SEATTLE -- Imagine sweeping through a snowy canyon on a bright clear afternoon, passing snowmen, igloos and snow robots that you can destroy by throwing snowball missiles at as you sweep by.
It may not compare to fantasy games Special Ops or Everquest in terms of adventure, but a new virtual reality game is a soothing escape for burn patients.
SnowWorld is made to distract burn victims from the agonies that they are put through daily as their wounds are scrubbed clean to prevent infection and their skin-grafted limbs are exercised to help stretch the growing tissue.
Doctors have been using virtual reality in all kinds of therapeutic situations. Burn therapy is just the latest for Dr. Hunter Hoffman of the University of Washington Human Interface Technology lab.
Hoffman began using VR five years ago to treat people who have a fear of spiders with a specially constructed virtual reality system and program called SpiderWorld. Set in a 3-D modeled kitchen, SpiderWorld also included a dangling furry tarantula that the patients could touch while they were in the virtual scene.
"SpiderWorld was effective for distracting the patients for a short amount of time," Hoffman said. "I think SpiderWorld would be much less effective the second or third time you used it. If you touched the spider, it only works for a few minutes and then it's not that cool anymore.
"SnowWorld is just a lot more popular and it's designed for treating burn patients in the scrub tank, which we couldn't do with SpiderWorld. You look at what you want to shoot and you press the spacebar and the snowballs shoot out with missile trails."
The distraction, however, doesn't take the place of other medical approaches.
"It's important to note that we don't take away pain medicines when we have patients participate in this study," said Gretchen Carrougher, a research nurse with UW's Department of Rehabilitation Medicine. "This is in addition to the pain medicines that they normally would have received."
Carrougher oversees the Virtual Reality Pain Management study at Seattle's Harborview Medical Center burn unit, which serves burn patients from a five-state area. Recent studies at Harborview showed that as many as three-quarters of the patients reported a large reduction in pain during both wound-cleaning and physical therapy procedures in SnowWorld sessions lasting up to 15 minutes.
"There's some (sensory) ambiguity with hot and cold; you can trick people into thinking you're burning them if you touch people with an ice cube," Hoffman said. "So I think that it's possible that the snowy environment may help to counteract the fires of pain that they are experiencing during their wound care. But the main mechanism is not so much the coldness as it is the distraction."
And while it seems to work to a degree, it's not a panacea.
"Chronic pain is going to be a greater challenge," said David Patterson, a clinical psychologist who described himself as the team's pain expert. "We think the potential's there, but chronic pain involves much more complex issues to screen."
Earlier this year the Paul Allen Foundation for Medical Research gave the project a $220,000 grant, which Hoffman said allowed them to stop using borrowed equipment.
Developments in PCs, pushed largely by gamers, have made VR systems much more affordable than the ones researchers began with five years ago, Hoffman said.
Matthew A. Cotten, the principal systems engineer at SimWright, which produced the simulation software, said that while the UW team is still using a Silicon Graphics machine to run SnowWorld, SimWright, in its shop, has it running on a Pentium III.
"Distraction with music and with videotapes has long been known to lead to some pain reduction," Hoffman said. With costs dropping, "more places are being interested in using VR for pain control. This is taking distraction to a new level."
