Robotically Augmented Mental Practice
Condition: Stroke
Study type: Interventional

Summary: 
      This project will develop and test a new paradigm of motor imagery for facilitating
      neuromotor excitability and performance of distal muscles in the upper limb by adopting a
      robotic prosthesis and integrating proven procedures for neuromotor facilitation. The
      scientific purpose of the study is to understand the effect of controlling a detached robotic
      prosthesis with proximal muscle activation on brain excitability of the resting arm muscles
      as well as reaction time. The efficacy of this task will be understood by comparing with
      other task conditions (motor imagery only, 2D visual feedback on a monitor, etc.) that do not
      involve the robotic prosthesis. The test of the developed system will be performed in healthy
      able-bodied adults. The feasibility of the system will be examined in post-stroke adults.
    

Detailed description: 
      This study consists of experiments on two non-consecutive days in the Human Neuromuscular
      Physiology Laboratory located in the Biological Sciences/Applied Physiology Building of
      Georgia Tech. If subjects qualify and agree to take part in this study, subjects will be
      asked to read and sign the consent form. The whole procedure will last about 3 hours per day,
      including preparation. Subjects will come to the lab on two separate days on the same tasks.
      The first day will serve as familiarization with the same tasks as the second day. Subjects
      will perform the following experiment. Individuals will sit upright and relax their hands and
      shoulders. The right hand and forearm will be rested on a plate hidden below a table. The
      robotic hand will be placed on the table as one would normally place own arm on the table.
      There will be no physical connection between the hand and the robotic hand. Subjects will
      activate the abdominal muscles for making a grasping movement of the robotic hand. For making
      a releasing movement of the robotic hand, subjects will activate the back muscles. Muscle
      activity will be recorded with two small sensors on each muscle. Subjects will practice
      activation of each muscle while watching the signal on a monitor. In each muscle, a clearer
      signal will be used for controlling the robotic digits. Healthy subjects only: Healthy
      subjects will perform the following tasks A-F. [A: Rest] Subjects will relax the muscles
      without physical or cognitive effort while gazing at the turned-off monitor. [B: Robotic
      action observation] Subjects will relax the muscles and focus on observing the
      computer-controlled grasp and release actions (2 s in each movement) of the robotic
      prosthesis. [C: Visual MI] Subjects will relax the muscles and perform conventional visual
      motor imagery (MI). With the guidance of audio instruction, the subjects will image the grasp
      and release motions with the right arm for 2 s in each motion in their mind. There will be no
      proximal muscle contraction. [D: Kinesthetic MI] The same MI procedure as Task C will be
      performed, except that the subjects will focus on the kinesthetic sensation that was felt
      with the imaged motions. [E: Robotic-Hand Interaction with MI] Subjects will perform
      robotically augmented mental practice (see below detailed description) for grasp and release
      motions with the activation control of the proximal muscles. During this task, subjects will
      also image the kinesthetic sensation that was felt with the corresponding motions with the
      right arm. [F: Virtual-Hand Interaction robot] Subjects will perform Task E with visual
      feedback of virtual robot actions in 2D on a monitor. [G: Robotic-Hand Interaction without
      MI] Subjects will perform Task E without MI. As a reaction task, subjects will flex the index
      finger as soon as they hear an auditory cue. Post-stroke subjects only: Tasks C [Visual MI],
      E [Robotic-Hand Interaction with MI], and A [Rest] above will be performed by post-stroke
      subjects with right-side hemiparesis who can volitionally activate fingers and proximal
      muscles. As a reaction task, subjects will flex the index finger as soon as an auditory cue
      is heard. TMS (both healthy and post-stroke subjects): During the above-mentioned tasks,
      brain stimulation (called TMS) will be applied over the motor cortex in the left hemisphere.
      The TMS procedure will follow the one used in the previous studies by the investigators. A
      TMS coil will be placed over a precise point on the scalp where the investigators will
      stimulate the brain to make the muscle move. The investigators will tell the subject when the
      stimulation portion of the procedure is about to begin. The first part of the procedure will
      be to find the area of the brain that controls muscles. These investigators will position the
      TMS coil on the head and will give the subject a series of stimulations (called magnetic
      pulses). Once the spot that controls the muscles is identified, the investigators will find
      the least amount of stimulation needed to activate the resting muscles. The second part of
      the procedure will be to evoke muscle contraction with TMS at rest and during the tasks
      described above. The investigators will apply TMS with 5-second intervals or more.
      Robotically augmented practice (Task E and F above): An individual will use proximal muscle
      contractions to flex and extend the robotic prosthesis digits for performing a grasp-release
      task. 1) Grasp. The individual will activate the proximal muscles as if for a retrieving
      motion (the back muscles) for 2 s. This muscle activation controls the robotic hand to flex
      the digits to grasp a cylinder-shaped object. 2) Release. The individual will relax the
      above-activated proximal muscles and activate the proximal muscles as if for a reaching
      motion (the abdominal muscles) for 2 s. This muscle activation controls the robotic hand to
      extend the digits to release the object. After releasing the object, the individual will
      relax the proximal muscles. The individual will repeat this sequence while observing and
      hearing the actions of the robotic hand.
    

Intervention name(s): Visual motor imagery (MI); Kinesthetic MI; Robotic-Hand Interaction with MI; Robotic-Hand Interaction without MI; Virtual-Hand Interaction; Robotic Action Observation; Rest
Intervention type(s): Behavioral; Behavioral; Behavioral; Behavioral; Behavioral; Behavioral; Behavioral
Intervention description(s): Subjects will relax their muscles and perform conventional visual motor imagery (MI). With the guidance of audio instruction, the subjects will imagine the grasp and release motions with the right arm for 2 s in each motion in their mind. There will be no proximal muscle contraction.; The same MI procedure as Visual MI will be performed, except that the subjects will focus on the kinesthetic sensation that they would feel with the imagined motions.; Subjects will perform robotically augmented mental practice for grasp and release motions with the activation control of the proximal muscles. During this task, subjects will also imagine the kinesthetic sensation that they would feel with the corresponding motions with the right arm.; Subjects will perform the Robot-Hand Interaction without MI.; Subjects will interact with visual feedback of virtual robot actions on a monitor.; Subjects will relax their muscles and focus on observing the computer-controlled grasp and release actions of the robotic hand.; Subjects will rest without a task.
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Intervention model description: Participants in a single group will receive various types of interventions in random order. The types of interventions are the same across subjects.
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Hand; Imagery; Robot