Toward a HomeBased System for Improving Functional Hand and Arm Movement Recovery

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Toward a Home-Based Systemfor Improving
Functional Hand and Arm Movement Recovery

• David Reinkensmeyer
• Department of Mechanical and Aerospace
  Engineering
• University of California at Irvine
• Robert Sanchez, Punit Shah, Vu Le, Sandhya Rao,
  Jim Bobrow, Steve Cramer _at_ UCI
• Sarah Housman _at_ RIC

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Working Hypothesis

• A non-robotic (i.e. passive) device that can
• allow practice of functional movements
• move in a 3-D workspace similar to the upper
  extremity
• relieve the weight of the arm
• integrate hand and arm movement
• provide quantitative feedback of movement ability
• Will be a safe, useful tool for assisting with
  movement training of severely weakened stroke
  patients

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T-WREX Design

• Based on WREX (Wilmington Robotic Exoskeleton),
  (Rahman et al., 2000).
• Counterbalances weight of arm using rubber bands
  and four-bar mechanisms
• T-WREX (Training-WREX) Modifications
• Adult Sized
• Stronger
• Sensorized (arm and handgrip)
• Easily Adjustable
• Designed for Manufacturability
• Total Manufacturing Cost
• 8,000

WREX
T-WREX
Rahman T, Sample W, Seliktar R, Alexander M,
Scavina M (2000) A body-powered functional upper
limb orthosis. Journal of Rehabilitation Research
and Development 37675-680.
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T-WREX Device Testing

• Phase I Effect of T-WREX on movement ability,
  measured in a single session
• Phase II Pilot study of training effects
• Phase III Randomized, controlled trial of
  T-WREXs efficacy (just started)

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Phase I Testing

• Research questions
• How well does the counterbalance work for stroke
  patients?
• Can stroke patients move better while they are
  wearing the device?

Sanchez R, Shah P, Liu J, Rao S, Smith R, Cramer
S, Rahman T, Bobrow JE, Reinkensmeyer D (2004)
Monitoring Functional Arm Movement for Home-Based
Therapy after Stroke. In Proceedings of the 2004
IEEE Engineering in Medicine and Biology Society
Meeting, San Francisco, California, September
1-5, pp 4787-4790.
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T-WREX Counterbalance Efficacy Test

• 4 chronic hemiparetic subjects
• moderate and severe arm impairment
• Therapist passively ranged affected and
  unaffected sides
• 13 target locations at the workspace boundaries.
• 2 conditions
• arm and device counterbalanced
• only device counterbalanced
• Analysis
• Determine how much less force is needed to move
  the arm when it is counterbalanced

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Experimental Setup
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Results

• Mean effect of gravity balance across 4 subjects.
  The circle radius is the magnitude of force
  required to hold the subjects arms at the 13
  test fixture locations. The vertical bars
  indicate one standard deviation across subjects.
  (A) Impaired arm. (B) Unimpaired arm.

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Testing of Effect on Movement Ability (while
device is worn, in a single session)

• 9 Subjects tested
• chronic stroke ( gt 6 months prior), chosen since
  motor function is constant
• with persistent motor deficits.
• exclusion criteria
• cognitive deficits, neglect, and shoulder pain.
• Functional Test 3 types of movement tests
• performed with and without gravity balance
  subject always wore orthosis.
• randomized presentation.

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Movement Tests

• Functional Test
• 14 tasks from the Fugl-Meyer Motor Function Test
  (Score range 0-28).
• Reaching Movements reached to targets located at
  the boundary of the arms passive workspace 8x,
  with affected arm.
• One contralateral, one ipsilateral target.
• also reached upwards from the lap to the highest
  point possible.
• Drawing movement test The subject traced circle
  patterns (diameter of 17.8cm) in the vertical
  plane, centered in front of them, 4-5 fist
  lengths from the front of the shoulder.

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Results Functional Test

• Subset of Fugl-Meyer Results out of possible 28
  points
• without gravity-balance was 11.33 (/- 6.3 SD)
• with gravity-balance was 12.11 (/- 6.2 SD)
• Average change in Fugl-Meyer Motor Function Test
  was
• 0.78(/-1.3 SD).
• Change in Fugl-Meyer Motor Function Test
• marginally significant (p .055) for a
  one-sided, paired t-test comparing the change to
  zero.

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Results Device expands range of motion

• Effect of gravity balance on reaching movements
  for 9 subjects.
• A) Average reaching range of motion across
  subjects to targets with and with out gravity
  balance (distance traveled to target/total
  distance to target).
• B) Average height reached above lap, with and
  without gravity balance.
• p lt .05, paired t-test.

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Results Circle Drawing

• The ability to perform coordinated arm movement
  persists
• even following 4.5 years of non-use, but is
  normally masked by gravity

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T-WREX Preliminary Testing,Discussion

• Gravity balance provides assistive force above
  the horizontal reference but resists movement
  below
• Gravity balance improved
• a clinical measure of arm movement
• range of motion of reaching movements
• accuracy of drawing movements
• These results highlight the threshold nature of
  gravity
• strength is required to move against gravity
• gravity balance appeared to unmask a latent motor
  coordination capability that was not apparent
  with gravitational loading
• All subjects were pleased with their experience
  and asked to participate in future studies

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Phase II Pilot Study of T-WREX as a Motor
Training System

• Research question
• Does regular movement practice with T-WREX
  improve the ability to move the arm?

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T-WREX, Java Therapy 2.0

• Functional Contextual games.
• Top To Do List. Each subject practices
  playing 7 games for an assigned number of times.
  
• Bottom Shopping Game. Subject uses a hand grip
  to pick up an item, moves it to the cart and
  releases their grasp to deposit the item.
• Other games
• Washing the stove
• Eating
• Cracking Eggs
• Making Lemonade
• Range of Motion
• Washing your arm

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T-WREX VIDEO
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T-WREX Therapy Efficacy Testing

• Entry criterion
• minimum of 6 months post stroke
• no shoulder pain
• limited aphasia (must have been able to
  communicate pain)
• For the first 2wks, enough rubber bands were used
  to balance the arm in the horizontal position,
  level with the shoulder
• Rubber band counterbalance provided was as
  follows
• Weeks 1-2, 100
• Weeks 3-4, 80
• Weeks 5-6, 60
• Weeks 7-8, 60

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T-WREX Therapy Efficacy Testing, continued.

• Subjects received 4 clinical assessments before
  and after 8 weeks of therapy
• Box and Blocks Test for Manual Dexterity
  (Mathiowetz et al., 1985)
• Modified Box and Blocks
• Rancho Functional Test for The Hemiplegic
  /Paretic Upper Extremity (Wilson et al., 1984)
• Fugl Meyer Motor Assessment (Fugl-Meyer et al.,
  1975)
• Subjects received 45min of movement training,
  3x/week, for 8 weeks
• Changes in motor performance across each training
  session were measured by
• grip strength (prior)
• the ability to reach to a target in
  three-dimensional space (prior)
• the ability to reach to a target with the arm
  supported (prior)

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Results Functional and Impairment Tests

• DELTA is the difference of the post evaluation to
  the pre evaluation.
• completed 15 of the 24 sessions.
• One sided t-test, p 0.002.

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Results Impairment Score Detail

• Improvement in Fugl-Meyer Score As a Function of
  Joint at which improvement occurred and nature
  of Scoring Change
• A change from 0-1 indicates a change from unable
  to perform movement to able to perform partially,
  and a change from 1-2 is a change from performs
  partially to performs fully.

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Results Free Reaching Range
Mean percent range of motion across four subjects
and three trials for 24 training sessions (Study
Two). Percent range of motion was calculated
by subtracting the mean distance traveled on the
first day from the daily movements, then dividing
the difference by the mean distance between the
start point and target.
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Results Reaching Range and Grip Strength

• completed 15 of the 24 sessions.
• significant regression, p lt 0.05.
• One sided t-test, comparing change to zero,
  across all therapy sessions, p lt 0.05.

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Results Game Scores
Java Therapy game scores across the 24 training
sessions (Study Two). Ensemble average of
normalized game scores (possible range 0 to 1)
for three games (Shopping, Ranging the Arm, and
Cleaning the Stove) across the four subjects who
completed all eight weeks of movement training.
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T-WREX Therapy Efficacy Testing, Discussion

• Subjects improved their arm movement ability with
  repetitive training with T-WREX
• Users of the device currently require about three
  minutes of assistance to don or doff
• Could allow a therapist to supervise several
  patients at a time for group therapy sessions, or
  possibly be used at home since it requires only
  minor assistance from a caregiver to use
• Ability to provide gradable levels of assistance
  make it well suited to customized training
  programs
• Ability to provide quantitative feedback of
  progress make it well suited for motivating motor
  training and for off-line monitoring of patient
  compliance and progress by a skilled
  rehabilitation therapist

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Phase III Testing Randomized Controlled Test of
T-WREXs Efficacy

• Research question
• What are the benefits of regular movement
  practice with T-WREX compared to a matched amount
  of conventional table top exercise

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T-WREX Therapy Phase III Efficacy Testing

• Just started at RIC under the supervision of
  Sarah Housman, O.T.
• Subacute and chronic subjects (at least 2 months
  post-stroke)
• Random assignment to T-WREX or Control Group
• Blind rater
• Train 1 hour per session, 3 sessions per week,
  for eight weeks
• Limited interaction with therapist to simulate
  home or group therapy setting
• Expect to have tested 25 subjects by this time
  next year, and 50 by project end

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T-WREX Therapy Phase III Efficacy Testing,
continued.

• Entry criterion
• Minimum of 2 months post stroke
• No shoulder pain
• No significant cognitive impairments, hemispatial
  neglect, apraxia, or aphasia
• Presence of moderate/severe to severe UE
  hemiparesis
• Clinical assessments administered before and
  after therapy and 6 months after therapy is
  completed
• Rancho Functional Test for The Hemiplegic
  /Paretic Upper Extremity (Wilson et al., 1984)
• Fugl Meyer Motor Assessment (Fugl-Meyer et al.,
  1975)
• Grip Strength Testing with Jamar Hand Dynamometer
• Flock of Birds Motion Capture System
• UE Motor Activity Log

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Phase III Testing Randomized Controlled Test of
T-WREXs Efficacy

• Control Group completes conventional exercises
  that are generally included in home exercise
  programs and group therapy sessions
• A) Self Range of Motion
• B) Active Assistive ROM

-C) Weight Bearing - D) Use of hemiparetic
arm in bilateral UE functional tasks
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Other Future Directions

• Robotic version of device Pneu-WREX
• Design of a different arm support better suited
  to the specific needs of movement training after
  stroke
• adjustability (rubber bands are problematic)
• shoulder internal/external rotation,
  supination/pronation
• Low-cost version
• computer vision
• Commercialization?
• Is there really a market?