A New Myohaptic Device to Assess Wrist Function in the Lab and in the Clinic – The Wristalyzer

Grimaldi, Giuliana; Lammertse, Piet; Braber, N. Van Den; Meuleman, Jos; Manto, Mario

doi:10.1007/978-3-540-69057-3_4

Cited by 10 publications

(5 citation statements)

References 25 publications

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“…Earlier work on measurement of joint neuromechanics [ 15 - 19 ] provided a comprehensive assessment protocol including passive, active and reflexive tests to measure non-neural and neural contributors to movement disorder after stroke [ 20 ]. To ensure standardized input signals and registration of output signals, a haptic wrist manipulator [ 21 , 22 ] was combined with surface-EMG measurements.…”

Section: Introductionmentioning

confidence: 99%

Comprehensive neuromechanical assessment in stroke patients: reliability and responsiveness of a protocol to measure neural and non-neural wrist properties

Krogt

Klomp

Groot

et al. 2015

J NeuroEngineering Rehabil

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BackgroundUnderstanding movement disorder after stroke and providing targeted treatment for post stroke patients requires valid and reliable identification of biomechanical (passive) and neural (active and reflexive) contributors. Aim of this study was to assess test-retest reliability of passive, active and reflexive parameters and to determine clinical responsiveness in a cohort of stroke patients with upper extremity impairments and healthy volunteers.MethodsThirty-two community-residing chronic stroke patients with an impairment of an upper limb and fourteen healthy volunteers were assessed with a comprehensive neuromechanical assessment protocol consisting of active and passive tasks and different stretch reflex-eliciting measuring velocities, using a haptic manipulator and surface electromyography of wrist flexor and extensor muscles (Netherlands Trial Registry number NTR1424).Intraclass correlation coefficients (ICC) and Standard Error of Measurement were calculated to establish relative and absolute test-retest reliability of passive, active and reflexive parameters. Clinical responsiveness was tested with Kruskal Wallis test for differences between groups.ResultsICC of passive parameters were fair to excellent (0.45 to 0.91). ICC of active parameters were excellent (0.88-0.99). ICC of reflexive parameters were fair to good (0.50-0.74). Only the reflexive loop time of the extensor muscles performed poor (ICC 0.18). Significant differences between chronic stroke patients and healthy volunteers were found in ten out of fourteen parameters.ConclusionsPassive, active and reflexive parameters can be assessed with high reliability in post-stroke patients. Parameters were responsive to clinical status. The next step is longitudinal measurement of passive, active and reflexive parameters to establish their predictive value for functional outcome after stroke.Electronic supplementary materialThe online version of this article (doi:10.1186/s12984-015-0021-9) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

Comprehensive neuromechanical assessment in stroke patients: reliability and responsiveness of a protocol to measure neural and non-neural wrist properties

Krogt

Klomp

Groot

et al. 2015

J NeuroEngineering Rehabil

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“…The impedance-controlled planar robot MIT Manus [12] has been widely used in robotaided therapy for stroke rehabilitation [3]. The Wristalyzer [13] is an admittance-controlled interface designed for wrist interaction, based on a traditional high-accuracy torque sensor. Both systems exhibit considerable end-effector inertia.…”

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confidence: 99%

Series Viscoelastic Actuators Can Match Human Force Perception

Parietti

Baud-Bovy

Gatti

et al. 2011

IEEE/ASME Trans. Mechatron.

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Series elastic actuators (SEAs) are frequently used for force control in haptic interaction, because they decouple actuator inertia from the end effector by a compliant element. This element is usually a metal spring or beam, where the static force-deformation relationship offers a cheap force sensor. For high-precision force control, however, the remaining small inertia of this elastic element and of the end effector still limit the sensing performance and rendering transparency. Here, we extend the concept to deformable end effectors manufactured of viscoelastic materials. These materials offer the advantage of extremely low mass at high maximum deformation and applicable load. However, force and deformation are no longer statically related, and history of force and deformation has to be accounted for. We describe an observer-based solution, which allows drift-free force measurement with high accuracy and precision. Although the description of the viscoelastic behavior involves higher-order derivatives, the proposed observer does not require any numerical differentiation. This new integrated concept of sensing and actuation, called series viscoelastic actuator (SVA), is applied to our high-precision haptic device OSVALD, which is targeted at perception experiments that require sensing and rendering of forces in the range of the human tactile threshold. User-device interaction force is controlled using state-of-the-art control strategies of SEAs. Force estimation and force control performance are evaluated experimentally and prove to be compatible with the intended applications, showing that SVAs open up new possibilities for the use of series compliance and damping in high-precision haptic interfaces. Abstract-Series elastic actuators (SEAs) are frequently used for force control in haptic interaction, because they decouple actuator inertia from the end effector by a compliant element. This element is usually a metal spring or beam, where the static forcedeformation relationship offers a cheap force sensor. For highprecision force control, however, the remaining small inertia of this elastic element and of the end effector still limit the sensing performance and rendering transparency. Here, we extend the concept to deformable end effectors manufactured of viscoelastic materials. These materials offer the advantage of extremely low mass at high maximum deformation and applicable load. However, force and deformation are no longer statically related, and history of force and deformation has to be accounted for. We describe an observerbased solution, which allows drift-free force measurement with high accuracy and precision. Although the description of the viscoelastic behavior involves higher-order derivatives, the proposed observer does not require any numerical differentiation. This new integrated concept of sensing and actuation, called series viscoelastic actuator (SVA), is applied to our high-precision haptic device OSVALD, which is targeted at perception experiments that require sensing and render...

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“…Tests were performed on a haptic wrist manipulator (Wristalyzer V R , Moog FCS, Nieuw Vennep, The Netherlands) [30], on which torque and wrist joint angle were recorded. Participants were comfortably seated on a chair in front of a video screen.…”

Section: Measurement Set-upmentioning

confidence: 99%

Loss of selective wrist muscle activation in post-stroke patients

Krogt

Kouwijzer

Klomp

et al. 2019

Disability and Rehabilitation

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Purpose: Loss of selective muscle activation after stroke contributes to impaired arm function, is difficult to quantify and is not systematically assessed yet. The aim of this study was to describe and validate a technique for quantification of selective muscle activation of wrist flexor and extensor muscles in a cohort of post-stroke patients. Patterns of selective muscle activation were compared to healthy volunteers and test-retest reliability was assessed. Materials and methods: Activation Ratios describe selective activation of a muscle during its expected optimal activation as agonist and antagonist. Activation Ratios were calculated from electromyography signals during an isometric maximal torque task in 31 post-stroke patients and 14 healthy volunteers. Participants with insufficient voluntary muscle activation (maximal electromyography signal <3SD higher than baseline) were excluded. Results: Activation Ratios at the wrist were reliably quantified (Intraclass correlation coefficients 0.77-0.78). Activation Ratios were significantly lower in post-stroke patients compared to healthy participants (p < 0.05). Conclusion: Activation Ratios allow for muscle-specific quantification of selective muscle activation at the wrist in post-stroke patients. Loss of selective muscle activation may be a relevant determinant in assigning and evaluating therapy to improve functional outcome. ä IMPLICATIONS FOR REHABILITATIONLoss of selective muscle activation after stroke contributes to impaired arm function, is difficult to quantify and is not systematically assessed yet. The ability for selective muscle activation is a relevant determinant in assigning and evaluating therapy to improve functional outcome, e.g., botulinum toxin. Activation Ratios allow for reliable and muscle-specific quantification of selective muscle activation in post-stroke patients.

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A New Myohaptic Device to Assess Wrist Function in the Lab and in the Clinic – The Wristalyzer

Cited by 10 publications

References 25 publications

Comprehensive neuromechanical assessment in stroke patients: reliability and responsiveness of a protocol to measure neural and non-neural wrist properties

Comprehensive neuromechanical assessment in stroke patients: reliability and responsiveness of a protocol to measure neural and non-neural wrist properties

Series Viscoelastic Actuators Can Match Human Force Perception

Loss of selective wrist muscle activation in post-stroke patients

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