University of South Florida

New simulator integrates technologies for interdisciplinary research, rehabilitation

USF recently acquired the CAREN virtual reality system, a powerful tool that helps people with disabilities increase their independence and reintegrate into the community

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When you see the Computer Assisted Rehabilitation Environment system (CAREN) in action, the room-sized simulator resembles a giant video game, complete with avatars. Scenes projected on its 180-degree screen range from walking through a forest to driving past cityscapes to riding on a wave-tossed boat.

The three-dimensional virtual reality system engages and entertains – but its purpose is serious.

The system’s immersive environment and interactive gaming elements safely challenge people to learn new strategies for coping with changes in their balance, coordination or mobility caused by disability, traumatic injury or aging.  The advanced technology also gives researchers the scientific tools they need to advance the diagnosis and treatment of musculoskeletal and neurological disorders.

Watch time-lapse video of CAREN’s installation:


Supported by a $450,000 National Science Foundation (NSF) grant, the University of South Florida recently became the first non-Department of Defense institution in the United States to obtain the CAREN extended model for research and rehabilitation, said William S. Quillen, DPT, PhD, associate dean of the USF Health Morsani College of Medicine and director of the School of Physical Therapy & Rehabilitation Sciences. Additional matching funds from colleges and schools across USF also helped purchase the approximately $1 million simulator

“The CAREN system will be a critical part of the university’s neuromusculoskeletal, traumatic brain injury and post-traumatic stress disorder research initiatives involving wounded warriors, warfighters and student veterans,” Dr. Quillen said. “The system will greatly facilitate our ongoing interdisciplinary research to analyze human mobility and function and to improve the quality of life for people with disabilities by increasing their independence and community reintegration.”


USF purchased the CAREN system with the support of grant from the National Science Foundation.

Integrated technologies add research and rehabilitation value

“This system integrates a lot of technologies typically used individually — like a split belt treadmill with force-sensing plates, a moveable base and motion capture analysis — to really help us better understand how an individual walks and moves in different terrains and environments,” said Kyle Reed, PhD, assistant professor of mechanical engineering in the College of Engineering.

The CAREN project will bring together more than 20 investigators with expertise in rehabilitation engineering and science from the colleges of Engineering, Medicine’s School Physical Therapy & Rehabilitation Sciences, Arts and Sciences, Behavioral and Community Sciences, Nursing, and Virtual and Performing Arts.  They will collaborate with researchers from James A. Haley Veterans’ Hospital and Draper Laboratories.


L to R: Seok Hun Kim, PT, PhD, of the USF School of Physical Therapay & Rehabilitation Sciences, with Kyle Reed, PhD, and Stephanie Carey, PhD, of the College of Engineering, look at the incoming information instantaneously displayed on CAREN’s control panel.

The system bridges the gap between the controlled environment of a laboratory or clinical rehabilitation setting and the uncontrolled community environments experienced in daily life.

“CAREN gives us a lot of opportunities to create variable scenarios that are closest to real-life environments,” said Seok Hun Kim, PT, PhD, assistant professor in the School of Physical Therapy & Rehabilitation Sciences.

Dr. Kim works with patients living with stroke, ataxia and other neurological disorders that significantly increase the risk for falls. “We can gradually increase the level of difficulty of the exercises based on patients’ performance using the CAREN system.  This allows patients to safely push their limits while working to regain balance control,” he said.


Dr. Carey secures the safety harness attached to Gordon Beadle before he begins a simulation exercise to try out his new prosthetic leg.

Gait analysis demo:  Strolling down a virtual path

During a recent demonstration in the USF Center for Assistive, Rehabilitation & Robotics Technology, Gordon “Skip” Beadle stood on CAREN’s platform safely secured in a harness suspended from a rigid frame attached to the platform.

The 71-year-old Vietnam veteran was there to try out a simulation exercise wearing his new prosthetic leg with a microprocessor-controlled knee and ankle, designed to more closely mimic natural gait.  Beadle lost his right leg in 1965 while his Marine infantry was clearing landmines as the unit advanced toward Chu Lai airbase north of South Vietnam.

Stephanie Carey, PhD, assistant research professor of mechanical engineering, leaned toward the simulator’s control panel, preparing to adjust settings and monitor the incoming data as Beadle began walking.  Jason Highsmith, DPT, PhD, CPO, associate professor in the USF School of Physical Therapy & Rehabilitation Sciences, watched from the side as the treadmill began.


The simulator’s integrated techologies, including the split-belt treadmill and motion capture system, provide real-time information to analyze gait.

As birds chirped through the surround-sound system, Beadle began his simulated stroll along a winding cobblestone path through the forest at a slow, steady pace.  Some bumps in the terrain were introduced by CAREN’s motion platform, and the treadmill’s speed gradually increased as Beadle picked up his pace when a cottage, the finish line, came into view ahead on the screen.

Dozens of reflective sensors on Beadle’s lower body detected by high-speed, infrared cameras tracked his every step and instantaneously relayed the information to the computer software overseen by Dr. Carey.


The CAREN project investigators eventually hope to work with virtual designers to recreate the terrain of the USF Tampa campus or downtown Tampa.

Engineering and scientific methods improve functional recovery

The immersive system precisely measures and integrates a variety of data valuable to researchers and therapists — including which muscles are working at any given time, length of stride, weight bearing distribution, and how an individual’s joints move and the amount of force placed on them.

The information can be used, for instance, to analyze and correct the asymmetric gait of patients recovering from stroke, to test and improve prosthetics for lower-limb amputees, and to design assistive devices such as orthotic shoes, crutches or canes that help users walk more efficiently without tiring easily.

The system, working in concert with a therapist, could also help desensitize those suffering from post-traumatic stress disorder by having them virtually re-experience situations that provoke anxiety in carefully controlled stages.


Beadle said the system’s safety harness significantly reduced his fear of falling.

The CAREN project investigators eventually hope to work with virtual designers to recreate the terrain of the USF campus or downtown Tampa for study participants or patients, Dr. Reed said.

“We’re just beginning to use the system for studies,” he said. “We expect in the next year or two we will have lots of results that can both help researchers at other universities and make life better for people with strokes, amputations, spinal cord injuries and other physical limitations.”

Pushing limits helps increase confidence, physical abilities

One of CAREN’s advantages is that patients feel protected by the safety harness that will quickly catch them if they begin to fall, so they become more comfortable stepping up their performance when challenged with new or more complex tasks – like negotiating a steeper incline, walking on an increasingly uneven surface, or maintaining balance while the ground beneath tilts to the right and left.


L to R: Jason Highsmith, DPT, PhD, School of Physical Therapy & Rehabilitation Sciences; Kyle Reed, PhD, College of Engineering; Dimitrios Menychtas, biomedical engineering doctoral student; Seok Hun Kim, PT, PhD; Physical Therapy & Rehabilitation Sciences; and Stephanie Carey, PhD, College of Engineering.

The safety feature definitely lessened his fear of falling, Beadle said when he finished the forest path exercise. “I can see where this type of therapy for someone just beginning to use a prosthesis would be beneficial in teaching balance and building confidence at the same time.”

CAREN allows therapists working with the system operators to gradually introduce obstacles that may be even more difficult than what patients would encounter in everyday life, Dr. Reed said.  “So, when they do face some small stairs or a street curb in a real-life situation, they can potentially say ‘I can handle that.  I’ve seen much bigger ones in the simulator system.’”

The NSF-funded project for USF’s CAREN virtual reality system is directed by principal investigators Rajiv Dubey, PhD, Sudeep Sakar, PhD, and Dr. Reed, College of Engineering; Dr. Quillen, School of Physical Therapy & Rehabilitation Sciences; and  David Diamond, PhD, College of Arts and Sciences and James A. Haley Veterans’ Hospital.


The simulation system mimics real-life environments. So, for instance, if the boat on video screen tilts left the ground beneath the person tilts left.


Video and photos by Eric Younghans, USF Health Communications

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