Asymmetrical Performance and Abnormal Synergies of the Post-Stroke Patient Wearing SCRIPT Passive Orthosis in Calibration, Exercise and Energy Evaluation

© 2014 Qin Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In the context of therapeutic human-robot interaction, it is important to detect human contribution in interaction with robots, thus to auto-tune a robot to compensate or resist based on such input. A passive orthosis is used to evaluate interaction based on kinematic data and energy flow model to identify human-contributions during interaction experiments with healthy subject and stroke patient. The results identified presence of abnormal synergies between wrist and fingers, showed a skewness apparent in stroke patient performance which seemed to decrease over-time after the rehabilitation practice and indicated lack of fine control. We hypothesise that the presented methods can be used as potential performance benchmarks allowing to identify subject’s contribution during an interaction session but also to observe extent of fine motor control over time.Peer reviewe

Formative Usability Evaluation of WiGlove - A Home-based Rehabilitation Device for Hand andWrist Therapy after Stroke

© 2023 Copyright held by the owner/author(s). Publication rights licensed to ACM.WiGlove is a passive dynamic orthosis aimed at home-based poststroke rehabilitation of the hand and wrist. This paper highlights results from WiGlove's formative evaluation as the first step towards its deployment. In this study, twenty healthy participants evaluated the usability and safety of the WiGlove compared to its predecessor, the state-of-the-art SCRIPT Passive Orthosis (SPO). In this within-subject experiment, they performed various tasks such as donning/doffing, adjusting the tension, grasping, etc., with both gloves and rated them using a Likert scale-based questionnaire. The results showed improvements in several aspects of usability and safety. This study provides preliminary evidence of WiGlove's fitness for the next assessment with its intended users, people recovering from stroke with sustained hand and wrist impairment

EEG Spectral Feature Modulations Associated with Fatigue in Robot-Mediated Upper Limb Gross and Fine Motor Interactions

© 2022 Dissanayake, Steuber and Amirabdollahian. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/This paper investigates the EEG spectral feature modulations associated with fatigue induced by robot-mediated upper limb gross and fine motor interactions. Twenty healthy participants were randomly assigned to perform a gross motor interaction with Haptic MASTER or a fine motor interaction with SCRIPT passive orthosis for 20 minutes or until volitional fatigue. Relative and ratio band power measures were estimated from the EEG data recorded before and after the robot-mediated interactions. Paired samples t-tests found a significant increase in the relative alpha band power and a significant decrease in the relative delta band power due to the fatigue induced by the robot-mediated gross and fine motor interactions. The gross motor task also significantly increased the (θ + α)/β and α/β ratio band power measures, whereas the fine motor task increased the relative theta band power. Furthermore, the robot-mediated gross movements mostly changed the EEG activity around the central and parietal brain regions, whereas the fine movements mostly changed the EEG activity around the frontopolar and central brain regions. The subjective ratings suggest that the gross motor task may have induced physical fatigue, whereas the fine motor task may have induced mental fatigue. Therefore, findings affirm that changes to localised brain activity patterns indicate fatigue developed from the robot-mediated interactions. It can also be concluded that the regional differences in the prominent EEG spectral features are most likely due to the differences in the nature of the task (fine/gross motor and distal/proximal upper limb) that may have differently altered an individual’s physical and mental fatigue level. The findings could potentially be used in future to detect fatigue during robot-mediated post-stroke therapies.Peer reviewedFinal Published versio

Locomotor adaptation to a powered ankle-foot orthosis depends on control method

<p>Abstract</p> <p>Background</p> <p>We studied human locomotor adaptation to powered ankle-foot orthoses with the intent of identifying differences between two different orthosis control methods. The first orthosis control method used a footswitch to provide bang-bang control (a kinematic control) and the second orthosis control method used a proportional myoelectric signal from the soleus (a physiological control). Both controllers activated an artificial pneumatic muscle providing plantar flexion torque.</p> <p>Methods</p> <p>Subjects walked on a treadmill for two thirty-minute sessions spaced three days apart under either footswitch control (n = 6) or myoelectric control (n = 6). We recorded lower limb electromyography (EMG), joint kinematics, and orthosis kinetics. We compared stance phase EMG amplitudes, correlation of joint angle patterns, and mechanical work performed by the powered orthosis between the two controllers over time.</p> <p>Results</p> <p>During steady state at the end of the second session, subjects using proportional myoelectric control had much lower soleus and gastrocnemius activation than the subjects using footswitch control. The substantial decrease in triceps surae recruitment allowed the proportional myoelectric control subjects to walk with ankle kinematics close to normal and reduce negative work performed by the orthosis. The footswitch control subjects walked with substantially perturbed ankle kinematics and performed more negative work with the orthosis.</p> <p>Conclusion</p> <p>These results provide evidence that the choice of orthosis control method can greatly alter how humans adapt to powered orthosis assistance during walking. Specifically, proportional myoelectric control results in larger reductions in muscle activation and gait kinematics more similar to normal compared to footswitch control.</p

Grasps recognition and evaluation of stroke patients for supporting rehabilitation therapy

Copyright © 2014 Beatriz Leon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Stroke survivors often suffer impairments on their wrist and hand. Robot-mediated rehabilitation techniques have been proposed as a way to enhance conventional therapy, based on intensive repeated movements. Amongst the set of activities of daily living, grasping is one of the most recurrent. Our aim is to incorporate the detection of grasps in the machine-mediated rehabilitation framework so that they can be incorporated into interactive therapeutic games. In this study, we developed and tested a method based on support vector machines for recognizing various grasp postures wearing a passive exoskeleton for hand and wrist rehabilitation after stroke. The experiment was conducted with ten healthy subjects and eight stroke patients performing the grasping gestures. The method was tested in terms of accuracy and robustness with respect to intersubjects' variability and differences between different grasps. Our results show reliable recognition while also indicating that the recognition accuracy can be used to assess the patients' ability to consistently repeat the gestures. Additionally, a grasp quality measure was proposed to measure the capabilities of the stroke patients to perform grasp postures in a similar way than healthy people. These two measures can be potentially used as complementary measures to other upper limb motion tests.Peer reviewedFinal Published versio