tactile exploration. Tactile sensation is required to be incorporated in artificial arms for rehabilitative and other human-computer interface applications to achieve efficient and human-like manoeuvring. To accomplish the same, surface recognition by tactile data analysis is one of the prerequisites. The aim of this work is to develop effective technique for identification of various surfaces based on deformability and texture by analysing tactile images which are obtained during dynamic exploration of the item by artificial arms whose gripper is fitted with tactile sensors. Tactile data have been acquired, while human beings as well as a robot hand fitted with tactile sensors explored the objects. The tactile images are pre-processed, and relevant features are extracted from the tactile images. These features are provided as input to the variants of support vector machine (SVM), linear discriminant analysis and k-nearest neighbour (kNN) for classification. Based on deformability, six household surfaces are recognized from their corresponding tactile images. Moreover, based on texture five surfaces of daily use are classified. The method adopted in the former two cases has also been applied for deformability- and texture-based recognition of four biomembranes, i.e. membranes prepared from biomaterials which can be used for various applications such as drug delivery and implants. Linear SVM performed best for recognizing surface deformability with an accuracy of 83 % in 82.60 ms, whereas kNN classifier recognizes surfaces of daily use having different textures with an accuracy of 89 % in 54.25 ms and SVM with radial basis function kernel recognizes biomembranes with an accuracy of 78 % in 53.35 ms. The classifiers are observed to generalize well on the unseen test datasets with very high performance to achieve efficient material recognition based on its deformability and texture.

A new device combining mechanical stimulation of plantar sole and Achilles' tendon to alleviate the consequences of muscle deconditioning

Limb immobilization or confinement to bed results in a severe atrophy and weakness of lower leg muscles. Full recovery of muscle strength and physical function is rare and may impact the patient's outcome. Studies performed on rodents have demonstrated that the deleterious structural and functional adaptations which occur during muscle deconditioning can be counteracted through adequate physiological stimuli. Thus, based on this fundamental work, we developed a device that combines mechanical stimulation of proprioceptors located in the plantar sole and Achilles' tendon. The device is adapted to patients immobilized and confined to bed. Stimulations can be applied on muscle in passive state. The protocol is non-invasive and is well accepted by patients. This paper presents the technical features of the device, as well as preliminary results of the first clinical study. This device might allow considering new therapeutic strategies for prevention of atrophy in many pathologies.