The Army says 86% of battlefield deaths come within 30 min. of the initial wounding, so the sooner bleeding GIs get attention, the better off they'll be. Needless to say, delivering appropriate care in the chaos of a battlefield is difficult and dangerous.

Still, military medical researchers are making progress on a variety of equipment and techniques such as a hospital in a box, a device that cleans blood with light, and a few robots itching for medical duty on front lines.

Mechanical medics

The Battlefield Extraction-Assist Robot, or Bear from Vecna Technologies Inc, College Park, Md. (vecnatech.com) is being designed to lift and carry an injured person out of harm's way. Initial models were built on the two-wheel Segway from Dean Kamen's company in Bedford, N.H. Most recent versions use a gyro system and tracked base to give it mobility over rough, uneven terrain and dynamic gyro-based balancing when there is a need for speed.

“Early prototypes combined a mobile base and an upper torso with powerful but sensitive arms,” says Vecna's information officer Jonathan Kline. “Later versions will use a segmented tracked base jointed at the so-called hips and knees. These articulated joints let the robot tilt forward or backward to maintain a low profile, and bend down or fold into a low crawl to pick up and carry casualties. The segmented design also lets the robot get back up after falling or being knocked over,” adds Kline.

The current design is remotely guided by a person using a joystick. A microphone and camera on the Bear lets the operator hear and see to evaluate the situation.

Hydraulics power the Bear's movements, and one of several onboard CPUs lets it lift loads by compensating for weight. The latest design features a torso and arms that use 700 psi hydraulic pressure in normal operations to let each arm lift 250 lb for a total payload of 500 lb. In emergencies, however, hydraulics can boost pressure to 2,500 psi. “Higher pressures let the robot lift a weight pinning someone down that a person could not lift,” says Kline. Smaller tracked robots that carry only a camera, he says, lift only about 20 lb. They may be useful finding people trapped in rubble, but are useless for lifting debris and pulling them out.

The latest versions will also have a CPU in each joint. So if an arm is shot or damaged it can be replaced and “know” what to do. And of course, final versions will be armored.

The controls for military robots will comply with Joint Architecture Unmanned System or JAUS standards. “It's an emerging military standard that will make all unmanned systems essentially plug-and-play,” says Kline. So all user interfaces — operator control units in mil speak — are compatible with each other.

The robot could also do other work such as load heavy cargo onto a truck. And since it's battery powered, the Bear can work indoors and might be used to help nurses lift heavy patients.

When two bots are better than one

Another rescue idea uses two robots working together. A Robotic Evacuation Vehicle (REV) would carry the battery powered Robotic Extraction Vehicle (REX) close to a wounded soldier. REX would roll off the REV and pull a sled to the wounded soldier who would roll onto the sled or be placed on it by comrades. REX would then pull the wounded soldier out of harm's way to a medic at the REV.

Prime contractor Applied Perception, Cranberry Township, Pa., (appliedperception.com) says the project's goal is to develop equipment that can extract and transport a wounded soldier from point of injury to a field hospital. A robot that can seek, detect, and extract a wounded soldier from a hostile situation also removes medics from danger,” says Applied Perception's Senior Research Scientist Patrick Rowe.

The larger REV is powered by a 30-hp diesel and carries two Life Support for Trauma and Transport (Lstat) stretchers. It's an individualized portable intensive care system and surgical platform that can resuscitate and stabilize patients with a combined suite of state-of-the-art medical devices.

“Moving a wounded soldier onto the Lstat litter may be the toughest aspect of this problem because you don't know how they are injured or how moving them might injure them more,” says Rowe. “So you can't take the human medic out of the loop, yet. You still need that person to assess patients. But without robots it takes at least two other troops to bring the wounded back. And that's two more in harm's way.”

The prototype REV and REX currently serve as test-beds for other sensors and ideas. For instance, GPS-based navigation lets the REV follow waypoints to a location. Should it run into an obstacle, it can navigate around it or radio for assistance.

The smaller REX has a motor at each wheel. It carries two cameras, one for color images and an infrared version to pick up body heat from a fallen soldier. “We use both cameras to locate people on the ground. The thermal camera is calibrated to wavelengths the human body emits. Superimposing color and thermal images helps operators find fallen and possibly well-hidden soldiers. During tests, operators have been up to a mile away, but that distance could be lengthened as necessary,” says Rowe.

Rowe adds that his team would like to make the REV move faster. “It should also be more maneuverable for emergencies.” The next version, son of REV or the Tactical Amphibious Ground Support System - Common Experimental, will meet those goals and be more modular. The two patient bays, for instance, will come off letting the motor base serve other duties.

Civilian ERs have a chaos all their own. But if tech transfers of these devices come off as some government agencies plan, a lot of what the U.S. armed forces have learned will be saving civilian lives as well.

Shunt could save arms and legs

The Temporary Limb Salvage Shunt should reduce the number of arm and leg amputations. It reconnects severed blood vessels, giving blood a route around damaged areas and restoring flow to injured limb. “The point is to keep soldiers from losing limbs,” says Mac Ritchie, vice president at shunt developer Vascutek Ltd, Ann Arbor, Mich. (vascutek.com). “Lose blood flow below the knee or elbow and the extremity dies. The shunt can be implanted on the battlefield to bypass damaged blood vessels and temporarily keep blood flowing to injured limbs until patients can be transported to a surgical facility.”

Ritchie says the device is a sandwich of two PTFE layers around an elastomer membrane and with tapered ends. “It's simple to use,” he says. “Apply a tourniquet above the laceration to slow blood flow, then slide one tapered end into the blood vessel and apply a stitch or ligature to hold it in place. Repeat that on the other end, loosen the tourniquet, and blood flows where it should. And you can inject drugs into the shunt because the membrane is self sealing.”

Medics should be able to apply the shunt, but for the time being, it's doctors only says Ritchie. The device has already won marketing clearance by the FDA.

Killing blood pathogens with light

U.S. Army's involvement in Iraq has sparked a clever way to clean blood in less than sterile environments. Scientists at Navigant Biotechnologies LLC, Lakewood, Colo, (navigantbiotech.com), noted that self-reproducing pathogens in blood have DNA and RNA. Red blood cells and platelets are not self reproducing and hence have no DNA. The scientists also observed that riboflavin (vitamin B2) has a mild affinity for DNA. So mixing riboflavin with a bag of platelets lets the B2 bind with the DNA and RNA of the pathogens. Then exposing this mixture to UV light activates the riboflavin making it pull electrons from the pathogen's DNA and RNA which inhibits their reproduction, effectively killing the pathogens. The company expects to receive market approval to start selling the product for cleaning platelets in Europe by end of 2007 and approval for the plasma-cleaning product in mid-2008.

Fluid pump in a patch

A nonstick hydrogel polymer bandage, TheraGauze, is said to stay moist for several days and help wounded soldiers heal faster and with less pain because the polymer acts like a molecular pump on dry skin to infuse water, saline, and drugs into the wound. And when the gauze, from Soluble Systems LLC, Hampton, Va., (solublesystems.com), is on moist tissue, it acts like a molecular sponge to remove liquids oozing from wounds.

The company says the gauze reduces pain because the dressing can be left in place longer, the moisture control quiets nerves, and the non-stick feature does not disturb the wound bed. The gauze is said to improve treatment of severe wounds, burns, skin grafts, and amputations.