A New Tool That Seals Bullet Wounds in Seconds With High-Tech Sponges

Caught in a fire fight, a soldier might hope for air support rained down from a Predator Drone, a kitted out AR-15 assault rifle, and soon, a tube full of high-tech cotton balls. The last item on the list might seem out of place, but the XStat syringe, filled with scientifically advanced sponges, can plug a life-threatening bullet wound in a matter of seconds.
Tourniquets are useful tools for injuries to extremities, but gushing wounds in the pelvis or shoulder require a different approach. The current standard of care is stuffing gauze into the wound. Not only is gauze not FDA cleared for this application, it’s often painful, imprecise, and ineffective, requiring field medics to repeat the agonizing process.
A company called RevMedx decided to approach the problem in a different manner after being inspired by expanding foams used to patch tires and walls. Realizing that foams wouldn’t be effective, they cut up ordinary sink sponges and stuffed them into wounded pigs. Their makeshift “medical device” worked, and a $5 million development contract from the U.S. Army followed shortly thereafter.

XSTAT was partially inspired by the expanding foams used to repair tires and fill walls. Image: Ziba Design

With cash in hand, the first goal was to refine the sponges. Deceptively simple, each one is made of wood fibers, coated with a coagulant derived from shrimp, and then compressed to a quarter of their original size. Once inside the body, a combination of pressure caused by their expansion and coagulant applied throughout the wound combine to staunch the blood flow.
Inserting the sponges was another challenge and RevMedx turned to design firm Ziba to help come up with a clever applicator. Eric Park, one of Ziba’s Creative Directors, led the product, and his first mission was to understand the user. “We needed to deliver a tool that’s easy for the medics,” he says. “We needed to understand the field kit and how he decides what to carry.”

Photo: RevMedx

Reducing the size and weight were the top priority, and Park came up with a crafty solution to store the plunger in the barrel of the syringe. Generous affordances were designed into the handle to optimize the ergonomics. “Since it’s meant to be used in the field, there is a high premium on making the operation as one-handed as possible,” says Park. “I don’t know if there was an actual calculation, but it’s clearly faster and clearly more effective.” One of the most challenging aspects of the procedure is reaching deep wounds. The sponges expanded so quickly they needed to be kept dry as they enter the wound, so Park and his team crafted a tip for the device made of grooved silicon that rips open as the sponges are forced through it, keeping them dry and clean until they reached their destination.
Removing the pellets from the injured soldier is the only sore spot in the current design. Forceps are used to pull out each sponge, though XSTAT is working on biodegradable designs that could be left in the body, or adding a string to the sponges so they could be pulled out like a string of gore-soaked beads. Until those developments make it to market, blue, radioactive threads are sewn into the sponges, allowing any strays stuck in the wound to be identified with x-rays and removed.
With the design finalized, more successful tests on live pigs followed at Fort Lewis in Tacoma, Washington, resulting in a submission to the FDA. If cleared, the company expects the syringes to sell for approximately $100.

Joseph Flaherty writes about design, DIY, and the intersection of physical and digital products. He designs award-winning medical devices and apps for smartphones at AgaMatrix, including the first FDA-cleared medical device that connects to the iPhone.
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http://www.wired.com/design/2014/02/seal-bullet-wound-q-tips/?cid=18756774