Virtual Reality in Gait
Rehabilitation
By
Nigel W. Tierney
Department of Computer Science
Old Dominion University
Co-Authors: Jessica Crouch, Hector Garcia, Martha Walker, Bonnie Van Lunen,
Gianluca DeLeo, George Maihafer, Stacie Ringleb
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Introduction – Issue
• Gait disabilities
–Serious problem
–Affect millions of people
–Accompanied by exorbitant
costs
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Introduction – Causes
• A multitude of causes lead to gait disability
– Stroke
– Limb amputation
– Traumatic brain injury
– Spinal cord injury
– Cerebral palsy
– Progressive neurological disorders
September 11-13, 2007
MODSIM World 2007
Conference & Expo
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Introduction – Solution
To create an innovative approach to gait
rehabilitation via a system that combines
the use of traditional and advanced
rehabilitation techniques with a virtual
reality (VR) training environment
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Introduction – Goal
The goal of this approach is to help patients
achieve their maximum functional capacity
as efficiently as possible
The first population targeted by this work is
stroke patients
September 11-13, 2007
MODSIM World 2007
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Virginia Beach, VA
Current Traditional Rehabilitation
• Patients practice motor
skills and compensatory
strategies for daily living
activities
– Within a clinical setting
• Skills gained in a clinical
environment
– Generalize to the patients’
home environments
September 11-13, 2007
MODSIM World 2007
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Virginia Beach, VA
Issues with Traditional Rehabilitation
• Labor intensive
• Limited in intensity and duration of
repetition
• Carryover outside of the rehabilitation
setting is uncertain
September 11-13, 2007
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Improvements to Traditional Rehab.
• Virtual reality technology can help address
these limitations
• Low-cost training environments
• Consistent with a client's environment
• Adaptable
• Practice under a variety of simulated
circumstances
September 11-13, 2007
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Virginia Beach, VA
Improvements to Trad. Rehab. Cont’d
• Adjust difficulty level of the training
scenarios
– Speed and slope of the treadmill
– Complexity of tasks
– Amount of body weight support
• Immediate feedback on performance
– Important component of learning*
*Shumway-Cook, et al. - “Motor Control: Theory and Practical Applications”
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Previous Work with VR
• Extensive research conducted
– Examine the efficacy of VR-enhanced training
and rehabilitation
• Successfully used in teaching both
decision-making skills and physical skills*
*Gallagher, et al. - “Virtual reality training for the operating room and catheterization laboratory,” Loftin, et al. - “Training in peacekeeping
operations using virtual environments,” Scerbo, et al. - “Assessing surgical skill training under hazardous conditions in a virtual environment,”
and Seymour, et al. - “Virtual reality training improves operating room performance: Results of a randomized, double-blinded study”
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Our Solution
• Aims to demonstrate improved gait
rehabilitation using a VR environment
constructed of hardware components
– Widely available
– Inexpensive
– Unobtrusive
• Easily replicated and deployed in a variety
of clinical settings
September 11-13, 2007
MODSIM World 2007
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Virginia Beach, VA
Methods Consist of…
•
•
•
•
•
Treadmill with overhead suspension
Interactive GUI
VR software
Avatar
Inertial Tracking Device
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Hardware Setup
 The overhead suspension
device: Biodex Unweighing
System
The inertial orientation
tracking device: Intersense
InertiaCube2
The mounted television
display: 51 inch Sharp Aquos
HDTV
 The programmable
treadmill: Biodex Gait Trainer 2
The desktop computer:
Windows™ Vista PC (Not
shown in photo)
September 11-13, 2007
MODSIM World 2007
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Interactive GUI Screenshot
 Accepts as input
 User’s personal
information
 Base speed
 Selection of
simulation
scenarios
 Data collection
tool
 Entry point into
the VR program
 Trigger early
termination of the
simulation
September 11-13, 2007
MODSIM World 2007
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VR Environment Screenshot
 Simulates a
cityscape
 Made up of a
series of blocks
 Order of
buildings, car, and
character models
are randomly
generated each
time the simulation
is run
 Different visual
experience for
each training
session
September 11-13, 2007
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VR Walkthrough Final Block
• End of simulation: Session completed or
triggering of early termination
– Call will be made for a final block
• Contains a model of the “l’Arc de Triomphe”
• Signifying the “triumphant” completion of the
simulation
– Acts as a positive method
• Informing the subject that he or she has
successfully completed a session
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Avatar
• Embedded within the VR environment
• Acts as virtual walking partner
• Provides support and feedback for the
subject within the system
• Recorded auditory cues are triggered
upon the performance of certain events
– Congratulatory messages when certain
milestones are achieved
September 11-13, 2007
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Inertial Tracker
• Monitors walking posture
• Mounted on a hat worn by patient
• Triggers some auditory cues
– Warning messages from the avatar when the
subject is looking down or leaning
September 11-13, 2007
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System Integration
• Combines many successful features that
have been shown to be associated with
motor learning and successful gait training
– Progressive decrease in body weight support
• Overhead suspension device
– Repetitive practice and positive feedback on
performance
• VR environment and inertial tracker
September 11-13, 2007
MODSIM World 2007
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Current Pilot Study
• 3 patients using the system
– All have had a stroke, completed their
traditional physical therapy, but still have
significant gait deviations
• Pre-test: Functional Gait Assessment and
Berg Balance Scale
– Patients showed limitations in gait speed,
balancing on one leg, and stepping over
objects
September 11-13, 2007
MODSIM World 2007
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Current Pilot Study Milestones
• Treatment will be conducted
– 12 sessions or until a subject can walk for 30
minutes at 3mph with 0% weight support
assistance
– Increasing Speed & Time
– Decreasing Body Weight
• Patients will be re-tested upon completion
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Pilot Study Patient Response
• 3 patients have completed 7 to 10 treatments
– Patient response is positive i.e. feel it is “helping”
– Patient 001
•
•
•
Using a 4-pronged cane and now uses a straight cane
Able to go grocery shopping, which she couldn’t do prior to the
intervention
Walked for 14 minutes
– Patient 002
•
Walk on the treadmill for 20 minutes
– Patient 003
•
•
Walk on the treadmill for 15 minutes
Came to treatment without his cane
September 11-13, 2007
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Future Work
• Treat any of the multiple gait disability
causing ailments
• Application with the amputee population
– Increased motivation and participation
• Add the gaming element of a scoring system
– Appealing to younger patients
• Such as young soldiers returning from combat
September 11-13, 2007
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Future Work cont’d
• Loss of vision on one side
– Common symptom of stroke patients
– Interactive events and distractions in the VR
environment in the hemisphere with diminished vision
– Stimulate development of a compensatory headturning habit
• Visual obstacles within the VR environment
– Sensors to track the leg motion
September 11-13, 2007
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Medical Decision Making
• Aid in medical decision making in patient
progress and prognosis
• Intelligent System
– Taking into account the patient’s abilities
•
•
•
•
Distance
Speed
Weight bearing
Movement responses
– Automatic decision making
• When and how much to advance the program’s difficulty
• Based on patient performance parameters
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
In Conclusion
• Establish a database of patient use parameters
and endpoints
– Track a patient’s starting point and the trajectory of
progress
– Predict the probable endpoint
• Predicting a patient’s functional abilities and
limitations
– Help the patient, family and healthcare providers
make decisions about the future
– Predict who will not benefit from continued treatment
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA
Questions???
Virtual Reality in Gait
Rehabilitation
By
Nigel W. Tierney
Department of Computer Science
Old Dominion University
Co-Authors: Jessica Crouch, Hector Garcia, Martha Walker, Bonnie Van Lunen,
Gianluca DeLeo, George Maihafer, Stacie Ringleb
September 11-13, 2007
MODSIM World 2007
Conference & Expo
Virginia Beach, VA