Seal A Gunshot Wound In 15 Seconds!
It’s like 50 tiny tampons.
The team’s early efforts were inspired by Fix-a-Flat foam for repairing tires. “That’s what we pictured as the perfect solution: something you could spray in, it would expand, and bleeding stops,” says Steinbaugh. “But we found that blood pressure is so high, blood would wash the foam right out.”
So the team tried a new idea: sponges. They bought some ordinary sponges from a hardware store and cut them into 1-centimeter circles, a size and shape they chose on a whim but later would discover were ideal for filling wounds. Then, they injected the bits of sponge into an animal injury. “The bleeding stopped,” says Steinbaugh. “Our eyes lit up. We knew we were onto something.” After seeing early prototypes, the U.S. Army gave the team $5 million to develop a finished product.
But kitchen sponges aren’t exactly safe to inject into the body. The final material would need to be sterile, biocompatible, and fast-expanding. The team settled on a sponge made from wood pulp and coated with chitosan, a blood-clotting, antimicrobial substance that comes from shrimp shells. To ensure that no sponges would be left inside the body accidentally, they added X-shaped markers that make each sponge visible on an x-ray image.
The sponges work fast: In just 15 seconds, they expand to fill the entire wound cavity, creating enough pressure to stop heavy bleeding. And because the sponges cling to moist surfaces, they aren’t pushed back out of the body by gushing blood. “By the time you even put a bandage over the wound, the bleeding has already stopped,” Steinbaugh says.
Getting the sponges into a wound, however, proved to be tricky. On the battlefield, medics must carry all their gear with them, along with heavy body armor. RevMedx needed a lightweight, compact way to get the sponges deep into an injury. The team designed a 30 millimeter-diameter, polycarbonate syringe that stores with the handle inside to save space. To use the applicator, a medic pulls out the handle, inserts the cylinder into the wound, and then pushes the plunger back down to inject the sponges as close to the artery as possible.”
EDIT – Sounds like vaporware – http://bfelabs.net/popsci-hypodermic-full-of-sponges/