Validation of a Novel Instrument Task for Assessing Upper Limb
Condition: Assessment of Arm and Hand Sensorimotor Functions in Multiple Sclerosis Subjects
MeSH terms: Multiple Sclerosis; Sclerosis
Study type: Observational

Summary: 
      The aim of this study i to investigate a new approach (Physical Peg Insertion Test, PPIT) to
      measure sensorimotor function in the arm and hand. To achieve this, this novel approach will
      be compared with an existing approach (Virtual Peg Insertion Test, VPIT).
    

Detailed description: 
      In movement disorders, such as multiple sclerosis, impairments in sensorimotor control of
      goal-directed upper limb movements are commonly present, leading to a decreased ability to
      perform daily life activities and increased dependence on caregivers . Due to the disabling
      nature of upper limb impairments, they are often a focus during the neurorehabilitation
      process of persons with movement disorders. This process relies on a precise description of
      the presence and severity of sensorimotor impairments through so-called assessments.
      Specifically, these assessments are essential to individualize therapeutic interventions, to
      provide documentation for insurances justifying further therapy, and to shed light on the
      often unknown mechanisms underlying the impairments and their temporal evolution.

      Technology-aided assessments can provide detailed movement (kinematic) and grip force
      (kinetic) data that allows an objective and traceable description of upper limb behaviour.
      This offers the potential to sensitively characterize sensorimotor impairments and could help
      significantly reducing sample sizes required in resource-demanding clinical trials. Such
      technology-aided assessments typically consist of a robotic interface (e.g., exoskeleton or
      end-effector) that functions as a joystick and a virtual reality environment with a
      goal-directed manipulation task that is rendered on a 2D computer screen located next to the
      robotic interface. While these approaches are widely used for research purposes and showed
      promising results in detecting sensorimotor impairments, certain subjects were observed to
      have atypical movement patterns and high variability when repeatedly performing the
      assessment task (high intra-subject variability). These artifacts can results from
      unintuitive perception of depth on the 2D screen and missing visuomotor collocation, which
      can induce a bias in the outcome measures of the assessment and reduce the ability of the
      assessment to capture longitudinal changes (reliability and sensitivity). To overcome these
      challenges, assessment tasks relying on virtual collocated visuomotor feedback or immersive
      head mounted displays have been proposed. However, the virtual collocated visuomotor feedback
      still has its limitations, especially when subjects are supposed to interact with the virtual
      objects, such as in 3D object manipulation tasks that are typically used in clinical
      settings. In addition, head mounted display are expected to have limited clinical feasibility
      in persons that are naïve to technologies or have cognitive impairments.

      The aim of this collaborative project between ETH Zurich (Prof. Dr. Gassert, Dr. Lambercy,
      Dr. Kanzler) and the Kliniken Valens (Dr. med. Dr. sc. nat. Roman Gonzenbach, Ramona
      Sylvester) is to validate the concept of assessing upper limb sensorimotor impairments with a
      robotic interface embedded in a novel physical 3D object manipulation task, the Physical Peg
      Insertion Test (PPIT), and compare it to an existing virtual assessment approach. In more
      details, the aim is to perform a longitudinal study with the PPIT and its previously
      validated virtual pendent, the Virtual Peg Insertion Test (VPIT), in persons with movement
      disorders. This will allow to compare the feasibility, validity, reliability, and sensitivity
      of both physical and virtual instrumented assessments. Both approaches rely on a CE-certified
      haptic end-effector device (Geomagic Touch, 3D Systems) and an instrumented handle. For the
      PPIT, an electromagnet that can be controlled through the applied grip forces is attached to
      the end-effector and is required to pick up physical magnetic pegs in a physical pegboard
      task. For the VPIT, a personal computer renders a virtual reality environment with virtual
      pegs that need to be transported into virtual holes. These approaches have been developed at
      the Rehabilitation Engineering Laboratory of ETH Zurich and have been shown to be feasible,
      safe, and time-efficient (5 repetitions of the task, approximately 15 min duration per body
      side) in able-bodied controls, and persons with stroke, multiple sclerosis, or cerebellar
      ataxia that have mild to moderate disability levels. While the PPIT has only been developed
      rather recently, the VPIT has already been extensively used in clinical studies world-wide.
      Most importantly, the VPIT has already been successfully established as a clinical routine
      assessment for all persons with multiple sclerosis that are admitted to the Kliniken Valens
      and is therefore well known to the clinic, which provides the basis for the smooth
      implementation of the planned project. Through these and other previous tests, sensor data
      from 120 able-bodied subjects, that serve as a normative database, and over 200 persons with
      movement disorders could already be recorded. The collected raw kinematic and kinetic data is
      typically transformed through a signal processing framework into 10 sensor-based metrics that
      provide information on different aspects of task performance, including for example movement
      smoothness, accuracy, and speed. Given that the PPIT provides the same sensor data as the
      VPIT, the signal processing framework of the VPIT can also be applied to the data collected
      with the PPIT, allowing to extract the 10 sensor-based metrics in both scenarios and serves
      as a basis for their comparison.
    

Intervention name(s): Assessment of the upper limb (VPIT + PPIT)
Intervention type(s): Other
Intervention description(s): Assessment of the upper limb sensorimotor function (VPIT and PPIT)
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Impaired subjects, that suffer from Multiple Sclerosis must be 18 years old and have mild
        to moderate upper limb disability. Further, they have no strong cognitive deficits or
        concomitant disease that might affect upper limb performance and they must be able to
        follow procedures and to give informed consent.

        Healthy subjects must be 18 years old and must not have any concomitant disease that might
        affect upper limb performance. Further, they have no strong cognitive deficits and must be
        able to follow procedures and to give informed consent.
      
Keywords: Rehabilitation; Multiple Sclerosis; Sensorimotor Impairment; Assessments; Neurological Disease