Wired reports: [edited]
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 agonising 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. Realising that foams wouldn’t be effective, they cut up ordinary sink sponges and stuffed them into wounded pigs. It worked, and a $5 million development contract from the U.S. Army followed.
Each sponge is made of wood fibres, 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. Reducing the size and weight were the top priority. 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.