While the apparent absence of chemical and biological weapons in Iraq has not helped the Bush administration’s political fortunes, the troops who fought—and are fighting—the war certainly cannot complain. After all, had Saddam Hussein possessed such weapons, he probably would have used them. And then we really would have had a fight on our hands.

But our troops, for the most part, were prepared for such an eventuality. In addition to individual protection systems against chemical/biological (CB) agents such as masks, suits, boots and gloves, medical personnel had collective protection systems—mainly in the form of Deployable Medical Systems (DEPMEDS) combat hospital shelters. DEPMEDS employ tent extendable modular personnel (TEMPER) tents, to which special M28 liners can be attached to prevent CB contamination.

Collective protection equipment includes two general categories: stand-alone shelters and integrated systems, in which multiple shelters are interconnected to form field hospitals with dozens or even hundreds of beds. The systems provide contamination-free, environmentally controlled environments for medical personnel to perform their functions.

These systems utilize overpressure, in which air pressure inside the shelter is greater than that outside the shelter, so that outflowing air is constantly preventing contaminants from entering the protected area. Another component is air locks, which are phone booth-sized chambers through which contaminated patients enter the tent after removing their outer layer of clothing. The air lock is flushed with clean air in order to expel airborne contaminants. Air filters and specialty fabrics are additional components.

But the DEPMEDS system is getting old. The basic design dates from the World War II era, and the shelters themselves are as much as 25 or 30 years old. Moreover, in disassembled form, they are heavy and bulky, complicating shipping and logistics. They take a long time to erect and require many people to do so.

DEPMEDS uses a disposable CB protective liner that is inserted inside of the tent. It is relatively inexpensive, but if it is exposed to contaminants, it has to be disposed of because it cannot be decontaminated. With new technology, CB-protective fabrics can serve as outer skin of the tent, in which case an additional liner is not needed. They can be decontaminable, so that the fabric can be reused.

DEPMEDS’ airlocks have disadvantages as well. There is a wait of about three to five minutes inside the chamber before anyone is allowed to enter safely into the shelter. “That presents a backup when you have several people trying to enter. So we’re trying to redesign the airlock system to make it more efficient and to use new technologies so that we can have rapid entry and exit into the shelter,” said Amy Leighton, chemical engineer, U.S. Army Natick Soldier Center, Collective Protection Directorate, Natick, MA.

The Army and the other services are in the process of replacing this old technology with several new systems.

Bringing the Future to the Present

Prominent among the new systems is the Future Medical Shelter System (FMSS).

Still in the testing and demonstration phase, the FMSS is a congressionally funded program designed to utilize both rigid and soft-walled shelters for forward deployed medical providers. The shelters will have quick erect/strike times and integrated electrical, water and medical packages. Much lighter and compact than DEPMEDS in their disassembled form, FMSS is intended to reduce the total “footprint” of field hospitals, necessitating fewer airlifts and other means of transport. The packing volume of the FMSS soft shelters is about 70 percent less than that of the TEMPER tents.

Facilitating the smaller logistical footprint and faster set-up time are air beam tents, which are essentially inflatable beams on which the tent fabric rests. When deflated, air beam material is soft and pliable. When inflated, it is hard and durable. One type of air beam uses high-pressure air, around 40 to 80 pounds per square inch (PSI), and another type of air beam technology uses low pressure, i.e. five to seven PSI.

“Many of the current shelters being used are based on old-fashioned pole tent technology,” said Reze Salavani, program manager, Air Force Research Laboratory, Tyndall Air Force Base, FL. “They take several people anywhere from several hours to days to construct. With air beam technology, we can significantly reduce deployment logistics, including the amount of time, people and aircraft required to set up bare-based operations.” He anticipates that the new technology will enable twice as many shelters to be shipped per aircraft.

The Natick Soldier Center, meanwhile, is advancing the technology of inflatable composite structures, in conjunction with Vertigo Inc. of Lake Elsinore, CA.

A shelter of 600 square feet can be deployed by three people in 15 minutes, according to Leighton. A standard military tent of comparable size would take eight personnel approximately 40 minutes.

“You want to cut down your packing volume as much as you can so you can ship more,” she said. “The air beam-supported shelters can be set up in about half the time of DEPMEDS or even less. You can quickly get out to where you need to be, quickly set up and have a protective environment.”

FMSS is actually a conglomeration of several distinct efforts. They all have a similar approach but they use different technologies to get there. The U.S. Army Medical Materiel Development Activity (USAMMDA), Fort Detrick, MD, which is the overseeing the efforts, has three of them ongoing under the FMSS banner.

The prime contractor for one of the programs is the Oak Ridge National Laboratory, Oak Ridge, TN. Its system consists of a three-to-one expandable international standards organization (ISO) container and 60 feet of air beam tentage. It involves two 30-foot air beam tents (600 square feet each) that can be set up and used as patient wards, according to Steven Reichard, FMSS product manager.

Another program is being developed by Mobile Medical International Corporation, St. Johnsbury, VT. And USAMMDA is just now entering into a contract with EADS/Dornier, Munich, Germany, for its version of the FMSS.

Oak Ridge delivered a prototype to USAMMDA in November, and Mobile Medical is expected to do so within a few months. EADS soon will be delivering a design drawing. All three companies are seeking additional congressional funds. “So we hope to have those funds to proceed on to a second round of prototypes and more testing,” said Reichard.

The final product will probably incorporate elements of all three designs. “We’re offering suggestions and guidance on how these corporations can best suit the Army’s needs. What we hope to do is, given that they involve slightly different technologies, meld components from all three designs together to form the end product,” he explained.

The prototype ISO containers, which are hard-walled 8 feet by 8 feet by 20 feet structures, are configured as a DEPMEDS operating room. It requires only about six people to set up the operating room. One person presses a button, and it opens up within a minute and a half. “All the medical equipment is stored in carts, and you just wheel them to where you need them. And you’re up and operating within 20 to 30 minutes, whereas it takes several hours to get the current DEPMEDS operating room operational,” said Reichard. It will have about 400 square feet of floor space—enough space for a two-table surgical suite and support rooms. The tents, meanwhile, will house the post-operative care wards.

The military wants to keep the cost to under $100,000 per unit, according to reports, and initial low-rate production is tentatively scheduled to begin in 2005 or 2006. The contract award for full production is expected to be around 2010. The expected life of these shelters is 20 years.

High Mobility

Another shelter system, much smaller and transportable than FMSS, is already being used in Iraq. Capable for transport on the back of HMMWVs, the Chemical Biological Protected Shelter (CBPS) serves as a battalion aid station or division clearing station in the event of chemical or biological contamination. Manufactured by Engineered Support Systems Inc., the tent inflates in three minutes and can be a fully operational medical facility in less than 20 minutes. It consists of four major components: the M-1113 HMMWV; a lightweight multipurpose shelter; the high-mobility trailer with a 10 kW tactical quiet generator; and the air beam-supported shelter. It is about 18 feet by 17 feet with a peak of 10 feet and fabricated with CB protective, decontaminable fabric.

Its environmental support system, which was designed and manufactured through the U.S. Army Research Development and Engineering Command, provides heating and air conditioning along with NBC filtration. It is equipped with a litter and air lock, and has overpressure.

As with the FMSS, it can serve functions other than medical, such as a command and control unit.

CBPS uses low-pressure air beams. And the shelters are significantly smaller at about 300 square feet, whereas FMSS will be 600 square feet and use high-pressure air beams.

While CBPSs can connect to other CBPSs via small passageways, they are mainly stand-alone shelters.

Reichard said he has received a lot of good feedback on these shelters from teams deployed in Iraq. “They’re mobile, and the overpressure and CB protection provides the clean environment—not only for chem/bio, but they also protect against the sand and dust in the harsh environment there.” In fact, during the infamous sandstorms there in the spring of 2003, such shelters were one of the few areas available personnel could go to totally escape the sand.

Reichard is also the product manager for what he is currently calling the interim Army medical shelter. It has an aluminum rather than air beam frame. USAMMDA is in the discussion phase of developing a CB liner for the shelter. The Air Force has been using this shelter for a few years, with a slightly different configuration and under the name of the Alaska shelter.

The interim Army medical shelter differs from the CBPS in that it is used for more permanent facilities such as combat support hospitals rather than forward surgical teams.

Articulating a Vision

TVI Corporation, Glendale, MD, supplies rapid deploy, chemical/biological/hazmat decontamination systems for military, public health and first response agencies. Rather than using air beam frames, its shelter systems employ articulating frames, which the company itself developed.

The company’s shelter systems are of various sizes; its largest being 20 feet wide by 25 feet long. They can be interconnected to create larger facilities as well. “We have the ability to use these systems for command and control, patient decontamination, and triage, as well as infection control,” said Chad Sample, TVI’s executive vice president.

The company also builds rapid deploy shelters with chemical and biological filtration units for patient isolation, so that contaminated individuals can be kept separated from the rest of the hospital community. “Our systems can be put up outside the hospital or inside the hospital to create an isolation area for patients who may be infected with highly contagious diseases. The filtration units separately may also be used to convert existing hospital rooms into isolation and or collective protection areas.”

The company prefers articulating frames over air beams. “Inflatable systems are quality systems, but it’s old technology,” said Sample. “The problem with the inflatable shelter is you need inflation devices such as electric blowers, compressed air bottles and pressure regulators to manage the day/night temperature differences and in some cases, the electric blowers must be left on all the time to keep the shelter up. Our shelters are approximately the same weight and stored size but with a much greater weight to strength ratio and need only two individuals to set up.”

The company’s decontamination systems use water provided by the company’s on-demand water heater. The water heater can supply up to 22 gallons per minute heated water within 30 seconds of start up, and inject into the water supply surfactants and   decontamination solutions. The decontamination shelters may decontaminate up to 40 mixed ambulatory and non-ambulatory patients at a time. “So you have a serious capability for handling mass casualty events,” said Sample.

The military would like to move away from water decontamination because of the logistics problems associated with it. “But the state-of-the-art isn’t there yet to really effectively do the kind of decontamination that’s needed to be done,” he said. New technologies are being developed such as foaming agents, but some are having trouble getting through the Food and Drug Administration approval process because they are somewhat caustic and may cause severe skin reactions. “So this is a technology that’s in flux and emerging,” Sample said.