Control investigation of a customizable/adjustable exoskeleton upper‐limb

Stopforth, Riaan

doi:10.1108/01439911311297739

Cited by 4 publications

(6 citation statements)

References 20 publications

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“…Gravity compensation can be provided by support devices (Herder et al, 2006;Kloosterman et al, 2010) or robotics (Kahn et al, 2006;Ladenheim et al, 2013), and can be generally grouped into three categories. Firstly, fixed or manually adjusted compensation were commonly used to counteract the gravity weight of upper limb (Nef et al, 2007;Stopforth, 2013;Lenzo et al, 2015). Similarly, a fixed external vertical force was applied to an upper limb robot by a motorized vertical cabling system for gravity compensation .…”

Section: Introductionmentioning

confidence: 99%

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

Dubey¹,

Yu²,

Low³

2019

Frontiers Research Topics

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The provision of continuous passive, and intent-based assisted movements for neuromuscular training can be incorporated into a robotic elbow sleeve. The objective of this study is to propose the design and test the functionality of a soft robotic elbow sleeve in assisting flexion and extension of the elbow, both passively and using intent-based motion reinforcement. First, the elbow sleeve was developed, using elastomeric and fabric-based pneumatic actuators, which are soft and lightweight, in order to address issues of non-portability and poor alignment with joints that conventional robotic rehabilitation devices are faced with. Second, the control system was developed to allow for: (i) continuous passive actuation, in which the actuators will be activated in cycles, alternating between flexion and extension; and (ii) an intent-based actuation, in which user intent is detected by surface electromyography (sEMG) sensors attached to the biceps and triceps, and passed through a logic sequence to allow for flexion or extension of the elbow. Using this setup, the elbow sleeve was tested on six healthy subjects to assess the functionality of the device, in terms of the range of motion afforded by the device while in the continuous passive actuation. The results showed that the elbow sleeve is capable of achieving approximately 50% of the full range of motion of the elbow joint among all subjects. Next, further experiments were conducted to test the efficacy of the intent-based actuation on these healthy subjects. The results showed that all subjects were capable of achieving electromyography (EMG) control of the elbow sleeve. These preliminary results show that the elbow sleeve is capable of carrying out continuous passive and intent-based assisted movements. Further investigation of the clinical implementation of the elbow sleeve for the neuromuscular training of neurologically-impaired persons, such as stroke survivors, is needed.

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Section: Introductionmentioning

confidence: 99%

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

Dubey¹,

Yu²,

Low³

2019

Frontiers Research Topics

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“…Firstly, fixed or manually adjusted compensation were commonly used to counteract the gravity weight of upper limb (Nef et al, 2007; Stopforth, 2013; Lenzo et al, 2015). Similarly, a fixed external vertical force was applied to an upper limb robot by a motorized vertical cabling system for gravity compensation (Ball et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…Gravity compensation can be provided by support devices (Herder et al, 2006 ; Kloosterman et al, 2010 ) or robotics (Kahn et al, 2006 ; Ball et al, 2007 ; Ladenheim et al, 2013 ), and can be generally grouped into three categories. Firstly, fixed or manually adjusted compensation were commonly used to counteract the gravity weight of upper limb (Nef et al, 2007 ; Stopforth, 2013 ; Lenzo et al, 2015 ). Similarly, a fixed external vertical force was applied to an upper limb robot by a motorized vertical cabling system for gravity compensation (Ball et al, 2007 ).…”

Section: Introductionmentioning

confidence: 99%

Assessment of Motor Control during Three-Dimensional Movements Tracking with Position-Varying Gravity Compensation

et al. 2017

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Active movements are important in the rehabilitation training for patients with neurological motor disorders, while weight of upper limb impedes movements due to muscles weakness. The objective of this study is to develop a position-varying gravity compensation strategy for a cable-based rehabilitation robot. The control strategy can estimate real-time gravity torque according to position feedback. Then, the performance of this control strategy was compared with the other two kinds of gravity compensation strategies (i.e., without compensation and with fixed compensation) during movements tracking. Seven healthy subjects were invited to conduct tracking tasks along four different directions (i.e., upward, forward, leftward, and rightward). The performance of movements with different compensation strategies was compared in terms of root mean square error (RMSE) between target and actual moving trajectories, normalized jerk score (NJS), mean velocity ratio (MVR) of main motion direction, and the activation of six muscles. The results showed that there were significant effects in control strategies in all four directions with the RMSE and NJS values in the following order: without compensation > fixed compensation > position-varying compensation and MVR values in the following order: without compensation < fixed compensation < position-varying compensation (p < 0.05). Comparing with movements without compensation in all four directions, the activation of muscles during movements with position-varying compensation showed significant reductions, except the activations of triceps and in forward and leftward movements, the activations of upper trapezius and middle parts of deltoid in upward movements and the activations of posterior parts of deltoid in all four directions (p < 0.05). Therefore, with position-varying gravity compensation, the upper limb cable-based rehabilitation robotic system might assist subjects to perform movements with higher quality and improve the participation of robot-aided rehabilitation training. Further studies are needed to explore the effectiveness and clinic application across pathologies.

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“…exoskeletons and operational-type machines (Pignolo, 2009). Exoskeletons are external mechanical structures with up to seven degrees of freedom that provide strength enhancement, therapeutic assistance, and haptic operation for virtual environment (Perry, Rosen, & Burns, 2007;Pignolo, 2009;Stopforth, 2013). Current research focused on the therapeutic usage of exoskeletons.…”

Section: Rehabilitation Robotsmentioning

confidence: 99%

“…The close interaction between the exoskeleton and human body presents high requirements for compatibility. The joints of exoskeletons do not always correctly align with human joints or rotate within the natural range of motion due to the lack of anthropometric and kinematic considerations (Stopforth, 2013;Rosen et al, 2005;Mao & Agrawal, 2012). This incompatibility between exoskeleton and human limbs can lead to hyperstaticity or overconstraint, causing discomfort for users (Gull, Bai, & Bak, 2020).…”

Section: Rehabilitation Robotsmentioning

confidence: 99%

Developing an upper limb kinematics database of activities of daily living

Huang

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Control investigation of a customizable/adjustable exoskeleton upper‐limb

Cited by 4 publications

References 20 publications

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

Assessment of Motor Control during Three-Dimensional Movements Tracking with Position-Varying Gravity Compensation

Developing an upper limb kinematics database of activities of daily living

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