Imagine an oblong tube the width of a Boeing 737, 46 feet long and dotted with portholes like a submarine. Sounds a bit like something you would expect to see in a science-fiction film.

However, this strange device — a hyperbaric chamber -— is, in fact, a medical marvel, providing help and relief to many people. One of the most advanced hyperbaric facilities in the nation is in our own backyard.

The concept behind hyperbaric medicine is to seal a patient in a pressurized environment and expose them to 100 percent oxygen. Oxygen dissolves from capillaries into tissue at a rate four times higher in a hyperbaric chamber than in normal conditions. The increased oxygen absorption can have a number of positive effects, and regiments of treatment in these conditions can help treat patients with a number of illnesses.

Dr. Neil Hampson is the head of hyperbaric medicine at Virginia Mason. Hampson, a Seattle native and Mercer Island resident, is the former president of the Undersea and Hyperbaric Medical Society. According to him, no other facilities he has seen compare to those at Virginia Mason.

The department has five staff members certified as specialists in hyperbaric medicine. It is the only hyperbaric facility in the Northwest accredited by the Undersea and Hyperbaric Medical Society and the second to receive such accreditation “with distinction,” according to Virginia Mason’s Web site.

Hyperbaric medicine is used on two categories of patients. Certain emergencies can be handled with amazing effectiveness, such as diving accidents. Divers who emerge too fast from high depths can suffer life-threatening air or gas embolisms due to the rapid change in pressure. The hyperbaric chamber is effective in countering the damage done by rapid decompression, easing the patient back into normal conditions.

Another life-threatening condition treated by hyperbaric medicine is carbon monoxide poisoning. A study in the New England Journal of Medicine compared the effect on victims of carbon monoxide poisoning treated in a normal environment and those treated in a hyperbaric environment. The results were impressive, the study determined. Those patients treated in the hyperbaric environment had issues of future cognitive impairment cut in half. For this reason, hyperbaric medicine is often the best option for treating cases of carbon monoxide poisoning.

Hampson and the staff at Virginia Mason’s hyperbaric chamber treat victims of carbon monoxide poisoning on a semi-regular basis. However, during the December storms of 2006, they were put to the test. Many people who had lost their power attempted to seek alternate ways to heat their homes, such as burning charcoal indoors, unaware of the dangers of carbon monoxide. In a four-day period, the Center for Hyperbaric Medicine treated 70 patients, with as many as 46 in one day — a world record, according to Hampson.

Emergencies such as carbon monoxide poisoning actually make up a small amount of the cases treated by hyperbaric medicine. Rather, the majority of patients suffer from chronic, non-healing wounds, such as diabetes or delayed tissue damage from radiation therapy. For these patients, a regiment of treatment in the hyperbaric chamber can often work wonders.

Although patients are only exposed to the hyperbaric environment for two hours a day, “the pressurized and oxygen environment inside the hyperbaric chamber stimulates basic biochemical processes that are vital in wound repair,” explained Hampson.

In one case, a patient was suffering from a wound on her heel stemming from diabetes. The wound would not heal, leaving her bound to a wheelchair and unemployed for two years. She began regular hyperbaric treatments in an attempt to limit the damage to her tissue.

As the treatments continued, the patient experienced a dramatic healing of her wound. Over the course of 40 treatments, she was able to get out of her wheelchair and walk on her own weight. She was even able to go out for margaritas with friends to celebrate, Hampson said.

This is a best-case scenario, of course. However, according to Hampson, the effects are usually quite positive, with a very low level of risk and very few significant side effects. For many sufferers of chronic illnesses, the hyperbaric chamber offers hope for conditions that might otherwise be untreatable.

The chamber is one of the largest in the country. Built in 2005, the facility cost $4.5 million to build, which was donated by individuals and businesses around the Northwest. The chamber was built to replace an aging and cramped chamber across the street from its current home at Virginia Mason. It was designed with patient comfort, flow and socialization in mind, according to Hampson.

As you enter the area housing it inside the hospital, you can see why. The part of the room where the chamber sits has an elevated ceiling, and a calming blue light behind the chamber draws attention away from the imposing machine. Patients waiting for treatment gather around a fish tank, chatting in a circle of couches. All these elements help create an environment quite different from many people’s expectations of a hospital.

“When you enter the room, it’s a bit reminiscent of Disneyland,” Hampson said.

The chamber itself is also designed for comfort. It has three independent chambers and can hold 18 patients. The size of the chamber allows for staff to work alongside the patients, who wear pressurized and oxygen-pure hoods which resemble astronaut helmets, during their two-hour sessions. The size of the chamber also helps reduce some of the claustrophobia that some patients feel.

“I worked at the old chamber,” said Chris Kramer, who is a chamber specialist and administrator in the department. “It was noisy and very labor intensive. The new facility is quiet, clean and easy to run. We get a chance to socialize and build relationships with the patients.

“Operating the chamber is a treat,” she added.

It is somewhat unusual for a premier facility to exist in a small, private medical center. However, Virginia Mason has a long history of innovation with hyperbaric medicine. Beginning with animal research in the 1960s, Virginia Mason originally engaged in hyperbaric research because of a shift in oil exploration from the Gulf of Mexico to the North Sea. Due to the deeper depths of the North Sea, oil companies began to fund research on diving decompression. The medical center took advantage of the chance and began researching hyperbaric medicine.

“The usual scientific method is to develop a hypothesis, develop an animal model, and then test it on humans,” said Hampson. “In this case, they sort of went backwards. The effects on all sorts of conditions were tested in the chamber, and they saw what worked. We have a good understanding of the science, but even today we are trying to understand the exact mechanisms of how these conditions affect these ailments.

“It’s frustrating for the patients and physicians [when ailments seem untreatable],” said Hampson. “The most rewarding aspect of this work is being able to help people who have been told they can’t be helped.”

Nicholas Tichy is a student in the University of Washington Department of Communication News Laboratory.