Soft Elbow Exoskeleton for Upper Limb Assistance Incorporating Dual Motor-Tendon Actuator

Loss of muscle functions, such as the elbow, can affect the quality of life of a person. This research is aimed at developing an affordable two DOF soft elbow exoskeleton incorporating a dual motor-tendon actuator. The soft elbow exoskeleton can be used to assist two DOF motions of the upper limb, especially elbow and wrist movements. The exoskeleton is developed using fabric for the convenience purpose of the user. The dual motor-tendon actuator subsystem employs two DC motors coupled with lead-to-screw converting motion from angular into linear motion. The output is connected to the upper arm hook on the soft exoskeleton elbow. With this mechanism, the proposed actuator system is able to assist two DOF movements for flexion/extension and pronation/supination motion. Proportional-Integral (PI) control is implemented for controlling the motion. The optimized value of Kp and Ki are 200 and 20, respectively. Based on the test results, there is a slight steady-state error between the first and the second DC motor. When the exoskeleton is worn by a user, it gives more steady-state errors because of the load from the arm weight. The test results demonstrate that the proposed soft exoskeleton elbow can be worn easily and comfortably by a user to assist two DOF for elbow and wrist motion. The resulted range of motion (ROM) for elbow flexion–extension can be varied from 90° to 157°, whereas the maximum of ROM that can be achieved for pronation and supination movements are 19° and 18°, respectively.

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Measures of Interjoint Coordination Post-stroke Across Different Upper Limb Movement Tasks

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2020.620805 ◽

2021 ◽

Vol 8 ◽

Author(s):

Anne Schwarz ◽

Janne M. Veerbeek ◽

Jeremia P. O. Held ◽

Jaap H. Buurke ◽

Andreas R. Luft

Keyword(s):

Upper Limb ◽

Elbow Flexion ◽

Shoulder Abduction ◽

Kinematic Parameters ◽

Limb Function ◽

Interjoint Coordination ◽

Upper Limb Function ◽

Shoulder Flexion ◽

Flexion Extension ◽

Median Slope

Background: Deficits in interjoint coordination, such as the inability to move out of synergy, are frequent symptoms in stroke subjects with upper limb impairments that hinder them from regaining normal motor function. Kinematic measurements allow a fine-grained assessment of movement pathologies, thereby complementing clinical scales, like the Fugl–Meyer Motor Assessment of the Upper Extremity (FMMA-UE). The study goal was to investigate the effects of the performed task, the tested arm, the dominant affected hand, upper limb function, and age on spatiotemporal parameters of the elbow, shoulder, and trunk. The construct validity of the metrics was examined by relating them with each other, the FMMA-UE, and its arm section.Methods: This is a cross-sectional observational study including chronic stroke patients with mild to moderate upper limb motor impairment. Kinematic measurements were taken using a wearable sensor suit while performing four movements with both upper limbs: (1) isolated shoulder flexion, (2) pointing, (3) reach-to-grasp a glass, and (4) key insertion. The kinematic parameters included the joint ranges of shoulder abduction/adduction, shoulder flexion/extension, and elbow flexion/extension; trunk displacement; shoulder–elbow correlation coefficient; median slope; and curve efficiency. The effects of the task and tested arm on the metrics were investigated using a mixed-model analysis. The validity of metrics compared to clinically measured interjoint coordination (FMMA-UE) was done by correlation analysis.Results: Twenty-six subjects were included in the analysis. The movement task and tested arm showed significant effects (p < 0.05) on all kinematic parameters. Hand dominance resulted in significant effects on shoulder flexion/extension and curve efficiency. The level of upper limb function showed influences on curve efficiency and the factor age on median slope. Relations with the FMMA-UE revealed the strongest and significant correlation for curve efficiency (r = 0.75), followed by shoulder flexion/extension (r = 0.68), elbow flexion/extension (r = 0.53), and shoulder abduction/adduction (r = 0.49). Curve efficiency additionally correlated significantly with the arm subsection, focusing on synergistic control (r = 0.59).Conclusion: The kinematic parameters of the upper limb after stroke were influenced largely by the task. These results underpin the necessity to assess different relevant functional movements close to real-world conditions rather than relying solely on clinical measures.Study Registration: clinicaltrials.gov, identifier NCT03135093 and BASEC-ID 2016-02075.

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Characterization of stroke-related upper limb motor impairments across various upper limb activities by use of kinematic core set measures

Journal of NeuroEngineering and Rehabilitation ◽

10.1186/s12984-021-00979-0 ◽

2022 ◽

Vol 19 (1) ◽

Author(s):

Anne Schwarz ◽

Miguel M. C. Bhagubai ◽

Saskia H. G. Nies ◽

Jeremia P. O. Held ◽

Peter H. Veltink ◽

...

Keyword(s):

Upper Limb ◽

Daily Living ◽

Healthy Subjects ◽

Peak Velocity ◽

Movement Time ◽

Elbow Flexion ◽

Wrist Flexion ◽

Shoulder Flexion ◽

Flexion Extension

Abstract Background Upper limb kinematic assessments provide quantifiable information on qualitative movement behavior and limitations after stroke. A comprehensive characterization of spatiotemporal kinematics of stroke subjects during upper limb daily living activities is lacking. Herein, kinematic expressions were investigated with respect to different movement types and impairment levels for the entire task as well as for motion subphases. Method Chronic stroke subjects with upper limb movement impairments and healthy subjects performed a set of daily living activities including gesture and grasp movements. Kinematic measures of trunk displacement, shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, movement time, hand peak velocity, number of velocity peaks (NVP), and spectral arc length (SPARC) were extracted for the whole movement as well as the subphases of reaching distally and proximally. The effects of the factors gesture versus grasp movements, and the impairment level on the kinematics of the whole task were tested. Similarities considering the metrics expressions and relations were investigated for the subphases of reaching proximally and distally between tasks and subgroups. Results Data of 26 stroke and 5 healthy subjects were included. Gesture and grasp movements were differently expressed across subjects. Gestures were performed with larger shoulder motions besides higher peak velocity. Grasp movements were expressed by larger trunk, forearm, and wrist motions. Trunk displacement, movement time, and NVP increased and shoulder flexion/extension decreased significantly with increased impairment level. Across tasks, phases of reaching distally were comparable in terms of trunk displacement, shoulder motions and peak velocity, while reaching proximally showed comparable expressions in trunk motions. Consistent metric relations during reaching distally were found between shoulder flexion/extension, elbow flexion/extension, peak velocity, and between movement time, NVP, and SPARC. Reaching proximally revealed reproducible correlations between forearm pronation/supination and wrist flexion/extension, movement time and NVP. Conclusion Spatiotemporal differences between gestures versus grasp movements and between different impairment levels were confirmed. The consistencies of metric expressions during movement subphases across tasks can be useful for linking kinematic assessment standards and daily living measures in future research and performing task and study comparisons. Trial registration: ClinicalTrials.gov Identifier NCT03135093. Registered 26 April 2017, https://clinicaltrials.gov/ct2/show/NCT03135093.

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Measuring Upper Limb Kinematics of Forehand and Backhand Topspin Drives with IMU Sensors in Wheelchair and Able-Bodied Table Tennis Players

Sensors ◽

10.3390/s21248303 ◽

2021 ◽

Vol 21 (24) ◽

pp. 8303

Author(s):

Jia-Wen Yam ◽

Jing-Wen Pan ◽

Pui-Wah Kong

Keyword(s):

Upper Limb ◽

Wrist Joint ◽

Elbow Flexion ◽

Measurement Unit ◽

Shoulder Abduction ◽

Table Tennis ◽

Tennis Players ◽

Movement Strategies ◽

Flexion Extension ◽

Limb Kinematics

To better understand the biomechanics of para-table tennis players, this study compared the shoulder, elbow, and wrist joint kinematics among able-bodied (AB) and wheelchair players in different classifications. Nineteen participants (AB, n = 9; classification 1 (C1), n = 3; C2, n = 3; C3, n = 4) executed 10 forehand and backhand topspin drives. Shoulder abduction/adduction, elbow flexion/extension, wrist extension/flexion, respective range of motion (ROM), and joint patterns were obtained using inertial measurement unit (IMU) sensors. The results showed clear differences in upper limb kinematics between the able-bodied and wheelchair players, especially in the elbow and wrist. For the para-players, noticeable variations in techniques were also observed among the different disability classes. In conclusion, wheelchair players likely adopted distinct movement strategies compared to AB to compensate for their physical impairments and functional limitations. Hence, traditional table tennis programs targeting skills and techniques for able-bodied players are unsuitable for para-players. Future work can investigate how best to customize training programs and to optimize movement strategies for para-players with varied types and degrees of impairment.

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Influence of the Sampling Rate on the Measurements of the Upper Limb Movements

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.601.163 ◽

2014 ◽

Vol 601 ◽

pp. 163-166 ◽

Cited By ~ 1

Author(s):

Mirela Toth-Taşcău ◽

Dan Ioan Stoia ◽

Flavia Bălănean

Keyword(s):

Upper Limb ◽

Sampling Rate ◽

Elbow Flexion ◽

Measuring System ◽

Shoulder Abduction ◽

Limb Movements ◽

Flexion Extension ◽

Upper Limb Movements ◽

Left And Right

The main objective of the study consists in determination of the most appropriate sampling rate of the measurements in instrumented kinematic analysis of the upper limb movements. The measuring system involved in the study is Zebris CMS-HS Measuring System, whose configuration was defined by ultrasound markers attached to specific body sites. The sampling rate interval was set from 10 to 25 Hz, according to the system’s range of frequencies. The kinematic parameters which have been analyzed are shoulder and elbow flexion-extension and shoulder abduction-adduction. A comparative kinematical analysis of the angle variations of flexion-extension and abduction-adduction in shoulder joint and flexion-extension in elbow joint was performed for both left and right upper limbs at each sampling rate.

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ACTIVE EXOSKELETONS FOR UPPER-LIMB MOTION ASSIST

International Journal of Humanoid Robotics ◽

10.1142/s0219843607001175 ◽

2007 ◽

Vol 04 (03) ◽

pp. 607-624 ◽

Cited By ~ 20

Author(s):

KAZUO KIGUCHI

Keyword(s):

Upper Limb ◽

Daily Living ◽

Elbow Flexion ◽

Daily Activities ◽

Current State ◽

Flexion Extension ◽

State Of Research ◽

Real Time Information ◽

Time Information ◽

Human Upper Limb

This paper presents the current state of research into power-assist exoskeletons for the upper limb. The assist of the upper limb is important for physically weak persons in daily activities, since upper-limb motion is involved in many important motions in daily living. The most important criterion is that power-assist exoskeletons assist the user's motion automatically in accordance with the user's motion intentions. Electromyogram (EMG) signals in which the user's motion intention is reflected could provide vital real-time information to facilitate accurate control of the power-assist exoskeleton in accordance with the user's motion intentions. A four degree-of-freedom active exoskeleton that assists human upper-limb motion (shoulder vertical flexion/extension, shoulder horizontal flexion/extension, elbow flexion/extension, and forearm supination/pronation) is also proposed.

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Wearable upper limb motion assist robot for eating activity

Applied Research and Smart Technology (ARSTech) ◽

10.23917/arstech.v1i1.28 ◽

2020 ◽

Vol 1 (1) ◽

pp. 1-10

Author(s):

Uzair Kashtwari ◽

Norsinnira Zainul Azlan ◽

Ifrah Shahdad

Keyword(s):

Upper Limb ◽

Daily Living ◽

Degrees Of Freedom ◽

Low Cost ◽

Elbow Flexion ◽

Disabled People ◽

Flexion Extension ◽

Feeding Cycle ◽

The Disabled ◽

Upper Limb Movements

Many people all around the world are suffering from various types of disabilities and need to depend on others to perform activities of daily living. One of the essential daily living activities is eating. The disabled people should be able to eat their food independently at any time and place, without relying on the caregivers. This paper presents the development of a new wearable upper limb motion assist robot for helping the disabled to eat by themselves. The motion assists robot consists of two degrees of freedom (DOF) movement, focusing on the two most crucial upper limb movements in eating activity, which is the elbow flexion/extension and forearm pronation/supination. A light-weight material was used for the fabrication of the wearable motion assist robot, and Arduino was utilized as the microcontroller. The originality of the study was in terms of the design, operational sequence setting, and kinematic analysis of the wearable upper limb motion assist robot that was explicitly focusing on eating activity. The resulted prototype was portable, compact, light in weight, simple and low cost. The experimental results have proven that the proposed wearable upper limb motion assist robot for eating activity was successful in helping the users to perform the main upper extremity motions in eating. The success rate of the proposed system was 80%, and it took 6 seconds for the system to complete one feeding cycle.

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Assessment of Upper Limb Movement Impairments after Stroke Using Wearable Inertial Sensing

Sensors ◽

10.3390/s20174770 ◽

2020 ◽

Vol 20 (17) ◽

pp. 4770

Author(s):

Anne Schwarz ◽

Miguel M. C. Bhagubai ◽

Gerjan Wolterink ◽

Jeremia P. O. Held ◽

Andreas R. Luft ◽

...

Keyword(s):

Upper Limb ◽

Elbow Flexion ◽

Limb Movement ◽

Target Height ◽

Reach To Grasp ◽

Inertial Sensing ◽

Object Weight ◽

Flexion Extension ◽

Task Conditions ◽

Clinical Measures

Precise and objective assessments of upper limb movement quality after strokes in functional task conditions are an important prerequisite to improve understanding of the pathophysiology of movement deficits and to prove the effectiveness of interventions. Herein, a wearable inertial sensing system was used to capture movements from the fingers to the trunk in 10 chronic stroke subjects when performing reach-to-grasp activities with the affected and non-affected upper limb. It was investigated whether the factors, tested arm, object weight, and target height, affect the expressions of range of motion in trunk compensation and flexion-extension of the elbow, wrist, and finger during object displacement. The relationship between these metrics and clinically measured impairment was explored. Nine subjects were included in the analysis, as one had to be excluded due to defective data. The tested arm and target height showed strong effects on all metrics, while an increased object weight showed effects on trunk compensation. High inter- and intrasubject variability was found in all metrics without clear relationships to clinical measures. Relating all metrics to each other resulted in significant negative correlations between trunk compensation and elbow flexion-extension in the affected arm. The findings support the clinical usability of sensor-based motion analysis.

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Human Weight Compensation with a Backdrivable Upper-Limb Exoskeleton: Identification and Control

10.21203/rs.3.rs-786361/v2 ◽

2021 ◽

Author(s):

Dorian VERDEL ◽

Simon Bastide ◽

Nicolas Vignais ◽

Olivier Bruneau ◽

Bastien Berret

Keyword(s):

Upper Limb ◽

Elbow Flexion ◽

Population Based ◽

Model Errors ◽

Tracking Errors ◽

Upper Limb Exoskeleton ◽

Weight Support ◽

Flexion Extension ◽

Weight Compensation ◽

And Control

Abstract Active exoskeletons are promising devices for improving rehabilitation procedures in patients and preventing musculoskeletal disorders in workers. In particular, exoskeletons implementing human limb’s weight support are interesting to restore some mobility in patients with muscle weakness and help in occupational load carrying tasks. The present study aims at improving weight support of the upper limb by providing a weight model considering joint misalignments and a control law including feedforward terms learned from a prior population-based analysis. Three experiments, for design and validation purposes, are conducted on a total of 65 participants who performed posture maintenance and elbow flexion/extension movements. The introduction of joint misalignments in the weight support model significantly reduced the model errors, in terms of weight estimation, and enhanced the estimation reliability. The introduced control architecture reduced model tracking errors regardless of the condition. Weight support significantly decreased the activity of antigravity muscles, as expected, but increased the activity of elbow extensors because gravity is usually exploited by humans to accelerate a limb downwards. These findings suggest that an adaptive weight support controller could be envisioned to further minimize human effort in certain applications.

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Design and evaluation of a novel upper limb rehabilitation robot with space training based on an end effector

Mechanical Sciences ◽

10.5194/ms-12-639-2021 ◽

2021 ◽

Vol 12 (1) ◽

pp. 639-648

Author(s):

Qiaoling Meng ◽

Zongqi Jiao ◽

Hongliu Yu ◽

Weisheng Zhang

Keyword(s):

Upper Limb ◽

Degrees Of Freedom ◽

Elbow Flexion ◽

Rehabilitation Robot ◽

End Effector ◽

Upper Limb Rehabilitation ◽

Flexion Extension ◽

Robot Configuration ◽

Limb Rehabilitation ◽

Equivalent Mechanism

Abstract. The target of this paper is to design a lightweight upper limb rehabilitation robot with space training based on end-effector configuration and to evaluate the performance of the proposed mechanism. In order to implement this purpose, an equivalent mechanism to the human being upper limb is proposed before the design. Then, a 4 degrees of freedom (DOF) end-effector-based upper limb rehabilitation robot configuration is designed to help stroke patients perform space rehabilitation training of the shoulder flexion/extension and adduction/abduction and elbow flexion/extension. Thereafter, its kinematical model is established together with the proposed equivalent upper limb mechanism. The Monte Carlo method is employed to establish their workspace. The results show that the overlap of the workspace between the proposed mechanism and the equivalent mechanism is 96.61 %. In addition, this paper also constructs a human–machine closed-chain mechanism to analyze the flexibility of the mechanism. According to the relative manipulability and manipulability ellipsoid, the highly flexible area of the mechanism accounts for 67.6 %, and the mechanism is far away from the singularity on the drinking trajectory. In the end, the single-joint training experiments and a drinking water training trajectory planning experiment are developed and the prototype is manufactured to verify it.

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Evaluation of the Efficiency of Supinator Tendon Transfer to Wrist Extensor in Brachial Plexus Injuries at C7-T1, A Case Study Based on OpenSIM Modelling Approach

10.21203/rs.3.rs-627453/v1 ◽

2021 ◽

Author(s):

mohammad Karimi ◽

Hamid Namazi

Keyword(s):

Brachial Plexus ◽

Upper Limb ◽

Inverse Kinematic ◽

Wrist Motion ◽

Flexion Extension ◽

Performance Limitation ◽

Lesion Level ◽

Analysis System ◽

Surgical Treatments ◽

Type Of Injury

Abstract BackgroundThe incidence of brachial plexus injuries (BPI) is increasing due to improvement in transportation technology. Those with BPI have upper limb performance limitation depends on the type of injury. Various surgical treatments have been used in this group of the subjects to restore their performance. The aim of this study was to evaluate the efficiency of supinator transferred to wrist extensors in those with lesion level at C7-T1 based on OpenSim modelling approach.MethodThe motions of the upper limb during vertical reaching, transverse reaching and wrist motion of a normal subject were achieved by use of motion analysis system. The ranges of motion of the upper limb joints were evaluated by inverse kinematic. OpenSim software was used to determine the muscles forces during aforementioned tasks. Tendon of supinator was transferred to extensors in modified models of OpenSim. Forward dynamic approach was used to determine the range of motion in tendon transferred condition. ResultsThe range of wrist motion in normal condition (extensors intake) were 85, 103 and 140 degrees for the first task (transverse reaching), the second task (vertical reaching) and the third task (only flexion/extension of wrist), respectively. Although the force of supinator was significantly less than that of wrist extensors, the pattern of its force is the same as wrist extensors.

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