Health and Fitness Get a Lift from Modeling and Simulation
With VMASC Taking the Lead, ODU Professors from Several Disciplines are Finding New Ways to Study, and Improve, Human Performance
By Brendan O’Hallarn
Breathing heavily, struggling under the weight of her 44-pound pack, the test subject shoulders her modified M-4 rifle.
She’s on the hunt for human targets. One at a time, outlines of human forms appear on a computer-generated backdrop. The woman fires a laser beam from the gun, aiming at the center of the target’s chest. Every few pulls of the trigger she pauses to check her heart rate from the device on her wrist, which she reads off to tester Courtney Butowicz. A dozen shots later, the test subject places the gun down carefully. It’s time to run again.
This is no soldier being trained. The test subject is an Old Dominion University student. Nine weeks earlier, she was one of a few dozen volunteers who navigated the same shooting course – firing the modified weapon at a series of targets four times – interspersed with running 200 meters within 60 seconds -- wearing a helmet, body armor and a military-style backpack with a total weight of 66 pounds for men, 44 pounds for women.
As you’d expect, the strenuous exercise isn’t a recipe for precise shooting. But that’s not the point.
The multidisciplinary research team – consisting of experts in engineering, modeling and simulation, biomechanics and exercise physiology – then put the test subjects through a nine-week course of strength and fitness training. After the training period, the subjects do the shoot-then-run-then-shoot-again test. The testers use the shooting simulation, along with several other fitness assessments, to track improvements in performance after the training regimen.
“Fitness is a huge factor for performance in the field for our soldiers, but there hasn’t been a great deal of research into what works and what doesn’t when it comes to fitness and performance,” said Stacie Ringleb, assistant professor of mechanical engineering at ODU’s Frank Batten College of Engineering and Technology, and the primary investigator for this study.
The shooting task, especially wearing the heavy vest and backpack, simulates some of the physical strain soldiers could face in combat. Ringleb said together with the workout regimen, it’s designed “to develop a model to help us understand how fitness affects tactical performance in the military.” The fitness study is currently funded by the Office of Naval Research’s Human Performance Training and Education Program.
The virtual-reality shooting simulator, called CAPTURE (Cognitive and Psychological Testing Urban Research Environment) was developed during a Phase I Small Business Innovative Research Grant, using technology pioneered by a woman-owned small business called VRR. It’s one of a handful of studies Ringleb and her team have performed using the Motion Analysis Lab at Old Dominion University’s Student Recreation Center.
The common theme for the studies addresses the question: how can researchers use modeling and simulation to improve human performance?
Ringleb co-leads the Medical and Health Care Modeling, Simulation and Visualization Cluster at ODU’s Virginia Modeling, Analysis and Simulation Center (VMASC).
MS&V researchers across many disciplines at ODU are taking the same approach as Ringleb. And as a result, the school has developed a stable of modeling and simulation expertise about the human body.
Not just doctors and nurses
When people think of modeling and simulation, they often visualize flight simulators or medical simulations.
John Sokolowski, VMASC executive director, said virtual-reality MS&V techniques are invaluable in traditional medical fields. But he added that researchers at ODU have tried to go further.
“Modeling and simulation, from the user perspective, is a tool that can address problems in all kinds of areas,” Sokolowski said.
“When we talk about this area, we really need to refer to it as medical/health care modeling, because there’s a difference. Medical MS&V is your doctors and nurses. But modeling and simulation can also address issues of cost and safety in the medical/health care field.”
It might be disease specialist Holly Gaff, assistant professor of community and environmental health in the College of Health Sciences, modeling the behavior of diseases. In 2008, Gaff received a $500,000 grant from the National Institutes of Health to support her innovative research, which uses mathematical modeling to study human monocytic ehrlichiosis, an emerging tick-borne disease.
Sokolowski himself worked as part of a team to simulate the evacuation of Naval Medical Center Portsmouth in the event of a catastrophic flood.
In fact, Mark Scerbo, professor of psychology and a human factors expert, and co-leader of the Medical and Health Care MS&V Cluster, said the fact ODU doesn’t have a medical school has been both a challenge and an opportunity for its multidisciplinary MS&V researchers.
“Most schools where there’s a lot of interest in medical simulation have a university medical school that’s part of the same institution. That doesn’t exist here. But what we offer is an approach to modeling and simulation that they don’t have in many other universities, that we can marry to medical research,” he said.
And certainly, the research being done has an interested partner in Eastern Virginia Medical School, located a few miles away from ODU’s Norfolk campus.
Along with EVMS, Old Dominion University founded the National Center for Collaboration in Medical Modeling and Simulation in 2001.
Some of the joint projects tackled by the two institutions include a simulation designed to mimic mass casualties from a hurricane or terrorist attack in Hampton Roads, and a virtual pathology stethoscope, programmed to produce heart and lung sounds that doctors and nurses would hear from patients with particular conditions, a virtual-reality system for wound debridement that provides sensory feedback, a system for training labor and delivery clinicians to recognize critical signs in heart-rate tracings of moms and their infants, and a virtual operating room for training surgical teams in problem solving and decision making.
Scerbo, whose background in human factors research came through the study of aviation, said ODU researchers were invited by EVMS to analyze some of the first training simulators the medical school had purchased. “They said, ‘We want to make sure they’re learning the right things before we invest a lot of money in these simulators.’”
ODU researchers evaluated the machines, found one to be pretty good as a training simulator, “but the other one, we found that if you trained on it, you were less prepared to see a patient than if you had trained on a rubber arm. It was that bad,” Scerbo said.
That led ODU researchers to look at the landscape of all simulation devices used in medicine. At the time, only about 3 percent of procedures could be tested with a simulator. “So we started to take a look at what was missing, and started to develop new systems that would target important needs in training that the commercial vendors did not address,” Scerbo said.
“And then, it became very clear to me once we got involved in this, unlike aviation, which is heavily invested in simulation for both training and research, there is no laboratory for researching how medicine is practiced.”
Maximizing human performance
Ringleb’s research is aimed at human performance modeling – for treatment, rehabilitation and patient care.
In addition to the shooting and running study, Ringleb has done research with the ODU women’s soccer team, testing reactions to the virtual-reality image of a ball rolling past in different directions. That research is an effort to optimize athletic performance, but also to study what predisposes female athletes to knee ligament tears, and create training strategies for how to prevent them.
Human performance modeling has an enthusiastic client in the various branches of the U.S. military in Hampton Roads.
“The traditional method of simulation in the medical and health care area is training people on mannequins – how to perform procedures. Everything we do here is beyond that. Nobody’s really looking at it the way that we look at it,” Ringleb said.
Ringleb is also working on a study to use virtual-reality assessment tools to determine a soldier’s readiness to return to combat, and is helping to create an Internet-based rehab protocol for soldiers who have hearing loss due to blast or traumatic brain injury.
“Everyone else looks at modeling and simulation as a tool. In our approach, we look at it as a discipline. We have this whole core of medical and health care expertise within the discipline of modeling and simulation, and look at all the ways we can apply it.”
Modeling the components of human health
While some researchers practice MS&V on a large scale, perhaps studying mass evacuations, pandemics and operating room efficiency, Mohammed Ferdjallah, a research associate professor at VMASC and co-leader of the Medical and Health Care Cluster, has to work on a smaller scale.
The associate professor of electrical and computer engineering is interested in modeling organ systems and biophysical phenomena, about which little is known. “For instance, a particular interest of mine is to model the electrophysiology of muscle fibers,” Ferdjallah said.
Muscle is a bundle of fibers grouped together into functional units referred to as motor units, but Ferdjallah wants to better understand how each muscle fiber contributes to the overall force generated by the muscle.
“It’s nearly impossible to measure the single-fiber action potential without invasive means,” he said. “You can measure it with an invasive needle electrode, and look very specifically at the local muscle fibers, but even then you can’t have a global picture of how the muscle fibers work together.
“But if you create a muscle model, and you fit the model to data collected from single muscle fibers, one could work backwards to generate a model that recreates the actual physical phenomenon.”
The goal of muscle models is to understand muscle changes during aging and space flights and design therapeutic interventions that could be tested on these models. The possibilities of this research are limitless, Ferdjallah said. With similar thinking, it might be possible to map cellular phenomena that occur in the brain, the liver, the kidney or the pancreas, things that can’t easily be studied in living patients.
Sokolowski said that’s what ODU’s researchers are keen to do – take that body of MS&V research in medicine and health care and move it forward to previously unexplored areas.
“How do you best utilize that kind of technology to provide the best kind of training available? What needs to be developed from a simulation standpoint to make that training effective?” Sokolowski said.
“That’s, I think, the short- and mid-term area where I see MS&V going. Probably in the next 10 years, we will try to fill those holes from a research standpoint, to make this coupling between the technology and the need to reduce patient deaths or injuries.”
Scerbo imagines even more advances.
“The folks involved in medical imaging are taking better and better resolution images of people in a non-invasive way. Health professionals would love to marry these systems with the simulators, so the health care professionals can practice on a model of you, instead of just a generic patient,” he said.
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