Dextrous exploration of a virtual world for improved prototyping

Caldwell, Darwin G.; Favede, C.; Tsagarakis, Nikos G.

doi:10.1109/robot.1998.676402

Cited by 13 publications

(4 citation statements)

References 8 publications

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“…Control parameters include feedback gains to maximize performance and minimize effort (Nataraj and van den Bogert, 2017) and to achieve desired movement features such as smoothness (Hogan and Sternad, 2009). Ultimately, VR platforms may be utilized to efficiently identify control parameters of rehabilitation devices that optimize not only functional mechanics but also user agency prior to eventual translation to real-world systems (Caldwell et al, 1995(Caldwell et al, , 1998Bar-Cohen, 2003;Perry et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Agency and Performance of Reach-to-Grasp With Modified Control of a Virtual Hand: Implications for Rehabilitation

Nataraj

Sanford

Shah

et al. 2020

Front. Hum. Neurosci.

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This study investigated how modified control of a virtual hand executing reach-to-grasp affects functional performance and agency (perception of control). The objective of this work was to demonstrate positive relationships between reaching performance and grasping agency and motivate greater consideration of agency in movement rehabilitation. We hypothesized that agency and performance have positive correlation across varying control modes of the virtual hand. In this study, each participant controlled motion of a virtual hand through motion of his or her own hand. Control of the virtual hand was modified according to a specific control mode. Each mode involved the virtual hand moving at a modified speed, having noise, or including a level of automation. These specific modes represent potential control features to adapt for a rehabilitation device such as a prosthetic arm and hand. In this study, significant changes in agency and performance were observed across the control modes. Overall, a significant positive relationship (p < 0.001) was observed between the primary performance metric of reach (tracking a minimum path length trajectory) and an implicit measurement of agency (intentional binding). Intentional binding was assessed through participant perceptions of time-intervals between grasp contact and a sound event. Other notable findings include improved movement efficiency (increased smoothness, reduced acceleration) during expression of higher agency and shift toward greater implicit versus explicit agency with higher control speed. Positively relating performance and agency incentivizes control adaptation of powered movement devices, such as prostheses or exoskeletons, to maximize both user engagement and functional performance. Agency-based approaches may foster user-device integration at a cognitive level and facilitate greater clinical retention of the device. Future work should identify robust and automated methods to adapt device control for increased agency. Objectives include how virtual reality (VR) may identify optimal control of real-world devices and assessing real-time agency from neurophysiological signals.

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Section: Introductionmentioning

confidence: 99%

Agency and Performance of Reach-to-Grasp With Modified Control of a Virtual Hand: Implications for Rehabilitation

Nataraj

Sanford

Shah

et al. 2020

Front. Hum. Neurosci.

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“…It has four shoulder degrees of freedom (three rotations and a scapula elevation), an elbow pitch joint, and a passive forearm pro/supination joint. It is capable of producing 134 N-m of torque at each shoulder joint and 64 N-m at the elbow, which is comparable to the output of the average adult male (Caldwell et al, 1998). The human interfaces consist of a torso mount for the scapula, an orthotic splint for the upper arm, and a hand grip.…”

Section: Case Study: the Mga Exoskeleton Rehabilitation Robotmentioning

confidence: 99%

Designing Safety-Critical Rehabilitation Robots

Roderick¹,

Carignan²

2007

Rehabilitation Robotics

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“…In the literature, the importance of the joint correspondence, to sustain ergonomy, has been first noticed for the design of the shoulder joint as the center of rotation of the shoulder joint changes significantly during arm movements. The need for an extra degrees of freedom (DoF) was first issued in [23]. Later on a fully articulated passive shoulder mechanism was introduced in [21].…”

Section: Introductionmentioning

confidence: 99%

A self-adjusting knee exoskeleton for robot-assisted treatment of knee injuries

Ergin

Patoğlu

2011

2011 IEEE/RSJ International Conference on Intelligent Robots and Systems

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In this study, we present a novel active device for robot-assisted rehabilitation that accommodates transitional movements of the knee joint as well as its rotation, enabling a perfect match between human joint axes and the device axes. Automatically adjusting its joint axes, the proposed device is not only capable of guaranteeing ergonomy and comfort throughout the therapy, but also extends the usable range of motion for the knee joint. Moreover, the adjustability feature significantly shortens the setup time required to attach the patient to the exoskeleton, allowing more effective time be spend on exercises instead of wasting it for adjustments. The proposed system is different from the similar works in literature in that it supports both passive translational movements of the knee joint and independent active control of these degrees of freedom. In particular, we introduce implementation details of a prototype that features compact design and combines the power of three actuators to achieve high rotational torques, detail the model based impedance controller utilized to adjust interaction forces and present the experimental characterization of the exoskeleton.

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Dextrous exploration of a virtual world for improved prototyping

Cited by 13 publications

References 8 publications

Agency and Performance of Reach-to-Grasp With Modified Control of a Virtual Hand: Implications for Rehabilitation

Agency and Performance of Reach-to-Grasp With Modified Control of a Virtual Hand: Implications for Rehabilitation

Designing Safety-Critical Rehabilitation Robots

A self-adjusting knee exoskeleton for robot-assisted treatment of knee injuries

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